New long-chain aliphatic compounds from Peperomia dindygulensis

Three long-chain aliphatic compounds, including one new polyketide derivative, dindygulerione C (1), one new octaketide derivative, dindygulerione D (2) and one new acylresorcinol derivative dindyguleranone (3) were isolated from the whole plant of the Chinese anticancer folk medicine Peperomia dindygulensis Miq. (Piperaceae). Dindygulerione C is an unprecedented example of a N-containing polyketide. The chemical structures and configurations of 1-3 were elucidated as (-)-(4S)-2-[(Z)-1'-(6″,7″-dihydroxyphenethyl-amino)octadec-11'-enylidene]-4-hydroxycyclohexane-1,3-dione (1), (+)-2-heptadecyl-4-hydroxy-3,4,7,8-tetrahydro-2H-chromen-5(6H)-one (2) and 2-(1,3-dihydroxyphenyl)-octacosan-1'-one (3), respectively, by comparing with the literature data and extensive spectroscopic methods, including 2-D NMR and circular dichroism spectroscopic analysis. The cytotoxicity of 1-3 was evaluated against Hep3B and HepG2 liver cancer cell lines.