The first two members of a new class of bryostatins designated 10 and 11 have been isolated from Gulf of California and Gulf of Mexico specimens of the marine animal Bugula neritina (Bryozoa phylum). Both bryostatins were found to closely resemble bryostatin 4 (lb) during isolation (~10_7% yields), and that relationship proved useful in initial structure studies. Definitive structural assignments for bryostatins 10 (2a) and 11 (2d) were based on analysis of 13C NMR and 400-MHz 1H NMR spectral data combined with results of selective acetylation (2a 2b), dehydration, and oxidation (2a→4b and 2a→4d) experiments. The two new 20-desoxybryostatins 10 (2a) and 11 (2d) displayed substantial cell growth inhibitory (2a, PS ED507.6 X 10-4μg/mL, and 2d, 1.8 X 10–5μg/mL) and antineoplastic activity against the P388 lymphocytic leukemia (PS) with bryostatin 11 leading to a 64% life extension at 92.5 μg/kg. The antineoplastic properties of bryostatins 10 and 11 eliminate an oxygen substituent at C-20 as a prerequisite for such important biological properties.
ASJC Scopus subject areas
- Organic Chemistry