Browsing by Author "Yoshinori Fujimoto"

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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.
Absolute stereochemistry of non-adjacent bis-tetrahydrofuranic acetogenins
(1994) Hiroyasu Shimada; Seiichi Nishioka; Sanjewon Singh; Mahedra Sahai; Yoshinori Fujimoto
Absolute stereochemistry of non-adjacent bis-tetrahydrofuranic acetogenins has been established by comparison of the 1H-NMR data of their MTPA esters with those of optically active model tetrahydrofurans. 12R, 15S, 16S, 19R, 20R, 23R, 24S configuration was assigned for squamostatins-B and -D, whereas 12R, 15S, 16S, 19R, 20R, 23R, 24R configuration was assigned for squamostatins-C and -E. © 1994.
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.
Annonaceous Acetogenins from the Seeds of Annona squamosa. Non-adjacent Bis-tetrahydrofuranic Acetogenins
(1994) Yoshinori Fujimoto; Chikako Murasaki; Hiroyasu Shimada; Seiichi Nishioka; Katsumi Kakinuma
Four non-adjacent bis-tetrahydrofuranic acetogenins, named squamostatins-B (2), -C (3), -D (4) and -E (5), have been isolated from the petroleum ether extract of Annona squamosa seeds. The structures of these acetogenins have been established on the basis of spectral evidence. C-15/C-16-threo, C-19/C-20-threo, C-23/C-24-erythro stereochemistry was assigned for squamostatins-B and -D, whereas C-15/C-16-threo, C-19/C-20-threo, C-23/C-24-threo stereochemistry was assigned for squamostatins-C and -E. All of these acetogenins, including squamostatin-A, have been established to have C-12/C-15-trans, C-20/C-23-trans stereochemistry by 13C-NMR comparison with synthetic model mono-tetrahydrofuranic compounds. An improved 13C-NMR assignment of squamostatin-A is presented. © 1994, The Pharmaceutical Society of Japan. All rights reserved.
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 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.
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.
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.
N-fatty acyl tryptamines from Annona reticulata
(1993) Uki Maeda; Noriyuki Hara; Yoshinori Fujimoto; Anjani Srivastava; Yogesh Kumar Gupra; Mahendra Sahai
A series of N-fatty acyl tryptamines, in which the acyl portion ranged from hexadecanoyl to hexacosanoyl, have been characterized in a petrol extract of the seeds of Annona reticulata. © 1993.
Squamocin, a New Cytotoxic Bis-tetrahydrofuran Containing Acetogenin from Annona squamosa
(1988) Yoshinori Fujimoto; Tadashi Eguchi; Katsumi Kakinuma; Nobuo Ikekawa; Mahendra Sahai; Yogesh Kumar Gupta; Tadashi Eguchi
Squamocin, a new trihydroxy-bis-tetrahydrofuran fatty acid γ-lactone (acetogenin), has been isolated from Annona squamosa L. (Annonaceae) and its structure has been elucidated on the basis of spectral evidence and chemical degradations. © 1988, The Pharmaceutical Society of Japan. All rights reserved.
Squamocin-O1 and squamocin-O2, new adjacent bis-tetrahydrofuran acetogenins from the seeds of Annona squamosa
(2002) Hiroshi Araya; Mahendra Sahai; Shubhra Singh; Ajit Kumar Singh; Mitsuzi Yoshida; Noriyuki Hara; Yoshinori Fujimoto
Two bis-tetrahydrofuran acetogenins, squamocin-O1 (1) and squamocin-O2 (2), were isolated from a MeOH extract of seeds of Annona squamosa L. Their structures were determined by spectral means including precursor-ion scanning mass spectral analysis for their aminal derivatives. The configurations at the oxymethine chiral centers were assigned as 12R, 15R, 16R, 19R, 20R, 23R, 24S, 28S, 36S for 1 and 12S, 15R, 16R, 19R, 20R, 23R, 24S, 28S, 36S for 2, based on 1H NMR analysis of their Mosher's ester derivatives and CD data, © 2002 Elsevier Science Ltd. All rights reserved.
Squamostanal-A, Apparently Derived from Tetrahydrofuranic Acetogenin, from Annona squamosa
(1994) Hiroshi Araya; Noriyuki Hara; Yoshinori Fujimoto; Mahendra Sahai
The seeds of Annona squamosa (Annonaceae) furnished squamostanal-A (1), a novel annonaceous acetogenin. The structure of squamostanal-A was established by spectral methods to be (5S)-3-(12-formyldodecyl)-5-methyl-2, 5-dihydrofuran-2-one. Copyright © 1994, Japan Society for Bioscience, Biotechnology, and Agrochemistry. All rights reserved.
Squamosten-A, a Novel Mono-tetrahydrofuranic Acetogenin with a Double Bond in the Hydrocarbon Chain, from Annona squamosa L.
(1994) Hiroshi Araya; Noriyuki Hara; Yoshinori Fujimoto; Anjani Srivastava; Mahendra Sahai
Squamosten-A, a new mono-tetrahydrofuranic acetogenin possessing a double bond in the hydrocarbon chain, has been isolated from the seeds of Annona squamosa L. (Annonaceae). The structure has been elucidated on the basis of spectral evidence, including precursor-ion scanning spectra. Chemical degradation was successfully employed to determine the position of the double bond. © 1994, The Pharmaceutical Society of Japan. All rights reserved.
Two novel acyl sucroses from Petunia nyctaginiflora
(2005) A. Sajeli Begum; Ajay Pratap Singh; Mahendra Sahai; Subhra Singh; Yoshinori Fujimoto
Two acyl sucroses, isolated from Petunia nyctaginiflora Jussieu (Solanaceae) have been characterized chemically as 2,3,4-tri(5-methylhexanoyl)- α-D-glucopyranosyl-β-D-6-acetyl fructo-furanoside 4 and 2,3,4-tri(6-methylheptanoyl)-α-D-glucopyranosyl-β-D-6-acetyl fructofuranoside 6, on the basis of chemical and spectroscopic evidence.