Browsing by Author "Mahendra Sahai"

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23-Hydroxyphysalolactone, a New Withanolide with a 23-Hydroxyl Group from Physalis peruviana (Solanaceae)
(1988) Tadashi Eguchi; Nobuo Ikekawa; Yoshinori Fujimoto; Katsumi Kakinuma; Mahendra Sahai; Munna Prasad Verma; Yogesh Kumar Gupta
A new withanolide having a hydroxyl group at the C-23 position has been isolated from the leaves of Physalis peruviana. The structure of this withanolide has been established to be (20S,22R,23R)-6α-chloro-4β,5β, 14α, 17β,20,2 3-hexahydroxy-1-oxowitha-2,24-dienolide (by spectroscopic evidence. © 1988, The Pharmaceutical Society of Japan. All rights reserved.
A new kaempferol diglycoside from Datura suaveolens Humb. & Bonpl. ex. Willd.
(2006) A. Sajeli Begum; Mahendra Sahai; Yoshinori Fujimoto; K. Asai; Kathrin Schneider; Graeme Nicholson; Roderich Suessmuth
A new flavonol glycoside, kaempferol 3-O-α-L-arabinopyranosyl-7- O-β-D-glucopyranoside (1), has been isolated from methanol extract of leaves of Datura suaveolens (Solanaceae), along with six other known compounds, which include kaempferol 3-O-α-L-arabinopyranoside (2), 3-phenyl lactic acid, 3-(3-indolyl) lactic acid, and its methyl ester, physalindicanol A and physalindicanol B. The structural elucidation of 1 and characterization of the known compounds are based on detailed spectral analysis (ESI-FTICR-MS and 2D-NMR). This is the first report of isolation of these compounds from this plant.
Additional alkaloids of thalictrum javanicum
(1985) Mahendra Sahai; S.C. Sinha; Anil B Ray; Sunil K Chattopadhyay; Suleiman Al-Khalil; David J Slatkin; Paul L Schiff
Thalictrum javanicum Bl. is an erect perennial herb indigenous to the Himalayas of India and occurring on the Nilgiris, Pulneys, and Anamalais above 6000 feet (1). Although various Thalcitrum species have been used as medicinals in Indian folkloric medicine, the only reference to previous work on T. javanicum reported the isolation of the protoberberine alkaloids palamatine, berberine, columbamine, jatrorrhizine, and demethyleneberberine, and the quaternary aporphine alkaloid magnoflorine from the stems and roots (2). The genus Thalictrum continues to be a profoundly abundant source of benzylisoquinoline-derived alkaloids with approximately two hundred different alkaloids, many with interesting biological activities, having been isolated and identified by the end of 1983 (3). An investigation of the alkaloid-containing fractions of the roots of T. javanicum via repeated column chromatography led to the isolation of the nonquaternary alkaloids oxyberberine, thalrugosaminine, rugosinone, and thalisopine plus the quaternary alkaloids berberine and thalifendine. This is the first report of the presence of nonquaternary alkaloids in this species. © 1985, American Chemical Society. All rights reserved.
Annonaceous Acetogenins from the Seeds of Annona squamosa. Adjacent Bis-tetrahydrofuranic Acetogenins
(1994) Mahendra Sahai; Sanjewon Singh; Manorama Singh; Yogesh Kumar Gupta; Satoko Akashi; Reiko Yuji; Kazuo Hirayama; Hitomi Asaki; Hiroshi Araya; Noriyuki Hara; Tadashi Eguchi; Katsumi Kakinuma; Yoshinori Fujimoto
The petroleum ether extract of the seeds of Annona squamosa L. yielded thirteen adjacent and four non-adjacent bis-tetrahydrofuranic acetogenins, in addition to squamocin (1) and squamostatin-A. The structures of the thirteen acetogenins, named as squamocins-B (2), -C (3), -D (4), -E (5), -F (6), -G (7), -H (8), -I (9), -J (10), -K (11), -L (12), -M (13) and -N (14), have been established on the basis of spectral evidence. Squamocins-B, -D, -E, -F, -I, -K and -N are new acetogenins. The structures of these acetogenins vary in the carbon number (C37 or C35), the number and position of hydroxyl groups (substituted at C-4, C-12, C-28 or C-29) and the stereochemistry at the bis-tetrahydrofuran moiety. Squamocin-N (14) has an unprecedented threo-cis-threo-cis-threo stereochemistry in its bis-tetrahydrofuran portion. Co-occurrence of a diastereoisomeric pair, 9 and 10, is noteworthy. © 1994, The Pharmaceutical Society of Japan. All rights reserved.
Anti-ulcer constituents of Annona squamosa twigs
(2011) Dinesh K. Yadav; Neetu Singh; Kapil Dev; Rolee Sharma; Mahendra Sahai; Gautam Palit; Rakesh Maurya
Phytochemical investigation of Annona squamosa twigs, resulted in isolation and identification of twelve known (1-12) compounds among them one 1-(4-β-D-glucopyranosyloxyphenyl)-2-(β-D-glucopyranosyloxy)-ethane (11) is synthetically known but first time isolated from natural sources. Their structures were elucidated using 1D and 2D NMR spectroscopic analysis. The isolated compounds (2-8, 11) were evaluated for H+ K +-ATPase activity. Three of these compounds (+)-O-methylarmepavine (2), N-methylcorydaldine (3), isocorydine (6) showed promising anti-secretory activity. Activity of these compounds, comparable to the standard drug omeprazole is novel to our finding. Moreover, there is no information accessible regarding the pharmacological effect of A. squamosa on the gastrointestinal system. This study is the first of its kind to show the significant anti-ulcer effect of A. squamosa. The present study aimed to evaluate the gastroprotective effect of A. squamosa (AS) and to identify its active constituents. Anti-ulcer activity was evaluated against cold restraint (CRU), pyloric ligation (PL), aspirin (ASP), alcohol (AL) induced gastric ulcer and histamine (HA) induced duodenal ulcer model and further confirmed through in vitro assay of H + K+-ATPase activity and plasma gastrin level. AS and its chloroform and hexane fraction attenuated ulcer formation in CRU, PL, HA model and displayed anti-secretory activity in vivo through reduced free, total acidity and pepsin in PL, confirmed by in vitro inhibition of H+ K+-ATPase activity with corresponding decrease in plasma gastrin level. Cytoprotection of AS was apparent with protection in AL, ASP models and enhanced mucin level in PL. © 2011 Elsevier B.V. All rights reserved.
Antimicrobial Activity of Phytochemicals Isolated from Selaginella bryopteris
(Springer Science and Business Media, LLC, 2015) Mradul Verma; Mayank Gangwar; Mahendra Sahai; Gopal Nath; Tryambak Deo Singh
[No abstract available]
Artabotryols A-E, new lanostane triterpenes from the seeds of artabotrys odoratissimus
(2010) Chitrasen Gupta; Subedar Prasad; Mahendra Sahai; Teigo Asai; Noriyuki Hara; Yoshinori Fujimoto
Six new lanostane triterpenes, artabotryols A, B, C1, C2, D, and E (1, 2, 3a, 3b, 4, and 5, resp.) have been isolated from the seeds of Artabotrys odoratissimus (Annonaceae). Their structures have been established as (3α,22S,25R)-3-hydroxy-22,26-epoxylanost-8-en-26-one (1), (3α,22S,25R)-22,26-epoxylanost-8-ene-3,26-diol (2), (3α,22S,25R,26R) -26-methoxy-22,26-epoxylanost-8-en-3-ol (3a), (3α,22S,25R, 26S)-26-methoxy-22,26-epoxylanost-8-en-3-ol (3b), (3α,22S,25R)-3,22- dihydroxylanost-8-en-26-oic acid (4) and (3α,7α,11α,22S,25R)- 3,7,11-trihydroxy-22,26-epoxylanost-8-en-26-one (5) by spectroscopic studies and chemical correlations. © 2010 Verlag Helvetica Chimica Acta AG, Zürich, Switzerland.
Chemical constituents of Anisodus luridus roots and their antimicrobial screening
(Scientific Publishers, 2015) Mradul Verma; Lalit Kumar Lal Das; Mayank Gangwar; Mahendra Sahai; Gopal Nath; Tryambak Deo Singh
The weak base and strong base fractions were separated from methanolic extract of roots of Anisodus luridus. Chromatographic resolution of both fractions yielded compounds 1-5 which were characterized as β-sitosterol (1), esculetin (2), β-sitosterol-β-D-glucoside (3), apohyoscyamine (4) and hyoscyamine (5) with the help of spectroscopic analysis. Four compounds, 1-4 were isolated from A. luridus for the first time. The weak base, strong base and isolated constituents were screened against six microbes viz. E. coli, S. aureus, E. faecalis, C. albicans, C. tropicalis and C. krusei. Weak base, strong base and isolated pure compounds exhibited their potential against these microbes. © 2015 Scientific Publishers.
Chemical constituents of Polyalthia suberosa. A one-pot synthesis of 1-carbamoylpyrrolidin-2-one, a constituent of the plant
(1996) Mahendra Sahai; Anjani Srivastava; Parveen Jamal; Subhash C. Sinha; Ajay P. Singh; Yoshinori Fujimoto
1-Carbamoylpyrrolidin-2-one (1) and tetrahydropalmatine (3) have been isolated from the bark of Polyalthia suberosa. A simple one-step synthesis of 1 is reported.
Chemical constituents of rhus wallichi
(1986) Subhash C. Sinha; Mahendra Sahai; Anil B. Ray
In our continuing chemical analysis (1,2) of Rhus species, we report here the isolation of three glycosides of quercetin in addition to six other known compounds from the leaves of Rhus wallichi Hook, f. (3,4). © 1986, American Chemical Society. All rights reserved.
Clerodane and ent-halimane diterpenes from polyalthia longifolia
(1995) Noriyuki Hara; Hitomi Asaki; Yoshinori Fujimoto; Yogesh Kumar Gupta; Ashish Kumar Singh; Mahendra Sahai
A hexane extract of the stem bark of Polyalthia longifolia furnished nine new clerodane and ent-halimane diterpenes, i.e. 16-hydroxycleroda-4(18),13-dien-16,15-olide, 16-oxocleroda-4(18),13E-dien-15-oic acid, cleroda-4(18),-13-dien-16,15-olide, 16-hydroxy-ent-halima-5(10),13-dien-16,15-olide, 16-oxo-ent-halima-5(10),13E-dien-15-oic acid, ent-halima-1(10),13E-dien-16,15-olide, 16-oxo-ent-halima-5(10),13E-dien-15-oic acid, ent-halima-5(10),13-dien-16,15-olide and ent-halima-5(10),13E-dien-16,15-olide, along with five known clerodane diterpenes. The structures of these compounds were elucidated by spectroscopic methods. The 13E configuration of two of the new ent-halimanes and one of the known clerodanes was firmly established by NOE experiments. © 1995.
Coptisine-induced cell cycle arrest at G2/M phase and reactive oxygen species–dependent mitochondria-mediated apoptosis in non-small-cell lung cancer A549 cells
(SAGE Publications Ltd, 2017) Poorna Chandra Rao; Sajeli Begum; Mahendra Sahai; D Saketh Sriram
This study aimed to explore the effect of coptisine on non-small-cell lung cancer and its mechanism through various in vitro cellular models (A549). Results claimed significant inhibition of proliferation by coptisine against A549, H460, and H2170 cells with IC50 values of 18.09, 29.50, and 21.60 µM, respectively. Also, coptisine exhibited upregulation of pH2AX, cell cycle arrest at G2/M phase, and downregulation of the expression of cyclin B1, cdc2, and cdc25C and upregulation of p21 dose dependently. Furthermore, induction of apoptosis in A549 cells by coptisine was characterized by the activation of caspase 9, caspase 8, and caspase 3, and cleavage of poly adenosine diphosphate ribose polymerase. In addition, coptisine was found to increase reactive oxygen species generation, upregulate Bax/Bcl-2 ratio, disrupt mitochondrial membrane potential, and cause cytochrome c release into the cytosol. Besides, treatment with a reactive oxygen species inhibitor (N-acetyl cysteine) abrogated coptisine-induced growth inhibition, apoptosis, reactive oxygen species generation, and mitochondrial dysfunction. Thus, the mediation of reactive oxygen species in the apoptosis-induced effect of coptisine in A549 cells was corroborated. These findings have offered new insights into the effect and mechanisms of action of coptisine against non-small-cell lung cancer. © 2017, © The Author(s) 2017.
Coumarinolignans from the seeds of Annona squamosa Linn.
(WWW Publications PTE India, 2009) Rakesh Ranjan; Mahendra Sahai
Phytochemical investigations of Annona squamosa seeds have led to the isolation of three lignans consisting of coumarin moiety, cleomiscosin A(1), cleomiscosin B(2) and cleomiscosin C(3). Their structures were arrived at by detailed spectroscopic analysis. Cleomiscosin A and cleomiscosin B are position isomer.
Cytotoxicity of withasteroids: withametelin induces cell cycle arrest at G2/M phase and mitochondria-mediated apoptosis in non-small cell lung cancer A549 cells
(Springer Science and Business Media B.V., 2016) Poorna Chandra Rao; Sajeli Begum; Mohammad Ali Farboodniay Jahromi; Zahra Hosseini Jahromi; Saketh Sriram; Mahendra Sahai
Considerable interest has been gained by withasteroids because of their structural uniqueness and wide spectrum of biological activities. However, limited systematic studies for proving their cytotoxic potential have so far been reported. Hence, an attempt was made to test the cytotoxicity of six withasteroids viz., withametelin (WM), withaphysalin D, withaphysalin E, 12-deoxywithastramonolide, Withaperuvin B, and physalolactone against A549, HT-29, and MDA-MB-231 cancer cell lines. Significant cytotoxic effect of WM against A549 cells (IC50 value of 6.0 μM), MDA-MB-231 cells (IC50 value of 7.6 μM), and HT-29 cells (IC50 value of 8.2 μM) was observed. Withaperuvin B and physalolactone were found to be effective against MDA-MB-231 cells. The significantly active WM arrested the A549 cells at G2/M phase and downregulated the expression of G2/M regulatory proteins such as cdc2, cyclin B1, and cdc25C. Apoptosis induced by WM in A549 cells was associated with the generation of ROS and depletion of MMP. Furthermore, WM treatment resulted in Bax upregulation, Bcl-2 downregulation, translocation of cytochrome c to mitochondria, activation of caspase-9 and −3, and PARP cleavage corroborating the apoptosis induction through intrinsic apoptotic pathway. Thus, WM possessing broader cytotoxic effect is a promising lead molecule which has the potential to be developed as a new therapeutic agent for NSCLC. © 2016, International Society of Oncology and BioMarkers (ISOBM).
Development of ultra performance liquid chromatography tandem mass spectrometry method for simultaneous identification and quantitation of potential osteogenic phytochemicals in butea monosperma
(Oxford University Press, 2018) Vikas Bajpai; Awantika Singh; Pratibha Singh; Khushbu Sharma; Bikarma Singh; Bhim Pratap Singh; Mahendra Sahai; Rakesh Maurya; Brijesh Kumar
An ultra performance liquid chromatography coupled with hybrid triple-quadrupole linear ion trap tandem mass spectrometry (UPLC-ESI-QqQLIT-MS-MS) method in multiple reaction monitoring mode was developed for identification and simultaneous determination of potential osteogenic compounds in ethanol extracts of different plant parts of Butea monosperma collected from different geographical regions. The chromatographic separation was carried out on an Acquity UPLC CSH C18 column (1.7 μm, 2.1 × 100 mm) with 0.1% (v/v) formic acid in water and methanol as mobile phase under gradient conditions in 8 min. The developed method was validated according to the guidelines of international conference on harmonization. The correlation coefficients of all the calibration curves were ≥0.9995 and recoveries ranged from 95.2 to 105.8% (RSD ≤ 1.95%). Relative standard deviations of intra-day, inter-day precisions and stability were ≤1.74, 1.84 and 2.8%, respectively. The quantitative results showed remarkable differences in the content of all potential osteogenic compounds in different parts of the plant as well as samples from different geographical regions. Quantitative variations studied from principal component analysis indicated tentative markers for B. monosperma cultivars which can discriminate sample of different geographical regions. © The Author(s) 2018. Published by Oxford University Press. All rights reserved.
Ethyl brevifolin carboxylate from Flueggea microcarpa
(1991) Hugo E. Gottlieb; Sandeep Kumar; Mahendra Sahai; Anil B. Ray
The leaves of Flueggea microcarpa contain the ethyl ester of brevifolin carboxylic acid. The elucidation of the structure of this isocoumarin involved extensive use of 1H and 13C NMR data, which are fully reported and analysed for the first time; especially useful were long-range CH coupling interactions. NMR parameters for some models, including norbergenin, as well as pyrogallol, gallic acid and their triacetates, are also reported. © 1991.
Flemiculosin, a novel chalcone from Flemengia fruticulosa
(Japan Institute of Heterocyclic Chemistry, 1984) Parth Sarathi Khattri; Mahendra Sahai; Eiswanath Dasgupta; Anil F. Fay
Flemiculosin, a novel chalcone isolated from the leaves of Flemengia fruticulosa Wall, has been shown to possess an annuler benzodipyran system, and its structure has been advanced as 1 on the basis of detailed spectroscopic evidence. © 1983 Japan Institute of Heterocyclic Chemistry. All rights reserved.
Hyoscyamal, a new tetrahydrofurano lignan from Hyoscyamus niger Linn.
(2009) A. Sajeli Begum; Shweta Verma; Mahendra Sahai; Kathrin Schneider; Roderich Sussmuth
In addition to the isolation and complete characterisation of a new lignan, hyoscyamal, three other compounds, balanophonin, pongamoside C and pongamoside D have been isolated from the seeds of Hyoscyamus niger. The structures of the compounds were settled on the basis of spectroscopic analysis. This is the first report on the isolation of these compounds from a solanaceous plant. © 2009 Taylor & Francis.
Hyosgerin, a new optically active coumarinolignan, from the seeds of Hyoscyamus niger
(2006) Begum Sajeli; Mahendra Sahai; Roderich Suessmuth; Teigo Asai; Noriyuki Hara; Yoshinori Fujimoto
Hyosgerin, a new optically active coumarinolignan, has been isolated and characterized along with three other coumarinolignans, venkatasin, cleomiscosin A and cleomiscosin B, from the seeds of Hyoscyamus niger L. The structure was determined on the basis of spectroscopic analysis and chemical conversion. The optical properties and absolute stereochemistry of these coumarinolignans have also been studied and discussed. © 2006 Pharmaceutical Society of Japan.
Hyosmin, a new lignan from Hyoscyamus niger L.
(Scientific Reviews Ltd., 2006) Ahil Sajeli Begum; Shweta Verma; Mahendra Sahai; Teigo Asai; Noriyuki Hara; Yoshinori Fujimoto
Hyosmin (1) a new lignan has been isolated from the seeds of Hyoscyamus niger L. (Solanaceae), and its structure shown to be the 3-{[(2R)-2- carbomethoxy-2-hydroxy]ethyl}benzoate ester of {(2R,3S,4S)-2-(4-hydroxy-3- methoxyphenyl)-3-hydroxymethyl-4-[(4-hydroxy-3-methoxyphenyl)methyl] tetrahydrofuran.