Studies On Secondary Metabolites Of Plant Resistance In Magnolia Officinalis And

Secondary metabolites from the plants have been the main source of antitumor drugs. There are aboudant of plant resources in China, one of the famous traditional Chinese medicinal materials names "Houpo" has been confirmed with potential antitumor through its secondary metabolity study. Magnolia sargentiana and Manglietia hookeri were used as substitudes of Houpo for a long time in minority area. The research intends to study the antitumor secondary metabolities which can induce DNA G-quadruplex in vitro of the two substitudes, circular dichroism spectra method was used to screen extracts on abilities to human telomere DNA into G-quadruplex.The selected chemical constituents were isolated and purified by various column chromatographic methods such as silica gel and Sephadex LH-20. The structures were identified by physicochemical properties and spectral analyses, including ID and 2D NMR, HR-ESI-MS and X-ray diffraction. Eighteen compounds were isolated from the two materials, one with novel structure.Ten compounds were purified from the acetone layer of 75%ethanol extract from Magnolia sargentiana, four sesquiterpenes:parthenolide (1), dihydroparthenolide (2), 1β,4a,11α-trihydroxyeudesmane (3), D-aromadendrane-4β, 10α-diol (4); five sterol derivatives:5a,8a-epidioxy-(22E), 24R)-ergosta-6,22-dien-3β-ol (5), stigmast-4-en-6β-ol-3-one (6), (22E)-Ergosta-6,9,22-triene-3α,5α,8β-triol (7),β-sitosterol (9), stigmasterol (10); one other compound:syringin (8). Compound 1-10 were isolated from Magnolia sargentiana for the first time. Compound 1-4、7、8 were isolated from Magnolia Linn for the first time.Eight compounds were obtained from the ethyl acetate layer of Manglietia hookeri, one sesquiterpene with novel structure:Manghookerins A (1); five eudesmane-type sesquiterpenes:eudesm-4 (14)-ene-3α,11-diol (2), 4-epicyptomeridiol (3), cyptomeridiol (4),4β,7β,11-enantioeudesmantriol (5), β-eudesmol (6); two sterol derivatives:7α-hydroxysitosterol (7), (24S)-24-methylcholestane-3β,5β,6a,25-tetrol (8). Compounds 2-5、7、8 were isolated from Manglietia hookeri for the first time.The research provided experimental basis for the development and utilization for the plant secondary metabolities, and also enriched relevant research of Houpo substitutes.