Chemical Constituents from <I>Helwingia japonica</I>

Abstract

AIM:To discover protein tyrosine phosphatase 1B(PTP1B) inhibitory compounds from the 95% etha-nol extract of the aerial parts of Helwingia japonica(Thunb.) Dietr..METHODS:Two plant samples(A and B) were collected respectively from Luding County and Pingwu County,Sichuan Province of China,and chromatography was used for separation,and spectroscopic methods were employed for the identification of isolated compounds.RESULTS:Fractions HC,HE,HF,HG of the 95% ethanol extract of sample A were active.From A nine compounds(1-9) were iso-lated.The AcOEt fraction of the 95% ethanol extract of the aerial parts of sample B showed PTP1B inhibitory activity with an IC50 of 4.63 μg.mL-1,and five compounds(10-14) were isolated from this fraction.The isolated compounds were identified as β-sitosterol(1),β-daucosterol(2),lupeol(3),betulin(4),betulinic acid(5),hexadecanoic acid 2,3-dihydroxypropyl ester(6),cinnamic acid(7),stignast-4-en-6β-3-one(8),stignast-4-en-6α-3-one(9),p-menth-2-en-1β,4β,8-triol(10),blumenol A(11),2',3',4',5',6'-pentahydroxychalcone(12),apigenin 7-O-β-D-glucopyranoside(13),and luteolin 7-O-β-D-glucopyranoside(14).CONCLUSION:Except compounds 13 and 14,all the other compounds are first isolated from Helwingia japonica(Thunb.) Dietr..Compound 5 is a known PTP1B inhibitor.It is necessary to study the active compounds in this plant further when taking the yield of compound 5 into account.