Indian Journal of Chemistry Section B-organic Chemistry Including Medicinal Chemistry, Dec 1, 2008
Two flavonoids, 5,6-dihydroxy-7,8,4'-trimethoxy flavone 1 and 5,2'-dihydroxy-8,3',4'-trimethoxyfl... more Two flavonoids, 5,6-dihydroxy-7,8,4'-trimethoxy flavone 1 and 5,2'-dihydroxy-8,3',4'-trimethoxyflavone 2 together with three known compounds, 5-hydroxy-7,2'-dimethoxyflavone 3, 5,2'-dihydroxy-7,8-dimethoxyflavone 4 and β-sitosterol 5, have been isolated from the aerial parts and roots of Limnophila indica (Scrophulariaceae). The structures of compounds 1-5 have been elucidated on the basis of spectral and chemical studies.
The chemical investigation of metanolic extract of the flowers of P. pterocarpum belonging to the... more The chemical investigation of metanolic extract of the flowers of P. pterocarpum belonging to the family Leguminosae led to the isolation of four bioactive phytoconstituents. These are characterized as hentriacontanol, bergenin, kaempferol and quercetin. The isolated compounds were characterized using various spectroscopic data as well as chemical studies.
The chemical investigation of methanol extract of the aerial parts of P. pterocarpum belonging to... more The chemical investigation of methanol extract of the aerial parts of P. pterocarpum belonging to the family Leguminosae led to the isolation of an isoflavone, mexitin. The isolated compound was characterized using various spectroscopic data as well as chemical studies.
International journal of pharmaceutical sciences and nanotechnology, Aug 31, 2014
The field of nanotechnology and nanoscience is the most currently an area of intense scientific i... more The field of nanotechnology and nanoscience is the most currently an area of intense scientific interest for researchers in modern materials science. However there are many chemical as well as physical methods, green synthesis of nanomaterials is the most emerging method of synthesis. We report the synthesis of antibacterial silver nanoparticles (AgNPs) using aqueous leaf extract of medicinal herb Synedrella nodiflora (L.) Gaertn (Family: Asteraceae) at direct sunlight and monitored by UV-Vis spectroscopy. Both leaf extract and resulting AgNPs is subjected to antibacterial study against five pathogenic bacterial strains such as Bacillus megaterium, Staphylococcus aureus, Listeria monocytogenes, Pseudomonas aeruginosa and Salmonella typhimurium. AgNPs exhibited higher antibacterial efficacy than leaf extract and found to be more effective against B. megaterium and S. aureus.
: Transition metals catalyzed C─H bond activation reactions have appeared as an emerging field to... more : Transition metals catalyzed C─H bond activation reactions have appeared as an emerging field to introduce different functional groups in the inactivated saturated and unsaturated C-H bonds. C─S and C─Se bond constructions in aromatic scaffolds are very interesting due to the important applications of organochalcogen reagents in pharmaceutical chemistry and the material world. The introduction of sulphur or selenium moiety to an inert C─H functionality of an arene under transition metal catalysis has become one of the prime challenges and targets in recent years. In this perspective, various transition metals such as Cu, Ni, Co, Pd, Rh, Ru etc. have been extensively studied. Aromatic arenes owning bearing suitable directing groups appeared as the most promising coupling partners to selectively synthesize differently substituted aryl sulfones and aryl sulfides/selenides. The synthetic strategies were highly convenient owing to the regioselectivity of products, broad substrate scope, mild reaction conditions and excellent functional group tolerance. The current review article comprehensively summarizes the extent of C─S/Se bond formation via transition metal-catalyzed C─H bond activation with the assistance of directing groups to govern the site selectivity.
Biflavonoids are dimers of monomeric flavonoids and have reported to exhibit several pharmacologi... more Biflavonoids are dimers of monomeric flavonoids and have reported to exhibit several pharmacological activities, like anti-microbial, anti-inflammatory, antienzymatic, antioxidant, anticancer, anti-Perkinson, anti-ulcer, anti-hypertensive, antidiabetic, anti-depressant and anti-protozoan. Extensive research work on this important segment of natural compounds is in progress. In this chapter, we report the progress of research on natural biflavonoids from the period of 2005 to early 2020; it includes enlisting newly isolated bioflavonoids from plant sources, biological activities exhibited by the known as well as new compounds and synthetic strategies developed for synthesizing such compounds. In this time period, a total of 247 biflavonoids have been reported either in terms of their first-time appearance or evaluation of their biological activities or both. Out of the reported 247 biflavonoids, 176 have been reported as new compounds from natural plant sources. They have been report...
International Journal of Pharmaceutical Sciences and Nanotechnology, 2020
Cassia sophera Linn (Leguminosae) plants are widely distributed worldwide, and find immense appli... more Cassia sophera Linn (Leguminosae) plants are widely distributed worldwide, and find immense applications in traditional systems of medicine in many countries. The plant has been partly explored by various research groups in the world. In our present study, two oils (OL-1 & OL-2) from aerial parts and roots of Cassia sophera have been evaluated by GC/MS using Perkin-Elmer Gas Chromatography–Mass Spectrometry and comparison of spectral data with the existing in National Institute of Standards and Technology (NIST) library. GC/MS analysis of the two oils revealed the presence of a number of chemical constituents. Again, the isolated oils exhibited considerable antibacterial activity against two Gram positive bacteria viz. Bacillus megaterium & Staphylococcus aureus and two Gram negative bacteria viz. Escherichia coli & Enterobacter aerogenes. Therefore, the present study will definitely inspire the researchers engaged in this direction to undertake further research work on this plant f...
Combretum is the largest and most widespread genus of Combretaceae. The genus comprises approxima... more Combretum is the largest and most widespread genus of Combretaceae. The genus comprises approximately 200-250 species being distributed throughout the tropical and subtropical regions mainly in Africa and Asia. Combretum has shown its potential as a source of various secondary metabolites. This review focuses on the chemistry of isolated compounds which is about 223 from 20 different species as well as biological activity of extracts and phytochemicalsof the genus Combretum.This review also focuses on ethnomedicinal practices of Combretum species. The result shows that phytochemicals reported from this genus are belonging to the various structural groups such as terpenoids, flavonoids, phenanthrenes and stilbenoids etc.Combretum extracts exhibitedin vitro bioactivities such as antibacterial, antifungal, antihyperglycemic, cytotoxicity against various human tumor cell lines, anti-inflammatory, anti-snake, antimalarial and antioxidant effects. In vivo studies through various animal mo...
The natural flavonoid, 5,6-dihydroxy-7,8,4'-trimethoxyflavone (DHF) has been isolated from the ae... more The natural flavonoid, 5,6-dihydroxy-7,8,4'-trimethoxyflavone (DHF) has been isolated from the aerial parts and roots of small aquatic herb Limnophila indica and characterized by experimental and computational methods. Optimized geometry of DHF shows a strong hydrogen bond as confirmed by Wiberg indices. The FTIR spectra of DHF were studied by vibrational energy distribution analysis (VEDA) using potential energy distribution (PED) analysis. The electronic spectra were carried out by TD-DFT procedure and compared with experimental results. The experimental and theoretical results corroborates very nicely with the present compound. To understand the biological efficacy of DHF to act as a therapeutic agent (antiviral), binding with protein α-Glucosidase residues has been studied. The nature of binding between DHF and α-Glucosidase residues is hydrophobic in nature. The study suggests further investigation on DHF for their pharmacological importance.
Zenodo (CERN European Organization for Nuclear Research), Feb 28, 2011
Rauvolfia tetraphylla Linn. (Apocynaceae) has been established as new source or lupeol characteri... more Rauvolfia tetraphylla Linn. (Apocynaceae) has been established as new source or lupeol characterized on the basis of detailed spectral studies including ID and 20 NMR; cold alcoholic extract of the ripe fruits or the plant yielded the pharmaceutically potent triterpenold.
The cold ethanol extract of air-dried and powdered roots of Combretum decandrum afforded two bioa... more The cold ethanol extract of air-dried and powdered roots of Combretum decandrum afforded two bioactive lupine triterpenes, betulinic acid and lupeol using column chromatography technique. Structure of these isolated phytochemicals have been elucidated on the basis of chemical as well as detailed spectral studies such as UV, IR, 1 HNMR, 13 C NMR, 2D NMR and EIMS. As per literature survey this is the first report of phytochemical studies on C. decandrum.
The present work offers a review addressing the chemistry and pharmacology of Limnophila aromatic... more The present work offers a review addressing the chemistry and pharmacology of Limnophila aromatica (Lamk.) Merr. (Belonging to Scrophulariaceae family) regarded as one of the most significant plant species in traditional system of medicine and is established as a source of flavonoids, terpenoids etc. The isolated phytochemicals as well as different extracts exhibited significant biological activities such as antimicrobial, antioxidant, vascular protective activities. Exhaustive research regarding isolation of more phytochemicals and pharmacology study on this medicinal plant is still necessary so as to explore the plant regarding its medicinal importance. Therefore, the aim of this review is to boost up present day researchers in this direction to undertake further investigation of this plant for searching new drugs. The present review covers literature up to January 2014 and enlists 24 references.
Flavones and Flavonols, two major sub-classes of flavonoids, are plant secondary metabolites poss... more Flavones and Flavonols, two major sub-classes of flavonoids, are plant secondary metabolites possessing immense biological activities including cytotoxic activities. They are polyphenolic phytochemicals that exist either as free aglycones or as glycosidic conjugates. Diversities in structural patterns of these two sub-classes of flavonoids make them promising agents in anticancer research. In the recent research, plant-derived natural compound become the hot point of study for the safe and effective drug. So search of new natural flavones or flavonol, cytotoxic to cancer cell is of major attention to the chemists now. The present review describes 146 new examples of naturally occurring flavones and flavonols having cytotoxic potential against different cancer cells reported during the period of 2005 to 2020.These compounds comprise flavones, flavonols and isoflavones. These compounds are classified according to their structures. Most of the flavones and flavonols are reported active against human breast cancer, liver cancer and lung cancer cells.The main topics addressed are source, structures, cytotoxic activity against various cancer cells in details, activity-wise classification of the compounds, mechanism of cytotoxicity and possible structure–activity relationship. The review cites 145 references.
Flavonoids consist of a large group of polyphenolic compounds having a benzo-Ƴ-pyrone skeleton an... more Flavonoids consist of a large group of polyphenolic compounds having a benzo-Ƴ-pyrone skeleton and are common constituent present in plants. Literature survey shows that secondary metabolites of phenolic nature including flavonoids are responsible for the variety of pharmacological activities like anti-oxidant, anti-microbial, anticancer, anti-diabetic, anti-HIV. Till date nearly about 131 flavonoids constituents including flavones, flavonols, flavanones, flavan-4-ols, isoflavones, isoflavans, petrocarpans have been isolated from 60 species of Astragalus genus. This led us to compile upto date isolated flavonoids isolated from Astragalus genus along with their recorded biological activities. This book will be very much helpful for the researcher working in the field of natural products chemistry. As this book quantifies the research on flavonoids of the genus Astragalus, it will also directs the future research on this important genus. Special thanks are due to LAMBERT ACADEMIC PUBL...
The chemical investigation of the methanol extract of aerial parts of Argemone mexicana belonging... more The chemical investigation of the methanol extract of aerial parts of Argemone mexicana belonging to the family Papaveraceae led to the isolation of two bioactive phytoconstituents namely stigmasterol and quercetin. The isolated compounds were characterized using various spectroscopic data as well as chemical studies. Out of the two compounds isolated, stigmasterol has been reported for the first time from the plant.
Flavonoids are considered as a significant class of compounds among the natural products, exhibit... more Flavonoids are considered as a significant class of compounds among the natural products, exhibiting a variety of structural skeletons as well as multidirectional biological potentials. In structural elucidations of natural products, Nuclear Magnetic Resonance (NMR) spectroscopy has been playing a vital role; the technique is one of the sharpest tools in the hands of natural products chemists. The present resume deals with hard-core applications of such spectral technique, particularly in structural elucidation of flavonoids; different NMR techniques including 1H-NMR, 13C-NMR, and 2D-NMR [viz. 1H-1H COSY, COLOC, HMBC, HMQC] are described in detail.
Indian Journal of Chemistry Section B-organic Chemistry Including Medicinal Chemistry, Dec 1, 2008
Two flavonoids, 5,6-dihydroxy-7,8,4'-trimethoxy flavone 1 and 5,2'-dihydroxy-8,3',4'-trimethoxyfl... more Two flavonoids, 5,6-dihydroxy-7,8,4'-trimethoxy flavone 1 and 5,2'-dihydroxy-8,3',4'-trimethoxyflavone 2 together with three known compounds, 5-hydroxy-7,2'-dimethoxyflavone 3, 5,2'-dihydroxy-7,8-dimethoxyflavone 4 and β-sitosterol 5, have been isolated from the aerial parts and roots of Limnophila indica (Scrophulariaceae). The structures of compounds 1-5 have been elucidated on the basis of spectral and chemical studies.
The chemical investigation of metanolic extract of the flowers of P. pterocarpum belonging to the... more The chemical investigation of metanolic extract of the flowers of P. pterocarpum belonging to the family Leguminosae led to the isolation of four bioactive phytoconstituents. These are characterized as hentriacontanol, bergenin, kaempferol and quercetin. The isolated compounds were characterized using various spectroscopic data as well as chemical studies.
The chemical investigation of methanol extract of the aerial parts of P. pterocarpum belonging to... more The chemical investigation of methanol extract of the aerial parts of P. pterocarpum belonging to the family Leguminosae led to the isolation of an isoflavone, mexitin. The isolated compound was characterized using various spectroscopic data as well as chemical studies.
International journal of pharmaceutical sciences and nanotechnology, Aug 31, 2014
The field of nanotechnology and nanoscience is the most currently an area of intense scientific i... more The field of nanotechnology and nanoscience is the most currently an area of intense scientific interest for researchers in modern materials science. However there are many chemical as well as physical methods, green synthesis of nanomaterials is the most emerging method of synthesis. We report the synthesis of antibacterial silver nanoparticles (AgNPs) using aqueous leaf extract of medicinal herb Synedrella nodiflora (L.) Gaertn (Family: Asteraceae) at direct sunlight and monitored by UV-Vis spectroscopy. Both leaf extract and resulting AgNPs is subjected to antibacterial study against five pathogenic bacterial strains such as Bacillus megaterium, Staphylococcus aureus, Listeria monocytogenes, Pseudomonas aeruginosa and Salmonella typhimurium. AgNPs exhibited higher antibacterial efficacy than leaf extract and found to be more effective against B. megaterium and S. aureus.
: Transition metals catalyzed C─H bond activation reactions have appeared as an emerging field to... more : Transition metals catalyzed C─H bond activation reactions have appeared as an emerging field to introduce different functional groups in the inactivated saturated and unsaturated C-H bonds. C─S and C─Se bond constructions in aromatic scaffolds are very interesting due to the important applications of organochalcogen reagents in pharmaceutical chemistry and the material world. The introduction of sulphur or selenium moiety to an inert C─H functionality of an arene under transition metal catalysis has become one of the prime challenges and targets in recent years. In this perspective, various transition metals such as Cu, Ni, Co, Pd, Rh, Ru etc. have been extensively studied. Aromatic arenes owning bearing suitable directing groups appeared as the most promising coupling partners to selectively synthesize differently substituted aryl sulfones and aryl sulfides/selenides. The synthetic strategies were highly convenient owing to the regioselectivity of products, broad substrate scope, mild reaction conditions and excellent functional group tolerance. The current review article comprehensively summarizes the extent of C─S/Se bond formation via transition metal-catalyzed C─H bond activation with the assistance of directing groups to govern the site selectivity.
Biflavonoids are dimers of monomeric flavonoids and have reported to exhibit several pharmacologi... more Biflavonoids are dimers of monomeric flavonoids and have reported to exhibit several pharmacological activities, like anti-microbial, anti-inflammatory, antienzymatic, antioxidant, anticancer, anti-Perkinson, anti-ulcer, anti-hypertensive, antidiabetic, anti-depressant and anti-protozoan. Extensive research work on this important segment of natural compounds is in progress. In this chapter, we report the progress of research on natural biflavonoids from the period of 2005 to early 2020; it includes enlisting newly isolated bioflavonoids from plant sources, biological activities exhibited by the known as well as new compounds and synthetic strategies developed for synthesizing such compounds. In this time period, a total of 247 biflavonoids have been reported either in terms of their first-time appearance or evaluation of their biological activities or both. Out of the reported 247 biflavonoids, 176 have been reported as new compounds from natural plant sources. They have been report...
International Journal of Pharmaceutical Sciences and Nanotechnology, 2020
Cassia sophera Linn (Leguminosae) plants are widely distributed worldwide, and find immense appli... more Cassia sophera Linn (Leguminosae) plants are widely distributed worldwide, and find immense applications in traditional systems of medicine in many countries. The plant has been partly explored by various research groups in the world. In our present study, two oils (OL-1 & OL-2) from aerial parts and roots of Cassia sophera have been evaluated by GC/MS using Perkin-Elmer Gas Chromatography–Mass Spectrometry and comparison of spectral data with the existing in National Institute of Standards and Technology (NIST) library. GC/MS analysis of the two oils revealed the presence of a number of chemical constituents. Again, the isolated oils exhibited considerable antibacterial activity against two Gram positive bacteria viz. Bacillus megaterium & Staphylococcus aureus and two Gram negative bacteria viz. Escherichia coli & Enterobacter aerogenes. Therefore, the present study will definitely inspire the researchers engaged in this direction to undertake further research work on this plant f...
Combretum is the largest and most widespread genus of Combretaceae. The genus comprises approxima... more Combretum is the largest and most widespread genus of Combretaceae. The genus comprises approximately 200-250 species being distributed throughout the tropical and subtropical regions mainly in Africa and Asia. Combretum has shown its potential as a source of various secondary metabolites. This review focuses on the chemistry of isolated compounds which is about 223 from 20 different species as well as biological activity of extracts and phytochemicalsof the genus Combretum.This review also focuses on ethnomedicinal practices of Combretum species. The result shows that phytochemicals reported from this genus are belonging to the various structural groups such as terpenoids, flavonoids, phenanthrenes and stilbenoids etc.Combretum extracts exhibitedin vitro bioactivities such as antibacterial, antifungal, antihyperglycemic, cytotoxicity against various human tumor cell lines, anti-inflammatory, anti-snake, antimalarial and antioxidant effects. In vivo studies through various animal mo...
The natural flavonoid, 5,6-dihydroxy-7,8,4'-trimethoxyflavone (DHF) has been isolated from the ae... more The natural flavonoid, 5,6-dihydroxy-7,8,4'-trimethoxyflavone (DHF) has been isolated from the aerial parts and roots of small aquatic herb Limnophila indica and characterized by experimental and computational methods. Optimized geometry of DHF shows a strong hydrogen bond as confirmed by Wiberg indices. The FTIR spectra of DHF were studied by vibrational energy distribution analysis (VEDA) using potential energy distribution (PED) analysis. The electronic spectra were carried out by TD-DFT procedure and compared with experimental results. The experimental and theoretical results corroborates very nicely with the present compound. To understand the biological efficacy of DHF to act as a therapeutic agent (antiviral), binding with protein α-Glucosidase residues has been studied. The nature of binding between DHF and α-Glucosidase residues is hydrophobic in nature. The study suggests further investigation on DHF for their pharmacological importance.
Zenodo (CERN European Organization for Nuclear Research), Feb 28, 2011
Rauvolfia tetraphylla Linn. (Apocynaceae) has been established as new source or lupeol characteri... more Rauvolfia tetraphylla Linn. (Apocynaceae) has been established as new source or lupeol characterized on the basis of detailed spectral studies including ID and 20 NMR; cold alcoholic extract of the ripe fruits or the plant yielded the pharmaceutically potent triterpenold.
The cold ethanol extract of air-dried and powdered roots of Combretum decandrum afforded two bioa... more The cold ethanol extract of air-dried and powdered roots of Combretum decandrum afforded two bioactive lupine triterpenes, betulinic acid and lupeol using column chromatography technique. Structure of these isolated phytochemicals have been elucidated on the basis of chemical as well as detailed spectral studies such as UV, IR, 1 HNMR, 13 C NMR, 2D NMR and EIMS. As per literature survey this is the first report of phytochemical studies on C. decandrum.
The present work offers a review addressing the chemistry and pharmacology of Limnophila aromatic... more The present work offers a review addressing the chemistry and pharmacology of Limnophila aromatica (Lamk.) Merr. (Belonging to Scrophulariaceae family) regarded as one of the most significant plant species in traditional system of medicine and is established as a source of flavonoids, terpenoids etc. The isolated phytochemicals as well as different extracts exhibited significant biological activities such as antimicrobial, antioxidant, vascular protective activities. Exhaustive research regarding isolation of more phytochemicals and pharmacology study on this medicinal plant is still necessary so as to explore the plant regarding its medicinal importance. Therefore, the aim of this review is to boost up present day researchers in this direction to undertake further investigation of this plant for searching new drugs. The present review covers literature up to January 2014 and enlists 24 references.
Flavones and Flavonols, two major sub-classes of flavonoids, are plant secondary metabolites poss... more Flavones and Flavonols, two major sub-classes of flavonoids, are plant secondary metabolites possessing immense biological activities including cytotoxic activities. They are polyphenolic phytochemicals that exist either as free aglycones or as glycosidic conjugates. Diversities in structural patterns of these two sub-classes of flavonoids make them promising agents in anticancer research. In the recent research, plant-derived natural compound become the hot point of study for the safe and effective drug. So search of new natural flavones or flavonol, cytotoxic to cancer cell is of major attention to the chemists now. The present review describes 146 new examples of naturally occurring flavones and flavonols having cytotoxic potential against different cancer cells reported during the period of 2005 to 2020.These compounds comprise flavones, flavonols and isoflavones. These compounds are classified according to their structures. Most of the flavones and flavonols are reported active against human breast cancer, liver cancer and lung cancer cells.The main topics addressed are source, structures, cytotoxic activity against various cancer cells in details, activity-wise classification of the compounds, mechanism of cytotoxicity and possible structure–activity relationship. The review cites 145 references.
Flavonoids consist of a large group of polyphenolic compounds having a benzo-Ƴ-pyrone skeleton an... more Flavonoids consist of a large group of polyphenolic compounds having a benzo-Ƴ-pyrone skeleton and are common constituent present in plants. Literature survey shows that secondary metabolites of phenolic nature including flavonoids are responsible for the variety of pharmacological activities like anti-oxidant, anti-microbial, anticancer, anti-diabetic, anti-HIV. Till date nearly about 131 flavonoids constituents including flavones, flavonols, flavanones, flavan-4-ols, isoflavones, isoflavans, petrocarpans have been isolated from 60 species of Astragalus genus. This led us to compile upto date isolated flavonoids isolated from Astragalus genus along with their recorded biological activities. This book will be very much helpful for the researcher working in the field of natural products chemistry. As this book quantifies the research on flavonoids of the genus Astragalus, it will also directs the future research on this important genus. Special thanks are due to LAMBERT ACADEMIC PUBL...
The chemical investigation of the methanol extract of aerial parts of Argemone mexicana belonging... more The chemical investigation of the methanol extract of aerial parts of Argemone mexicana belonging to the family Papaveraceae led to the isolation of two bioactive phytoconstituents namely stigmasterol and quercetin. The isolated compounds were characterized using various spectroscopic data as well as chemical studies. Out of the two compounds isolated, stigmasterol has been reported for the first time from the plant.
Flavonoids are considered as a significant class of compounds among the natural products, exhibit... more Flavonoids are considered as a significant class of compounds among the natural products, exhibiting a variety of structural skeletons as well as multidirectional biological potentials. In structural elucidations of natural products, Nuclear Magnetic Resonance (NMR) spectroscopy has been playing a vital role; the technique is one of the sharpest tools in the hands of natural products chemists. The present resume deals with hard-core applications of such spectral technique, particularly in structural elucidation of flavonoids; different NMR techniques including 1H-NMR, 13C-NMR, and 2D-NMR [viz. 1H-1H COSY, COLOC, HMBC, HMQC] are described in detail.
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