Three new compounds from Piper montealegreanum Yuncker (Piperaceae)

Three new compounds: two flavonoids [(S)-8-formyl-3',5-dihydroxy-7-methoxy-6methylflavanone (1) and 3'-formyl-3,4',6'-trihydroxy-2'-methoxy-5'-methylchalcone (2)] and one phenylpropanoid [ethyl 3,4-methylenedioxy-5-methoxy-7,8-dihydrocinnamate (3)] were isolated from dried branches of Piper montealegreanum. Their structures were established by UV, IR, MS, 1D and 2D (¹H and 13C) NMR spectroscopic techniques, besides interpretation of spectral data (¹H and 13C NMR) of methylated derivatives of 1 and 2 compounds.