Characterization And Bioactivity Of Secondary Metabolites From Salvia Aerea Levl.and Leucosceptrum Canum Smith

Two medicinal plants,Salvia aerea Levl.and Leucosceptrum canum Smith,were chemically investigated,and a total of 57 compounds including 3 new ones were isolated.In addition,the terpenoids obtained in this research were tested for their α-glucosidase inhibition activity and LPS induced NO production inhibition activity.Some of the compounds showed biological activities.The chemical constituents of the ethanolic extract of the aerial part of Salvia aerea Levl.were studied systematically,and a total of 27 compounds including 2 new and 25 known ones were isolated after column chromatography of silica gel and Sephadex LH-20,as well as semipreparative HPLC.The new compounds were characterized as two diterpenoids,(5S,7R,1 0S,15S,2’S)-16-(2-methylbutyryloxy)-7,12-dihydroxy-8,12-abietadien-11,14-dione(1)and(5S,7S,10S,15S,2’S)-16-(2-methylbutyryloxy)-7,12-dihydroxy-8,12-abietadien-11,14dione(2).The 25 known compounds were identified as two diterpenoids,16-acetoxy-7αethoxyroyleanone(3)and cassipourol(4);16 triterpenoids,3-O-acetyloleanolic acid(5),(3β)28-norolean-12-ene-3,17-diol(6),28-hydroxy-12-oleanen-3-one(7),2 α,3 α-dihydroxy-24nor-4(23),12-oleanadien-28-oic acid(8),przewanoic acid B(9),23-hydroxy-3-oxo-urs-12-en28-oic acid(10),pololic acid(11),ursolic acid(12),28-nor-urs-12-ene-3β,17β-diol(13),ursolic acid lactone(14),3,4-seco-ursan-4-hydroxy-12-en-3,28-dioic acid(15),heterobetulonic acid(16),betulonic acid(17),betulinic acid(18),betulone(19),and hydroxydammarenone-II(20);two steroids,β-sitosterol(21)and stigmasta-3,6-dione(22);four aromatics,4hydroxybenzaldehyde(23),vanillin(24),acetovanillone(25),and ethyl ferulate(26);and one fatty acid,linolenic acid(27).Among them,compounds 11,13,16,17,and 19 exhibited strong inhibitory activity against α-glucosidase,while compounds 5,7,9,13-16,and 19 exhibited a dose-dependent inhibitory activity against LPS-induced NO production,with strong activity and no significant cytotoxicity.Various techniques were used to isolate and identify the petroleum ether and ethyl acetate extracts of the 95%ethanol extract from the branches and leaves of Leucosceptrum canum Smith,and a total of 33 compounds including 1 new and 32 known ones were isolated after column chromatography of silica gel and Sephadex LH-20,as well as semi-preparative HPLC.The new compound was characterized as one sesquiterpenoid,arbusculin E ethyl ester(28).The 33 known compounds were identified as four triterpenoids,3-O-acetyloleanolic acid(5),22,29-dihydroxyhopane(29),6α,22-dihydroxyhopane(30),and 6 α,11α,22-trihydroxyhopane(31);nine sesquiterpenoids,11α,13-dihydro-β-cyclocostunolide(32),colartin(33),11β,13dihydrosantamarin(34),santamarine(35),reynosin(36),8α-hydroxyoplop-11(12)-en-14-one(37),(+)-epiloliolide(38),arbusculin E methyl ester(39),and vomifoliol(40);three steroids,stigmasta-3,6-dione(22),stigmasterol(41),and β-sitosterol palmitate(42);five aromatics,4methoxybenzoic acid(43),vanillic acid(44),syringic acid(45),3-hydroxy-1-(4-hydroxy-3methoxyphenyl)propan-l-one(46),and 3,4,5-trimethoxycinnamic acid(47);three flavonoids,5,7-dihydroxy-6,4’-dimethoxyflavone(48),acacetin(49),and hispidulin(50);five long-chain aliphatic compounds,linolenic acid(27),linoleic acid(51),(10E,12E)-9-oxo-10,12octadecadienoic acid(52),(7E,9E)-11-oxo-7,9-hexadecadienoic acid(53)and ethyl linoleate(54);and three miscellaneous,lunularin(55),5-hydroxymethyl-2-furancarboxaldehyde(56),and succinic acid(57).Among them,compounds 5,30,and 31 exhibited strong inhibitory activity against α-glucosidase.Compounds 5,28-31,and 39 had significant inhibitory activity against LPS-induced NO over production in a dose dependent manner.Various types of compounds have been found in the study of the chemical constituents of the upper parts of Salvia aerea and the branches and leaves of Leucosceptrum canum.Three of these compounds have been isolated from natural products for the first time,which is helpful to enrich the natural products database.Some compounds with strong biological activity were found in vitro activity testing,providing a basis for further research on hypoglycemic and antiinflammatory drugs.