MAOI activity of thiosemicarbazides and related 2-thiazolylhydrazines

The preparation is described of hydrazides I, thiosemicarbazides II, III, IV and hydrazinothiazoles VIII, which can be considered as "precursors" or "open models" for the synthesized benzoyl-, benzilidene- and benzyl-hydrazinothiazoles V, VI and VII, analogous to 4-methyl and 4-phenyl substituted derivatives A, B and C, described and tested for their MAOI activity in a previous paper. Biochemical assay on the new prepared compounds allowed us to better clarify the structure-activity relationship also of compounds A, B and C of the precedent note. Moreover, on a group of derivatives, which showed a higher activity, a further test was performed to observe the possible correlation between MAOI activity and both their lipophilicity and ability in interacting with liposome bilayers, taken as a model of cell membrane.