Hazem A. Ghabbour

Sickle cell disease in Saudi Arabia: the phenotype in adults with the Arab-Indian haplotype is not benign.

Sickle cell disease (SCD) in Saudi patients from the Eastern Province is associated with the Arab‐Indian (AI) HBB (β‐globin gene) haplotype. The phenotype of AI SCD in children was described as benign and was attributed to their high fetal haemoglobin (HbF). We conducted a hospital‐based study to assess the pattern of SCD complications in adults. A total of 104 patients with average age of 27 years were enrolled. Ninety‐six per cent of these patients reported history of painful crisis; 47% had at least one episode of acute chest syndrome, however, only 15% had two or more episodes; symptomatic osteonecrosis was reported in 18%; priapism in 17%; overt stroke in 6%; none had leg ulcers. The majority of patients had persistent splenomegaly and 66% had gallstones. Half of the patients co‐inherited α‐thalassaemia and about one‐third had glucose‐6‐phosphate dehydrogenase deficiency. Higher HbF correlated with higher rate of splenic sequestration but not with other phenotypes. The phenotype of adult patients with AI SCD is not benign despite their relatively high HbF level. This is probably due to the continued decline in HbF level in adults and the heterocellular and variable distribution of HbF amongst F‐cells.

Tandem Aldol-Michael Reactions in Aqueous Diethylamine Medium: A Greener and Efficient Approach to Bis-Pyrimidine Derivatives

A simple protocol, involving the green synthesis for the construction of novel bis-pyrimidine derivatives, 3a–i and 4a–e are accomplished by the aqueous diethylamine media promoted tandem Aldol-Michael reaction between two molecules of barbituric acid derivatives 1a,b with various aldehydes. This efficient synthetic protocol using an economic and environmentally friendly reaction media with versatility and shorter reaction time provides bis-pyrimidine derivatives with high yields (88%–99%).

Amido/ureidosubstituted benzenesulfonamides-isatin conjugates as low nanomolar/subnanomolar inhibitors of the tumor-associated carbonic anhydrase isoform XII

By using a molecular hybridization approach, two series of amido/ureidosubstituted benzenesulfonamides incorporating substituted-isatin moieties were synthesized. The prepared derivatives were in vitro evaluated for their inhibitory activity against human carbonic anhydrase (hCA, EC 4.2.1.1) I, II (cytosolic) and IX, XII (transmembrane, tumor-associated) isoforms. All these isoforms were inhibited in variable degrees by the sulfonamides reported here. hCA I was inhibited with KIs in the range of 7.9-894 nM, hCA II in the range of 7.5-1645 nM (with one compound having a KI > 10 μM); hCA IX in the range of 5.0-240 nM, whereas hCA XII in the range of 0.47-2.83 nM. As all these isoforms are involved in various pathologies, in which their inhibition can be exploited therapeutically, the derivatives reported here may represent interesting extensions to the field of CA inhibitors of the sulfonamide type.

Fluorescence spectroscopic and molecular docking studies of the binding interaction between the new anaplastic lymphoma kinase inhibitor crizotinib and bovine serum albumin.

Binding of the recently introduced anti-cancer drug, crizotinib (CRB) with the bovine serum albumin (BSA) was comprehensively studied with the aid of fluorescence and UV-Vis spectroscopic as well as molecular docking techniques. The collective results of the study under the simulated physiological conditions proposed a static type of binding occurring between the CRB and BSA with binding constants of 104Lmol-1. BSA conformational changes were investigated using three dimensional (3D) and synchronous fluorescence measurements. Moreover, the results of site marker competitive experiments and molecular docking, it could be deduced that CRB was inserted into the subdomain IIA (site I) of BSA yielding a more stabilized system. This was further confirmed with the molecular docking results which revealed that CRB is located in the active site residues Try149, Glu152, Ser191, Arg194, Arg198, Trp213, Arg217, Arg256, His287, Ala290, Glu291, Ser343, Asp450 within a radius of 6Å. Combining the molecular docking studies and the computed thermodynamic parameters, it can be inferred that hydrophobic and electrostatic interactions are the major binding forces involved in formation of the CRB-BSA complex.

Sickle cell disease subphenotypes in patients from Southwestern Province of Saudi Arabia.

Sickle cell disease (SCD) is common in the Eastern and Southwestern (SW) Provinces of Saudi Arabia. We studied 159 patients with SCD to better characterize its phenotype in the SW Province, where patients usually have a HBB haplotype of African origin. All cases had history and examination, chart review, and laboratory testing. Blood tests were obtained during steady state and included: complete blood count, reticulocytes, hemoglobin electrophoresis, lactate dehydrogenase, and G6PD level. HBB haplotype and presence of &agr;-thalassemia were also determined. Frequency of various SCD complications was as follows: painful episodes of variable severity occurred in majority of patients (98%), osteonecrosis (14%), acute chest syndrome (22%), splenic sequestration (23%), gallstones (34%), stroke (7.5%), priapism (2.6%), serious infections (11.5%), and persistent splenomegaly (11%) beyond 5 years of age. No patient had leg ulcer. History of asthma and high steady state white blood cells count were associated with increased risk of acute chest syndrome. Coinheritance of &agr;-thalassemia was associated with a lower frequency of gallstones. Higher fetal hemoglobin level was associated with persistent splenomegaly but not with other complications. Splenic sequestration was more common among males and was associated with lower steady state hemoglobin. SCD phenotype in the SW Province is variable and comparable with African Americans except for the rarity of priapism and the absence of leg ulcers. Fetal hemoglobin level was not associated with SCD vaso-occlusive complications. New genetic modifiers and environmental factors might modulate the phenotype of SCD in Saudi Arabia.

Synthesis and in vitro anti-proliferative activity of some novel isatins conjugated with quinazoline/phthalazine hydrazines against triple-negative breast cancer MDA-MB-231 cells as apoptosis-inducing agents

Abstract Treatment of patients with triple-negative breast cancer (TNBC) is challenging due to the absence of well- defined molecular targets and the heterogeneity of such disease. In our endeavor to develop potent isatin-based anti-proliferative agents, we utilized the hybrid-pharmacophore approach to synthesize three series of novel isatin-based hybrids 5a–h, 10a–h and 13a–c, with the prime goal of developing potent anti-proliferative agents toward TNBC MDA-MB-231 cell line. In particular, compounds 5e and 10g were the most active hybrids against MDA-MB-231 cells (IC50 = 12.35 ± 0.12 and 12.00 ± 0.13 μM), with 2.37- and 2.44-fold increased activity than 5-fluorouracil (5-FU) (IC50 = 29.38 ± 1.24 μM). Compounds 5e and 10g induced the intrinsic apoptotic mitochondrial pathway in MDA-MB-231; evidenced by the reduced expression of the anti-apoptotic protein Bcl-2, the enhanced expression of the pro-apoptotic protein Bax and the up-regulated active caspase-9 and caspase-3 levels. Furthermore, 10g showed significant increase in the percent of annexin V-FITC positive apoptotic cells from 3.88 to 31.21% (8.4 folds compared to control).

An efficient and green procedure for synthesis of rhodanine derivatives by aldol-thia-Michael protocol using aqueous diethylamine medium

A simple, economical, and green approach to the synthesis of rhodanine derivatives using a tandem aldol condensation-thia-Michael addition process in aqueous diethylamine medium was described. The experiment protocol features simple operations, and the products were isolated in high to excellent yields (82–96%). As spontaneous precipitation always occurs at the end of the process, this leads to easy separation of the products via a simple filtration.

Synthesis, in vitro biological activities and in silico study of dihydropyrimidines derivatives

We describe here the synthesis of dihydropyrimidines derivatives 3a-p, and evaluation of their α-glucosidase enzyme inhibition activities. Compounds 3b (IC50=62.4±1.5 μM), 3c (IC50=25.3±1.26 μM), 3d (IC50=12.4±0.15 μM), 3e (IC50=22.9±0.25 μM), 3g (IC50=23.8±0.17 μM), 3h (IC50=163.3±5.1 μM), 3i (IC50=30.6±0.6 μM), 3m (IC50=26.4±0.34 μM), and 3o (IC50=136.1±6.63 μM) were found to be potent α-glucosidase inhibitors in comparison to the standard drug acarbose (IC50=840±1.73 μM). The compounds were also evaluated for their in vitro cytotoxic activity against PC-3, HeLa, and MCF-3 cancer cell lines, and 3T3 mouse fibroblast cell line. All compounds were found to be non cytotoxic, except compounds 3f and 3m (IC50=17.79±0.66-20.44±0.30 μM), which showed a weak cytotoxic activity against the HeLa, and 3T3 cell lines. In molecular docking simulation study, all the compounds were docked into the active site of the predicted homology model of α-glucosidase enzyme. From the docking result, it was observed that most of the synthesized compounds showed interaction through carbonyl oxygen atom and polar phenyl ring with active site residues of the enzyme.

Increasing the binding affinity of VEGFR-2 inhibitors by extending their hydrophobic interaction with the active site: Design, synthesis and biological evaluation of 1-substituted-4-(4-methoxybenzyl)phthalazine derivatives

A series of anilinophthalazine derivatives 4a-j was initially synthesized and tested for its VEGFR-2 inhibitory activity where it showed promising activity (IC50 = 0.636-5.76 μM). Molecular docking studies guidance was used to improve the binding affinity for series 4a-j towards VEGFR-2 active site. This improvement was achieved by increasing the hydrophobic interaction with the hydrophobic back pocket of the VEGFR-2 active site lined with the hydrophobic side chains of Ile888, Leu889, Ile892, Val898, Val899, Leu1019 and Ile1044. Increasing the hydrophobic interaction was accomplished by extending the anilinophthalazine scaffold with a substituted phenyl moiety through an uriedo linker which should give this extension the flexibility required to accommodate itself deeply into the hydrophobic back pocket. As planned, the designed uriedo-anilinophthalazines 7a-i showed superior binding affinity than their anilinophthalazine parents (IC50 = 0.083-0.473 μM). In particular, compounds 7g-i showed IC50 of 0.086, 0.083 and 0.086 μM, respectively, which are better than that of the reference drug sorafenib (IC50 = 0.09 μM).

A Greener, Efficient Approach to Michael Addition of Barbituric Acid to Nitroalkene in Aqueous Diethylamine Medium

An efficient method for the synthesis of a variety of pyrimidine derivatives 3a–t by reaction of barbituric acids 1a,b as Michael donor with nitroalkenes 2a–k as Michael acceptor using an aqueous medium and diethylamine is described. This 1,4-addition strategy offers several advantages, such as using an economic and environmentally benign reaction media, high yields, versatility, and shorter reaction times. The synthesized compounds were identified by 1H-NMR, 13C-NMR, CHN, IR, and MS. The structure of compound 3a was further confirmed by single crystal X-ray structure determination.