Synthesis of N-aryl-5-amino-4-cyanopyrazole derivatives as potent xanthine oxidase inhibitors

Synthesis and biological evaluation of pyrazolo[4,3-d]pyrimidine analogues

A series of pyrazolo[3,4-d]pyrimidine analogues 3, 4, 5a-f, 6a-f with various amines and ester groups at C-4 and N-1 were synthesized and evaluated for antitumour activity. They were also evaluated for xanthine oxidase inhibitory activity, with most compounds having no significant impact. Compound 5e had the strongest activity against human hepatoma carcinoma cells 7402 and 7221, with half-maximal inhibitory concentration values of 4.55 and 6.28, respectively. Structure-activity relationship studies indicate that chlorine atoms in the structure of 4-((4-(substituted amides)phenyl)amino pyrazolo[4,3-d]pyrimidine analogues is crucial for antitumour activity.

Trisubstituted thiophene analogues of 1-thiazolyl-2-pyrazoline, super oxidase inhibitors and free radical scavengers

Xanthine oxidase (XO) generates superoxide anions and H(2)O(2) for the self-defence system of organism. Abnormal production of this superoxide's (reactive oxygen species) is responsible for a number of complications including inflammation, metabolic disorder, cellular aging, reperfusion damage, atherosclerosis and carcinogenesis. Series of novel trisubstituted thiophenyl-1-thiazolyl-2-pyrazoline libraries are synthesized containing 2,5-dichloro thiophene, 5-chloro-2-(benzylthio) thiophene and 5-chlorothiophene-2-sulphonamide, from chalcones in PEG-400 as green solvent. Superoxide (XO) inhibitory and free radical scavenging activities were also figured out with molecular modeling analysis, bearing in mind their possible future for super oxide inhibitor (Gout) therapeutics, compound 3k shows interesting superoxide inhibitory and free radical scavenger activity with IC(50)=6.2 μM, in comparison with allopurinol.

Design, Synthesis, and Antitumor Evaluation of Novel Pyrazolo[3,4-d]pyrimidine Derivatives

A new series of pyrazolo[3,4-d]pyrimidines has been synthesized. The new compounds were tested for their antitumor activity on 60 different cell lines, and some of the compounds were found to have potent antitumor activity. In particular, 2-hydroxybenzaldehyde [1-(4-chlorophenyl)-3-methyl-1H-pyrazolo-[3,4-d]pyrimidin-4-yl]hydrazone (VIIa) was found to be the most effective among the other derivatives, showing IC50 values of 0.326 to 4.31 μM on 57 different cell lines.

Synthesis and in vitro cytotoxic activity of novel pyrazolo[3,4-d]pyrimidines and related pyrazole hydrazones toward breast adenocarcinoma MCF-7 cell line

New series of pyrazolo[3,4-d]pyrimidines (7a-e and 13a-d) and pyrazole hydrazones 17a-d were synthesized and evaluated for their antiproliferative activity against human breast adenocarcinoma MCF-7 cell line. Most of the tested compounds exploited potent to moderate growth inhibitory activity, in particular compound 7e exhibited superior potency to the reference drug cisplatin (IC(50)=7.60 and 13.29 μM, respectively). The antitumor activity of the new compounds was accompanied by significant increase in the activity of superoxide dismutase with concomitant decrease in the activities of catalase and glutathione peroxidase and reduced glutathione level. Accordingly, the overproduction of hydrogen peroxide, nitric oxide and other free radicals allowed reactive oxygen species (ROS)-mediated tumor cells death, as monitored by reduction in the synthesis of protein and nucleic acids.

Synthesis and xanthine oxidase inhibitory activity of 7-methyl-2-(phenoxymethyl)-5H-[1,3,4]thiadiazolo[3,2-a]pyrimidin-5-one derivatives

An elevated level of blood uric acid (hyperuricemia) is the underlying cause of gout. Xanthine oxidase is the key enzyme that catalyzes the oxidation of hypoxanthine to xanthine and then to uric acid. Allopurinol, a widely used xanthine oxidase inhibitor is the most commonly used drug to treat gout. However, a small but significant portion of the population suffers from adverse effects of allopurinol that includes gastrointestinal upset, skin rashes and hypersensitivity reactions. Moreover, an elevated level of uric acid is considered as an independent risk factor for cardiovascular diseases. Therefore use of allopurinol-like drugs with minimum side effects is the ideal drug of choice against gout. In this study, we report the synthesis of a series of pyrimidin-5-one analogues as effective and a new class of xanthine oxidase inhibitors. All the synthesized pyrimidin-5-one analogues are characterized by spectroscopic techniques and elemental analysis. Four (6a, 6b, 6d and 6f) out of 20 synthesized molecules in this class showed good inhibition against three different sources of xanthine oxidase, which were more potent than allopurinol based on their respective IC(50) values. Molecular modeling and docking studies revealed that the molecule 6a has very good interactions with the Molybdenum-Oxygen-Sulfur (MOS) complex a key component in xanthine oxidase. These results highlight the identification of a new class of xanthine oxidase inhibitors that have potential to be more efficacious, than allopurinol, to treat gout and possibly against cardiovascular diseases.

Synthesis of some new pyrazolo[3,4-d]pyrimidine derivatives of expected anticancer and radioprotective activity

On the account of the reported anticancer activity of pyrazolo[3,4-d]pyrimidines, a new series of pyrazolo[3,4-d]pyrimidine derivatives were synthesized and tested for in-vitro anticancer activity against Ehrlich Ascites Carcinoma (EAC) cell line. Moreover, one of the target products was evaluated for in-vivo radioprotective activity. The reaction of o-aminoester 1 with benzylamine in presence of triethylorthoformate yielded the corresponding 5-benzylpyrazolopyrimidine derivative 2. The N-amino derivative 3 was used to synthesize new derivatives of pyrazolopyrimidines 4-7. The corresponding 1,3,4-oxadiazolopyrazolopyrimidine derivatives 12 and 14 were obtained via reaction of compound 9 with reagent 10 and/or triethylorthoformate. Thiophosgenation of compound 1 furnished the corresponding 5-isothiocyanate derivative 15, which was reacted with o-phenylenediamine, thiosemicarbazide and anthranilic acid to give benzimidazolopyrazolopyrimidine, 17, pyrazolotriazolopyrimidine, 19 and pyrazolopyrimidobenzoxazine, 20 respectively. The structures of the synthesized compounds were confirmed by microanalyses, IR, NMR, and mass spectral data. Compounds 2 and 9 showed intermediate anticancer activity compared to doxorubicin as positive control with IC50 values of 90 and 100 microg/ml, respectively. On the other hand, compound 5 showed significant radioprotective effect.

NMR analysis of a series of substituted pyrazolo[3,4-d] pyrimidines-4-amines

A series of 21 substituted pyrazolo[3,4-d]pyrimidines-4-amines were studied by (1)H and (13)C NMR. The application of two-dimensional techniques, HMQC and HMBC, allowed the complete assignment of the spectra for all the compounds.