Synthesis, Cytotoxicity, Antimicrobial and Docking Simulation of Novel Pyrazolo[3,4-d]pyrimidine and pyrazolo[4,3-e][1,2,4]triazolo[3,4-c] pyrimidine Derivatives.

BACKGROUND: Isobutyrohydrazonoyl bromide 1 was used as a precursor for the synthesis of 4-imino-3-isopropyl-1-(4-nitrophenyl)-1,4-dihydro-5H-pyrazolo[3,4-d]pyrimidin-5-amine 4, which was converted into hydrazino derivative 5 by heating with hydrazine hydrate at reflux. Hydrazino, as well as imino-amino derivatives, underwent condensation and cyclization reactions to give pyrazolo[ 3,4-d]pyrimidine and pyrazolo[4,3-e][1,2,4]triazolo[3,4-c]pyrimidine derivatives, respectively. METHOD: Antimicrobial studies are performed using two-gram positive bacteria and two-gram negative bacteria. RESULTS: Data revealed that compound 9a is the most promising antibacterial agent with high efficiency (low MIC value (48 µg/ml)). The cytotoxic assay was investigated for in vitro antitumor screening against Caucasian breast adenocarcinoma MCF7, hepatocellular carcinoma HepG2 and colon carcinoma HCT-116 cell lines. CONCLUSION: The results are compared with doxorubicin standard anticancer drugs as well as normal cell lines like MCF10 and MCF12. Molecular docking was carried out for the highest potent compound 8c with the binding site of dihydrofolate reductase enzyme DHFR PDB:ID (1DLS).

Enterohemorrhagic Escherichia coli O157 in milk and dairy products from Libya: Isolation and molecular identification by partial sequencing of 16S rDNA.

AIM: The aim of this work was to isolate and molecularly identify enterohemorrhagic Escherichia coli (EHEC) O157 in milk and dairy products in Libya, in addition; to clear the accuracy of cultural and biochemical identification as compared with molecular identification by partial sequencing of 16S rDNA for the existing isolates. MATERIALS AND METHODS: A total of 108 samples of raw milk (cow, she-camel, and goat) and locally made dairy products (fermented cow's milk, Maasora, Ricotta and ice cream) were collected from some regions (Janzour, Tripoli, Kremiya, Tajoura and Tobruk) in Libya. Samples were subjected to microbiological analysis for isolation of E. coli that was detected by conventional cultural and molecular method using polymerase chain reaction and partial sequencing of 16S rDNA. RESULTS: Out of 108 samples, only 27 isolates were found to be EHEC O157 based on their cultural characteristics (Tellurite-Cefixime-Sorbitol MacConkey) that include 3 isolates from cow's milk (11%), 3 isolates from she-camel's milk (11%), two isolates from goat's milk (7.4%) and 7 isolates from fermented raw milk samples (26%), isolates from fresh locally made soft cheeses (Maasora and Ricotta) were 9 (33%) and 3 (11%), respectively, while none of the ice cream samples revealed any growth. However, out of these 27 isolates, only 11 were confirmed to be E. coli by partial sequencing of 16S rDNA and E. coli O157 Latex agglutination test. Phylogenetic analysis revealed that majority of local E. coli isolates were related to E. coli O157:H7 FRIK944 strain. CONCLUSION: These results can be used for further studies on EHEC O157 as an emerging foodborne pathogen and its role in human infection in Libya.

New Potent SARS-CoV 3C-Like Protease Inhibitors Derived from Thieno[2,3-d]-pyrimidine Derivatives.

2-Amino-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxamide (1) condensed with carbaldehydes 2a,b to give the respective thienopyrimidines (3a,b), which reacted with phosphoryl chloride and hydrazine hydrate to afford the respective pyrimidinohydrazines (4a,b). Compound 4a condensed with acetophenone under Vilsmeier conditions to afford the formylated pyrazolopyrimidine 6. Condensation of 4a with active methylenes produced the respective pyrazolopyrimidines (7-11). Besides, 4a condensed with succinic anhydride and with phthalic anhydride, yielding the pyrrolidine-2,5-dione 12 and the isoindoline-1,3-dione 13, respectively. Moreover, 4a reacted with isatin to afford the hydrazono-indolin-2-one 14. Structural elucidations for the new thienopyrimidines were based upon compatible analytical and spectroscopic results. Eleven of the new compounds were tested and found active against influenza A neuraminidase virus (H3N2). Compounds 12 and 13 were the most potent.

2-(4-Chlorophenyl)-1,3-dicyano-6,7-dihydro-4-imino-9,10-dimethoxybenzo[a]quinolizine-water (2/5).

Crystals of the title compound, C(23)H(17)ClN(4)O(2).2.5H(2)O, contain channels filled with highly disordered water molecules. The best structure refinement was obtained by removing the solvent contribution from the intensity data and refining against a solvent-free model. The central six-membered ring of the quinolizine molecule has a slightly distorted screw-boat conformation.