Papers by Ratnakaram Venkata Nadh
Research Journal of Pharmacy and Technology, 2019
Polyethylene glycol-400 (PEG-400) has a spectrum of applications in pharmaceutical field. PEG-400... more Polyethylene glycol-400 (PEG-400) has a spectrum of applications in pharmaceutical field. PEG-400 oxidation was carried out in alkaline medium by using potassium periodate as an oxidant. Rate of the reaction was found to be first order dependence on the oxidant concentration. In the studied range, substrate concentration didn't change the reaction rate. Increase of alkali concentration decreased the reaction rate and order of the reaction with respect to alkali was inverse fractional. Effect of temperature on reaction rate was studied and then Arrhenius parameters were calculated. A suitable rate law was proposed based on the observed experimental results.
ORIENTAL JOURNAL OF CHEMISTRY , 2019
A simple method is described to determine the amount of gemigliptin in bulk and tablet formulatio... more A simple method is described to determine the amount of gemigliptin in bulk and tablet formulation by visible spectrophotometry. Basis of the proposed method is the reaction of the primary amine present on gemigliptin with ninhydrin in alkaline pH (alkaline borate buffer) medium to produce a purple color (Ruhemann's purple) which has maximum absorption at 558 nm. The method was validated as per the current ICH guidelines. The obtained regression equation (y = 0.0148x+0.0011) in the range of 5-30 μg mL-1 has a good correlation coefficient (> 0.999). As the method does not require any separation, it is rapid and simple. The recovery levels of the drug were in the range of 99.73-99.96. This method is a green method as it no organic solvents were employed.
Asian Journal of Organic & Medicinal Chemistry, 2019
Satranidazole, Ion-Associative complex, Tropaeolin OOO, Validation, Visible spectrophotometry. AR... more Satranidazole, Ion-Associative complex, Tropaeolin OOO, Validation, Visible spectrophotometry. ARTICLE Available online at: http://ajomc.asianpubs.org I N T R O D U C T I O N Satranidazole {1-methylsulfonyl-3-(1-methyl-5-nitro-2-imidazolyl)-2-imidazolidinone} (Fig. 1) is a nitroimidazole derivative and widely used as antiprotozoal agent in the treatment of amoebiasis [1]. Literature survey revealed that few analytical methods have been developed for the determination of satranidazole in pharmaceutical formulations and biological materials include spectrophotometric [2-5], HPLC [6-11], HPTLC [12,13] and electron-capture gas chromatographic determination [14]. N N S O O O N N O 2 N Fig. 1. Structure of satranidazole Previously reported spectrophotometric methods [2,4] for the determination of satranidazole in pharmaceutical formulations and biological materials were complicated and not economical. The aim of the present study is to develop a relatively simple, sensitive, validated and low-cost visible spectropho-tometric method for the determination of satranidazole in bulk drug and pharmaceutical dosage form. A simple, selective, accurate and low-cost spectrophotometric method has been described for determination of satranidazole in bulk and pharmaceutical formulations. The developed method involves the formation of chloroform extractable colored ion-association complex of satranidazole with Tropaeolin OOO (TPooo). The extracted colored complex showed absorbance maximum at wavelength 484 nm and obeying Beer′s law in the concentration 4-20 µg mL-1 with the correlation coeffiecent of 0.9998. The results of statistical analysis of the proposed method reveals high accuracy and good precession. Thus, the proposed method can be used commercially for the determination of satranidazole in bulk and pharmaceutical formulations.
ORIENTAL JOURNAL OF CHEMISTRY, 2019
A simple spectrophotometric method was developed to determine riociguat in bulk and tablet formul... more A simple spectrophotometric method was developed to determine riociguat in bulk and tablet formulation. The present method lies on the oxidation of MBTH by Fe +3 ions in acidic medium to form active coupling species and followed by its coupling with riociguat to form the chromophore having lmax 660 nm. Validated the proposed method as per the existing guidelines of ICH. Good linearity (r~ 0.999) was observed for calibration curve in the studied concentration range (6.25-37.50 μg mL-1). Reproducibility, accuracy and precision of the method were confirmed from low values of % RSD.
Letters in Organic Chemistry, 2019
Background: Nowadays, hybrid drugs have gained a significant role in the treatment of different h... more Background: Nowadays, hybrid drugs have gained a significant role in the treatment of different health problems. Most of the hybrid molecules with different heterocyclic moieties were proved to be potent anti-tumor agents in cancer chemotherapy. Hence, the present study is aimed at the evaluation of in vitro anticancer activity of novel hybrid molecules (pyrazolyl benzoxazole conjugates) and to investigate their anticancer activity by molecular docking studies. Methods: Designed, synthesized and characterized the novel pyrazolyl benzoxazole conjugates. Anticancer activity of these compounds was determined by SRB assay. Then molecular docking studies were carried out against proto-oncogene tyrosine-protein kinase (ATP-Src, PDB: 2BDF), a putative target for cancer. Results: All the synthesized compound derivatives were evaluated against MCF-7, KB, Hop62 and A549 cancer cell lines. Compounds 9b and 9c exhibited excellent anticancer activities with GI 50 values of <0.1 µM against MCF-7 and A549 cell lines. Compound 9e exhibited good antitumor activity on MCF-7 and A-549 with GI 50 values of 0.12 µM and 0.19 µM respectively. Compound 9g showed better anticancer activity on A-549 cancer cell line with GI 50 value of 0.34 µM. Conclusion: The two-hybrid molecules 9b and 9c are found to be comparably potent with the standard drug doxorubicin and may act as drug lead compounds in medicinal chemistry aspect. The present docking investigation proved that having benzoxazole of compound 9c at benzofuran of reference compound N-acetyl pyrazoline derivative might be valid for contributing to anti-cancer activity.
Journal of Analytical Chemistry, 2019
A simple, sensitive, precise, accurate, highly reproducible and economical, visible spectrophoto-... more A simple, sensitive, precise, accurate, highly reproducible and economical, visible spectrophoto-metric method for the determination lurasidone in bulk form was developed and validated. The method is based on the formation of an oxidative coupling product by the reaction of lurasidone with 3-methylbenzo-thiazolin-2-one hydrazone as a chromogenic reagent in presence of ferric chloride. The linear regression analysis data for the calibration plot showed good linear relationship within the concentration range of 0-100 μg/mL with a correlation coefficient (r) value of 0.9997. The limits of detection and quantitation are 0.6 and 1.7 μg/mL, respectively. The method was tested and validated according to ICH guidelines. The results demonstrated that the procedure is accurate, precise and reproducible (RSD < 2%).
ORIENTAL JOURNAL OF CHEMISTRY, 2019
A visible spectrophotometric method was developed and validated for the determination of gemiglip... more A visible spectrophotometric method was developed and validated for the determination of gemigliptin present in bulk drug and tablet formulation. It involves an indirect method of charge transfer complex formation in presence of NBS, metol and suphanilic acid. Gemigliptin was subjected to oxidation with excess amount of oxidant (NBS) and the unconsumed NBS oxidizes metol to give p-N-methylbenzoquinone monoamine (PNMM) which in turn forms a charge transfer complex with sulphanilic acid. Then validated the above developed method as per the current ICH guidelines. An excellent correlation coefficient (> 0.999) was found for the obtained regression equation (y =-0.0302x + 0.928) in the range of 2.0-30.0 μg mL-1. The method was found to be simple and rapid because it does not involve any solvent extraction. The recovery levels of the drug were in the range 99.92-100.08.
Toxicology in Vitro, 2019
The new pyrimidine-pyrrole scaffolds (7a-7m) with substituted 1,2,3-traizole moiety were synthesi... more The new pyrimidine-pyrrole scaffolds (7a-7m) with substituted 1,2,3-traizole moiety were synthesized in good to mild yields and subjected for anti-cancer activity against melanoma and breast cancer cell lines using MTT assay. The compounds 7f and 7m exhibited highest anti-cancer activity against both the tested cell lines in in vitro assay. The molecular docking analysis provided the insights of binding orientation of pyrimidine-pyrrole nucleus of current ligands and their crucial interactions with Cys797 and other residues of the EGFR tyrosine kinase active site. The interactions of triazole and its various substituted groups with EGFR tyrosine kinase have been discussed.
Letters in Organic Chemistry, 2019
Cancer is a second leading cause of death after heart attack, in developing as well as undevelope... more Cancer is a second leading cause of death after heart attack, in developing as well as undeveloped countries. It is caused by unregulated growth and metastasis of the abnormal cancer cells. Cancer can be cured by radiation, immunotherapy and chemotherapy, among them; chemotherapy is a good treatment for cancer, in which chemotherapeutic drug is used. The anticancer activity of newly synthesized compounds (13a-j) was carried out on four different types of human cancer cell lines like MCF-7 (breast), A549 (lung), Colo-205 (colon) and A2780 (ovarian) by the MTT method, and compared to etoposide used as a positive control. Among them, compound 13g with electron-withdrawing (3,5-dinitro) group, exhibited more promising activity in all cell lines (MCF-7 = 0.10±0.076 µM, A549 = 0.17±0.039 µM, Colo-205= 0.13±0.022 µM and A2780 = 0.87±0.027µM). This compound may act as lead drug in cancer chemotherapy. In future, this compound can be examined for clinical studies.
Theoretical Foundations of Chemical Engineering, 2019
Three distinct agricultural waste materials, viz., casuarina fruit powder (CFP), sorghum stem pow... more Three distinct agricultural waste materials, viz., casuarina fruit powder (CFP), sorghum stem powder (SSP), and banana stem powder (BSP) were used as low-cost adsorbents for the removal of toxic lead(II) from aqueous solutions. Acid treated adsorbents were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and Fourier transform infrared spectroscopy (FTIR). The effects of parameters like adsorbent dose, pH, temperature, initial metal ion concentration, and time of adsorption on the removal of Pb(II) were analyzed for each adsorbent individually and the efficiency order was BSP > SSP > CFP. Based on the extent of compatibility to Freundlich/Langmuir/Dubinin-Radushkev-ich/Temkin adsorption isotherms and different models (pseudo-first and second order, Boyd, Weber's, and Elovich), chemisorption primarily involved in the case of BSP and SSP, whereas simultaneous occurrence of chemisorption and physisorption was proposed in the case of CFP which was correlating with the thermody-namic study results conducted at different temperatures. Based on the observations, it was proposed that three kinetic stages involve in the adsorption process, viz., diffusion of sorbate to sorbent, intra particle diffusion, and then establishment of equilibrium. These adsorbents have a promising role towards the removal of Pb(II) from industrial wastewater to contribute environmental protection.
INTERNATIONAL JOURNAL OF RESEARCH IN PHARMACEUTICAL SCIENCES, 2019
Polyoxyethylene-300 (POE) is a well-known biodegradable pharmaceutical polymer. In order to under... more Polyoxyethylene-300 (POE) is a well-known biodegradable pharmaceutical polymer. In order to understand the stability of POE and to derive the reaction rate law, the title reaction was carried out in aqueous alkaline medium. Reaction was found to be irst order dependent on the concentration oxidant (periodate) and independent of substrate (POE) concentration. A retardation of reaction rate with an increase in hydroxide concentration shows an inverse fractional order in it. Based on the studies of the temperature dependence of reaction, evaluated the activation parameters.
International Journal of Applied Pharmaceutics, 2019
Objective: To study the kinetics of periodate oxidation of polyethylene glycol-600 (PEG-600), a f... more Objective: To study the kinetics of periodate oxidation of polyethylene glycol-600 (PEG-600), a familiar non-toxic polymer used in pharmaceutical and other fields of industry. Methods: Reactions were carried out in alkaline medium and measured the kinetics by iodometry. One oxygen atom loss or two electrons transfer was observed per each molecule of periodate i.e., the rate of reaction was measured periodate converts to iodate because the formed iodate species is unable to oxidize the substrate molecules. Results: Based on log (a-x) versus t plots, order w. r. t. oxidant (periodate) is unity. Reactions were found to be independent of substrate (PEG-600) concentration. A decrease in rate with an increase in alkali concentration [OH-] was found and order was inverse fractional. Temperature dependence of reaction rate was studied and then calculated the corresponding Arrhenius parameters. Conclusion: An appropriate rate law was proposed by considering the above experimental results.
Rasayan Journal of Chemistry, 2019
Kinetics of PEG-200 oxidation by potassium periodatewas studied in alkaline medium. First-order d... more Kinetics of PEG-200 oxidation by potassium periodatewas studied in alkaline medium. First-order dependence of reaction on periodate was observed. Rate of the reaction was found to be independent of substrate concentration. An inverse fractional order with respect to alkaliwas shown. Arrhenius parameters were calculated. Rate law was postulated taking into consideration of experimental results.
Books by Ratnakaram Venkata Nadh
Women: The Key to Ensure Food Security (ISBN: 978-93-5396- 589-1), pp: 95-105, 2019
A massive quantity of food waste is generated due to the improvement in living standards of peopl... more A massive quantity of food waste is generated due to the improvement in living standards of people
in addition to their increase in population. Anthropogenic impression on the environment can be
reduced by usage of biorefinery processes for the conversion of food wastage to biochemicals. The
present article enlightens about various physico-chemical and biological processes involved in the
conversion of food waste into platform chemicals and other products.
Women Empowerment, 2020
Maximum exploitation of existing human resources is possible by immediate engagement of women in
... more Maximum exploitation of existing human resources is possible by immediate engagement of women in
science. But, historically, scientific field is found to be male-dominated. Women empowerment
embraces the good quality education. Sensitizing and encouraging the women towards education
embracement enables them to set free from ignorance, poverty and starvation. Hence, education is
continuing as the most practicable avenue for women empowerment. Imparting science education to
the entire population expedites the accomplishment of scientific and technological progression. The
present article enlightens the efforts of Indian government and United Nations towards empowerment
of women through science education and research.
Women Empowerment -Awakening of a New Era , 2020
Development and growth of a nation is determined by the effective utilization of human resources,... more Development and growth of a nation is determined by the effective utilization of human resources, both male and female. Though, female category is about half of world's population, they are underrepresented in most of the sectors. Chemistry is playing a synergetic role in shifting the equilibrium towards the women's success. It is the social responsibility to eradicate the gender bias in chemical related fields (academic, professional, industrial, and research). The mean and methods for the same are discussed in the present article. INTRODUCTION As women number occupies half of the population, encouraging their abilities and brain-power makes the usage of these precious human resources, which is essential for the growth of technological and scientific fields [1]. Only 20 Nobel Prizes were given to women out of the 607 in sciences. Five, three and twelve were the number of awards in Chemistry, Physics and Medicine / Physiology respectively. Noble prize winners in Chemistry are Marie Sklodowska Curie (1911); Irene Joliot-Curie (1935); Dorothy Crowfoot Hodgkin (1964); Ada E. Yonath (2009); Frances H. Arnold (2018) [2]. At present, women's share in chemistry doctoral degrees per year is about 40% [3]. This article discuss about impact of society on women chemists, support to women in chemical education, women role models, recognition and awards to women chemists, importance of mentoring to women chemists and supportive measures from Governments and NGO's.
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Papers by Ratnakaram Venkata Nadh
Books by Ratnakaram Venkata Nadh
in addition to their increase in population. Anthropogenic impression on the environment can be
reduced by usage of biorefinery processes for the conversion of food wastage to biochemicals. The
present article enlightens about various physico-chemical and biological processes involved in the
conversion of food waste into platform chemicals and other products.
science. But, historically, scientific field is found to be male-dominated. Women empowerment
embraces the good quality education. Sensitizing and encouraging the women towards education
embracement enables them to set free from ignorance, poverty and starvation. Hence, education is
continuing as the most practicable avenue for women empowerment. Imparting science education to
the entire population expedites the accomplishment of scientific and technological progression. The
present article enlightens the efforts of Indian government and United Nations towards empowerment
of women through science education and research.
in addition to their increase in population. Anthropogenic impression on the environment can be
reduced by usage of biorefinery processes for the conversion of food wastage to biochemicals. The
present article enlightens about various physico-chemical and biological processes involved in the
conversion of food waste into platform chemicals and other products.
science. But, historically, scientific field is found to be male-dominated. Women empowerment
embraces the good quality education. Sensitizing and encouraging the women towards education
embracement enables them to set free from ignorance, poverty and starvation. Hence, education is
continuing as the most practicable avenue for women empowerment. Imparting science education to
the entire population expedites the accomplishment of scientific and technological progression. The
present article enlightens the efforts of Indian government and United Nations towards empowerment
of women through science education and research.