Effective synthesis of novel dihydrobenzisoxazoles bearing the 2-aminothiazole moiety and evaluation of the antiproliferative activity of their acylated derivatives.

An effective method for the synthesis of 8-aryl-4,5-dihydrothiazolo[4',5':3,4]benzo[1,2-]isoxazol-2-amines was developed. This method includes the α-keto bromination of 3-aryl-6,7-dihydrobenzo[]isoxazol-4(5)-ones followed by the condensation of the obtained bromo derivatives with thiourea in acetonitrile. Using virtual screening, a series of acylated derivatives of the obtained compounds were selected as potential HSP90 inhibitors.

Novel O-acylated (E)-3-aryl-6,7-dihydrobenzisoxazol-4(5H)-one oximes targeting HSP90-HER2 axis in breast cancer cells.

Novel O-acylated (E)-3-aryl-6,7-dihydrobenzisoxazol-4(5H)-one oximes were designed as potential HSP90 inhibitors. A series of the compounds was synthesized by oximation of (E)-3-aryl-6,7-dihydrobenzisoxazol-4(5H)-ones followed by O-acylation with acylamidobenzoic acids. The obtained compounds showed an antiproliferative effect on three breast cancer cell lines (MCF7, MDA-MB-231 and HCC1954).

Betulinic Acid-Azaprostanoid Hybrids: Synthesis and Pharmacological Evaluation as Anti-inflammatory Agents.

Background: Prevention and treatment of chronic inflammatory diseases require effective and low-toxic medicines. Molecular hybridization is an effective strategy to enhance the biological activity of new compounds. Triterpenoid scaffolds are in the focus of attention owing to their anti-inflammatory, antiviral, antiproliferative, and immunomodulatory activities.

Fluorine-containing lupane triterpenoid acid derivatives: Design, synthesis and biological evaluation as potential anti-inflammatory agents.

A series of novel fluorine-containing lupane triterpenoid acid derivatives with fluoroaromatic amide moieties at the C-28 position (1-8) or with 2-(fluoroacyl)cyclopentane-1,3-dione fragments at the C-3 position (9-18) of lupane skeleton was synthesized. A simple synthesis of novel lupane triterpenoid hybrids with 2-(fluoroacyl)-2-cyclopenten-1-one moieties was developed. An interaction of 2-acyl-3-chlorocyclopent-2-en-1-ones, obtained from corresponding cyclic β-triketones, with methyl 3-amino-3-deoxybetulinate gave 3β-isomers (9-13) and 3α-isomers (14-18) of target hybrids, which were isolated as individual compounds.

Synthesis of novel lupane triterpenoid-indazolone hybrids with oxime ester linkage.

An efficient protocol for the synthesis of novel lupane triterpenoid-indazolone hybrids with oxime ester linkage has been developed from naturally accessible precursor betulin. For the first time a series of betulonic acid-indazolone hybrids have been synthesized via an acylation of corresponding 6,7-dihydro-1H-indazol-4(5H)-one oximes with betulonic acid chloride. Diastereoselective reduction of the obtained betulonic acid conjugates with NaBH resulted in a formation of betulinic acid-indazolone hybrids in excellent yields.

Structural features of prostanoid analogues involved in hepatocytes protection against CCl4-induced injury.

The ability of natural prostaglandins (PGs) and synthetic prostanoids of B, H and E(1)-types to prevent CCl(4)-induced liver injury in vitro was examined. Seven analogs of PGB, 3 derivatives of PGH and two 11-deoxy-analogs of PGE(1) decreased cytotoxic index of CCl(4) by 2-fold and were more effective then such well-known hepatoprotectors as silymarin, curcumin and PGI(2). These prostanoids reduced trien conjugates formation by 25-95% and strongly prevented LDH leakage through plasma membrane.

The mechanism of the rat liver cytochrome P4502E1 inhibition by the synthetic prostanoids of A-type.

Aim: The elucidation of mechanism of A-type synthetic prostanoids inhibitory action on microsomal cytochrome P(450)2E1 (CYP2E1) from rat liver activity was carried out.

Results: Analogs U-34 and U-26 in a final concentration of 1 x 10(-5)M inhibited CYP2E1 activity by 93% and 46%, respectively; however natural prostaglandins had no effect. These synthetic prostanoids of A-type (5 x 10(-8) to 10(-4)M) inhibited chlorzoxazone hydroxylation in a dose-dependent manner while IC(50)=7.

Hepatoprotective action of prostaglandin A(2) analogs under CCl(4)-induced liver injury in vitro.

Aim: The cytoprotective effects of six novel synthetic prostaglandin A(2) analogs against carbon tetrachloride (CCl(4)) as a toxic agent were studied with isolated rat liver hepatocytes in vitro.

Results: It was found that hepatocytes treatment with CCl(4) induced: (i) a significant increase of lactic dehydrogenase (LDH) release from cytoplasm; (ii) leakage of glutamate dehydrogenase (GDH) and acid phosphatase from mitochondria and lysosomes, respectively; (iii) 10-fold increase of trien conjugates formation; and (iv) a reduction of free SH-groups by 50%. Prostanoids U-26, U-9 and U-34 decreased cytotoxic index of CCl(4) on average by 1.

Synthetic heteroprostanoids of A- and E-types as novel non-comprehensive inhibitors of adenylyl cyclase in rat hepatocytes.

Treatment of rat hepatocyte plasma membranes with five novel synthetic heteroprostanoids of A- and E-types significantly decreased basal activity of adenylyl cyclase. Inhibition of forskolin-stimulated activity of the enzyme was seen as well. The maximal effective concentration for all substances tested was found at approximately 5x10(-6)-1x10(-5) M.

[Radiosensitization of human tumor HeLa cells induced by methyl ester of 6-oxo-6-[2,2-ethylenedioxy-5-(dimethoxycarbonylmethyl)-cyclope nt- 1-yL]-hexanoic acid].

Methyl ester of 6-oxo-6-[2,2-ethylenedioxy-5-(dimethoxycarbonylmethyl)- cyclopent-1-yl]-hexanoic acid (7-keto-9,9-ethylenedioxiprostanoid, that is analogue of 11-deoxy-PGE1 with modified chains) at concentration 10(-6) mol/l displayed maximal (25%) sensitizing effect when was tested in a range of concentrations 10(-7)-10(-5) mol/l and HeLa cells were gamma-irradiated at dose of 2 Gy, that was compared with metronidazol action. Optimal time of prostanoid contact with cells was between 30 and 60 min, and metronidazol--60 min. Prostanoid effect was exhibited at irradiation doses from 2 to 4 Gy and reached maximum of 46% at 4 Gy, its DMF was 1.

[The modification of a radiation lesion with 9a-homo-13-thiaprostanoids].

The radioprotective properties of 12 compounds of 9a-homo-13-thiaprostanoid series were investigated under gamma irradiation using the molecular model of beta-carotene radio-oxidation in oleic acid in vitro, erythrocyte radiomimetic model in ex vivo-in vitro system as well as in vivo radiation damage in mice. Most of these compounds stimulated the radio-oxidation of beta-carotene, however in this model two prostanoids with natural alpha-chain displayed radioprotective properties. Expressed membrane stabilizing effect of two 9a-homo-13-thiaprostanoid nor-analogues was revealed in radiomimetic model experiments.

[The gastroprotective and antiaggregant activities of 13-azaprostanoids].

Some 13-azaprostanoic acid derivatives were shown to have a high cytoprotective activity against the damaging effect of ethanol on the gastric mucosa in non-strain rats and affect ATP- and arachidonate-induced platelet aggregation in the whole blood of rabbits and rats in a different way. The gastroprotective activity that is common to natural and synthetic prostanoids is not closely related to the chemical structure of the compounds. On the contrary, the trends of these compounds to affect the induced platelet aggregation depend on the modification of both the cyclic moiety and both chains of a prostanoid molecule.

[Effect of 7-aza- and 13-aza-prostanoids on platelet aggregation].

The effects of 11 new analogues of 7-aza- and 13-azaprostanoic acid on platelet aggregation of the rat were studied in vitro and ex vivo. The analogues of 13-azaprostanoic acid in vitro (10(-7)-10(-8) mol/l) were found to exhibit the antiaggregation activity in the blood. The compounds containing five-member cycle are more active antiaggregants.

[Kinetics of 15 alpha-methyl-8-aza-16-oxagona-1,3,5(10), 13-tetraen-17-ona oxidation by cytochrome P-450 from rat liver microsomes].

The kinetics of oxidation of 15 alpha-methyl-8-aza-16-oxagona-1,3,5(10),13-tetraen-17-on with rat liver microsomal cytochrome P-450 was investigated. The kinetic parameters, Km and Vmax, of the oxidation reaction were found to be equal to 1,3 X 10(-4) M and 4.0 X 10(-7) M X s-1, respectively.

[Interaction of 8-aza-16-oxasteroids with rat liver microsomal cytochrome P-450].

The interaction of the 8-aza-16-oxasteroid series (8-AS) with cytochrome P-450 from liver microsomes of intact and phenobarbital-induced rats has been studied. It has been shown that 8-AS are the substrates for the cytochrome P-450-dependent enzyme system, and that their affinity for cytochrome P-450 is determined by the structure of the compounds tested. Using inhibitory analysis, the site in the active center of hemoprotein responsible for 8-AS binding was examined.