Chemical structure of neristatin 1, a polyketide isolated from Bugula neritina.  Ki for protein kinase C: 21.2 nM (PDBu: 0.53 nM). Absolute stereochemistries of northern hemisphere of neristatin were firstly assigned as 3(R), 5(R), 7(S), 9(S), and 15(R) based upon the known absolute stereochemistry of the related bryostatins, but X-ray crystal structure in the patent document indicates that absolute stereochemistry at position C-9 (hemiketal position) is R.
Pettit, G. R.; Gao, F.; Herald, D. L.; Blumberg, P. M.; Lewin, N. E.; Nieman, R. A. (1991). "Antineoplastic agents. 224. Isolation and structure of neristatin 1". J. Am. Chem. Soc. 113 (17): 6693–6695. DOI:10.1021/ja00017a062.

US patent 5196447
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