Development of Promising Thiopyrimidine-Based Anti-cancer and Antimicrobial Agents: Synthesis and QSAR Analysis.

Objective & Methodology: New hybrids of thiopyrimidine-five/six heterocyclic rings were synthesized and in vitro evaluated for their antiproliferative activity against three human cancer cell lines, namely HCT116 (human colorectal carcinoma), PC-3 (human prostate adenocarcinoma) and HepG2 (human liver carcinoma) cell lines. The most potency was elicited by the target candidates against the viability of HCT116 cell lines. It was higher than that obtained by the positive control 5-Fluorouracil (IC50 range; 0.11-0.49 µM, IC50, 5-FU; 1.10 µM). Results: Cell cycle analysis and apoptosis activation revealed that compound 20 induced G2/M phase arrest and apoptosis in HCT116 cells. In addition, compound 20 activates the caspases-9 and -3, a process which might mediate the apoptosis of HCT116 cells. Quantitative structure activity relationship study was done and revealed a high predictive power R2 suggesting goodness of the models. Conclusion: Furthermore, there is a good agreement between the observed pIC50 and the predicted pIC50 values, in addition, the low RMSD and standard error values indicate the accuracy of the model. Antimicrobial evaluation revealed that some of these compounds exhibited significant activities against the tested pathogenic bacteria and fungi, wherein compounds 7a, 14, 15a, 21a, produced the most potent and broad spectrum antibacterial and antifungal potency that was equivalent to that revealed by Vibramycin and Ketoconazole (MIC; 125 µg/mL). Moreover, compounds 15a, 21c, investigated dual potent antimicrobial and anticancer activity.

NEW PYRIDINE AND TRIAZOLOPYRIDINE DERIVATIVES: SYNTHESIS, ANTIMICROBIAL AND ANTIOXIDANT EVALUATION.

A novel series of pyridine and triazolopyridine derivatives have been synthesized (1-17) and characterized on the basis of their elemental analyses and spectral data. In vitro antibacterial, antifungal and antioxidant evaluation were carried out for most of the new products. Compounds 3, 5b, 6c, 6d and 13 showed promising growth inhibition against Candida albicans and Aspergillus niger comparable to fluconazole as a reference antifungal drug. Furthermore, the derivatives 5d, 6c, 6d and 9 showed higher scavenging activity (99.4, 97.2, 94.8 and 90%) than that of ascorbic acid (86.4%) towards the DPPH radicals.

SYNTHESIS AND IN VITRO ANTIMICROBIAL ACTIVITY OF NOVEL SERIES OF 3,5-DIACETYLPYRIDINE COMPOUNDS.

Bis diacetylpyridine derivative (1) was prepared and reacted with different halo-compounds, namely: epichlorohydrine and dichloroethyl ethyl ether to give 2a,b, respectively, and reacted with morpholine and piperidine to afford Mannich products 3a,b, successively. Compound 4 was synthesized by reaction of 1 with potassium thiocyanate. Reaction of 4 with 4-chlorobenzaldehyde, glucose and phthalic or maleic anhydrides produced 5, 6 and 7a,b. Compound 1 reacted with 4-chlorobenzaldehyde to give bisanylmethylene derivative 8. Also some new compounds 9-11 were prepared from the reaction of compound 8 with nucleophiles, namely: hydrazine hydrate, thiosemicarbazide and hydroxylamine via Michael condensation reaction. On the other hand, compound 8 was reacted with cyclohexanone and cyclopentanone to give 12a,b. The structures of newly synthesized products have been deduced on the basis of elemental analysis and spectral data. Some synthesized compounds were screened for their antimicrobial evaluation. Among the assayed compounds, derivatives 3b and 12a showed the highest antimicrobial activities.

A concise synthesis and antimicrobial activity of a novel series of naphthylpyridine-3-carbonitrile compounds.

A novel series of acyclic nucleosides 2-5 and 13a-c were synthesized by utilizing 4-phenyl-6(naphthalen-2-yl)-2-oxo-1,2-dihydropridine-3-carbonitrile (1) as a key starting material. Chlorination of 1 yielded the chloro analogue 6 that was allowed to react with urea, thiourea, thiosemicarbazide and alicyclic secondary amines to produce the corresponding derivatives 7a-c and 11a-c. Further condensation of 6 with various amino acids provided the compounds 8-10, whereas hydrazinolysis of 6 yielded the hydrazinyl analogue 12 which was condensed with different isothiocyanates and acid anhydrides to afford derivatives 18-20, respectively. Upon treatment of 12 with sodium nitrite, the azide derivative 14 was obtained which was subjected to reaction with various active methylene compounds to obtain the corresponding triazolo derivatives 15-17. The structure assignment of the new compounds is based on chemicaland spectroscopic evidence. Antimicrobial evaluation of the newly synthesized derivatives was performed using ciprofloxacin and fluconazole as reference antibacterial and antifungal drugs. The most effective compounds against the tested bacterial and fungal isolates were the benzothiohydrazide compound 18b followed by the hydrazone and the phthalic anhydride derivatives 13c and 20, respectively.