Norlignans from Pouzolzia zeylanica var. microphylla and their nitric oxide inhibitory activity

Five new compounds, pouzolignan F 4-hydroxy-3-(3,5-dihydroxyphenyl)-2-bis(4-hydroxy-3-methoxyphenyl)methyl]butyl acetate] (1), pouzolignan G 4-hydroxy-3-(3,5-dihydroxyphenyl)-2-(4-hydroxy-3,5-dimethoxyphenyl)(4-hydroxy-3-methoxyphenyl)methyl]butyl acetate] (2), pouzolignan H 1,4-dihydroxy-3-(3,5-dihydroxyphenyl)-2-bis(4-hydroxy-3-methoxyphenyl)methyl]butane] (3), pouzolignan I 1,4-dihydroxy-3-(3,5-dihydroxyphenyl)-2-(4-hydroxy-3,5-dime thoxyphenyl)-(4-hydroxy-3-methoxyphenyl)methyl]butane] (4), and pouzolignan J 1,4-dihydroxy-3-(3,5-dihydroxyphenyl) -2-(3,4,5-trimethoxyphenyl)(4-hydroxy-3-methoxyphenyl)methyl]butane] (5), along with two known compounds, indolyl-3-carboxylic acid (6) and uracil (7), were isolated from the aerial parts of Pouzolzia zeylanica (L.) Benn. var. microphylla (Wedd.) W.T.Wang. The structures of these compounds were characterized based on spectroscopic methods, including IR, NMR (¹H–¹H COSY, HSQC, HMBC, and NOESY), and HR-ESI/TOF-MS experiments. All the new norlignans were assayed for inhibitory activity against lipopolysaccharide (LPS)-induced nitric oxide (NO) production in mouse peritoneal macrophages.