Some novel adenosine mimics: synthesis and anticancer potential against cervical cancer caused by human papilloma virus

Adenosine: An endogenous mediator in the pathogenesis of gynecological cancer

Extracellular concentration of adenosine increases in the hypoxic tumor microenvironment. Adenosine signaling regulates apoptosis, angiogenesis, metastasis, and immune suppression in cancer cells. Adenosine-induced cell responses depend upon different subtypes of adenosine receptors activation and type of cancer. Suppression of adenosine signaling via inhibition of adenosine receptors or adenosine generating enzymes including CD39 and CD73 on ovarian or cervical cancer cells is a potentially novel therapeutic approach for gynecological cancer patients. This review summarizes the role of adenosine in the pathogenesis of gynecological cancer for a better understanding and hence a better management of this disease.

Rhodium(II) acetate-catalyzed stereoselective synthesis, SAR and anti-HIV activity of novel oxindoles bearing cyclopropane ring

Novel oxindole derivatives bearing substituted cyclopropane ring have been designed on the basis of docking studies with HIV-1 RT using the software DS 2.5 and synthesized as probable NNRTIs against HIV-1 using rhodium(II) acetate-catalyzed stereoselective cyclopropanation reaction. The cyclopropane isomer, having trans relationship with respect to carbonyl of lactam moiety and functional group on the cyclopropane ring, was the major product in all cases along with a small amount of cis and methylene products. The trans isomers interacted well with HIV-1 RT through H-bonding with amino acids, like Lys101, Lys103, His235, Tyr318, constituting the non-nucleoside inhibitor binding pocket (NNIBP) during docking experiments. However, the compounds showed very little activity when subjected to in vitro anti-HIV-1 screening using β-galactosidase assay (TZM-bl cells) and GFP quantification (CEM-GFP cells). The very low level of in vitro HIV inhibition, in comparison to predicted EC(50) values on the basis of computational studies, during CEM-GFP screening using AZT as positive control indicated that probably the HIV RT is not the viral target and the molecules work through some different mechanism.

Synthesis, structure-activity relationship and antiviral activity of 3'-N,N-dimethylamino-2',3'-dideoxythymidine and its prodrugs

A probable NRTI molecule, viz. 3'-N,N-dimethylamino-2',3'-dideoxythymidine (4) and its 5'-O-carboxyl ester prodrugs - 5'-(N-alpha-BOC-L-phenylalanyl)-3'-N,N-dimethylamino-2',3'-dideoxythymidine (5), 5'-L-phenylalanyl-3'-N,N-dimethylamino-2',3'-dideoxythymidine (6) and 5'-decanoyl-3'-N,N-dimethylamino-2',3'-dideoxythymidine (7) have been synthesized and screened against HIV, HSV-1 and 2, parainfluenza-3, vesicular stomatitis and several other viruses. The compound 6 showed good antiviral activity with EC(50) value 0.03 microM (SI=8) against VSV in Hela and HEL cell lines. However, the lead compound 4 and its derivatives 5, 6 and 7 showed no remarkable activity against HIV-1 and other viruses. Molecular docking studies with HIV-1 RT using DS 2.5 and pymol softwares have shown marked differences in the interaction patterns between the lead compound 4 and AZT.

Synthesis, antibacterial and antiviral properties of curcumin bioconjugates bearing dipeptide, fatty acids and folic acid

Curcumin bioconjugates, viz. di-O-tryptophanylphenylalanine curcumin (2), di-O-decanoyl curcumin (3), di-O-pamitoyl curcumin (4), di-O-bis-(γ,γ)folyl curcumin (6), C⁴-ethyl-O-γ-folyl curcumin (8) and 4-O-ethyl-O-γ-folyl curcumin (10) have been synthesized and tested for their antibacterial and antiviral activities. The conjugates 2, 3, 4, 6 and 8 have shown very promising antibacterial activity with MIC ranging between 0.09 and 0.67 μM against Gram-positive cocci and Gram-negative bacilli. Further, the conjugates 2, 3, 6, 8 and 10 have been screened for their antiviral activities against HSV, VSV, FIPV, PIV-3, RSV and FHV and the molecules 2 and 3 have shown good results with EC₅₀ 0.011 μM and 0.029 μM against VSV and FIPV/FHV, respectively. However, the molecules did not show expected results against HIV-1 III_B and ROD strains in MTT assay.

Synthesis of N6 ,N6-Dialkyl Adenine Nucleosides With In Situ Formed Hexaalkylphosphorus Triamides

Reactions between secondary amines and phosphorus trichloride (PCl₃) leads to the formation of the corresponding tris(dialkylamino)phosphines or hexaalkylphosphorus triamides [HAPT: (R₂N)₃P]. Reaction of silyl-protected 2'-deoxyinosine and acetyl-protected inosine with the in situ formed HAPT and iodine (I₂) leads to the formation of N⁶,N⁶-dialkyl adenosine and 2'-deoxyadenosine. In some cases the stoichiometry of the amine is important as also the use of a tertiary amine base. The effect of amine stoichiometry on the reaction of HAPT with I₂ has been studied by ³¹P{¹H} NMR.