Conversion of antibacterial quinolone drug levofloxacin to potent cytotoxic agents.

Levofloxacin, the optical S-(-) isomer of ofloxacin, is a broad-spectrum antibacterial agent widely used to control various infections caused by Gram-positive and Gram-negative bacteria. While the COOH group is necessary for antibacterial activity, its modification can offer anticancer activity to the fluoroquinolone framework. Therefore, several levofloxacin carboxamides 11a-j and 12 containing 5-substituted-1,3,4-thiadiazole residue were synthesized and screened in vitro for their anticancer activity.

Application of kojic acid scaffold in the design of non-tyrosinase enzyme inhibitors.

Kojic acid (KA) is a hydroxypyranone natural metabolite mainly known as tyrosinase inhibitor. Currently, this compound is used as a whitening agent in cosmetics and as an anti-browning agent in food industry. Given the easy-manipulation in different positions of the KA molecule, many investigations have been carried out to find new tyrosinase inhibitors derived from KA.

Synthesis and biological assessment of ciprofloxacin-derived 1,3,4-thiadiazoles as anticancer agents.

The quinolone-3-carboxylic acid scaffold is essential structure for antibacterial activity of fluoroquinolones such as ciprofloxacin. Modification of 3-carboxylic functionality in this structure can be used for switching its activity from antibacterial to anticancer. Accordingly, a series of C-3 modified ciprofloxacin derivatives containing N-(5-(benzylthio)-1,3,4-thiadiazol-2-yl)-carboxamide moiety was synthesized as novel anticancer agents.

Modification of 7-piperazinylquinolone antibacterials to promising anticancer lead compounds: Synthesis and in vitro studies.

Amongst the fluoroquinolone antibacterials, the 7-piperazinyl containing chemotypes such as norfloxacin, enoxacin, ciprofloxacin, pefloxacin, lomefloxacin, enrofloxacin, ofloxacin, levofloxacin, gatifloxacin and sparfloxacin have been shown to possess non-classical activities including cytotoxicity against different cancer cell lines, induction of apoptosis, and cell cycle arrest at the S/G2 stage. Additionally, piperazinylquinolones (PQs) have enough flexibility for chemical modification via their N-4 of piperazine ring and carboxylic acid at C-3. Therefore, PQs have been considered as a starting point for design and development of new anticancer agents.

The genus Hymenocrater: a comprehensive review.

Context: The genus Hymenocrater Fisch. et Mey. (Lamiaceae) contains over 21 species in the world.