Cosmas O. Okoro

• MS; Ph.D.
• Professor (Full) at Tennessee State University

Cancer is a leading cause of death globally, claiming about 9.6 million lives and approximately 420 million new cases of cancer will be diagnosed in the world by the year 2025. The aim of this study was to synthesize and computa-tionally evaluate pharmacological potential of some derivatives of 9-amino-3-phenylacridone, as topoisomerase II (Topo II...

Several reviews of inhibitors of topoisomerase II have been published, covering research before 2018. Therefore, this review is focused primarily on more recent publications with relevant points from the earlier literature. Topoisomerase II is an established target for anticancer drugs, which are further subdivided into poisons and catalytic inhibi...

Several reviews of inhibitors of topoisomerase II literature have been published covering research before 2018. Therefore, this review is focused primarily on more recent publications with relevant points from the earlier literature. Topoisomerase II is an established target for anticancer drugs, that are further subdivided into poisons and catalyt...

DNA topoisomerases are essential enzymes that detangle chromosomes and modulate DNA supercoiling. Type II topoisomerases act by cleaving both strands of a DNA double helix and passing another double helix through the break. The catalytic cycle of the enzyme includes a transient "cleavage complex" in which the enzyme is covalently bound to the cleav...

Eleven novel acridone derivatives were synthesized and evaluated for their anticancer activity against 60 human cancer cell lines. Five compounds 8b, 8d, 8g, 8h, and 8k displayed very good in vitro antiproliferative activities well over 95% of the panels. The most active compound is 8k (5, 7-dibromo-3-phenyl-3,4-dihydroacridin-1 (2H)-one). In addit...

Inspite of progress made for the discovery of novel antiepileptic drugs, epilepsy remains an unmet medical need. We synthesized nine trifluoromethylated enaminone derivatives and tested them for their anticonvulsant activity using maximal electroshock seizure (MES) test, subcutaneous pentylenetetrazole (scPTZ) test, and rotorod test for neurotoxici...

A number of topoisomerase II-targeted anticancer drugs, including amsacrine, utilize an acridine or related aromatic core as a scaffold. Therefore, to further explore the potential of acridine-related compounds to act as topoisomerase II poisons, we synthesized a series of novel trifluoromethylated 9-amino-3,4-dihydroacridin-1(2H)-one derivatives a...

A simple synthesis of 5-trifluoromethyl)cyclohexane-1,2,3-trione is demonstrated in one step, by reacting 5-(trifluoromethyl)cyclohexane-1,3-dione with cerium (IV) ammonium nitrate (CAN) in methanol. The compound represents a highly functionalized oxygen-rich reactive intermediate for the synthesis of organic and heterocyclic compounds containing f...

A series of novel fluorinated cyclic enaminone derivatives was synthesized and evaluated as potential anticonvulsants in four animal models of epilepsy, MES, ScPTZ, rotorod neurotoxicity and 6Hz assay. Phase I screening test data indicated significant anticonvulsant activity for compounds 2a, 4a, 4b, 7 and 8. Except for 2a and 4c all the above comp...

Background Plants that are used as traditional medicine represent a relevant pool for selecting plant candidates that may have anticancer properties. In this study, the ethnomedicinal approach was used to select several medicinal plants native to Nigeria, on the basis of their local or traditional uses. The collected plants were then evaluated for...

This article describes one-pot synthesis of new fluorinated hexahydroquinoline derivatives via unsymmetric Hantzsch reaction involving 5-trifluoromethyl-1,3-cyclohexanedione, aldehydes, acetoacetate ester, and ammonium acetate in trifluoroethanol (TFE). The reaction is simple and rapid with high yield.

3D-QSAR models of a series of fluorinated hexahydropyrimidine derivatives with cytotoxic activities have been developed using CoMFA and CoMSIA. These models provide a better understanding of the mechanism of action and structure-activity relationship of these compounds. By applying leave-one-out (LOO) cross validation study, the best predictive CoM...

A series of substituted dibenzalacetones prepared using standard procedures were condensed with 5-methyl, 5-phenyl, and 5-trifluoromethyl-1,3-cyclohexanediones respectively, in toluene containing BF(3).OEt as the Lewis acid catalyst. The reaction was found to be highly diastereoselective (dr, 9:1). The resulting spiroketals 1a-r were formed in mode...

In the title compound, C14H8Br2F3NO, the mol­ecule is disordered across an approximate non-crystallographic mirror plane, which is in the plane of the fused ring system [The tetrahedral C atom bearing the trifluormethyl substituent is disordered with site occupancy factors of 0.80 (2) and 0.20 (2)]. In the crystal, a one-dimensional stacking of mol...

The alkoxides of o-silyl benzyl alcohols 4 undergo cleavage reactions under mild conditions allowing transfer of a benzyl or silyl group to an electrophile. Reactions 3a 8, and 3c or 4c 11 illustrate their potential as benzyl and silyl anion equivalents.Key words: silyl migration, benzyl anion equivalent, silyl anion equivalent, β-silyl ketone, γ-h...

A series of trifluoromethylated hexahydropyrimidine and tetrahydropyrimidine derivatives were synthesized and their in vitro cytotoxic activities were determined in colon cancer cell line (COLO 320 HSR). Compounds 4f, 4g, 4k, 5, and 7 proved to be the most active in this series of compounds. They represent promising new leads for the development of...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

A simple synthesis of 5-(trifluoromethyl)cyclohexane-1,3-dione and 3-amino-5-(trifluoromethyl)cyclohex-2-en-1-one from the sodium salt of methyl or ethyl-4-hydroxy-2-oxo-6-(trifluoromethyl)cyclohex-3-en-1-oate is demonstrated. The compounds represent highly functionalized reactive intermediates for the synthesis of organic and heterocyclic compound...

We report on the synthesis of a novel series of fluorinated acridones from 5-trifluoromethyl-1,3-cyclohexanedione. The cytotoxic activities of the compounds were studied in several cancer cells. Compounds 9a, 9c, 9e, 9f, and 9h exhibited significant anticancer activities in selected cell lines. Compound 9c is the most active showing GI(50) that ran...

A two-step procedure for the preparation of ethyl 4-amino-2-oxo-6-(trifluoromethyl)cyclohex-3-ene-l-carboxylate (enaminone) and methyl 4-hydroxy-2-oxo-6-(trifluoromethyl)cyclohex-3-ene-l-carboxylate (vinylogous acid) has been accomplished, using reactive Michael acceptors under basic condition. In addition, acyclic trifluoromethylated ester derivat...

gamma-Hydroxysilanes 4 can be easily prepared from bromosilyl ethers 3 by a reaction involving 1,4-migration of the silicon group from oxygen to carbon.

A series of 3-trifluoromethyl-1,2,3,4-tetrahydroisoquinolines was synthesized and evaluated for their phenylethanolamine N-methyltransferase (PNMT) inhibitory potency and affinity for the alpha(2)-adrenoceptor. Although their PNMT inhibitory potency decreased compared with corresponding 3-methyl-, 3-hydroxymethyl- or 3-unsubstituted-THIQs, some of...

The three-dimensional structures of active derivatives of N-(substitutedphenylcarbonylamino)-4-(1-hydroxymethylphenyl)-1,2,3,6-tetrahydropyri-dines, which have previously been shown to possess anti-inflammatory activities, were built using BIOMEDCAche 5.0 software program. In addition, the three dimensional structures of some of the inactive ones w...

The three-dimensional structures of active derivatives of N-(substitutedphenylcarbonylamino)-4-(]hydroxymethylphenyl)-1,2,3,6-tetrahydropyri-dines, which have previously been shown to possess anti-inflammatory activities, were built using BIOMEDCAche 5.0 software program. In addition, the three dimensional structures of some of the inactive ones we...

The alkoxides of o-silyl benzyl alcohols 4 undergo cleavage reactions under mild conditions allowing transfer of a benzyl or silyl group to an electrophile. Reactions 3a --> 8, and 3c or 4c --> 11 illustrate their potential as benzyl and silyl anion equivalents.

Several novel N-(substituted benzoylamino)-5-carbethoxymethyl-1,2,3,6- tetrahydropyridines 6 were synthesized via sodium borohydride reduction of the corresponding N-(substituted benzoylimino)-3-carbethoxymethyl pyridinium ylides 5 in absolute ethanol. The anti-inflammatory activities were determined using the carrageenan-induced rat paw edema assa...

Several novel N-(substituted phenylcarbonylamino)-4-(1-hydroxymethylphenyl)-1,2,3,6-tetrahydropyridines were synthesized via sodium borohydride reduction of the corresponding N-(substituted phenylcarbonylimino)-4-benzoylpyridinium ylides in absolute ethanol. The anti-inflammatory activities using the carrageenan-induced rat paw edema assay and hype...

Several N-(substituted phenylcarbonylamino)-4-cyclohexenyl-1,2,3,6-tetrahydropyridines 7 were synthesized via sodium borohydride reduction of the corresponding N-(substituted phenylcarbonylimino)-4-cyclohexenylpyridinium ylides 6 in absolute ethanol.