Neochlorogenin, Neosolaspigenin, and Solaspigenin from Solanum torvum Leaves

Mahmood, Umar; Thakur, Raghunath S.; Blunden, Gerald

doi:10.1021/np50027a023

Cited by 10 publications

(11 citation statements)

References 6 publications

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“…1) As regard with the former reports of the constituents in this plant, neochlorogenin, 2,3) chlorogenin, 3,4) paniculogenin, 2,5) solaspigenin, 5,6) neosolaspigenin, 5,6) and torvonin-B 7) were known. Recently, an additional steroidal glycoside, torvoside H 8) was reported.…”

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confidence: 80%

Three Unusual 22-.BETA.-O-23-Hydroxy-(5.ALPHA.)-spirostanol Glycosides from the Fruits of Solanum torvum

Iida

Yanai

Ono

et al. 2005

CHEMICAL & PHARMACEUTICAL BULLETIN

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Solanum torvum SWARTZ (Solanaceae) is a small shrub, of which fruits are commonly available in the markets and are used as a vegetable regarded as an essential ingredient in Thai cuisine. Previously, we reported seven steroidal glycosides from the aerial parts and the roots of this plant.1) As regard with the former reports of the constituents in this plant, neochlorogenin, 2,3) chlorogenin, 3,4) paniculogenin, 2,5) solaspigenin, 5,6) neosolaspigenin, 5,6) and torvonin-B 7) were known. Recently, an additional steroidal glycoside, torvoside H 8) was reported. In this time, three unusual 22-b-O-spirostanol glycosides have been isolated from the fruits of this plant.The methanolic extract (33.4 g) of fresh fruits (600 g) of Solanum torvum was subjected to high-porous polystyrene gel (Diaion) to elute gradually with H 2 O→50% MeOH→ MeOH→acetone. The MeOH eluate was subsequently separated by using silica gel chromatography and HPLC to afford torvoside J (1, 5.4 mg), torvoside K (2, 8.3 mg), and torvoside L (3, 4.2 mg) together with known steroidal glycosides, torvosides A 1) (2.54 g) and H 8) (29.2 mg). Torvoside J (1), obtained as an amorphous powder, [a] D ϩ53.1°(MeOH) showed a quasimolecular ion peak at m/z 763 due to [MϩNa] ϩ in the positive FAB-MS. The Table 1. The absolute configurations of the respective sugars were determined by using HPLC equipped optical rotatory instrument after acid hydrolysis of 1. The remaining 27 carbons originating from the sapogenol moiety were constituted of eight methylene carbons at d 21. 1, 32.3, 32.5, 33.2, 37.8, 37.9, 39.9, 41.4, seven methine carbons at d 24.6, 34.4, 41.4, 51.4, 54.0, 56.5, 64.9, two Since signals due to H-3 and H-6 were overlapped to other sugar signals, their coupling constants could not be discriminated. However, the 13 C-NMR signals due to C-3, C-6 and their surrounding carbons at C-2, C-4, C-5, and C-7 were coincident with those of 1, 1) so that the configuration at C-3 and C-6 were conceivable to be identical with those of 1. Usually, the configuration at C-25 is determined by the signal pattern of H 2 -26. However, the signals due to H 2 -26 appeared around at d 3.70, which were overlapped with the other signals of H-3 and H-6 in the sapogenol and of the quinovosyl H-4 and H-5, so that they could not be discriminated. When the methyl group at C-25 is axial, it would show a remarkable lower shift due to 1,3-diaxial correlation with the hydroxyl group at C-23. But, the signal due to H 3 -27 practically appeared at d 0.73, suggesting it to be equatorial. Next, as for the configuration at C-22, the H 3 -21 signals in other C-23-hydroxyl spirostanol derivatives were referred. The H 3 -21 appeared at

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confidence: 80%

Three Unusual 22-.BETA.-O-23-Hydroxy-(5.ALPHA.)-spirostanol Glycosides from the Fruits of Solanum torvum

Iida

Yanai

Ono

et al. 2005

CHEMICAL & PHARMACEUTICAL BULLETIN

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“…Hence, to investigate the effects of the ester moiety together with the caffeoyl moiety against -glucosidase inhibition, we synthesized or purchased a series of caffeoyl ester 2-8 and methyl caffeate analogs 9-14, and tested for sucrase and maltase inhibitory activities. The compounds tested included four linear alkyl caffeates (2-4), two branched-chain alkyl caffeates (5, 6), phenyl caffeate (7), a ketone analog (10), methyl dihydrocaffeate (11), and two trihydroxycinnamates (13,14), and chlorogenic acid (8), caffeic acid (9), and methyl protocatechuate (12) (Fig. 1).…”

Section: Resultsmentioning

confidence: 99%

“…Methyl caffeate (1) and several derivatives (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14) were tested for -glucosidase inhibitory activity, and it was determined that 1 had a favorable structure for both sucrase and maltase inhibition, except for the slightly higher activity of 14 against sucrase. Its moderate -glucosidase inhibitory action provides a promising application of Solanum torvum fruit as an antidiabetic agent.…”

Section: Resultsmentioning

confidence: 99%

“…Preparation of methyl 2,3,4-trihydroxycinnamate (13). To a stirred solution of 2,3,4-tris(methoxymethoxy)benzaldehyde 21) (1.43 g, 5 mmol) in dioxane (10 ml) were added (methoxycarbonylmethyl)triphenylphosphonium chloride (1.85 g, 5 mmol, 1 eq) in chloroform (10 ml) and KHCO 3 (2.5 g, 25 mmol, 5 eq).…”

Section: Methodsmentioning

confidence: 99%

“…In the screening experiments for rat intestinal sucrase and/or maltase inhibitors in 325 plants, potent sucrase and maltase inhibiting activity was found in extract of the fruit of Solanum torvum (Solanaceae), an edible herbaceous perennial plant. There have been several reports on the chemical constituents of this plant, which include welldocumented steroidal compounds [13][14][15] and antiviral activities, 16) but no other biologically active compounds from this plant have been reported to date. Hence, the promising screening result prompted us to isolate and elucidate the structures of active compounds in this plant.…”

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Methyl Caffeate as an α-Glucosidase Inhibitor fromSolanum torvumFruits and the Activity of Related Compounds

Takahashi

Yoshioka

Kato

et al. 2010

Bioscience, Biotechnology, and Biochemistry

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In screening experiments for rat intestinal -glucosidase (sucrase and maltase) inhibitors in 325 plants cultivated in Japan's southern island, of Tanegashima, marked inhibition against both sucrase and maltase was found in the extract of the fruit of Solanum torvum. Enzyme-assay guided fractionation of the extract led to the isolation of methyl caffeate (1) as a rat intestinal sucrase and maltase inhibitor. We examined 13 caffeoyl derivatives for sucrase-and maltase-inhibitory activities. The results showed that methyl caffeate (1) had a most favorable structure for both sucrase and maltase inhibition, except for a higher activity of methyl 3,4,5-trihydroxycinnamate (14) against sucrase. Its moderate inhibitory action against -glucosidase provides a prospect for antidiabetic usage of S. torvum fruit.Key words: Solanum torvum; -glucosidase inhibitor; methyl caffeate; Tanegashima Diabetes mellitus is one of the most serious chronic diseases. It is caused by continual hyperglycemia and develops along with increases in obesity and aging in the general population. 1) One of the therapeutic approaches to decreasing postprandial hyperglycemia is to retard absorption of glucose by inhibition of carbohydrate hydrolyzing enzymes -amylase and -glucosidase in the digestive organs.2) In recent years, many efforts have been made to search for effective -glucosidase inhibitors from natural sources in order to develop a physiological functional food or to discover lead compounds for medicinal usage against diabetes.3) In the course of our search for rat intestinal -glucosidaseinhibiting principles from various plants, we have isolated and identified several active compounds from plants grown in Asian regions, including Japan, [4][5][6][7] Thailand, 8,9) China, 10,11) and Nepal. 12) In this paper, we present the results of a screening of plants cultivated in Tanegashima, a southern island of Japan, for rat intestinal -glucosidase inhibition. In the screening experiments for rat intestinal sucrase and/or maltase inhibitors in 325 plants, potent sucrase and maltase inhibiting activity was found in extract of the fruit of Solanum torvum (Solanaceae), an edible herbaceous perennial plant. There have been several reports on the chemical constituents of this plant, which include welldocumented steroidal compounds [13][14][15] and antiviral activities, 16) but no other biologically active compounds from this plant have been reported to date. Hence, the promising screening result prompted us to isolate and elucidate the structures of active compounds in this plant. Separation of S. torvum fruit extract using various column chromatographic techniques lead to the isolation of methyl caffeate (1) as one of active principles. Some -glucosidase inhibitors previously isolated from plants contain the caffeoyl moiety as the part of their structure and have been found to be important in exerting inhibitory activity, 3,7) but the contribution of an ester part to the -glucosidase-inhibitory activity of caffeic esters has not been studied. Hence ...

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Terpenoids (Isoprenoids)

2008

Solanaceae and Convolvulaceae: Secondary Metabolites

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Neochlorogenin, Neosolaspigenin, and Solaspigenin from Solanum torvum Leaves

Cited by 10 publications

References 6 publications

Three Unusual 22-.BETA.-O-23-Hydroxy-(5.ALPHA.)-spirostanol Glycosides from the Fruits of Solanum torvum

Three Unusual 22-.BETA.-O-23-Hydroxy-(5.ALPHA.)-spirostanol Glycosides from the Fruits of Solanum torvum

Methyl Caffeate as an α-Glucosidase Inhibitor fromSolanum torvumFruits and the Activity of Related Compounds

Terpenoids (Isoprenoids)

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