Design, synthesis and in vivo/in vitro screening of novel chlorokojic acid derivatives

Abstract

A series of novel Mannich bases of chlorokojic acid (2-chloromethyl-5-hydroxy-4H-pyran-4-one) were synthesized and their biological activities were investigated. Anticonvulsant activity results according to phase-I tests of Antiepileptic Drug Development (ADD) Program revealed that compound 13 was the most effective one at 4 h against subcutaneous pentylenetetrazole (scPTZ)-induced seizure test. Antimicrobial activities were evaluated in vitro against bacteria and fungi by using broth microdilution method. The antitubercular activities against Mycobacterium tuberculosis and M. avium were discussed with Resazurin microplate assay (REMA). The antimicrobial activity results indicated that compounds 1 and 12 (MIC: 8–16 µg/mL) showed higher activity against Gram negative bacteria while compound 12 had MIC: 4–16 µg/mL against Gram positive bacteria. Compound 1 was the most active one with MIC values of 8–32 µg/mL against fungi. Mannich bases also exhibit significant antitubercular activity in a MIC range of 4 to 32 µg/mL, especially compound 18 against M. avium.

Keywords::

• Chlorokojic acid
• Mannich bases
• anticonvulsant
• antimicrobial
• antimycobacterial

Acknowledgement

We would like to thank Professor Erhan Palaska for his help with the mass spectra analysis. The Ankara University Central Laboratory, Faculty of Pharmacy provided support for acquisition of the ¹H and ¹³C NMR spectrometer and CHNS-932 (LECO) used in this work.

Declaration of interest

This project was supported as a M.Sc. thesis by Hacettepe University Scientific Research Fund (Project no. 09D01301002-4756). The authors state that there is no conflict of interest.