Calvatic acid

Research communications in chemical pathology and pharmacology, 1987, 56(2):265-272.

Some biological effects of calvatic acid and its analog on isolated hepatocytes.[Reference: WebLink]

Calvatic acid is a new antibiotic with both a carboxylic group and an azoxy function in the benzene ring.
METHODS AND RESULTS:
The relationship between structure and biological activity in this substance and one of its analog, phenylazoxyxyanide, was investigated. Isolated hepatocytes were used as an experimental system: the release of lactate dehydrogenase and the colchicine-binding activity of tubulin were first evaluated; effects were dose and time dependent. micromolar concentrations of these drugs determined a significant decrease of the glucose-6-phosphatase activity and a slight inhibition of aminopyrene demethylation.
CONCLUSIONS:
A toxic effect at the microsomal level and an interaction with the microtubular system are thus possible.

Cell Biochemistry & Function, 1995, 13(4):231-238.

Antimicrotubular effect of calvatic acid and of some related compounds.[Reference: WebLink]

METHODS AND RESULTS:
A structure–activity relationship has been established between Calvatic acid and some related synthetic compounds, and their ability to inhibit GTP‐induced microtubular protein polymerization in vitro. These compounds were effective in a dose‐ and a time‐dependent manner. The most active drug was the p‐chloro substituted compound, which showed its inhibitory activity without any preincubation period, which the others needed.
CONCLUSIONS:
Since if cysteine was present, polymerization was no longer affected, an involvement of titratable –SH groups of tubulin could be suggested. In contrast, taxol‐induced polymerization was only slightly inhibited by these compounds, and colchicine‐binding activity was not generally impaired.