Six new sesquiterpenoids, aristoyunnolins A-F (1-6), an artifact of isolation [7-O-ethyl madolin W (7)], and 12 known analogues were isolated from stems of Aristolochia yunnanensis. The structures were determined by combined chemical and spectral methods, and the absolute configurations of compounds 2, 3, 5-7, 9, 14, and 17 were determined by the modified Mosher's method and CD analysis. Compounds 1-19 were screened using a bioassay system designed to evaluate the effect on mitogen-activated protein kinases (MAPKs) signaling pathways. Among three MAPKs (ERK1/2, JNK, and p38), compounds 1, 4, 10-13, 16, 18, and 19 exhibited selective inhibition of the phosphorylation of ERK1/2. Compounds 16 and 19 were more active than the positive control PD98059, a known inhibitor of the ERK1/2 signaling pathway.

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A new compound was isolated from the traditional Chinese folk herb Crotalaria ferruginea. The structure of the new compound was identified as ()crotaferruphenol (1) based on analyses of its spectroscopic data including NMR, MS, and specific rotation values. ()-Crotaferruphenol was a novel heterodimer characteristic of a unique spiroketal moiety, which was produced by the condensation reaction of a chromanone and a 2-isopropenybenzofuran. ()-Crotaferruphenol exhibited inhibitory activity (IC 50 = 6.57 M.) against phosphodiesterase-4 (PDE4), a drug target for the treatment of chronic obstructive pulmonary disease and asthma.