Study On Chemical Components Of Two Plants Of Hypericum Genus

The plants of Hypericum genus are distributed in a large area of China,mainly concentrated in the southwestern region.There are about 55 species and 8 subspecies in China,which are rich in species types.In recent years,many polyprenylated acylphloroglucinol derivatives with novel skeletons had been isolated from Hypericum genus,which have antitumor,antiviral,antibacterial and other biological activities.Polyprenylated acylphloroglucinol derivatives are characterized by polycyclic and branched-chain substitutions in their structures,so their structure types are diverse.It has great potential to find more compounds with novel structures and biological activities from Hypericum genus.The present research was focused on the effective fractions of two plants of Hypericum genus using phytochemical experimental methods.A variety of chromatographic and spectroscopic methods have been used for purification,separation,and structural identification.And pharmacological experimental analyses for monomeric compounds were also conducted.The purpose is to find natural products with biological activity or novel structures.Finally,74 compounds were isolated and identified.These compounds are structurally diverse and include flavonoids,xanthones,anthraquinones,fatty acids,triterpenoids,aromatics,sterols and polyprenylated acylphloroglucinol derivatives,including seven new compounds.In addition,the screening for the antidiabetic activity of some monomeric compounds was performed.The petroleum ether fraction(HA-PE)and ethyl acetate fraction(HA-Et OAc)of Hypericum attenuatum Choisy exhibited significantly antidiabetic activity in vivo and in vitro.Six compounds were isolated from the HA-PE fraction,in which one xanthone compound was identified as 1,7-dihydroxy-4-methoxyxanthone(1),one dihydroflavone compound was identified as 5,4’-dihydroxy-6,8-dimethyl-7-methoxydihydroflavone(2),one imidazole alkaloid was identified as 1H-imidazole-2-carboxylic acid butyl ester(3),one anthraquinone compound was identified as emodin(4),and two long-chain unsaturated fatty acids were identified as 9,12,15-octadecadienoic acid(5)and 9,12-octadecadienoic acid(6).Thirty-one compounds were isolated from the HA-Et OAc fraction.Eight flavonoids were identified as hyperin(7),quercetin(8),isoquercitrin(9),quercetin 3’-O-β-D-galactoside(10),and quercetin 7-O-β-D-glucoside(11),quercetin 4’-O-β-D-galactoside(12),luteolin 8-C-α-L-arabinoside(29)and farrerol(37).Six aromatic compounds were identified as vanillic acid(13),p-hydroxybenzoic acid(14),isovanillic acid(15),3,4-dihydroxybenzoic acid(16),3-(β-D-glucopyranosyloxy)-4-methoxybenzoic acid(17)and ethyl 3,4-dihydroxybenzoate(18).Four phenylacrylic compounds were identified as trans-ferulic acid-β-D-glucoside(19),3,4-dihydroxycinnamic acid(20),trans-p-hydroxycinnamic acid(21)and cis-p-hydroxycinnamic acid(25).One benzo-γ-pyrone compound was identified as 2,5-dimethyl-7-hydroxychromone-7-O-β-D-glucoside(26).One phenylpropionic acid compound was identified as p-hydroxyphenylpropionic acid(27).One xanthone compound was identified as mangiferin(34).Ten other compounds were identified as(6R,9R)-3-oxo-α-ionol-9-O-β-D-glucopyranoside(22),(6S,9R)-roseoside(23),icaraside B2(24),coryoctalactone D(28),dihydrodehydrodiconiferyl alcohol 9’-O-β-D-glucoside(30),4,7,9-trihydroxy-3,3’-dimethoxy-8-O-4’-neolignan-9’-O-β-D-glucopyranoside(31),2-Oxabicyclo[3.2.2]nona-5,7,8-triene(32),cannabiside D(33),salidroside(35)and 3-hydroxy-4,4-dimethyl-4-butyrolactone(36).We performed a glucose uptake assay against main compounds from HA-Et OAc.The bioassay results showed that compounds 7,8,21,26-28,34,35,37 exhibited good effects on glucose uptake by 1.51,1.56,1.62,2.00,1.70,1.56,1.46,1.42 and 2.06 folds,respectively.The petroleum ether fraction of Hypericum wilsonii(HW-PE)exhibited significantly antidiabetic activity in vitro.Thirty-nine compounds were isolated from HW-PE,including three flavonoids,one catechin,two steroids,two triterpenes,one saturated fatty acid ester and five xanthones as well as twenty-five polyprenylated acylphloroglucinol derivatives.Three flavonoids were identified as hyperin(7),quercetin(8)and folecitin(38).One catechin was identified as epicatechin(39).Two steroids were identified as β-sitosterol(40)and β-daucosterol(41).Two triterpenoids were identified as zeorin(42)and betulonic acid(43).One saturated fatty acid ester was identified as glyceroyl monopalmitate(44).Five xanthone compounds were identified as 1,7-dimethoxy-3,6-dihydroxyxanthone(45),3,4-dihydroxy-2-methoxyxanthone(46),ananixanthone(47),wilsonxanthone A(48)and wilsonxanthone B(49),in which compounds 48 and 49 were new compounds.Twenty-five polyprenylated acylphloroglucinol derivatives were identified as furohyperforin(50),furoadhyperforin(51),uralione E(52),uraloidin A(53),hyperwilone E(54),27-epifurohyperforin isomer 1(55),uralodin B(56),furoadhyperforin isomer B(57),uralione H(58),oxepahyperforin(59),attenuatumione E(60),pseudohenone E(61),sampsonione G(62),hyperwilone D(63),hyperwilone C(64),pseudohenone F(65),hyperwilone B(66),sampsonione K(67),attenuatumione C(68),hyperwilone A(69),pseudohenone C(70),otogirinin D(71),hypersampsonone C(72),attenuatumione G(73)and otogirinin B(74),in which compounds 54,63,64,66 and 69 were new compounds.We performed a glucose uptake assay on main compounds from HW-PE.The bioassay results showed that compounds 50,51,54,55,57,62,65,67 exhibited good effects on glucose uptake by 1.43,1.57,1.75,1.53,1.85,1.58,1.93 and 1.92 folds,respectively.