The current investigation deals with the <em>in vitro </em>antioxidative and toxicity... more The current investigation deals with the <em>in vitro </em>antioxidative and toxicity effects of methanol and chloroform extracts from the stem bark of <em>Sterculia setigera</em>. The stem bark of the plant was extracted using organic solvents (methanol and chloroform) to afford methanol extract (ME) and chloroform extract (CE). The extracts were evaluated for antioxidative potentials using 2.2-diphenyl-1-picrylhydraxyl (DPPH) radical, also toxicity effect of the methanol extract was investigated against <em>Artemia salina larvae</em>. The antioxidative effects for the extracts uncovered promising activity on the DPPH with significant scavenging effects of 80.64% and 18.3% at 1000 and 7.813 µg/mL respectively. These values were found to be comparable with those of ascorbic acid (97.80 and 49.62%) and butylated hydroxytoluene (94.44 and 20.98%). The methanol extract was found to be as toxic as the positive control (potassium dichromate) with <e...
The genus Eucalyptus has been used in African traditional medicine for the treatment of cardiovas... more The genus Eucalyptus has been used in African traditional medicine for the treatment of cardiovascular diseases and diabetes. In this work, chloroform and methanol extracts from the leaves of Eucalyptus citriodora was investigated for their phytochemicals, cytotoxicity and antioxidant potentials. Phytochemical screening of the extracts showed the presence of alkaloid, flavonoid, phenols, reducing sugar and steroids in the methanol extract. IR absorptions of the extract supported the presence of these phytochemicals by revealing the bands 3335 cm-1 (O-H), 1613, 1480 cm-1 (C=C) and 1721 cm-1 (C=O). Evaluation of the cytotoxicity of the methanol extract using brine shrimp assay, suggested that, the extract was not toxic with LC50 value of 1.64 mg/mL. Antioxidant potentials of both chloroform and methanol extracts were determined using phenolic content quantification and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging. Methanol extract (37.32 μg TAE/mg) had higher phenolic conte...
Wound healing process could be disrupted by oxidative stress due to presence of reactive oxygen s... more Wound healing process could be disrupted by oxidative stress due to presence of reactive oxygen specie (ROS) around the wound. The present study was undertaken to evaluate the antioxidant properties of bioactive aqueous fraction of M. oleifera for potential wound healing application. Phytochemical screening was conducted using established methods to identify phytochemical composition of the aqueous fraction. Antioxidant activity was evaluated using standard methods of DPPH, phosphomolybdenum, FRAP, nitric oxide and hydrogen peroxide scavenging assays. Phytochemical compounds such as tannins, flavonoids, saponins, glycosides, alkaloids, cardiac glycosides, saponin glycosides, steroids and volatile oils were found in the bioactive aqueous fraction. The antioxidant assay results showed high antioxidant capacity of aqueous fraction when compared to positive control (standard ascorbic acid). We may therefore conclude that, the capacity to modulate production and quenching of free radical...
Chemical investigation of the stem bark of Bauhinia rufescens resulted in the isolation of a new ... more Chemical investigation of the stem bark of Bauhinia rufescens resulted in the isolation of a new cyanoglucoside and menisdaurin from methanol extract and oxepin from petroleum ether extract. The isolated compounds were tested for their anti-inflammatory potentials based on the cyclooxygenase-2 enzyme (COX-2) model. Cyanoglucoside exhibited the highest activity among the compounds with an inhibition activity of 49.34 % at 100 µM (IC50 0.46 µM) compared to the positive control, indomethacin (79.20 %, IC50 0.24 µM).
Cassia singueana (Delile) Lock from the family Fabaceae is a well-known medicinal plant that grow... more Cassia singueana (Delile) Lock from the family Fabaceae is a well-known medicinal plant that grows abundantly in Nigeria and other African countries, and has long been used in the treatment of various ailments including malaria and other infectious diseases. The present study aimed at assessing the composition, and bioactivity of the essential oil of the flowers of C. singueana collected from Nigeria. The essential oil was extracted by hydrodistillation and the chemical composition was analyzed by gas chromatography (GC) coupled with a flame ionization detector (GC-FID) and GC coupled to mass spectrometry (GC–MS). The bioactivity of the oil was determined using the brine shrimp lethality assay, agar diffusion antimicrobial test, the 2, 2-diphenylpicrylhydrazyl, metal chelation, and superoxide anion antioxidant assays. The essential oil yield and the percentage of identified compounds were 1.58% and 97.91%, respectively. More than 20 compounds were identified. The major component was...
Abstract: Nigeria is blessed with abundant natural and human resources-the basic ingredients requ... more Abstract: Nigeria is blessed with abundant natural and human resources-the basic ingredients required by any nation to reach the pinnacle of industrial development. The nation&#x27;s abundant fossil fuel resource, and in particular natural gas, is a double blessing ...
The stem bark extracts of Bauhinia rufescens Lam. (Fabaceae) yielded 6-methoxy-7-methyl-8-hydroxy... more The stem bark extracts of Bauhinia rufescens Lam. (Fabaceae) yielded 6-methoxy-7-methyl-8-hydroxydibenz[b,f]oxepin, alpha-amyrin acetate, beta-sitosterol 3-O-beta-D-xylopyranoside, 4-(2'-Hydroxyphenethyl)-5-methoxy-2-methylphenol, menisdaurin and sequoyitol. Their structures were determined using spectroscopic methods and comparisons with the literature data. For the antimicrobial assay Gram-positive and Gram-negative bacterial and fungal strains were tested, while the tyrosinase inhibition assay utilized L-DOPA as a substrate for the tyrosinase enzyme. 6-Methoxy-7-methyl-8-hydroxydibenz[b,f]oxepin, a-amyrin acetate, beta-sitosterol 3-O-D-xylopyranoside, menisdaurin and sequoyitol showed weak to moderate activities with minimum inhibition concentration (MIC) values in the range of 112.5-900 microg/mL against all bacterial strains, while the MIC values for the fungal strains were in the range of 28.1-450 microg/mL. In the tyrosinase inhibition assay, a-amyrin acetate was found to...
ABSTRACT: Query expansion (QE) is the process of transforming a seed query to improve retrieval p... more ABSTRACT: Query expansion (QE) is the process of transforming a seed query to improve retrieval performance in information retrieval operations. It is often intended to overcome a vocabulary mismatch between the query and the document collection. Query expansion is ...
ABSTRACT Asphaltenes from coals of different rank were oxidised using ruthenium tetroxide with th... more ABSTRACT Asphaltenes from coals of different rank were oxidised using ruthenium tetroxide with the aim of investigating the changes in bound biomarker distributions as a function of increasing maturity. There is preliminary evidence for epimerization of bound hopanoid biomarkers from the biological configuration into the more stable geological configuration. The 22R↔22S epimerization in the bound 17α(H),21β(H) homohopanoids lags behind the corresponding isomerization in the maltenes between mean vitrinite reflectance (Ro) values of ca. 0.5% to 0.7%. In general, the asphaltenes evolve towards a more thermally stable structure with decreasing amounts of aliphatic moieties and increasing amounts of lower molecular weight side chains relative to the higher molecular weight ones. Bound biomarkers in coal asphaltenes could be important sources of information particularly where free hydrocarbon biomarkers have been altered or completely lost to biodegradation which occurs during the generation of microbial gas.
1. School of Civil Engineering and Geosciences, Drummond Building, University of Newcastle upon T... more 1. School of Civil Engineering and Geosciences, Drummond Building, University of Newcastle upon Tyne, Newcastle upon Tyne, NE1 7RU, United Kingdom 2. Procter Department of Food Science, University of Leeds, Leeds, LS2 9JT, United Kingdom. ... Asphaltenes are the ...
The current investigation deals with the <em>in vitro </em>antioxidative and toxicity... more The current investigation deals with the <em>in vitro </em>antioxidative and toxicity effects of methanol and chloroform extracts from the stem bark of <em>Sterculia setigera</em>. The stem bark of the plant was extracted using organic solvents (methanol and chloroform) to afford methanol extract (ME) and chloroform extract (CE). The extracts were evaluated for antioxidative potentials using 2.2-diphenyl-1-picrylhydraxyl (DPPH) radical, also toxicity effect of the methanol extract was investigated against <em>Artemia salina larvae</em>. The antioxidative effects for the extracts uncovered promising activity on the DPPH with significant scavenging effects of 80.64% and 18.3% at 1000 and 7.813 µg/mL respectively. These values were found to be comparable with those of ascorbic acid (97.80 and 49.62%) and butylated hydroxytoluene (94.44 and 20.98%). The methanol extract was found to be as toxic as the positive control (potassium dichromate) with <e...
The genus Eucalyptus has been used in African traditional medicine for the treatment of cardiovas... more The genus Eucalyptus has been used in African traditional medicine for the treatment of cardiovascular diseases and diabetes. In this work, chloroform and methanol extracts from the leaves of Eucalyptus citriodora was investigated for their phytochemicals, cytotoxicity and antioxidant potentials. Phytochemical screening of the extracts showed the presence of alkaloid, flavonoid, phenols, reducing sugar and steroids in the methanol extract. IR absorptions of the extract supported the presence of these phytochemicals by revealing the bands 3335 cm-1 (O-H), 1613, 1480 cm-1 (C=C) and 1721 cm-1 (C=O). Evaluation of the cytotoxicity of the methanol extract using brine shrimp assay, suggested that, the extract was not toxic with LC50 value of 1.64 mg/mL. Antioxidant potentials of both chloroform and methanol extracts were determined using phenolic content quantification and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging. Methanol extract (37.32 μg TAE/mg) had higher phenolic conte...
Wound healing process could be disrupted by oxidative stress due to presence of reactive oxygen s... more Wound healing process could be disrupted by oxidative stress due to presence of reactive oxygen specie (ROS) around the wound. The present study was undertaken to evaluate the antioxidant properties of bioactive aqueous fraction of M. oleifera for potential wound healing application. Phytochemical screening was conducted using established methods to identify phytochemical composition of the aqueous fraction. Antioxidant activity was evaluated using standard methods of DPPH, phosphomolybdenum, FRAP, nitric oxide and hydrogen peroxide scavenging assays. Phytochemical compounds such as tannins, flavonoids, saponins, glycosides, alkaloids, cardiac glycosides, saponin glycosides, steroids and volatile oils were found in the bioactive aqueous fraction. The antioxidant assay results showed high antioxidant capacity of aqueous fraction when compared to positive control (standard ascorbic acid). We may therefore conclude that, the capacity to modulate production and quenching of free radical...
Chemical investigation of the stem bark of Bauhinia rufescens resulted in the isolation of a new ... more Chemical investigation of the stem bark of Bauhinia rufescens resulted in the isolation of a new cyanoglucoside and menisdaurin from methanol extract and oxepin from petroleum ether extract. The isolated compounds were tested for their anti-inflammatory potentials based on the cyclooxygenase-2 enzyme (COX-2) model. Cyanoglucoside exhibited the highest activity among the compounds with an inhibition activity of 49.34 % at 100 µM (IC50 0.46 µM) compared to the positive control, indomethacin (79.20 %, IC50 0.24 µM).
Cassia singueana (Delile) Lock from the family Fabaceae is a well-known medicinal plant that grow... more Cassia singueana (Delile) Lock from the family Fabaceae is a well-known medicinal plant that grows abundantly in Nigeria and other African countries, and has long been used in the treatment of various ailments including malaria and other infectious diseases. The present study aimed at assessing the composition, and bioactivity of the essential oil of the flowers of C. singueana collected from Nigeria. The essential oil was extracted by hydrodistillation and the chemical composition was analyzed by gas chromatography (GC) coupled with a flame ionization detector (GC-FID) and GC coupled to mass spectrometry (GC–MS). The bioactivity of the oil was determined using the brine shrimp lethality assay, agar diffusion antimicrobial test, the 2, 2-diphenylpicrylhydrazyl, metal chelation, and superoxide anion antioxidant assays. The essential oil yield and the percentage of identified compounds were 1.58% and 97.91%, respectively. More than 20 compounds were identified. The major component was...
Abstract: Nigeria is blessed with abundant natural and human resources-the basic ingredients requ... more Abstract: Nigeria is blessed with abundant natural and human resources-the basic ingredients required by any nation to reach the pinnacle of industrial development. The nation&#x27;s abundant fossil fuel resource, and in particular natural gas, is a double blessing ...
The stem bark extracts of Bauhinia rufescens Lam. (Fabaceae) yielded 6-methoxy-7-methyl-8-hydroxy... more The stem bark extracts of Bauhinia rufescens Lam. (Fabaceae) yielded 6-methoxy-7-methyl-8-hydroxydibenz[b,f]oxepin, alpha-amyrin acetate, beta-sitosterol 3-O-beta-D-xylopyranoside, 4-(2'-Hydroxyphenethyl)-5-methoxy-2-methylphenol, menisdaurin and sequoyitol. Their structures were determined using spectroscopic methods and comparisons with the literature data. For the antimicrobial assay Gram-positive and Gram-negative bacterial and fungal strains were tested, while the tyrosinase inhibition assay utilized L-DOPA as a substrate for the tyrosinase enzyme. 6-Methoxy-7-methyl-8-hydroxydibenz[b,f]oxepin, a-amyrin acetate, beta-sitosterol 3-O-D-xylopyranoside, menisdaurin and sequoyitol showed weak to moderate activities with minimum inhibition concentration (MIC) values in the range of 112.5-900 microg/mL against all bacterial strains, while the MIC values for the fungal strains were in the range of 28.1-450 microg/mL. In the tyrosinase inhibition assay, a-amyrin acetate was found to...
ABSTRACT: Query expansion (QE) is the process of transforming a seed query to improve retrieval p... more ABSTRACT: Query expansion (QE) is the process of transforming a seed query to improve retrieval performance in information retrieval operations. It is often intended to overcome a vocabulary mismatch between the query and the document collection. Query expansion is ...
ABSTRACT Asphaltenes from coals of different rank were oxidised using ruthenium tetroxide with th... more ABSTRACT Asphaltenes from coals of different rank were oxidised using ruthenium tetroxide with the aim of investigating the changes in bound biomarker distributions as a function of increasing maturity. There is preliminary evidence for epimerization of bound hopanoid biomarkers from the biological configuration into the more stable geological configuration. The 22R↔22S epimerization in the bound 17α(H),21β(H) homohopanoids lags behind the corresponding isomerization in the maltenes between mean vitrinite reflectance (Ro) values of ca. 0.5% to 0.7%. In general, the asphaltenes evolve towards a more thermally stable structure with decreasing amounts of aliphatic moieties and increasing amounts of lower molecular weight side chains relative to the higher molecular weight ones. Bound biomarkers in coal asphaltenes could be important sources of information particularly where free hydrocarbon biomarkers have been altered or completely lost to biodegradation which occurs during the generation of microbial gas.
1. School of Civil Engineering and Geosciences, Drummond Building, University of Newcastle upon T... more 1. School of Civil Engineering and Geosciences, Drummond Building, University of Newcastle upon Tyne, Newcastle upon Tyne, NE1 7RU, United Kingdom 2. Procter Department of Food Science, University of Leeds, Leeds, LS2 9JT, United Kingdom. ... Asphaltenes are the ...
Uploads