INTRODUCTION Zingiber montanum (J.Koenig) Link ex A.Dietr. is a popular medicinal plant in Thaila... more INTRODUCTION Zingiber montanum (J.Koenig) Link ex A.Dietr. is a popular medicinal plant in Thailand. Its rhizomes have been used as an ingredient in various Thai traditional medicine formulas. While many reports have focused on the chemical constituents and biological activities of this plant, a comprehensive study on secondary metabolite profiling using tandem mass spectrometry has, to this point, never been documented. OBJECTIVE To analyze the chemical constituents in Z. montanum rhizomes using ultra-high performance liquid chromatography coupled with ultra-high-resolution electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UHPLC-HR-ESI-QTOF-MS/MS) analyses and to utilize the characteristic fragmentation patterns of these compounds to facilitate their identification. METHODOLOGY UHPLC-HR-ESI-QTOF-MS/MS in positive ion mode was used for chemical identification of secondary metabolites from the ethanolic extract of the plant material. MS/MS data of some known reference compounds, together with detailed fragmentation pattern information of several compounds obtained from the crude extract, were used to elucidate their chemical structures. RESULTS In this work, one benzaldehyde, ten phenylbutenoid monomers, six curcuminoids, and nine phenylbutenoid dimers were assigned based on their characteristic fragment ions. Among these compounds, 2-(3,4-dimethoxystyryl)oxirane was tentatively suggested as a potential new compound. Several characteristic fragment ions from these compounds were assigned and the relative ion abundance of these was also used to differentiate the chemical structures of compounds having the same molecular mass. CONCLUSIONS The results will benefit future high-throughput screening of bioactive compounds and method development for the quality control of raw materials and herbal drugs derived from Z. montanum rhizome extracts.
Organic Preparations and Procedures International, 2015
Background: Endocrine tissues play a fundamental role in maintaining homeostasis of plasma metabo... more Background: Endocrine tissues play a fundamental role in maintaining homeostasis of plasma metabolites such as non-esterified fatty acids and glucose, the levels of which reflect the energy balance or the health status of animals. However, the relationship between the transcriptome of endocrine tissues and plasma metabolites has been poorly studied. Methods: We determined the blood levels of 12 plasma metabolites in 27 pigs belonging to five breeds, each breed consisting of both females and males. The transcriptome of five endocrine tissues i.e. hypothalamus, adenohypophysis, thyroid gland, gonads and backfat tissues from 16 out of the 27 pigs was also determined. Sex and breed effects on the 12 plasma metabolites were investigated and associations between genes expressed in the five endocrine tissues and the 12 plasma metabolites measured were analyzed. A probeset was defined as a quantitative trait transcript (QTT) when its association with a particular metabolic trait achieved a nominal P value < 0.01. Results: A larger than expected number of QTT was found for non-esterified fatty acids and alanine aminotransferase in at least two tissues. The associations were highly tissue-specific. The QTT within the tissues were divided into co-expression network modules enriched for genes in Kyoto Encyclopedia of Genes and Genomes or gene ontology categories that are related to the physiological functions of the corresponding tissues. We also explored a multi-tissue co-expression network using QTT for non-esterified fatty acids from the five tissues and found that a module, enriched in hypothalamus QTT, was positioned at the centre of the entire multi-tissue network. Conclusions: These results emphasize the relationships between endocrine tissues and plasma metabolites in terms of gene expression. Highly tissue-specific association patterns suggest that candidate genes or gene pathways should be investigated in the context of specific tissues.
Many studies have shown that minocycline, an antibacterial tetracycline, suppresses experimental ... more Many studies have shown that minocycline, an antibacterial tetracycline, suppresses experimental pain. While minocycline's positive effects on pain resolution suggest that clinical use of such drugs may prove beneficial, minocycline's antibiotic actions and divalent cation (Ca 2+ ; Mg 2+ ) chelating effects detract from its potential utility. Thus, we tested the antiallodynic effect induced by a non-antibacterial, non-chelating minocycline derivative in a model of neuropathic pain and performed an initial investigation of its anti-inflammatory effects in vitro. Intraperitoneal minocycline (100 mg/kg) and 23.75, 47.50 or 95.00 mg/kg) reduce the mechanical allodynia induced by chronic constriction injury of mouse sciatic nerve. PMIN reduces the LPS-induced production of PGE 2 by primary microglial cell cultures. Human embryonic kidney cells were transfected to express human toll-like receptors 2 and 4, and the signaling via both receptors stimulated with PAM3CSK4 or LPS (respectively) was
a,a-Difluoro-a-phenylsulfanyl-a-trimethylsilylmethane (PhSCF 2 SiMe 3 ) has been demonstrated as ... more a,a-Difluoro-a-phenylsulfanyl-a-trimethylsilylmethane (PhSCF 2 SiMe 3 ) has been demonstrated as an a,a-difluoro-a-phenylsulfanylmethyl carbanion equivalent. gem-Difluorophenylsulfanylmethylation of carbonyl compounds has been successfully achieved by using PhSCF 2 SiMe 3 in the presence of TBAF in THF. The adducts have been converted to the corresponding gem-difluoroalkenes by a novel pyrolytic and/or FVP elimination of the b-hydroxy-a-phenylsufinyl derivatives under reduced pressure.
Background and purpose: Many in vitro and fewer in vivo studies have shown that tetracyclines pre... more Background and purpose: Many in vitro and fewer in vivo studies have shown that tetracyclines present anti-inflammatory activity. We investigated if a novel non-antibacterial, non-chelating hydroxypyrazoline derivative of minocycline, 12S-hydroxy-1,12-pyrazolinominocycline (PMIN), also induced antinociceptive and anti-inflammatory effects. Experimental approach: Antibacterial effects against a minocycline-sensitive Staphylococcus aureus strain were evaluated by applying a cylinder-plate agar diffusion technique. Antibacterial effects of diluted serum from mice pre-treated with minocycline or PMIN were also evaluated. Ca 2 þ binding activity was assessed by spectrophotometry. Formalin-induced nociceptive responses and carrageenan-induced paw oedema were evaluated in mice. The rota-rod apparatus was used to evaluate motor coordination. Key results: Minocycline, but not PMIN, inhibited bacterial growth. Serum from mice treated with minocycline, but not with PMIN, also induced such an effect. The UV absorption spectrum of solutions of minocycline, but not those of PMIN, was markedly changed in the presence of Ca 2 þ . Minocycline or PMIN inhibited both phases of formalin-induced nociception and carrageenan-induced paw oedema. It is unlikely that antinociception resulted from lack of motor coordination, as tetracycline did not impair the performance of mice on the rotating rod. Conclusions and implications: These results indicate that inhibition of nociception and oedema by tetracyclines is neither necessarily linked to antibacterial nor to Ca 2 þ chelating activities. This study supports the evaluation of the potential usefulness of PMIN in the treatment of painful and inflammatory diseases, as its lack of antibacterial and Ca 2 þ chelating activities might confer greater safety over conventional tetracyclines.
Gymnemic acid (GA) is known as the antidiabetic phytoconstituent in Gymnema species, and is used ... more Gymnemic acid (GA) is known as the antidiabetic phytoconstituent in Gymnema species, and is used for standardization and quality control. Recently, a number of nutraceutical products of G. inodorum (Lour.) Decne. (GI) are available in Thailand. However, the standardized GA content and the safety usage guidelines for GI have yet to be published on. The aims of this study were to investigate the amount of GA constituent and to characterize the in vitro cytotoxicity of GI extract. The total GA was extracted from dried GI leaves (Jomthong District, Chaing Mai Province, Thailand) by ethanol and subcritical water (SCW) methods, and analyzed by liquid chromatography/electrospray ionization mass spectroscopy method. The calculation of total GA was based on aglycone gymnemagenin. The cytotoxicity assay of the GI extracts at 0-500 g/mL was carried out on Caco2 cells by MTT assay. The results showed that the GI extracts obtained from both extraction methods contained total GA less than 0.01% ...
Nanoparticle targeting of cancer cell surface markers to allow the specific delivery of chemother... more Nanoparticle targeting of cancer cell surface markers to allow the specific delivery of chemotherapeutic agents is an attractive concept in cancer treatment. Prior to in vivo studies, newly developed nanomedicines must be tested in preclinical in vitro models fully representative of physiological conditions. The aim of this study was to develop an in vitro method for characterizing the cell binding properties of active targeting nanoparticles, using an integrated flow chamber. Anti-vascular endothelial growth factor (VEGF) antibody conjugated liposome/PLGA hybrid nanoparticles were generated, characterized, and utilized in binding studies with three different VEGF-positive cancer cell lines, in addition to VEGF-negative fibroblasts. Binding, and subsequent VEGF expression was examined through immunostaining, confocal microscopy and Western blot analysis. Our results indicated that targeted and non-targeted nanoparticles cannot be distinguished under static in vitro cell binding cond...
Six coumarin caged compounds of NAA comprising different substituents on the coumarin moiety were... more Six coumarin caged compounds of NAA comprising different substituents on the coumarin moiety were synthesized and evaluated for their photo-physical and chemical properties as light-responsive controlled-release plant root stimulators. The 1H-NMR and HPLC techniques were used to verify the release of NAA from the caged compounds. After irradiation at 365 nm, the caged compounds exhibited the fastest release rate at t1/2 of 6.7 days and the slowest release rate at t1/2 of 73.7 days. Caged compounds at high concentration (10-5 M and 10-6 M) significantly stimulate secondary root germination while free NAA at the same level is toxic and leads to inhibition of secondary root germination. Cytotoxicity of the caged compounds against Fibroblasts and Vero cells were evaluated and the results suggested that at 10-5 - 10-6 M, caged compounds exhibit no significant cytotoxic to the cells. Thus, the caged compounds of NAA in this study can be of great benefits as efficient agrochemicals.
Gymnemic acid (GA) is known as the antidiabetic phytoconstituent in Gymnema species, and is used ... more Gymnemic acid (GA) is known as the antidiabetic phytoconstituent in Gymnema species, and is used for quality control and standardization of Gymnema products. In Thailand, a number of nutraceutical products of Gymnema inodorum (Lour.) Decne. (GI) are commercially available and this number is increasing. However, standardized GA content information and safety usage guidelines for GI have not been published. The aim of this study was to investigate the amount of GA constituent in GI leaves using mass spectrometry. Leaf samples were randomly collected in the Northern part of Thailand. Total GA was extracted using an ethanolic solution. The calculation of total GA was based on the detection of aglycone gymnemagenin using the liquid chromatography/electrospray ionization mass spectrometry with multiple reaction monitoring. The results showed that GI contained total GA content in range of 0.20-1.44 mg per one kilogram dry leaves.
In this work, we designed and synthesized two photoresponsive materials with 3-indoleacetic acid ... more In this work, we designed and synthesized two photoresponsive materials with 3-indoleacetic acid (IAA) plant hormone which can be monitored from the photoreposive properties of coumarin. The varied position of the long alkoxy side chain (-OC16H33) was purposely introduced to adhesive on the plant leaves. Two coumarin-caged nanomaterials showed average particle diameter about 400 nm and gave the maximum emission wavelength at 425 and 450 nm. The formulated nanoemulsion showed good wettability (θ=48o) withCassia fistulaleave surface. Interestingly, CM2 gave the short photoresponse of photolysis within one day.
Abstract In this study, a new graft copolymer (SS-g-PLA) was constructed by combining sericin and... more Abstract In this study, a new graft copolymer (SS-g-PLA) was constructed by combining sericin and polylactide (PLA) via ring-opening polymerization (ROP) having Sn(Oct)2 as a catalyst. In this synthetic strategy based on the grafting from concept, sericin molecule acts as a bio-initiator where its hydroxyl groups existing in serine units. The effects of polymerization parameters, including reaction temperature, the concentration of catalyst and sericin, on the copolymer structure and properties were investigated. XPS spectra of SS-g-PLA copolymer showed C1S and N1S signals clearly and differed form that of the neat PLA. 2D HMBC NMR spectra showed correlation assigned to the carbon atom of PLA polymer chains and hydrogen atom in hydroxyl group of serine. Molecular weight of the graft copolymer by GPC was in range of 4000–5600 g mol−1. From soxhlet extraction, the results showed that PLA content in the graft copolymer molecules increased with increasing sericin content. The weight ratio of PLA to sericin in the SS-g-PLA5, SS-g-PLA10 and SS-g-PLA15 graft copolymers were 0.6:1, 1.4:1 and 2.1:1, respectively. By nitrogen analyzer,%protein increased significantly with increasing sericin content. Thermal analysis showed that the graft copolymer presented a single glass-transition temperature (Tg) belonging to PLA. This Tg decreased with increasing sericin content. The thermal degradation temperature (Td) of SS-g-PLA copolymer decreased to about 60 °C. Furthermore, SS-g-PLA is expected to utilize in biomedical applications.
In this study, the inclusion complex formation between α-mangostin and water-soluble quaternized ... more In this study, the inclusion complex formation between α-mangostin and water-soluble quaternized β-CD grafted-chitosan (QCD-g-CS) was investigated. Inclusion complex formation with encapsulation efficiency (%EE) of 5, 15 and 75% can be varied using high speed homogenizer. Tuning %EE plays a role on physicochemical and biological properties of α-mangostin/QCD-g-CS complex. Molecular dynamics simulations indicate that α-mangostin is included within the hydrophobic β-CD cavity and being absorbed on the QCD-g-CS surface, with these results being confirmed by Fourier transform infrared (FTIR) spectroscopy. Probing the release characteristics of the inclusion complex at various %EE (5%, 15% and 75%) in simulated saliva (pH 6.8) demonstrated that α-mangostin release rates were dependent on % EE (order 5% > 15% > 75%). Additionally, higher antimicrobial and anti-inflammation activities were observed for the inclusion complex than those of free α-mangostin due to enhance the solubility of α-mangostin through the inclusion complex with QCD-g-CS.
The development of targeted contrast agents for magnetic resonance imaging (MRI) facilitates enha... more The development of targeted contrast agents for magnetic resonance imaging (MRI) facilitates enhanced cancer imaging and more accurate diagnosis. In the present study, a novel contrast agent was developed by conjugating anti-EpCAM humanized scFv with gadolinium chelate to achieve target specificity. The material design strategy involved site-specific conjugation of the chelating agent to scFv. The scFv monomer was linked to maleimide-DTPA via unpaired cysteine at the scFv C-terminus, followed by chelation with gadolinium (Gd). Successful scFv-DTPA conjugation was achieved at 1:10 molar ratio of scFv to maleimide-DTPA at pH 6.5. The developed anti-EpCAM-Gd-DTPA MRI contrast agent was evaluated for cell targeting ability, in vitro serum stability, cell cytotoxicity, relaxivity, and MR contrast enhancement. A high level of targeting efficacy of anti-EpCAM-Gd-DTPA to an EpCAM-overexpressing HT29 colorectal cell was demonstrated by confocal microscopy. Good stability of the contrast agen...
Coumarin, which is an important material class of substrate in agricultural and pharmaceutical in... more Coumarin, which is an important material class of substrate in agricultural and pharmaceutical industries, can be obtained by the Pechmann condensation reaction. In this work, coumarin was synthesized from ethyl acetoacetate and resorcinol with sulfuric acid as the catalyst with 86% yield under a mild condition. The product was confirmed by IR, 1H NMR, and 13C NMR spectroscopy. Reaction rates at difference temperatures between 273 and 313 K were used to determine the apparent activation energy of the reaction to be 34.7 kJ/mol. Molecular-level understanding about the mechanism of Pechmann condensation reaction was revealed by the complimentary M06-2X density functional theory. The reaction proceeded via a three-step mechanism; transesterification, intramolecular hydroxylalkylation, and dehydration. The intrinsic activation energies of these three steps were calculated to be 136.7, 76.5, and 134.0 kJ/mol, respectively. The calculated apparent activation energy of 40.0 kJ/mol was in agreement with the experimental data. The transesterification was considered as the rate-determining step of the reaction.Graphical abstract
In this study, tea (Camellia oleifera) seed oil was formulated into self-emulsifying oil formulat... more In this study, tea (Camellia oleifera) seed oil was formulated into self-emulsifying oil formulations (SEOF) to enhance the aqueous dispersibility and intestinal retention to achieve higher bioavailability. Self-emulsifying tea seed oils were developed by using different concentrations of lecithin in combination with surfactant blends (Span ® 80 and Tween ® 80). The lecithin/surfactant systems were able to provide clear and stable liquid formulations. The SEOF were investigated for physicochemical properties including appearance, emulsion droplets size, PDI and zeta potential. The chemical compositions of tea seed oil and SEOF were compared using GC-MS techniques. In addition, the oil adsorption measurement on artificial membranes was performed using a Franz cell apparatus and colorimetric analysis. The microscopic structure of membranes was observed with scanning electron microscopy (SEM). After aqueous dilution with fed-state simulated gastric fluid (FeSSGF), the droplet size of all SEOF was close to 200 nm with low PDI values and the zeta potential was negative. GC-MS chromatograms revealed that the chemical compositions of SEOF were not significantly different from that of the original tea seed oil. The morphological study showed that only the SEOF could form film layers. The oil droplets were extracted both from membrane treated with tea seed oil and the SEOF in order to evaluate the chemical compositions by GC-MS.
International Journal of Biological Macromolecules, 2015
Two guest molecules (eugenol and (-)-menthol) were investigated on inclusion complex formation wi... more Two guest molecules (eugenol and (-)-menthol) were investigated on inclusion complex formation with water-soluble quaternized β-CD grafted with chitosan (QCD-g-CS). The inclusion complexes were prepared at varying mole ratios between eugenol or (-)-menthol and β-CD (substituted on QCD-g-CS) by a conventional shaking method and obtained as solid powder by freeze-drying process. The results showed that encapsulation efficiency %EE decreased with increasing of initial eugenol or (-)-menthol loading whereas %loading increased with increasing of initial eugenol or (-)-menthol loading. The results indicated that inclusion complex formation between eugenol and QCD-g-CS was more favorable than that of (-)-menthol. To clarify this mechanism, molecular dynamics simulations were performed to explore their binding energy, solvation energy and total free energy of those complexes. It was found that the total free energy (ΔG) of eugenol and (-)-menthol against QCD-g-CS (mole ratio of 1) in water-explicit system were -2108.91kJ/mol and -344.45kJ/mol, respectively. Moreover, molecular dynamic simulation of eugenol absorbed on surface QCD-g-CS (-205.73kJ/mol) was shown to have a higher negative value than that of (-)-menthol on QCD-gCS (3182.31kJ/mol). Furthermore, the release characteristics of the encapsulated powder were also investigated in simulated saliva pH 6.8 at 32°C. The results suggested that (-)-menthol had higher release rate from the complexes than eugenol. In all cases, the release characteristics for those guest molecules could be characterized by the limited-diffusion kinetics.
INTRODUCTION Zingiber montanum (J.Koenig) Link ex A.Dietr. is a popular medicinal plant in Thaila... more INTRODUCTION Zingiber montanum (J.Koenig) Link ex A.Dietr. is a popular medicinal plant in Thailand. Its rhizomes have been used as an ingredient in various Thai traditional medicine formulas. While many reports have focused on the chemical constituents and biological activities of this plant, a comprehensive study on secondary metabolite profiling using tandem mass spectrometry has, to this point, never been documented. OBJECTIVE To analyze the chemical constituents in Z. montanum rhizomes using ultra-high performance liquid chromatography coupled with ultra-high-resolution electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UHPLC-HR-ESI-QTOF-MS/MS) analyses and to utilize the characteristic fragmentation patterns of these compounds to facilitate their identification. METHODOLOGY UHPLC-HR-ESI-QTOF-MS/MS in positive ion mode was used for chemical identification of secondary metabolites from the ethanolic extract of the plant material. MS/MS data of some known reference compounds, together with detailed fragmentation pattern information of several compounds obtained from the crude extract, were used to elucidate their chemical structures. RESULTS In this work, one benzaldehyde, ten phenylbutenoid monomers, six curcuminoids, and nine phenylbutenoid dimers were assigned based on their characteristic fragment ions. Among these compounds, 2-(3,4-dimethoxystyryl)oxirane was tentatively suggested as a potential new compound. Several characteristic fragment ions from these compounds were assigned and the relative ion abundance of these was also used to differentiate the chemical structures of compounds having the same molecular mass. CONCLUSIONS The results will benefit future high-throughput screening of bioactive compounds and method development for the quality control of raw materials and herbal drugs derived from Z. montanum rhizome extracts.
Organic Preparations and Procedures International, 2015
Background: Endocrine tissues play a fundamental role in maintaining homeostasis of plasma metabo... more Background: Endocrine tissues play a fundamental role in maintaining homeostasis of plasma metabolites such as non-esterified fatty acids and glucose, the levels of which reflect the energy balance or the health status of animals. However, the relationship between the transcriptome of endocrine tissues and plasma metabolites has been poorly studied. Methods: We determined the blood levels of 12 plasma metabolites in 27 pigs belonging to five breeds, each breed consisting of both females and males. The transcriptome of five endocrine tissues i.e. hypothalamus, adenohypophysis, thyroid gland, gonads and backfat tissues from 16 out of the 27 pigs was also determined. Sex and breed effects on the 12 plasma metabolites were investigated and associations between genes expressed in the five endocrine tissues and the 12 plasma metabolites measured were analyzed. A probeset was defined as a quantitative trait transcript (QTT) when its association with a particular metabolic trait achieved a nominal P value < 0.01. Results: A larger than expected number of QTT was found for non-esterified fatty acids and alanine aminotransferase in at least two tissues. The associations were highly tissue-specific. The QTT within the tissues were divided into co-expression network modules enriched for genes in Kyoto Encyclopedia of Genes and Genomes or gene ontology categories that are related to the physiological functions of the corresponding tissues. We also explored a multi-tissue co-expression network using QTT for non-esterified fatty acids from the five tissues and found that a module, enriched in hypothalamus QTT, was positioned at the centre of the entire multi-tissue network. Conclusions: These results emphasize the relationships between endocrine tissues and plasma metabolites in terms of gene expression. Highly tissue-specific association patterns suggest that candidate genes or gene pathways should be investigated in the context of specific tissues.
Many studies have shown that minocycline, an antibacterial tetracycline, suppresses experimental ... more Many studies have shown that minocycline, an antibacterial tetracycline, suppresses experimental pain. While minocycline's positive effects on pain resolution suggest that clinical use of such drugs may prove beneficial, minocycline's antibiotic actions and divalent cation (Ca 2+ ; Mg 2+ ) chelating effects detract from its potential utility. Thus, we tested the antiallodynic effect induced by a non-antibacterial, non-chelating minocycline derivative in a model of neuropathic pain and performed an initial investigation of its anti-inflammatory effects in vitro. Intraperitoneal minocycline (100 mg/kg) and 23.75, 47.50 or 95.00 mg/kg) reduce the mechanical allodynia induced by chronic constriction injury of mouse sciatic nerve. PMIN reduces the LPS-induced production of PGE 2 by primary microglial cell cultures. Human embryonic kidney cells were transfected to express human toll-like receptors 2 and 4, and the signaling via both receptors stimulated with PAM3CSK4 or LPS (respectively) was
a,a-Difluoro-a-phenylsulfanyl-a-trimethylsilylmethane (PhSCF 2 SiMe 3 ) has been demonstrated as ... more a,a-Difluoro-a-phenylsulfanyl-a-trimethylsilylmethane (PhSCF 2 SiMe 3 ) has been demonstrated as an a,a-difluoro-a-phenylsulfanylmethyl carbanion equivalent. gem-Difluorophenylsulfanylmethylation of carbonyl compounds has been successfully achieved by using PhSCF 2 SiMe 3 in the presence of TBAF in THF. The adducts have been converted to the corresponding gem-difluoroalkenes by a novel pyrolytic and/or FVP elimination of the b-hydroxy-a-phenylsufinyl derivatives under reduced pressure.
Background and purpose: Many in vitro and fewer in vivo studies have shown that tetracyclines pre... more Background and purpose: Many in vitro and fewer in vivo studies have shown that tetracyclines present anti-inflammatory activity. We investigated if a novel non-antibacterial, non-chelating hydroxypyrazoline derivative of minocycline, 12S-hydroxy-1,12-pyrazolinominocycline (PMIN), also induced antinociceptive and anti-inflammatory effects. Experimental approach: Antibacterial effects against a minocycline-sensitive Staphylococcus aureus strain were evaluated by applying a cylinder-plate agar diffusion technique. Antibacterial effects of diluted serum from mice pre-treated with minocycline or PMIN were also evaluated. Ca 2 þ binding activity was assessed by spectrophotometry. Formalin-induced nociceptive responses and carrageenan-induced paw oedema were evaluated in mice. The rota-rod apparatus was used to evaluate motor coordination. Key results: Minocycline, but not PMIN, inhibited bacterial growth. Serum from mice treated with minocycline, but not with PMIN, also induced such an effect. The UV absorption spectrum of solutions of minocycline, but not those of PMIN, was markedly changed in the presence of Ca 2 þ . Minocycline or PMIN inhibited both phases of formalin-induced nociception and carrageenan-induced paw oedema. It is unlikely that antinociception resulted from lack of motor coordination, as tetracycline did not impair the performance of mice on the rotating rod. Conclusions and implications: These results indicate that inhibition of nociception and oedema by tetracyclines is neither necessarily linked to antibacterial nor to Ca 2 þ chelating activities. This study supports the evaluation of the potential usefulness of PMIN in the treatment of painful and inflammatory diseases, as its lack of antibacterial and Ca 2 þ chelating activities might confer greater safety over conventional tetracyclines.
Gymnemic acid (GA) is known as the antidiabetic phytoconstituent in Gymnema species, and is used ... more Gymnemic acid (GA) is known as the antidiabetic phytoconstituent in Gymnema species, and is used for standardization and quality control. Recently, a number of nutraceutical products of G. inodorum (Lour.) Decne. (GI) are available in Thailand. However, the standardized GA content and the safety usage guidelines for GI have yet to be published on. The aims of this study were to investigate the amount of GA constituent and to characterize the in vitro cytotoxicity of GI extract. The total GA was extracted from dried GI leaves (Jomthong District, Chaing Mai Province, Thailand) by ethanol and subcritical water (SCW) methods, and analyzed by liquid chromatography/electrospray ionization mass spectroscopy method. The calculation of total GA was based on aglycone gymnemagenin. The cytotoxicity assay of the GI extracts at 0-500 g/mL was carried out on Caco2 cells by MTT assay. The results showed that the GI extracts obtained from both extraction methods contained total GA less than 0.01% ...
Nanoparticle targeting of cancer cell surface markers to allow the specific delivery of chemother... more Nanoparticle targeting of cancer cell surface markers to allow the specific delivery of chemotherapeutic agents is an attractive concept in cancer treatment. Prior to in vivo studies, newly developed nanomedicines must be tested in preclinical in vitro models fully representative of physiological conditions. The aim of this study was to develop an in vitro method for characterizing the cell binding properties of active targeting nanoparticles, using an integrated flow chamber. Anti-vascular endothelial growth factor (VEGF) antibody conjugated liposome/PLGA hybrid nanoparticles were generated, characterized, and utilized in binding studies with three different VEGF-positive cancer cell lines, in addition to VEGF-negative fibroblasts. Binding, and subsequent VEGF expression was examined through immunostaining, confocal microscopy and Western blot analysis. Our results indicated that targeted and non-targeted nanoparticles cannot be distinguished under static in vitro cell binding cond...
Six coumarin caged compounds of NAA comprising different substituents on the coumarin moiety were... more Six coumarin caged compounds of NAA comprising different substituents on the coumarin moiety were synthesized and evaluated for their photo-physical and chemical properties as light-responsive controlled-release plant root stimulators. The 1H-NMR and HPLC techniques were used to verify the release of NAA from the caged compounds. After irradiation at 365 nm, the caged compounds exhibited the fastest release rate at t1/2 of 6.7 days and the slowest release rate at t1/2 of 73.7 days. Caged compounds at high concentration (10-5 M and 10-6 M) significantly stimulate secondary root germination while free NAA at the same level is toxic and leads to inhibition of secondary root germination. Cytotoxicity of the caged compounds against Fibroblasts and Vero cells were evaluated and the results suggested that at 10-5 - 10-6 M, caged compounds exhibit no significant cytotoxic to the cells. Thus, the caged compounds of NAA in this study can be of great benefits as efficient agrochemicals.
Gymnemic acid (GA) is known as the antidiabetic phytoconstituent in Gymnema species, and is used ... more Gymnemic acid (GA) is known as the antidiabetic phytoconstituent in Gymnema species, and is used for quality control and standardization of Gymnema products. In Thailand, a number of nutraceutical products of Gymnema inodorum (Lour.) Decne. (GI) are commercially available and this number is increasing. However, standardized GA content information and safety usage guidelines for GI have not been published. The aim of this study was to investigate the amount of GA constituent in GI leaves using mass spectrometry. Leaf samples were randomly collected in the Northern part of Thailand. Total GA was extracted using an ethanolic solution. The calculation of total GA was based on the detection of aglycone gymnemagenin using the liquid chromatography/electrospray ionization mass spectrometry with multiple reaction monitoring. The results showed that GI contained total GA content in range of 0.20-1.44 mg per one kilogram dry leaves.
In this work, we designed and synthesized two photoresponsive materials with 3-indoleacetic acid ... more In this work, we designed and synthesized two photoresponsive materials with 3-indoleacetic acid (IAA) plant hormone which can be monitored from the photoreposive properties of coumarin. The varied position of the long alkoxy side chain (-OC16H33) was purposely introduced to adhesive on the plant leaves. Two coumarin-caged nanomaterials showed average particle diameter about 400 nm and gave the maximum emission wavelength at 425 and 450 nm. The formulated nanoemulsion showed good wettability (θ=48o) withCassia fistulaleave surface. Interestingly, CM2 gave the short photoresponse of photolysis within one day.
Abstract In this study, a new graft copolymer (SS-g-PLA) was constructed by combining sericin and... more Abstract In this study, a new graft copolymer (SS-g-PLA) was constructed by combining sericin and polylactide (PLA) via ring-opening polymerization (ROP) having Sn(Oct)2 as a catalyst. In this synthetic strategy based on the grafting from concept, sericin molecule acts as a bio-initiator where its hydroxyl groups existing in serine units. The effects of polymerization parameters, including reaction temperature, the concentration of catalyst and sericin, on the copolymer structure and properties were investigated. XPS spectra of SS-g-PLA copolymer showed C1S and N1S signals clearly and differed form that of the neat PLA. 2D HMBC NMR spectra showed correlation assigned to the carbon atom of PLA polymer chains and hydrogen atom in hydroxyl group of serine. Molecular weight of the graft copolymer by GPC was in range of 4000–5600 g mol−1. From soxhlet extraction, the results showed that PLA content in the graft copolymer molecules increased with increasing sericin content. The weight ratio of PLA to sericin in the SS-g-PLA5, SS-g-PLA10 and SS-g-PLA15 graft copolymers were 0.6:1, 1.4:1 and 2.1:1, respectively. By nitrogen analyzer,%protein increased significantly with increasing sericin content. Thermal analysis showed that the graft copolymer presented a single glass-transition temperature (Tg) belonging to PLA. This Tg decreased with increasing sericin content. The thermal degradation temperature (Td) of SS-g-PLA copolymer decreased to about 60 °C. Furthermore, SS-g-PLA is expected to utilize in biomedical applications.
In this study, the inclusion complex formation between α-mangostin and water-soluble quaternized ... more In this study, the inclusion complex formation between α-mangostin and water-soluble quaternized β-CD grafted-chitosan (QCD-g-CS) was investigated. Inclusion complex formation with encapsulation efficiency (%EE) of 5, 15 and 75% can be varied using high speed homogenizer. Tuning %EE plays a role on physicochemical and biological properties of α-mangostin/QCD-g-CS complex. Molecular dynamics simulations indicate that α-mangostin is included within the hydrophobic β-CD cavity and being absorbed on the QCD-g-CS surface, with these results being confirmed by Fourier transform infrared (FTIR) spectroscopy. Probing the release characteristics of the inclusion complex at various %EE (5%, 15% and 75%) in simulated saliva (pH 6.8) demonstrated that α-mangostin release rates were dependent on % EE (order 5% > 15% > 75%). Additionally, higher antimicrobial and anti-inflammation activities were observed for the inclusion complex than those of free α-mangostin due to enhance the solubility of α-mangostin through the inclusion complex with QCD-g-CS.
The development of targeted contrast agents for magnetic resonance imaging (MRI) facilitates enha... more The development of targeted contrast agents for magnetic resonance imaging (MRI) facilitates enhanced cancer imaging and more accurate diagnosis. In the present study, a novel contrast agent was developed by conjugating anti-EpCAM humanized scFv with gadolinium chelate to achieve target specificity. The material design strategy involved site-specific conjugation of the chelating agent to scFv. The scFv monomer was linked to maleimide-DTPA via unpaired cysteine at the scFv C-terminus, followed by chelation with gadolinium (Gd). Successful scFv-DTPA conjugation was achieved at 1:10 molar ratio of scFv to maleimide-DTPA at pH 6.5. The developed anti-EpCAM-Gd-DTPA MRI contrast agent was evaluated for cell targeting ability, in vitro serum stability, cell cytotoxicity, relaxivity, and MR contrast enhancement. A high level of targeting efficacy of anti-EpCAM-Gd-DTPA to an EpCAM-overexpressing HT29 colorectal cell was demonstrated by confocal microscopy. Good stability of the contrast agen...
Coumarin, which is an important material class of substrate in agricultural and pharmaceutical in... more Coumarin, which is an important material class of substrate in agricultural and pharmaceutical industries, can be obtained by the Pechmann condensation reaction. In this work, coumarin was synthesized from ethyl acetoacetate and resorcinol with sulfuric acid as the catalyst with 86% yield under a mild condition. The product was confirmed by IR, 1H NMR, and 13C NMR spectroscopy. Reaction rates at difference temperatures between 273 and 313 K were used to determine the apparent activation energy of the reaction to be 34.7 kJ/mol. Molecular-level understanding about the mechanism of Pechmann condensation reaction was revealed by the complimentary M06-2X density functional theory. The reaction proceeded via a three-step mechanism; transesterification, intramolecular hydroxylalkylation, and dehydration. The intrinsic activation energies of these three steps were calculated to be 136.7, 76.5, and 134.0 kJ/mol, respectively. The calculated apparent activation energy of 40.0 kJ/mol was in agreement with the experimental data. The transesterification was considered as the rate-determining step of the reaction.Graphical abstract
In this study, tea (Camellia oleifera) seed oil was formulated into self-emulsifying oil formulat... more In this study, tea (Camellia oleifera) seed oil was formulated into self-emulsifying oil formulations (SEOF) to enhance the aqueous dispersibility and intestinal retention to achieve higher bioavailability. Self-emulsifying tea seed oils were developed by using different concentrations of lecithin in combination with surfactant blends (Span ® 80 and Tween ® 80). The lecithin/surfactant systems were able to provide clear and stable liquid formulations. The SEOF were investigated for physicochemical properties including appearance, emulsion droplets size, PDI and zeta potential. The chemical compositions of tea seed oil and SEOF were compared using GC-MS techniques. In addition, the oil adsorption measurement on artificial membranes was performed using a Franz cell apparatus and colorimetric analysis. The microscopic structure of membranes was observed with scanning electron microscopy (SEM). After aqueous dilution with fed-state simulated gastric fluid (FeSSGF), the droplet size of all SEOF was close to 200 nm with low PDI values and the zeta potential was negative. GC-MS chromatograms revealed that the chemical compositions of SEOF were not significantly different from that of the original tea seed oil. The morphological study showed that only the SEOF could form film layers. The oil droplets were extracted both from membrane treated with tea seed oil and the SEOF in order to evaluate the chemical compositions by GC-MS.
International Journal of Biological Macromolecules, 2015
Two guest molecules (eugenol and (-)-menthol) were investigated on inclusion complex formation wi... more Two guest molecules (eugenol and (-)-menthol) were investigated on inclusion complex formation with water-soluble quaternized β-CD grafted with chitosan (QCD-g-CS). The inclusion complexes were prepared at varying mole ratios between eugenol or (-)-menthol and β-CD (substituted on QCD-g-CS) by a conventional shaking method and obtained as solid powder by freeze-drying process. The results showed that encapsulation efficiency %EE decreased with increasing of initial eugenol or (-)-menthol loading whereas %loading increased with increasing of initial eugenol or (-)-menthol loading. The results indicated that inclusion complex formation between eugenol and QCD-g-CS was more favorable than that of (-)-menthol. To clarify this mechanism, molecular dynamics simulations were performed to explore their binding energy, solvation energy and total free energy of those complexes. It was found that the total free energy (ΔG) of eugenol and (-)-menthol against QCD-g-CS (mole ratio of 1) in water-explicit system were -2108.91kJ/mol and -344.45kJ/mol, respectively. Moreover, molecular dynamic simulation of eugenol absorbed on surface QCD-g-CS (-205.73kJ/mol) was shown to have a higher negative value than that of (-)-menthol on QCD-gCS (3182.31kJ/mol). Furthermore, the release characteristics of the encapsulated powder were also investigated in simulated saliva pH 6.8 at 32°C. The results suggested that (-)-menthol had higher release rate from the complexes than eugenol. In all cases, the release characteristics for those guest molecules could be characterized by the limited-diffusion kinetics.
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Papers by Suwatchai Jarussophon