Figure 2.

Stereochemical SAR for Inhibition of Secretory Function by Diastereoisomers of Coibamide A. Molecular structures and bioactivity profile of (A) coibamide A (1), (B) [L-Hiv²]-CbA (2), (C) [L-Hiv², L-MeAla¹¹]-CbA (3), (D) [L-Hiv², D-allo-Ile⁷]-CbA (4), (E) [L-Hiv², D-allo-Ile⁷, L-MeAla¹¹]-CbA (5) and (F) apratoxin A (AprA). Secretory function of human U87-MG cells expressing Gaussia luciferase (GLuc) was assessed in the presence or absence (0.1% DMSO), of compounds. After 18 h, GLuc activity was measured in conditioned medium while viability was assessed in the adherent Gluc-U87 cells. Data points show mean luminescence ± standard error (S.E.) as a percentage of vehicle-treated cells and curves represent the fit of data points by nonlinear regression analysis to a logistic equation from a comparison that was repeated in at least three independent experiments.