Ahmed H. Shamroukh

Synthesis and screening of some novel fused thiophene and thienopyrimidine derivatives for anti-avian influenza virus (H5N1) activity.

Several derivatives containing dihydronaphtho, naphtho[2,1-b]thiophene and thieno[2,3-d]pyrimidine ring systems were prepared starting from 2-amino-4,5-dihydronaphtho[2,1-b]thiophene-1-carbonitrile (1). Structure characterization of the thioxo derivative 7 was also performed and its reaction with some chloro and bromoalkyl reagents was studied. Moreover, the prepared products were tested for antiviral activity against H5N1 virus [A/chicken/Egypt/1/2006 (H5N1)] by determination of both EC50 and LD50 and confirmed by plaque reduction assay on MDCK cells. Compounds 5, 7 and 8 showed the highest effect compared with the other tested compounds.

Synthesis of Some Pyrazolo[3, 4]pyrimidine Derivatives for Biological Evaluation

Abstract A novel β -enaminonitrile of 1-(6-p-tolyl-pyridazin-3-yl)-pyrazole derivative 2 was formed using (6-p-tolyl-pyridazin-3-yl)-hydrazine ( 1 ) and 2-ethoxymethylenemalononitrile. The β-enaminonitrile derivative 2 was in turn used as a precursor for the preparation of pyrazoles ( 4 , 6 ), pyrazolo[3, 4-d]-pyrimidines ( 3 , 7–12 ) and pyrazolo[4, 3-e][1,2,4]triazolo[4,3-c]pyrimidine ( 13 ). Also, N- and S-acyclic nucleosides 14 and 15 were prepared. Some of the prepared products showed potent antimicrobial activity.

Synthesis, Reactions, and Antimicrobial Evaluation of Some Polycondensed Thienopyrimidine Derivatives

Some novel indeno[2,1-b]thiophenes, indeno[1′,2′:4,5]thieno[2,3-d][1,2,3]triazines, indeno[1′,2′:4,5]thieno[2,3-d]pyrimidines, indeno[1′,2′:4,5]thieno[2,3-d][1,3]thiazolo[3,2-a]pyrimidines, and indeno[1′,2′:4,5]thieno[2,3-d][1,2,4]triazolo[4,3-a]pyrimidines 2–16 were prepared starting with 2-aminoindeno[2,1-b]thiophene-3-carboxylic acid amide ( 1 ). Furthermore, the antimicrobial evaluation of the prepared products showed that many of them revealed promising antimicrobial activity.

Preparation of Some Fused Pyridopyrimidine and Pyridothienotriazine Derivatives for Biological Evaluation

Compounds 2 and 9 were formed using 3-(4-chloro-phenyl)-1-pyridin-2-yl propenone ( 1 ) and malononitrile or ethyl cyanoacetate, respectively. The pyridine derivative 2 was in turn used as a precursor for the preparation of some pyridopyrimidine and fused pyridopyrimidine derivatives 3–8 On the other hand, the pyridine derivative 9 was used for the preparation of thienopyridine derivatives 11 and 12 Nitrozation of compound 12 afforded pyridothienotriazine derivative 13 Some of the prepared products showed potent antimicrobial activity.

Studies on the Reactivity of (9-Methyl-5,6-dihydronaphtho[1',2':4,5]- thieno[2,3-d]pyrimidin-11-yl)hydrazine Towards Some Reagents for Biological Evaluation

(9-Methyl-5,6-dihydronaphtho[1′,2′:4,5]thieno[2,3-d]pyrimidin-11-yl)hydrazine (1) was used as a precursor for preparation of some novel 1-(9-methyl-5,6-dihydronaphtho[1′,2′:4,5]thieno[2,3-d]pyrimidin-11-yl)-1H-pyrazoles 2–7, -1H-isoindole-1,3(2H)-dione 8, and -pyridazin-3(2H)-one 9. Moreover, the acyclic C-nucleosides 10 and 11 were prepared by treating compound 1 with D-glucose. The in vitro antimicrobial activity of the tested compounds was evaluated by measuring the zone diameters and some of the prepared products showed potent antimicrobial activity in compared with those of well known drugs (standard). In general, the non-acetylated sugar hydrazone derivative 10 showed the highest antibacterial and antifungal potency among the tested compounds and standard with IZ = 22, 21 and 22 mm and MIC = 62.5 and 31.25 μg/ml, respectively.

A Facile Synthesis and Anti-Avian Influenza Virus (H5N1) Screening of Some Novel Pyrazolopyrimidine Nucleoside Derivatives

Treatment of 5-amino-1-(9-methyl-5,6-dihydronaphtho[1′,2′:4,5]thieno[2,3-d]pyrimidin-11-yl)-1H-pyrazole-4-carbonitrile (1) with formic acid afforded pyrazolo[3,4-d]pyrimidin-4-one derivative 2. The sodium salt of the latter compound (generated in situ) was treated with some alkyl halides to afford the corresponding N-substituted compounds 3–7. The siloxy derivative 8 (generated also in situ from 2) was ribosylated and glycosylated to yield compounds 9 and 11, respectively. Deprotection of compounds 9 and 11 in methanolic ammonia produced the free nucleosides 10 and 12, respectively. Moreover, the prepared compounds were tested for antiviral activity against H5N1 virus [A/chicken/Egypt/1/2006] and some of them revealed moderate results compared with the other tested compounds.

Anti-HAV Activity of Some Newly Synthesized Triazolo[4,3-b]pyridazines

6‐Phenyl‐[1,2,4]triazolo[4,3‐b]pyridazine‐3(2H)‐thione 2 was used as precursor for the preparation of some novel 3‐S‐substituted‐6‐phenyl‐[1,2,4]triazolo[4,3‐b]pyridazine derivatives 3–11. Furthermore, the preparation of 1‐[2‐(6‐phenyl‐[1,2,4]triazolo[4,3‐b]pyridazin‐3‐ylsulfanyl)‐acetyl]‐1H‐pyrazole derivative 13 and 5‐(6‐phenyl‐[1,2,4]triazolo[4,3‐b]pyridazin‐3‐ylsulfanylmethyl)‐[1,3,4]oxadiazole derivatives 15 and 17, are described. Some of the prepared products revealed a promising antiviral activity against hepatitis‐A virus (HAV, MBB‐cell culture adapted strain). Plaque reduction infectivity assay was used to determine virus count reduction as a result of treatment with the test compounds. Compound 15 showed the highest effect on HAV compared to the other tested compounds.

Some pyrazole and pyrazolo[3,4-d]pyrimidine derivatives: synthesis and anticancer evaluation.

5‐Amino‐1‐p‐tolyl‐1H‐pyrazole‐4‐carbonitrile (1) was used for the preparation of some novel pyrazoles and pyrazolo[3,4‐d]pyrimidines 2–10. Moreover, the cytotoxicity and in vitro anticancer activities of the prepared compounds were also assessed against the MCF‐7 breast cancer, HepG2 liver cancer, and A549 lung carcinoma cell lines, along with investigation of the effect of the synthesized compounds on the expression of urokinase plasminogen activator (uPA). The tested compounds exhibited remarkable cytotoxic activity against MCF‐7 and HepG2 cells. Among the tested compounds, 2 and 9 revealed promising anticancer activity compared to the activity of the commonly used anticancer drug, doxorubicin, by inhibiting the expression of uPA.

Some Novel Thiopyrimidine Nucleoside Analogs: Synthesis and In Vitro Antimicrobial Evaluation

Abstract Some new S-alkyl derivatives of indeno[1′,2′:4,5]thieno[2,3-d]pyrimidine 2–8 were prepared starting with pyrimidine-2(1H)-thione derivative (1). Also, treatment of compound 1 with 2,3,4,6-tetra-O-acetyl-α-D-glucopyranosyl bromide or 1-O-acetyl-2,3,5-tri-O-benzoyl-β-D-ribofuranose afforded nucleosides 9 and 12, respectively. Furthermore, deprotection of the latter blocked nucleosides was achieved in methanolic ammonia to afford the desired free S-nucleoside derivatives 10 and 13, respectively. Some prepared products were screened for antimicrobial activity, and some of them showed promising activity.

Anticancer evaluation of some newly synthesized N-nicotinonitrile derivative

Some novel N-nicotinonitrile derivatives 3-14 have been synthesized starting with compound 1. The key step of this work is the coupling between compound 1 and activated sugars to afford the corresponding cyclic nucleosides 3-6. Moreover, the cytotoxicity and in vitro anticancer evaluation of the prepared compounds have also been assessed against breast MCF-7 cancer, liver HepG2 cancer and lung A549 carcinoma cell lines with investigation the effect of the synthesized compounds on the expression of urokinase plasminogen activator (uPA). The results revealed that, although all the compounds showed no anticancer activity against A549 cells without showing any effect on the expression of uPA, the tested compounds exhibited remarkable cytotoxicity activity against MCF-7 and HepG2 cell lines. Among the tested compounds, compounds 11 and 12 revealed promising anticancer activity compared to the activity of the commonly used anticancer drug, doxorubicin with inhibiting the expression of uPA.