No abstract

Brine shrimp lethality-directed fractionation of the 95% EtOH extract of ripe berries from Lindera benzoin led to the isolation of three new C21 alkane-alkene gamma-lactones designated isolinderanolide, isolinderenolide, and linderanolide as well as the known series of C17 and C19 obtusilactones (isoobtusilactone A, obtusilactone A, isoobtusilactone, and obtusilactone) previously isolated from Lindera obtusiloba. The novel (6Z,9Z,12Z)-pentadecatrien-2-one, the known (6Z,9Z)-pentadecadien-2-one, and the known (+)-(Z)-nerolidol were also isolated as bioactive compounds. The structural elucidation and biological activities of these compounds are reported.

Extracts of Micromelum integerrimum (Buch.-Ham. ex Coleb.) M. Roem. were fractionated based on in vivo activity in mice in the P-388 lymphocytic leukemia system. Activity in ethanol extracts was concentrated in the chloroform partition fraction, which was further resolved by chromatography on silica gel. The known coumarins, micromelin and scopoletin, were crystallized from the active fractions and demonstrated to have antitumor activities. Micromelin was converted to the corresponding butenolide (deoxymicromelin) which was inactive in the 9KB assay.

An investigation of Witheringia coccoloboides (Dammer) A. T. Hunziker [Capsicum fuscoviolaceum (Cufodontis) Mort. And Standl.] roots has resulted in the isolation of two cytotoxic compounds: physalin B (1) and a novel physalin, which was characterized by spectral analysis as 25,26-epidihydrophysalin C (2). Both compounds have demonstrated cytotoxic activity in 9KB and 9PS tumor cells (in vitro). Physalin B (1) has demonstrated moderate activity against the 3PS mouse leukemia (in vivo).

Cytotoxicity-guided fractionation of an organic solvent extract of the plant Crossosoma bigelovii led to the discovery of a new strophanthidin glycoside (1) and two new 2-methylchromone glycosides (2 and 3). Also isolated were the known chromones eugenin and noreugenin, the indole alkaloid ajmalicine, the dibenzylbutane lignan secoisolariciresinol, the dibenzylbutyrolactone lignan matairesinol, and the furanone 5-tetradec-5-enyldihydrofuran-2-one. Further investigation into the biological properties of strophanthidin glycosides revealed a connection between inhibition of HIF-1 activation and the glycosylation of the genin. This work is the first published study of the bioactive phytochemicals of the family Crossosomataceae.