Synthesis and antimicrobial evaluation of piperic acid amides and their lower homologues

Seven piperic acid amides along with their lower homologs (12) were synthesized using HATU-DIPEA coupling reagent. All the synthesized derivatives were evaluated for their antibacterial activities against Staphylococcus aureus, Pseudomonas aeruginosa, and vancomycin-resistant P. aeruginosa. They were found to be more active on P. aeruginosa than on S. aureus. However, they did not exhibit potent activity on Vancomycin resistant P. aeruginosa. Among the tested compounds, methylenedioxycinnamic acid amide of anthranilic acid (MDCA-AA, 2a) was found to be most active against S. aureus with MIC of 3.125 μg/ml. The PAS and INH amides of piperic acid were screened against Mycobacterium tuberculosis H37R_a strain. They were found to be most active among all the tested compounds but were found to be less active than the standard drug, isoniazid.     

Synthesis, evaluation of 6,8-dibromo-2-aryl-2,3-dihydroquinolin-4(1H)-ones in MCF-7 (breast cancer) cell lines and their docking studies

A series of novel 6,8-dibromo-2-aryl-2,3-dihydroquinolin-4(1H)-ones have been synthesized and evaluated in vitro (in MCF-7 breast cancer cell lines). Compounds 5a, 5d, 5e, and 5g exhibited potent GI₅₀ and TGI values compared with reference standard and compounds 5b and 5c showed moderate activity. The docking studies (in silico) were conducted to recognize the hypothetical binding motif of the title compounds within the active site of aromatase enzyme employing GOLD docking software. The binding mode and SAR of the title compounds has been proposed based on the docking studies.     

β-galactoside prodrugs of doxorubicin for application in antibody directed enzyme prodrug therapy/prodrug monotherapy

Anthracycline antibiotics, particularly doxorubicin and daunorubicin, have been used exten sively in the treatment of human malignancies. However cardiotoxicity and multidrug resistance are significant problems that limit the clinical efficacy of such agents. Rational design to avoid these side effects includes strategies such as drug targeting and prodrug synthesis. Described here are the synthesis and preliminary biological evaluation of the enzymatically activated two new prodrugs (6 & 11) of doxorubicin. These prodrugs were designed as potential candidates for selective chemotherapy in ADEPT or PMT strategies. They are constituted of a galactose moiety, a spacer and the cytotoxic drug and they differ by the type of spacer. The prodrugs were stable in a buffer, and the in vitro studies showed good detoxification and hydrolysis kinetics. As prodrug 11 was readily hydrolyzed, this could be a valuable candidate for further development.     

Synthesis and adenosine receptor binding studies of some novel triazolothienopyrimidines

A new series of 5-alkyl/aryl-8,9-dimethyl/8,9,10,11-tetrahydro[1]benzothieno[3,2-e][1,2,4]triazolo[4,3-c]pyrimidine-3(2H)-thiones (4a-k) have been synthesized through a facile cyclization reaction of 4-hydrazino-2-alkyl/aryl-5,6-dimethyl/5,6,7,8-tetrahydro[1]benzothieno[2,3-d]pyrimidines (3a-k) using carbon disulphide under basic conditions. 4-Hydrazino-2-alkyl/aryl-5,6-dimethyl/5,6,7,8-tetrahydro[1]benzothieno[2,3-d]pyrimidines (3a-k) were prepared by replacing the chloro group of 4-chloro-2-substituted-5,6-dimethyl/5,6,7,8-tetrahydro[1]benzothieno[2,3-d]pyrimidines (2a-k) with hydrazine hydrate which were obtained by a known one-pot synthesis. The affinities of these compounds for adenosine A(1)/A(2A) receptors were determined at 1 microM concentration. The test compounds which exhibited more than 20% inhibition were selected and further screened at six different concentration levels to estimate their EC(50)/K(i) values. The most potent compounds in the series were 4c and 4d having an ethyl side chain at C(5) position with dimethyl and cyclohexyl substitution at the C(8)-C(9) positions, exhibiting K(i) values of 2.1 and 1.1 microM, respectively, at A(1)ARs. The SAR indicates that by increasing or decreasing the alkyl chain length at C(5) led to reduced affinity. The remaining aryl/arylalkyl derivatives of the series were inactive showing that a simple alkyl side chain at C(5) is necessary for these ligands to bind at A(1)ARs. However, none of the compounds showed inhibition on A(2A) receptors at 1 microM concentration indicating their selectivity. This communication describes the design, synthesis and evaluation of these new molecules.     

Anti-inflammatory potential of thienopyridines as possible alternative to NSAIDs

The present study was designed to evaluate the anti-inflammatory and antiarthritic activity of the new synthetic thienopyridine analogs. The anti-inflammatory activity of thienopyridines was assayed by using carrageenan; dextran and arachidonic acid induced paw edema models (acute), cotton pellet granuloma model (Sub acute) and Freund's complete adjuvant induced arthritis (chronic) in experimental rats. The compounds BN-4, BN-14 and BN-16 have shown significant inhibition of edema in carrageenan and arachidonic acid induced paw edema model at a dose of 100mg/kg compared to the dextran induced paw edema model and also showed significant inhibition in granuloma tissue formation and Freund's complete adjuvant induced arthritis in experimental rats. These thienopyridine analogs also inhibited the proinflammatory mediators such as Tumor necrosis factor (TNF)-α, Interleukin (IL)-1β and Nitric Oxide (NO) in Lipopolysaccharide (LPS) challenged murine macrophages. Ulcerogenecity study results revealed less ulcerogenic potential of BN-4, BN-14 and BN-16 compared to nonsteroidal anti-inflammatory drug (NSAID) indomethacin in rats. In conclusion, the new thienopyridine analogs were promising for the potential use as anti-inflammatory agents for both acute and chronic inflammatory disorders with low toxic effects.