Studies On The Chemical Constituents Of Two Nontoxic Medicinal Plants From Rhododendron

This dissertation reported the investigation on the chemical constituents of two Chinese medicinal plants Rhododendron alutaceum Balf. f. and Rhododendron delavayi FranchTotally 35 compouds, including 3 new ones, were isolated and identified from the leaves of Rhododendron alutaceum Balf. f. and Rhododendron delavayi Franch. These compounds were isolated and purified by silica gel comlumn chromatography, ODS, Sephadex LH-20 and HPLC. Their chemical structures were elucidated on the basis of spectral data. The classses of these compounds included one new sesquilignan named alutaceuol (1), one new aromatic compound called alutaceuketoside (2), one new diterpenes named alutaceusinⅠ(3). The compounds types included sesquilignans, aromatic compounds, diterpenes, triterpenoids, steroids and flavones.Rhododendron alutaceum Balf. f. is an evergreen tree which is mainly distributed in China (Yunnan and Sichuan provinces). We have investigated the chemical constituents of the leaves of this plant collected in Dali Cang Montain, Yunnan Province.27 compounds were isolated from this plant, including three new compounds named alutaceumol (1), alutaceuketoside (2) and alutaceusinⅠ(3). The known compounds were identified as Acernikol (4), ficusequilignan A (5), Ehletianol C (6), rhodojaponin-III (7), Grayanotoxin-III (8), rhodomollein-Ⅱ(9),2,3-Dihydrobenzofuran-2-(4'-hydroxy-3'-methoxyphenyl)-3-a-L-rhamnopyranosyloxym--ethyl-7-methoxy-5-propanol (10), hyperin (11), quercetin-3-O-α-D-arabinofuranside (12), catechin (13), quercetin (14), myricetin (15), Niga-ichigoside F2 (16), Niga-ichigoside F1 (17),2α,3β,23-trihydroxyurs-12-en-28-oic-28-O-β-D-glucopyranosyl (18),2α,3β,23-trihydroxyolean-12-en-28-oic-28-O-β-D-gluco-pyranosyl (19),3β,19α,23-trihydroxyurs-12-en-28-oic-28-O-β-D-glucopyranosyl (20),2α,3β,19α-trihydroxyurs-12-en-28-oic-28-O-β-D-glucopyranosyl (21), ursolic acid (22), daucosterol (23),β-stitosterol (24), Epirhododendrin (25), (2S)-4-(3,4-dihydroxyphenyl)-2-butanol (26), (2S)-4-(4-hydroxyphenyl)-2-butanol (27). All of the compounds were isolated from this plant for the first time.Rhododendron delavayi Franch is mainly distributed in Guangxi and Yunnan provinces of the People's Republic of China. Eight known compounds were isolated from the leaves of this plant collected in Jingdong wuliang Montain, Yunnan Province. Their structures were elucidated as 3',4',7-trihydroxy-3,5-dimethoxyflavone (1),3', 4',5,7-tetrahydroxy-3-methoxyflavone (2), quercetin-3-O-β-D-arabinopyranoside (3), catechin (4), epicatechin (5), epicatechin-(2β→O→7,4β→8)-ent-epicatechin (6), (2S)-4-(3,4-dihydroxyphenyl)-2-butanol (7), (3,4-dihydroxyphenyl)-2-ethanol (8). Compounds 2,3,6,7,8 were isolated from this plant for the first time.