Synthesis, characterisation and biological activity of novel 4-thiazolidinones, 1,3,4-oxadiazoles and some related compounds

Two novel series of 4-thiazolidinone derivatives namely 2-substituted-3-{[4-(4-methoxybenzoylamino)benzoyl]amino}-4-thiazolidinones (7a-e) and 2-[4-(4-methoxybenzoylamino)benzoylhydrazono]-3-alkyl-4-thiazolidinones (5a-c) together with 2-[4-(4-methoxybenzoylamino)phenyl]-5-(substituted phenyl)amino-1,3,4-oxadiazoles (6a-c) have been synthesised as title compounds. N-1-[4-(4-methoxybenzoylamino)benzoyl]-N-2-substituted methylene hydrazines (3a-e) and 1-[4-(4-methoxybenzoylamino)benzoyl]4-substituted phenyl thiosemicarbazides (4a-f) were also prepared and used as intermediate to give the title compounds. All synthesised compounds were screened for their antimycobacterial activity against Mycobacterium tuberculosis H37Rv and antimicrobial activities against various bacteria and fungi. Compounds 7a and 7b were found as the most active derivatives demonstrating 90 and 98% inhibition of mycobacterial growth of M. tuberculosis H37Rv, in the primary screen at 6.25 mug mL(-1), respectively. However, level 11 assay revealed that the MIC values were not less than 6.25 mug mL(-1). None of the compounds showed significant antimicrobial activity against the microorganisms used whereas 3a and 7a inhibited the growth of several bacteria and fungi. (C) 2002 Editions scientifiques et medicales Elsevier SAS. All rights reserved

Comparative evaluation of ELISA kits' reliability for the aflatoxin M-1 determination in goat milk

Enzyme-linked immunosorbent assay (ELISA) is widely used in the food industry for detecting aflatoxin M-1 (AFM(1)) in milk. The purpose of this survey was to compare the performance of three ELISA kits for the determination of AFM(1) in goat milk by evaluating specific performance parameters such as precision, accuracy, repeatability and specificity, with AFM(2) coexistence. Goat milk, with known AFM(1) concentration (5 ng l(-1)), was spiked with AFM(1) at 12.5, 25, 50, 75 and 100 ng l(-1) and also with AFM(2) in the same concentrations. At extremely low concentrations of AFM(1) (17.5 ng l(-1)), all kits were imprecise, while by increasing the AFM(1) concentration, at levels close to or higher than the maximum tolerable limit (55, 80 and 100 ng l(-1)) precision significantly improved for all kits. All kits presented high repeatability and fairly good specificity, regardless of the AFM(2) presence that was examined for the first time