A series of analogues of etoposide, the C-4 amino- and alkylamino-substituted 4'-demethyl-epipodophyllotoxins, have been synthesized and studied for their activity to inhibit type II human DNA topoisomerase as well as their activity in causing cellular protein-linked DNA breakage. Substitution of the glycosidic moiety of 1 by a 2"-hydroxyethylamino or 2"-methoxyethylamino chain at the C-4 beta position resulted in potent inhibitors of the human DNA topoisomerase II. This inhibitory activity correlates reasonably well with their activity in causing protein-linked DNA breakage in KB cells. The in vitro cytotoxicity (KB) appears to have no correlation with the inhibitory activity of the human DNA topoisomerase II.

Two new macrolide sesquiterpene pyridine alkaloids, emarginatine F [1] and emarginatine G [2], were isolated from Maytenus emarginata. The structural determinations of 1 and 2 by 2D nmr techniques and spectral comparison with a related compound, emarginatine A [3], are discussed. Biological evaluation showed that emarginatine F [1] demonstrated strong cytotoxicity against human epidermoid carcinoma of the nasopharynx (KB), ileocecal adenocarcinoma (HCT-8), melanoma (RPMI-7951) and medulloblastoma (TE-671) tumor cells, and against murine leukemia (P-388).

Five new compounds, including four C(17) gamma-lactones, dihydroisoobtusilactone (1), dihydroobtusilactone (2), 3-epilitsenolide D(2) (3), and 3-epilitsenolide D(1) (4), and one furanone alseodafuranone (5), were isolated from the root and stem of Alseodaphne andersonii. Their structures were elucidated mainly by spectral analysis (NMR and MS) and partially by chemical correlation.

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