Portal de Periódicos da CAPES

Megastigmane Glycosides from the Leaves of Salacia chinensis

2008; Elsevier BV; Volume: 75; Issue: 1 Linguagem: Inglês

10.3987/com-07-11193

1881-0942

Masayuki Yoshikawa, Seikou Nakamura, Yi Zhang, Yutana Pongpiriyadacha, Tao Wang, Hisashi Matsuda,

Phytochemistry and Bioactive Compounds

Six new megastigmane glycosides, foliasalaciosides A 1 (1), A 2 (2), B 1(3), B 2 (4), C (5), and D (6), were isolated from the methanolic extract of the leaves of Salacia chinensis (Hippocrateaceae) collected in Thailand together with 16 known constituents.The absolute stereostructures of 1-6 were elucidated on the basis of chemical and physicochemical evidence including the application of the modified Mosher's method.Salacia chinensis L. (syn.S. prinoides, Hippocrateaceae) is widely distributed in Thailand, Myanmar, and India.The stems of S. chinensis have been used as a laxative and to relieve muscular pain in Thai traditional medicine. 1On the other hand, the decoctions of the stems and leaves are given to cure diabetes mellitus in the Ayurvedic system of Indian traditional medicine. 24][5][6] However, the chemical constituents as well as the pharmacological properties of the leaves of S. chinensis have not been characterized.During the course of our serial studies on the bioactive constituents from Salacia species, 7-14 six new megastigmane glycosides, foliasalaciosides A 1 (1), A 2 (2), B 1 (3), B 2 (4), C (5), and D (6), were isolated from the methanolic extract of the leaves of Salacia chinensis together with 16 known constituents.This paper deals with the isolation and structure elucidation including the absolute configuration of 1-6.The leaves of S. chinensis were cut and extracted with methanol under reflux.The methanolic extract was partitioned into a mixture of ethyl acetate (EtOAc) and water to furnish an EtOAc-soluble portion and an aqueous layer.The aqueous layer was further extracted with n-butanol (n-BuOH) to give a n-BuOHsoluble portion.The n-BuOH-soluble portion was subjected to Diaion HP-20 column chromatography (H 2 O → MeOH) to give the water-and methanol-eluted fractions.The methanol-eluted fraction was subjected to normal-and reversed-phase silica gel column chromatographies, and finally HPLC to give foliasalaciosides A 1 (1, 0.0003% from the natural medicine), A 2 (2, 0.0003%), B 1 (3, 0.0004%), B 2 (4, HETEROCYCLES, Vol.75, No. 1, 2008 131 0.0003%), C (5, 0.0001%), and D (6, 0.0001%), together with 7 known megastigman glycosides, blumenyl C β-D-glucopyranoside (7, 0.0032%), 15 roseoside A (8, 0.0001%), 16 dendranthemoside A (9, 0.0004%), 17 alangioside A (10, 0.0002%), 18 (6S,7E,9R)-6,9-dihydroxy-4,7-megastigmadien-3-one 9-O-α-L-arabinopyranosyl(1→6)-β-D-glucopyranoside (11, 0.0001%), 16 icariside B 1 (12, 0.0002%), 19 and citroside B (13, 0.0004%), 20 and nine known flavonol glycosides, paeonoside (14, 0.0008%), 21 kaempferol 3-O-rutinosyl-7-O-β-D-glucopyranoside (15, 0.0008%), 22 kaempferol 3-O-α-Lrhamnopyranosyl(1→6)-β-D-galactopyranosyl-7-O-β-D-glucopyranoside (16, 0.0017%), 23 clitorin (17, 0.0045%), 24 kaempferol 3-O-(2,6-α-L-dirhamnopyranosyl-β-D-glucopyranosyl)-7-O-β-Dglucopyranoside (18, 0.0061%), 24 rutin (19, 0.027%), 25 quercetin 3-O-rutinosyl-7-O-β-D-glucopyranoside (20, 0.0016%), 26 manghaslin (21, 0.0019%), 24 and myricetin 3-O-β-D-rutinoside (22, 0.0015%).