Mohamed F. Zayed

Design, synthesis, and biological evaluation studies of novel quinazolinone derivatives as anticonvulsant agents

In view of their expected anticonvulsant activity, some novel derivatives of 6,8-diiodo-2-methyl-3-substituted-quinazolin-4(3H)-ones (4–14) were synthesized, evaluated for their anticonvulsant activity by the maximal electroshock-induced seizure and subcutaneous pentylenetetrazole tests. The neurotoxicity was assessed using rotorod test. All the tested compounds showed considerable anticonvulsant activity in at least one of the anticonvulsant tests. Compounds 5, 6, and 8 proved to be the most potent compounds of this series with relatively low neurotoxicity and low toxicity in the median lethal dose test when compared with the reference drugs. The obtained results showed that the most potent compounds could be useful as a template for future design, optimization, and investigation to produce more active analogs.

Fusaripeptide A: new antifungal and anti-malarial cyclodepsipeptide from the endophytic fungus Fusarium sp.

Abstract From the culture of the endophytic fungus Fusarium sp. isolated from the roots of Mentha longifolia L. (Labiatae) growing in Saudi Arabia, a new cyclodepsipeptide, namely fusaripeptide A (1), along with three known compounds adenosine (2), 2[(2-hydroxypropionyl)amino]benzamide (3), and cyclopentanol (4), have been isolated. Their structures were determined, using extensive 1D and 2D NMR and HRESI and GC mass spectral data. That is the first report for the isolation of compound 4 from natural source. In addition, compounds 2 and 3 are reported here for the first time from Fusarium sp. The absolute configuration of the amino acid residues of 1 was assigned by chiral GCMS and Marfey’s analysis after acid hydrolysis. Fusaripeptide A differs from the reported ones from Fusarium sp. in the length of fatty acidic alkyl chain. Compound 1 was evaluated for its antifungal, anti-malarial, and cytotoxic activities. It exhibited potent antifungal activity toward C. albicans, C. glabrata, C. krusei, and A. fumigates with IC50 values of 0.11, 0.24, 0.19, and 0.14 μM, respectively. Furthermore, it had significant anti-malarial activity toward P. falciparum (D6 clone) with IC50 value of 0.34 μM. However, it showed cytotoxic activity toward the tested cell lines.

Design, synthesis, docking, and biological evaluation of some novel 5-chloro-2-substituted sulfanylbenzoxazole derivatives as anticonvulsant agents

AbstractIn view of their expected anticonvulsant activity, some novel derivatives of 5-chloro-2-substituted sulfanylbenzoxazoles (5–15f) were synthesized and evaluated for their anticonvulsant activity against pentylenetetrazole-induced seizures in mice. The molecular docking was performed for all the synthesized compounds to assess their binding affinities to KCNQ2 receptor in order to rationalize their anticonvulsant activities in a qualitative way. The data obtained from the molecular modeling were correlated with that obtained from the biological screening. These data revealed that compounds 15f, 7c, 15b, and 15d showed the highest binding affinities toward KCNQ2 receptor along with the highest anticonvulsant activities in experimental mice. The highest active compounds showed relative potencies of 0.98, 0.94, 0.91, and 0.83, respectively, in comparing to phenobarbital sodium.

Ingenines A and B, Two New Alkaloids from the Indonesian Sponge Acanthostrongylophora ingens.

As a continuation of the work on EtOAc fraction of the Indonesian sponge Acanthostrongylophora ingens, 2 new alkaloids: one pyrimidine-β-carboline alkaloid named ingenine A (2) and one pyrimidine-γ-carboline alkaloid named ingenine B (3), along with annomontine (1) were isolated. Their structures were unambiguously established on the basis of NMR spectroscopy ((1) H, (13)C, (1) H-(1) H COSY, HMQC, and HMBC) and mass spectral data. This is the first report of isolation pyrimidine-γ-carboline alkaloid from natural source. Compounds 1 and 3 showed pronounced cytotoxicity against the murine lymphoma L5178Y cancer cell line with ED50 7.8 and 9.1 μg/mL respectively, while compound 2 showed weak activity.

Design, synthesis and biological evaluation studies of novel quinazoline derivatives as cytotoxic agents.

Some novel quinazoline derivatives 6a-h were designed, synthesized and evaluated for their in vitro cytotoxic activity against lymphoma cell line compared to etoposide as a reference drug. Compounds (S)-2-(6,8-diiodo-2-phenylquinazolin-4-ylamino)-3-phenylpropanoic acid (6 f), (S)-2-(6,8-diiodo-2-phenylquinazolin-4-ylamino)-3-(1H-imidazol-4-yl)propanoic acid (6 g) and (S)-2-(6,8-diiodo-2-phenylquinazolin-4-ylamino)-3-(1H-indol-3-yl) propanoic acid (6 h) had comparable higher cytotoxic activity than the reference drug. Compound 6 f, the most active compound, had IC50=13.2 µM. In an attempt to interpret such anti-cancer activity of these derivatives, their anti-inflammatory action was examined using the carrageenan induced rat paw edema method. The most active compounds showed moderate anti-inflammatory activity compared to the reference drug. In order to identify the most relevant physicochemical features important for high antitumor activity of the target compounds, specific 2D descriptors were calculated and correlated with the antileukemic activity.

Some novel anticonvulsant agents derived from phthalazinedione.

A series of phthalazinedione bearing substituted oxadiazole moiety derivatives X(1-7) were synthesized in good yield and evaluated for their possible anticonvulsant activity. The structures of the synthesized compounds were confirmed on the basis of their spectral data and elemental analysis. Their anticonvulsant activities were evaluated by the maximal electroshock induced seizure (MES) and subcutaneous pentylenetetrazole (PTZ) tests. All the tested compounds showed considerable anticonvulsant activities in at least one of the anticonvulsant tests. Moreover, some of the tested compounds exhibited moderate anticonvulsant activities in both MES and PTZ tests. From these results,[3-)2-Alkoxycarbonylmethylthioxadiozol-5-yl)methyl -6-Iodophthalazine - 1,4- (2H,3H)-1,4-dion] (X1-7) derivatives could be recommended as novel structures of broad spectrum anticonvulsants.

Mangostanaxanthone VII, a new cytotoxic xanthone from Garcinia mangostana

Abstract Garcinia mangostana L. (the queen of fruits, mangosteen, family Guttiferae) is a wealthy source of xanthones. The CHCl3 soluble fraction of the air-dried pericarps of G. mangostana provided a new xanthone: mangostanaxanthone VII (5), along with four known xanthones: mangostanaxanthones I (1) and II (2), gartanin (3) and γ-mangostin (4). The structural verification of these metabolites was achieved by different spectral techniques, including UV, IR, 1D and 2D NMR and HRESIMS. The new metabolite was assessed for cytotoxic potential, using sulforhodamine B (SRB) assay towards the A549 and MCF-7 cancer cell lines. Moreover, its antimicrobial effects were evaluated against various bacterial and fungal strains, using agar disc diffusion assay. Mangostanaxanthone VII showed moderate cytotoxic activity against the A549 and MCF7 cell lines with IC50s 26.1 and 34.8 μM, respectively, compared with doxorubicin (0.74 and 0.41 μM, respectively).

The Design and Development of Potent Small Molecules as Anticancer Agents Targeting EGFR TK and Tubulin Polymerization

Some novel anthranilate diamides derivatives 4a–e, 6a–c and 9a–d were designed and synthesized to be evaluated for their in vitro anticancer activity. Structures of all newly synthesized compounds were confirmed by infra-red (IR), high-resolution mass (HR-MS) spectra, 1H nuclear magnetic resonance (NMR) and 13C nuclear magnetic resonance (NMR) analyses. Cytotoxic screening was performed according to (3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide) tetrazolium (MTT) assay method using erlotinib as a reference drug against two different types of breast cancer cells. The molecular docking study was performed for representative compounds against two targets, epidermal growth factor receptor (EGFR) and tubulin in colchicine binding site to assess their binding affinities in order to rationalize their anticancer activity in a qualitative way. The data obtained from the molecular modeling was correlated with that obtained from the biological screening. These data showed considerable anticancer activity for these newly synthesized compounds. Biological data for most of the anthranilate diamide showed excellent activity with nanomolar or sub nanomolar half maximal inhibitory concentration (IC50) values against tumor cells. EGFR tyrosine kinase (TK) inhibition assay, tubulin inhibition assay and apoptosis analysis were performed for selected compounds to get more details about their mechanism of action. Extensive structure activity relationship (SAR) analyses were also carried out.

Rational design, synthesis, pharmacophore modeling, and docking studies for identification of novel potent DNA-PK inhibitors

Drugs of cancer based upon ionizing radiation or chemotherapeutic treatment may affect breaking of DNA double strand in cell. DNA-PK enzyme has emerged as an attractive target for drug discovery efforts toward DNA repair pathways. Hence, the search for potent and selective DNA-PK inhibitors has particularly considered state-of-the art and several series of inhibitors have been designed. In this article, a novel benchmark DNA-PK database of 43 compounds was built and described. Ligand-based approaches including pharmacophore and QSAR modeling were applied and novel models were introduced and analyzed for predicting activity test for DNA-PK drug candidates. Based upon the modeling results, we gave a report of synthesis of fifteen novel 2-((8-methyl-2-morpholino-4-oxo-4H-benzo[e][1,3]oxazin-7-yl)oxy)acetamide derivatives and in vitro evaluation for DNA-PK inhibitory and antiproliferative activities. These fifteen compounds overall are satisfied with Lipinskis rule of five. The biological testing of target compounds showed five promising active compounds 7c, 7d, 7f, 9e and 9f with micromolar DNA-PK activity range from 0.25 to 5µM. In addition, SAR of the compounds activity was investigated and confirmed that the terminal aryl moiety was found to be quite crucial for DNA-PK activity. Moreover flexible docking simulation was done for the potent compounds into the putative binding site of the 3D homology model of DNA-PK enzyme and the probable interaction model between DNA-PK and the ligands was investigated and interpreted.

Garcixanthone A, a new cytotoxic xanthone from the pericarps of Garcinia mangostana

Abstract A new prenylated xanthone, garcixanthone A (5), together with eight known compounds, mangostanaxanthones I (1) and II (2), garcinone E (3), β-mangostin (4), 8-hydroxycudraxanthone G (6), garcinone C (7), cudraxanthone G (8), and (-)-epicatechin (9) were isolated from the EtOAc-soluble fraction of the air-dried pericarps of Garcinia mangostana (family Clusiaceae). Their structures were verified on the basis of spectroscopic data interpretation as well as comparison with the literature. The cytotoxic and antimicrobial activities of the new compound were assessed using sulforhodamine B (SRB) and agar disk diffusion assays, respectively. Compound 5 showed significant cytotoxic potential against epithelial lung carcinoma (A549) and breast carcinoma (MCF7) cell lines with IC50s 3.0 and 4.2 μM, respectively, compared to doxorubicin (0.74 and 0.41 μM, respectively).