3,4,5-Trisubstituted Furan-2(5H)-one Derivatives: Efficient one-pot Synthesis and Evaluation of Cytotoxic Activity.

A series of 3,4,5-trisubstituted 2(5H)-furanone derivatives was synthesized through one-pot reaction of amines, aldehydes and diethyl acetylenedicarboxylate. Silica sulfuric acid efficiently catalyzes the 3-component reaction to afford the corresponding 2(5H)-furanones in high yields. The synthesized compounds were tested against HEPG2, MCF7 and CACO tumor cell lines. The cytotoxic activity for the tested compounds showed that: ethyl 2-(4-fluorophenyl)-5-oxo-4-(phenylamino)-2,5-dihydrofuran-3-carboxylate exhibited significant antitumor activity against HEPG2 and MCF7 cell lines (IC50 values 0.002 and 0.002 µM, respectively) more than reference drug (IC50 0.007, 0.005 µM).

Characterization and immobilization of purified Aspergillus flavipesl-methioninase: continuous production of methanethiol.

AIMS: To immobilize the purified Aspergillus flavipesl-methioninase on solid carriers for continuous production of methanethiol with high purity, by the enzymatic methods. METHODS AND RESULTS: The purified l-methioninase was immobilized using different methods, and physicochemical and kinetic studies for the potent immobilized enzyme were conducted parallel to the soluble one. The activity of the purified extracellular enzyme was 1·8-fold higher than intracellular one from submerged cultures of A. flavipes. Among the tested methods, polyacrylamide (42·2%), Ca-alginate (40·9%) and chitin (40·8%) displayed the highest immobilization efficiency. The thermal inactivation rate was strongly decreased for chitin-immobilized enzyme (0·222 s⁻¹) comparing to soluble enzyme (0·51 s⁻¹). Enzyme immobilization efficiency was greatly improved using 4·0% glutaraldehyde and 41·6/6·3 (T/C) as spacers for chitin and polyacrylamide-enzyme conjugates, comparing to their controls. Also the incorporation of lysine, glutathione, cysteine and dithiothreitol as active site protectants significantly enhance the catalytic efficiency of immobilized enzyme. The activity of enzyme was increased by 4·5- and 3·5-fold using glutathione plus DDT and glutathione plus methionine, for chitin and polyacrylamide enzyme, respectively. CONCLUSION: Chitin enzyme gave a plausible stability till fourth cycle for production of methanethiol under controlled system. Applying GC and HNMR analysis, methanethiol has identical chemical structure to the standard compound. SIGNIFICANCE AND IMPACT OF THE STUDY: Technically, a new method for continuous production of pure methanethiol, with broad applications, was developed using a simple low expenses method.

Evaluation of a PCR-ELISA to detect Wuchereria bancrofti in Culex pipiens from an Egyptian village with a low prevalence of filariasis.

The programmes for the elimination of bancroftian filariasis that have been implemented in the Nile delta of Egypt are expected to lead to substantial reductions in filarial loads in the treated populations. Better methods than those currently available are needed for monitoring the efficacy of these and similar efforts at intervention. A PCR-ELISA was therefore evaluated as an epidemiological tool for the detection of the Wuchereria-bancrofti-specific SspI repeat in pools of Culex pipiens collected in a village with a low prevalence of filarial infection in its human residents (2.1%). Indoor-resting mosquitoes were collected by aspiration from 114 randomly selected houses (during one to nine visits/house) and separated into 673 pools, each of which held the mosquitoes collected during one night from one house. Although 18 (2.7%) of the pools showed PCR inhibition and had to be excluded, filarial DNA was detected, using the PCR-ELISA, in 91 (13.9%) of the 655 remaining mosquito pools. The minimum prevalence of W. bancrofti infection in the mosquitoes caught (assuming one infected mosquito/positive pool) was 2.8%. The mean (S.D.) number of mosquitoes/pool did not vary significantly between positive [5.5 (3.4)] and negative [4.9 (3.5)] pools. The assay detected parasite DNA in mosquitoes from 19.3% of 114 houses when only the first visit was considered and from 73.9% of the 88 houses visited more than once. The PCR-ELISA yielded results comparable with those of the regular PCR-SspI assay. The latter assay is recommended for the routine examination, in laboratories in endemic areas, of mosquito pools from randomly selected houses, as the ELISA component of the PCR-ELISA is exceedingly time-consuming, expensive and requires special equipment.