Abdou O. Abdelhamid

Bio: Abdou O. Abdelhamid is an academic researcher from Cairo University. The author has contributed to research in topics: Pyrazole & Thiadiazoles. The author has an hindex of 21, co-authored 194 publications receiving 1824 citations. Previous affiliations of Abdou O. Abdelhamid include University of Texas at El Paso & Beni-Suef University.

Synthesis, characterization, and pharmacological evaluation of some novel thiadiazoles and thiazoles incorporating pyrazole moiety as anticancer agents

Abstract: Two series of novel 2-[[1-(5-methyl-1-phenyl-5-substituted-1H-pyrazol-4-yl)ethylidene]hydrazono]-3-phenyl-2,3-dihydro-1,3,4-thiadiazole derivatives and 2-[5-(4-chlorophenyl)-5′-methyl-1′-phenyl-3,4-dihydro-1′H,2H-[3,4′-bipyrazol]-2-yl]-4-substituted-5-(phenyldiazenyl)thiazole derivatives were prepared from reaction of hydrazonoyl halides with methyl 2-[1-(5-methyl-1-phenyl-1H-pyrazol-4-yl)ethylidene]hydrazine-carbodithioate and thiosemicarbazide derivative, respectively. The newly synthesized derivatives were elucidated by elemental analysis, spectral data, and alternative synthetic routes, whenever possible. The anti-cancer activity of the selected products against the breast carcinoma cell line MCF-7 was determined by WST-1 assay indicating concentration-dependent cellular growth inhibitory effect especially for three compounds with dose response curves indicating IC 50 values of 21.3 ± 0.72, 21.3 ± 0.72, and 23.56 ± 0.81 µg cm−3, respectively. Confocal laser scanning imaging of the treated cells stained by rhodamin 123 and acridine orange dyes confirms that the selected compounds inhibit the mitochondrial lactate dehydrogenase enzymes. The obtained results revealed promising anticancer activity.

Synthesis and cytotoxicity evaluation of some novel thiazoles, thiadiazoles, and pyrido[2,3-d][1,2,4]triazolo[4,3-a]pyrimidin-5(1H)-ones incorporating triazole moiety.

Abstract: Reactions of hydrazonoyl halides and each of methyl 2-(1-(5-methyl-1-phenyl-1H-1,2,3-triazol-4-yl)ethylidene)hydrazine-1-carbodithioate and 2-(1-(5-methyl-1-phenyl-1H-1,2,3-triazol-4-yl)ethylidene)hydrazine-1-carbothioamide afforded 2-(1-(5-methyl-1-phenyl-1H-1,2,3-triazol-4-yl)ethylidene)hydrazono)-3-phenyl-5-substituted-2,3-dihydro-1,3,4-thiadiazoles and 5-(4-substituted)diazenyl)-2-(2-(1-(5-methyl-1-phenyl-1H-1,2,3-triazol-4-yl)ethylidene)hydrazinyl)-4-arylthiazoles, respectively. Analogously, the reactions of hydrazonoyl halides with 7-(5-methyl-1-phenyl-1H-1,2,3-triazol-4-yl)-5-phenyl-2-thioxo-2,3-dihydropyrido[2,3-d]pyrimidin-4(1H)-one gave 3-(4-substituted)-8-(5-methyl-1-phenyl-1H-1,2,3-triazol-4-yl)-6-phenyl-1-arylpyrido[2,3-d]-[1,2,4]-triazolo-[4,3-a]pyrimidin- 5(1H)-ones in a good yield. The structures of the newly synthesized were elucidated via elemental analysis, spectral data and alternative synthesis routes whenever possible. Twelve of the newly synthesized compounds have been evaluated for their antitumor activity against human breast carcinoma (MCF-7) and human hepatocellular carcinoma (HepG2) cell lines. Their structure activity relationships (SAR) were also studied. The 1,3,4-thiadiazole derivative 9b (IC50 = 2.94 µM) has promising antitumor activity against the human hepatocellular carcinoma cell line and the thiazole derivative 12a has promising inhibitory activity against both the human hepatocellular carcinoma cell line and the breast carcinoma cell line (IC50 = 1.19, and 3.4 µM, respectively).

Utility of 3-Acetyl-6-bromo-2H-chromen-2-one for the Synthesis of New Heterocycles as Potential Antiproliferative Agents.

Abstract: Coumarin derivatives containing pyrazolo[1,5-a]pyrimidine, tetrazolo[1,5-a]pyrimidine, imidazo[1,2-a]pyrimidine, pyrazolo[3,4-d]pyrimidine, 1,3,4-thiadiazoles and thiazoles were synthesized from 6-bromo-3-(3-(dimethylamino)acryloyl)-2H-chromen-2-one, methyl 2-(1-(6-bromo-2-oxo-2H-chromen-3-yl)ethylidene)hydrazine carbodithioate, 2-(1-(6-bromo-2-oxo-2H-chromen-3-yl)ethylidene) hydrazine carbothioamide and each of heterocyclic amine, hydrazonoyl chlorides and hydroximoyl chlorides. The structures of the newly synthesized compounds were elucidated on the basis of elemental analysis, spectral data, and alternative synthetic routes whenever possible. Moreover, selected newly synthesized products were evaluated for their antitumor activity against a liver carcinoma cancer cell line (HEPG2-1). The results revealed that pyrazolo[1,5-a]pyrimidine 7c, thiazole 23g and 1,3,4-thiadiazole 18a (IC50 = 2.70 ± 0.28, 3.50 ± 0.23 and 4.90 ± 0.69 µM, respectively) have promising antitumor activity against liver carcinoma (HEPG2-1) while most of the tested compounds showed moderate activity.

One Pot Single Step Synthesis and Biological Evaluation of Some Novel Bis(1,3,4-thiadiazole) Derivatives as Potential Cytotoxic Agents

Abstract: A novel series of bis(1,3,4-thiadiazole) derivatives were synthesized in one step methodology with good yields by condensation reaction between bis-hydrazonoyl chloride 1 and various reagents. The structures of the prepared compounds were confirmed by spectral data (IR, NMR, and MS), and elemental analysis. The anticancer activity against human breast carcinoma (MCF-7) cancer cell lines was evaluated in MTT assay. The results revealed that the bis-thiadiazole derivatives 5c,d, 7b,c and 9c had higher antitumor activity than the standard drug Imatinib.

Synthesis of New 3-Heteroarylindoles as Potential Anticancer Agents

Abstract: 2-(3-(1H-Indol-3-yl)-5-(p-tolyl)-4,5-dihydro-1H-pyrazol-1-yl)-4-substituted-5-(substituted diazenyl)thiazoles and 2-(1H-indol-3-yl)-9-substituted-4,7-disubstituted pyrido[3,2-e][1,2,4]triazolo[4,3-a]pyrimidin-5(7H)-ones were synthesized via reaction of hydrazonoyl halides with each of 3-(1H-indol-2-yl)-5-(p-tolyl)-4,5-dihydro-1H-pyrazole-1-carbothioamide and 7-(1H-indol-3-yl)-2- thioxo-5-substituted-2,3-dihydropyrido[2,3-d]pyrimidin-4(1H)-ones, respectively. Also, hydrazonoyl halides were reacted with N’-(1-(1H-indol-3-yl)ethylidene)-2-cyanoacetohydrazide to afford 1,3,4-thiadiazole derivatives. Structures of the new synthesis were elucidated on the basis of elemental analysis, spectral data, and alternative synthetic routes whenever possible. Fifteen of the new compounds have been evaluated for their antitumor activity against the MCF-7 human breast carcinoma cell line. The results indicated that many of the tested compounds showed moderate to high anticancer activity when compared with doxorubicin as a reference drug.

Syringic acid triggers reactive oxygen species-mediated cytotoxicity in HepG2 cells.

Abstract: Hepatocellular carcinoma is the second most common cause of cancer death in the world and its incidence has dramatically increased worldwide in the past two decades. Syringic acid (SA) has been studied for its hepatoprotective, anti-inflammatory, immunomodulatory, free radical scavenging, and antioxidant activities. We aimed to evaluate the cytotoxic effect of SA against human hepatoma HepG2 cell line. Cytotoxicity was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. HepG2 cells were treated with SA at concentration ranges of 25, 50, and 100 µM for 24 h. Reactive oxygen species (ROS) expression was investigated by dichlorofluorescein staining assay. Morphological changes of SA-treated HepG2 cells were evaluated by acridine orange (AO) and ethidium bromide (EB) dual staining. Apoptotic marker gene expressions were evaluated by qPCR. SA treatment caused significant cytotoxicity and liberation of ROS in HepG2 cells. AO and EB staining showed membrane blebbing and distortion in SA-treated cells. Apoptotic markers such as caspases 3 and 9, cytochrome c, Apaf-1, Bax, and p53 gene expressions were significantly increased upon SA treatment indicating the possibility of apoptosis induction in HepG2 cells. This treatment also caused significant downregulation of Bcl-2 gene expression. SA has a cytotoxic effect on human HepG2 cell line, and this might be a promising agent in anticancer research.

Prescribed drugs containing nitrogen heterocycles: an overview

Abstract: Heteroatoms as well as heterocyclic scaffolds are frequently present as the common cores in a plethora of active pharmaceuticals natural products. Statistically, more than 85% of all biologically active compounds are heterocycles or comprise a heterocycle and most frequently, nitrogen heterocycles as a backbone in their complex structures. These facts disclose and emphasize the vital role of heterocycles in modern drug design and drug discovery. In this review, we try to present a comprehensive overview of top prescribed drugs containing nitrogen heterocycles, describing their pharmacological properties, medical applications and their selected synthetic pathways. It is worth mentioning that the reported examples are actually limited to current top selling drugs, being or containing N-heterocycles and their synthetic information has been extracted from both scientific journals and the wider patent literature.

Advances in Heterocyclic Chemistry

Abstract: Cover -- Advancesin Heterocyclic Chemistry13; -- Copyright Page -- Contents -- Contributors -- Preface13; -- Chapter 113; Hexameric Macrocyclic Architectures in Heterocyclic Chemistry -- 1. Introduction -- 2. Macrocycles with Five-Membered Heterocyclic Subunits -- 3. Six-Membered Ring Heterocycles -- 4. Miscellaneous Heterocyclic Materials -- 5. Conclusions -- References -- Chapter 2 13;Metal-Catalyzed Intramolecular Heteroatom (X)!Carbon(C) Functional Group Migration Reactions Involving Additionsof X2;Y Bonds Across Alkynes -- 1. Introduction -- 2. Synthesis of O-Containing Heterocycles -- 3. Synthesis of N-Containing Heterocycles -- 4. Synthesis of S-Containing Heterocycles -- 5. Synthesis of Se-Containing Heterocycles -- 6. Conclusions -- Acknowledgments -- References -- Chapter 313; Biindolyls -- 1. Introduction -- 2. Synthesis -- 3. Reactions -- 4. Conclusion -- References -- Chapter 413; The Annulation of 2-Imidazolines -- 1. Introduction -- 2. Polar Annulation Strategy -- 3. Imidazolines as Double Nucleophiles -- 4. Annulations of the Enamino Ester/Ketene Aminal -- 5. Annulations of N-Unsubstituted 2-Imidazolines -- 6. Imidazolines as Sources of 1,3-Dipoles -- 7. Azomethine Ylides by Alkylation2;Deprotonation -- 8. Azomethine Ylides by Carbene Insertion in a Catalytic Cycle -- 9. Azomethine Ylides by Conjugate Addition-Proton Transfer -- 10. Annulations Using Chiral Imidazolines -- 11. Optically Active Piperidines via Enamino Ester Annulation -- 12. Dipolar Cycloaddition of Optically Active Imidazolinium Ylides -- 13. Chiral Imidazoline Nitrones in Cycloadditions -- 14. Summary -- References -- Chapter 5 Recent Advances in the Dimroth Rearrangement: A ValuableTool for the Synthesis of Heterocycles -- 1. Introduction -- 2. Translocation of Heteroatoms in Fused Heterocycles (Type 1) -- 3. Translocation of Exo- and Endocyclic Heteroatoms in Heterocycles(Type 2) -- Acknowledgments -- References -- Subject Index.