Four New Stilbenoid C-Glucosides Isolated from the Stem Bark of Shorea hemsleyana.

Abstract

Four new C-glucopyranosides of resveratrol oligomers, hemsleyanosides A-D, were isolated from the bark of Shorea hemsleyana. The structures were established on the basis of spectroscopic evidence, including 1H-1H and 1H-13C long-range couplings and nuclear Overhauser effect experiments in the NMR spectrum.

Oligostilbenoids from Shorea gibbosa and their cytotoxic properties against P-388 cells

“…Previous phytochemical works disclosed a number of C-glucoside derivatives of dimer-and trimerstilbenes from S. hemsleyana [12,15] and S. seminis [4]. Thus, the presence of these C-glucoside derivatives in some species of Shorea could be one of important chemical characters for the chemotaxonomical analysis of the genus.…”

Inhibitory Effects of Resveratrol Derivatives from Dipterocarpaceae Plants on Tyrosinase Activity

“…In our previous phytochemical studies of Dipterocarpaceae, we reported the isolation and chemical structure analysis of various resveratrol derivatives including new compounds. [6][7][8][9][10][11][12][13][14] In this study, we evaluated the inhibitory eŠect of resveratrol derivatives isolated from Dipterocarpaceae on murine tyrosinase.…”

“…The isolation procedures of these compounds were described in the previous papers. [6][7][8][9][10][11][12][13][14] Ten stilbene compounds (resveratrol oligomers) tested here are resveratrol, piceid, and dihydroresveratrol as monomers; (-)-e-viniferin as a dimer; vaticanol A, vaticanol G, and a-viniferin as trimers; vaticanol B, vaticanol C, and (-)-hopeaphenol as tetramers. The tyrosinase was prepared from murine B16 melanoma cells (Riken Cell Bank, Tsukuba, Japan).…”

Resveratrol oligomer structure in Dipterocarpaceaeous plants

“…For example, phytochemical investigations of the extract of the stem bark of S. hemsleyana failed to isolate the nonglucosylated derivatives of hemsleyanosides A-F (C-G-RO) and the C-glucosylated derivatives of hemsleyanols A-E (RO) [48][49][50]. Another crucial aspect of their structural diversity is that C-C bond formation in the regioselective 8-10′ mode proceeds in an non-enantioselective fashion when the aliphatic 8-position of 3 is coupled to another aromatic 10′-position; this can be seen in the isolation of uliginoside A (65: C 8a (R)) and hemsleyanoside B (66: C 8a (S)) from S. uliginosa (Fig.…”

“…Initial research goals mainly encompassed two topics: to define the structural diversity afforded by the condensation degree, varying skeletons, and isomerisms due to the number of asymmetric carbons found in this class of natural products; to gain insight into the research area of polyphenol (i.e., the chemistry of RO), which requires expanding the existing chemical library and accumulating spectroscopic details. In the last 2 decades, phytochemical studies have achieved the isolation and structural elucidation of roughly 200 ROs in species belonging to the following seven genus: Vatica (V. rassak [16][17][18][19], V. pauciflora [20,21], V. albiramis [22][23][24][25], and V. chinensis [25][26][27]), V. bantamensis [25], Vateria (V. indica) [28][29][30][31][32][33], Upuna (U. borneensis) [34][35][36][37][38][39][40][41], Cotylelobium, (C. lanceolatum) [42][43][44], Dipterocarpus (D. grandiflorus) [45,46], Shorea (S. hemsleyana [33,[47][48][49][50], S. uliginosa [33,[51][52][53]…”