Isolation And Bioactivity Of Natural Products From Chonemorpha,megacalyx And Podocarpus Wallichiana

Chonemorpha megacalyx(Apocynaceae)and Podocarpus wallichiana(Podocarpaceae)were chemically investigated and their anticancer activities have also been evaluated.A total of 57 compounds were isolated from the ethyl acetate soluble fractions of the ethanol extracts of these two plants after repeated column chromatography of silica gel,MCI gel,C18 reverse-phased silica gel,and Sephadex LH-20 as well as semi-preparative HPLC.Their structures were determined on the basis of NMR,MS,IR,UV,and single-crystal X-ray diffraction analysis.Some compounds were screened for their cytotoxic activity,and one of the C21 steroidal glycosides from C.megacalyx exhibited significant cytotoxic activity.Seventeen new compounds,including three C21 pregnane steroids,chonemorphols A-C(1,3,and 4),11 C21 steroidal glycosides,chonemorphosides A-K(2 and 5-14),two triterpenoids,chonemegacins A and B(15 and 16),and one sesquiterpenoid,chonemegacin C(17),as well as 33 known compounds,3-hydroxy-6-oxo-5(6?7)abeo-stigmast-5(7)-ene(18),?-sitosterol(19),7-ketositosterol(20),3?,7?-dihydroxy-4a,14a-dimethyl-5a-ergosta-8,24(28)-dien-ll-one(21),(24S)-3?-hydroxy-5?-stigma-stan-6-one(22),stigmast-4-en-6?-ol-3-one(23),3?,14?-dihydroxypregn-5-en-18,20-lactone(24),ecdysantheroside A(25),7?-hydroxy-?-sitosterol(26),ecdysoside A(27),ecdysoside B(28),(3?,24S)-eupha-7,25-dien-3,24-diol(29),(3S,24R)-tirucalla-7-en-3,24,25-triol(30),tirucalla-7,23,25-trien-3?-ol(31),30-hydroxylup-20(29)-en-3-one(32),(23E)-27-nor-3?-hydroxycycloart-23-en-25-one(33),3?-acetoxy-20-hydroxy-28-oic-lupeol(34),29-nor-20-oxolupeol(35),3?-hydroxyolean-12-en-11-one(36),3?-hydroxyursan-12-en-11-one(37),3?-hydroxyursan-9(11),12-diene(38),2,3-bis-(a-hydroxy-4-hydroxy-3-methoxybenzyl)-butane-1,4-diol(39),(3,3',4,4'-tetrahydro-6,6'-dimethoxy-3,3'-bi-2H-benzopyran)-4,4'-diol(40),nirtetralin B(41),niranthin(42),(+)-lyoniresinol(43),scopoletin(44),fraxidin(45),isofraxidin(46),vanillin(47),ethyl 4-hydroxybenzoate(48),and epipinoresinol(49)were isolated from the vines and leaves of C.megacalyx Pierre.The antiproliferative activity of compounds 1-14 was assayed and compound 7 exhibited significant inhibitory activity with IC50 values of 2.4 ?M,2.0?M,and 3.6 ?M against the A-549,Hep G2,and PC3 cancer cell lines,respectively.Eight known compounds,(R)-2,3-dihydroxy-1-(4-hydroxyphenyl)propan-l-one(50),C-veratroylglycol(51),?-hydroxypropiovanillone(52),protocatechuic acid(53),vanilic acid(54),3,4-dehydrotheaspirone(55),nagilactone F(56),and blumenol B(57)were isolated from P.wallichiana.The structures were elucidated by comparing their NMR and MS data with those reported in the literature.