Characterization And Bioactivity Of Natural Products From Mallotus Macrostachyus And Hypericum Forrestii

Two medicinal plants,Mallotus macrostachyus and Hypericum forrestii,were chemically investigated.A total of 53 compounds including 5 new ones were isolated from the ethyl acetate soluble fractions of the ethanol extracts.Compounds 1-14 were tested for the in vitro anti-inflammatory activity,and compounds 2 and 10 exhibited significant anti-inflammatory activity by inhibiting LPS-induced release of nitric oxide(NO).The chemical constituents of the ethanolic extract of the twigs and leaves of M.macrostachyus were studied systematically,and a total of 36 compounds including 3 new and 33 known ones were isolates after column chromatography of silica gel,Sephadex LH-20,and C18 reverse-phased silica gel as well as semi-preparative HPLC.The structures of the compounds were established on the basis of HRESIMS,UV,IR,NMR,and single-crystal X-ray diffraction analysis.The three new compounds were characterized as triterpenoids:mallomacrostins A-C(1-3).The 34 known compounds were identified as 11 triterpenoids,supinenolone 2f(4),friedelin(5),epifriedelanol(6),friedelanol(7),foliasalacin D2(8),foliasalacin D3(9),cycloarta-23E,25-dien-3?-ol(10),ursolic acid(11),3a-acetoxy-28-hydroxy-12-oleanene-3-one(12),12-oleanene-3,11-dione(13),and 3-O-acetylaleuritolic acid(14);one monoterpenoids,loliolide(15);one alkaloid,glaucenamide(16);5 steroids,?-sitosterol(17),7?-hydroxysitosterol(18),7-oxo-?-sitosterol(19),stigmast-4-en-3-one(20),and(24R)24-ethyl-6?-hydroperoxy-cholest-4-en-3-one(21);12 aromatic compounds,vanillic acid(22),4-hydroxybenzaldehyde(23),4-hydroxyacetophenone(24),4-(4-hydroxyphenyl)-2-butanone(25),syringic acid(26),syringaldehyde(27),protocatechoic acid(28),p-methoxybenzenepropionic acid(29),tran-sisoferulic acid(30),4-hydroxycinnamic aicd(31),scopoletin(32),and 2,6-dimethoxy-4-nitrophenol(33)as well as three miscellaneous types of compounds,ozoroalide(34),3,3'-di-O-methylellagic acid(35),and paeoveitol B(36).The triterpenoids obtained in this research were tested for the anti-inflammatory activity by inhibiting LPS-induced release of nitric oxide.Compounds 2 and 10 exhibited significant inhibitory activity,while compounds 8,13,and 14 showed moderate inhibitory effects.Two new dihydrodibenzodioxinones,including forrestin A(37)and forrestin B(38),as well as 17 known compounds were isolated from the ethanolic extract of the twigs and leaves of H.forrestii.The known ones were identified as one dihydrodibenzodioxinone,2,7,4a-trimethoxy-1,4,4a,8b-tetrahydrodibenzo-p-dioxin-4-one(39);eight xanthone,1,2,5-trihydroxyxanthone(40),2,3-dimethoxyxanthone(41),1,5-dihydroxy-6,7-dimethoxyxanthone(42),1,7-dihydroxyxanthone(43),4-hydroxy-2,3-dimethoxyxanthone(44),1,5,6-trihydroxy-3-methoxyxanthone(45),mbarraxan-thone(46),toxyloxanthone B(47);one flavanones,5,4'-dihydroxy-6-methyl-7-methoxyflavanone(48);one furanones,dihydrosesamin(49);four aromatic compounds,4-(4-hydroxyphenyl)-2-butanone(25),(4S,5R)-5-(4'-methyl-3'-pentenyl)-4-hydroxy-5-methyldihydrofuran-2-one(50),3,5-dihydroxybiphenyl(51),methy ?-orsellinate(52)and two triterpenoids,friedelin(5)and 3?-acetoxybetulinic(53).