Mohamed S. Gomaa

Design, synthesis, and biological evaluation of novel thiazolidinediones as PPARγ/FFAR1 dual agonists.

Diabetes mellitus is a chronic metabolic disorder that affects more than 180 million people worldwide. Peroxisome proliferator activated receptors (PPARs) are a group of nuclear receptors that have been targeted by the thiazolidinedione (TZD) class of compounds for the management of type II diabetes. PPARγ is known to regulate adipogenesis and glucose metabolism. Another emerging target for the design of antidiabetic agents is the free fatty acid receptor 1 (FFAR1), previously known as GPR40. Agonists of this receptor were found to enhance insulin secretion in diabetic patients. It has been reported that some thiazolidinediones (TZDs) activate FFAR1 with micromolar potency. In this study, based on docking studies into the crystal structure of PPARγ and a homology model of FFAR1, nineteen compounds were designed, synthesized, and biologically tested for agonistic activity on both receptors. Nine compounds showed promising dual activity, with two compounds, 11a and 5b, having affinities in the low micromolar range on both targets. These molecules represent the first antidiabetic agents that could act as insulin sensitizers as well as insulin secretagogues.

Bis(acridine-9-carboxylate)-nitro-europium(III) dihydrate complex a new apoptotic agent through Flk-1 down regulation, caspase-3 activation and oligonucleosomes DNA fragmentation

New bis(acridine-9-carboxylate)-nitro-europium(III) dihydrate complex was synthesized and characterized. In vivo anti-angiogenic activities of bis(acridine-9-carboxylate)-nitro-europium(III) dihydrate complex against Ehrlich ascites carcinoma (EAC) cells are described. The newly synthesized complex resulted in inhibition of proliferation of EAC cells and ascites formation. The anti-tumor effect was found to be through anti-angiogenic activity as evident by the reduction of microvessel density in EAC solid tumors. The anti-angiogenic effect is mediated through down-regulation of VEGF receptor type-2 (Flk-1). The complex was also found to significantly increase the level of caspase-3 in laboratory animals compared to the acridine ligand and to the control group. This was also consistent with the DNA fragmentation detected by capillary electrophoresis that proved the apoptotic effect of the new complex. Our complex exhibited anti-angiogenic and apoptotic activity in vivo, a thing that makes it a potential effective chemotherapeutic agent. The interaction of calf thymus DNA (ct-DNA) with bis(acridine-9-carboxylate)-nitro-europium(III) dihydrate complex has been investigated using fluorescence technique. A competitive experiment of the europium(III)-acridine complex with ethidium bromide (EB) to bind DNA revealed that interaction between the europium(III)-acridine and DNA was via intercalation. The interaction of the synthesized complex with tyrosine kinases was also studied using molecular docking simulation to further substantiate its mode of action.

Mechanism of action of antiepileptic ceramide from Red Sea soft coral Sarcophyton auritum.

Chemical investigation of the Red Sea soft coral Sarcophyton auritum led to the isolation and structure elucidation of a new ceramide N-((2S,3R,4E,6E)-1,3-dihydroxyhenicosa-4,6-dien-2-yl)tridecanamide (1). Structure elucidation was achieved using spectroscopic techniques, including 1D and 2D NMR and HRMS. The anticonvulsant activity of the isolated ceramide was measured in vivo using the pentylenetetrazole (PTZ)-induced seizure model, where it successfully antagonized the lethality of pentylenetetrazole in mice. In addition, the isolated ceramide showed good anxiolytic activity when used in the light–dark transition box and the elevated plus maze compared to diazepam. The molecular modeling studies for the antiepileptic and antianxiety mechanism of the isolated ceramide suggested a CNS depressing activity possibly through GABA and serotonin receptors modulation. The pharmacological activity of the ceramide involved agonistic activity on GABA-A receptors but not 5HT3 receptors.

Synthesis, biological evaluation, and molecular docking investigation of benzhydrol- and indole-based dual PPAR-γ/FFAR1 agonists

Type-2 diabetes mellitus is a progressive cluster of metabolic disorders, representing a global public health burden affecting more than 366 million people worldwide. We recently reported the discovery of three series of novel agents showing balanced activity on two metabolic receptors, peroxisome proliferator activated receptor-γ (PPAR-γ) and free fatty acid receptor 1 (FFAR1), also known as GPCR40. Our designing strategy relied on linking the thiazolidinedione head with known GPCR privilege structures. To further investigate this concept, two new scaffolds, the benzhydrol- and indole-based chemotypes, were introduced here in. Our optimization campaign resulted in three compounds; 15a, 15c, and 15d, with affinities in the low micromolar range on both targets. In vivo study of selected test compounds, revealed that 15c possesses a significant anti-hyperglycemic and anti-hyperlipidemic activities superior to rosiglitazone in fat-fed animal models. Molecular docking analysis was conducted to explain the binding modes of both series. These compounds could lead to the development of the unique antidiabetic agent acting as insulin sensitizer as well as insulin secretagogue.

Discovery of tetrahydro-ß-carboline derivatives as a new class of phosphodiesterase 4 inhibitors

Phosphodiesterase 4 is the primary enzyme responsible for degradation of the second messenger cAMP in many of the cells releasing proinflammatory mediators. Inhibition of this enzyme could help in the management of various inflammatory conditions such as asthma, chronic obstructive pulmonary disorder, arthritis, and psoriasis. In this study, two novel series of tetrahydro-β-carbolines were designed by combining the pharmacophoric features of both tadalafil and piclamilast. Twenty-two compounds were synthesized and assessed for Phosphodiesterase 4 inhibition, four of them showed superior activity to the reference compound IBMX. Docking studies showed that the prepared compounds interact with the crucial Gln443 with variable interactions with the hydrophobic pocket Q2. This is the first report of tetrahydro-β-carbolines as a scaffold for Phosphodiesterase 4 inhibition. Currently, further optimization of the substituents is carried out to fine-tune the hydrophobic interactions and enhance the potency of this novel series of inhibitors.Graphical abstract

Comparative Study of New Hplc And Hptlc Methods For Simultaneous Determination of Dipyrone And Camylofin Dihydrochloride Using Hyoscine Butyl Bromide As Internal Standard

Two new methods are developed for simultaneous determination of dipyrone (Dip) and camylofin dihydrochloride (Cam) in bulk and in pharmaceutical formulation (Spasmopyralgin M ® tablet) using hyoscine butyl bromide as internal standard (I.S.) to further increase the applicability of the methods. The first method was based on HPLC separation of studied compounds using 250 x 4.6 mm (i.d.) phenomenex (5μm particle size) C18 column as stationary phase and mixture of 50 mM ammonium acetate (pH adjusted to 5.3 using acetic acid) and acetonitrile as mobile phase. The second one was HPTLC method where the separation was achieved on Merck HPTLC aluminium plates of silica gel 60 F254 using acetone: methanol: acetic acid (52: 28: 20, v/v/v) as mobile phase. Comparative study was performed to argue the advantage of each method and determine which one is better for routine analysis of studied drugs.