In Vitro Inhibitory Analysis of Rationally Designed siRNAs against MERS-CoV Replication in Huh7 Cells

MERS-CoV was identified for the first time in Jeddah, Saudi Arabia in 2012 in a hospitalized patient. This virus subsequently spread to 27 countries with a total of 939 deaths and 2586 confirmed cases and now has become a serious concern globally. Camels are well known for the transmission of the virus to the human population. In this report, we have discussed the prediction, designing, and evaluation of potential siRNA targeting the ORF1ab gene for the inhibition of MERS-CoV replication. The online software, siDirect 2.0 was used to predict and design the siRNAs, their secondary structure and their target accessibility. ORF1ab gene folding was performed by RNAxs and RNAfold software. A total of twenty-one siRNAs were selected from 462 siRNAs according to their scoring and specificity. siRNAs were evaluated in vitro for their cytotoxicity and antiviral efficacy in Huh7 cell line. No significant cytotoxicity was observed for all siRNAs in Huh7 cells. The in vitro study showed the inhibition of viral replication by three siRNAs. The data generated in this study provide preliminary and encouraging information to evaluate the siRNAs separately as well as in combination against MERS-CoV replication in other cell lines. The prediction of siRNAs using online software resulted in the filtration and selection of potential siRNAs with high accuracy and strength. This computational approach resulted in three effective siRNAs that can be taken further to in vivo animal studies and can be used to develop safe and effective antiviral therapies for other prevalent disease-causing viruses.     

Behaviour of 4-(4-chlorophenyl)-6-(4-tolyl)-4,5-dihydro pyrimidine-2(1H) thione and 2-hydrazino derivative toward carbon electrophiles

The reaction of thiourea with p-methyl-β-p-chlorophenyl acrylophenone ( 1 ) is, in principle, an attractive [3 + 3]-fragment approach to the synthesis of dihydropyrimidine bearing aryl groups.     

Surface and Thermodynamic Properties of Nonionic Surfactants Based on Rosin-Maleic Anhydride and Acrylic Acid Adducts

Ester-adduct derivatives of rosin were synthesized by reacting rosin maleic anhydride (RMA) or rosin acrylic acid (RAA) adducts with polyethylene glycol 600 (PEG600), 1000 (PEG1000) or 2000 (PEG2000) and at elevated temperature. These derivatives were evaluated for acid number, FTIR spectroscopy, molecular weight (Mw) and polydispersity. The surface properties of the prepared surfactants were determined by measuring the surface tension at different temperatures. The surface tension, critical micelle concentration, and surface activities were determined at different temperatures. Surface parameters such as surface excess concentration (Γmax), the area per molecule at interface (Amin) and the effectiveness of surface tension reduction (πCMC) were determined from the adsorption isotherms of the prepared surfactants. Some thermodynamic data for the adsorption process were calculated and are discussed.     

Synthesis,characterization, and evaluation of polymeric oil sorbent for remediation of hydrocarbons spillage

The preparation and evaluation of polymeric oil sorbent based on styrene acrylate ester and ethylhexyl acrylate (EHA) are the main target of this work. In this respect, poly styrene-co-p-chloromethyl styrene (PSCMS) was synthesized through radical copolymerization of p-CMS with styrene in the presence of benzoyl peroxide initiator. Then, the PSCMS was reacted with acrylic acid to produce macromonomer containing polymerizable C?C poly {styrene-co-[4-(methyl acrylate) styrene]} (PSSMA) that subsequently copolymerized with EHA in the presence of a cross-linker to obtain the cross-linked copolymers PSSMA/EHA (organogel). The prepared compounds were characterized by using FTIR, ¹H NMR, and gel permeation chromatography. The thermal properties of the cross-linked oil absorbents were investigated using thermogravimetric analysis, and the morphology was characterized by scanning electron microscope (SEM). The oil absorbency of oil gel was determined through oil absorption tests; the highest oil absorbencies of oil gel were found to be 82.6, 74.4, 46.7, and 38.1 g/g in N,N-dimethyl formamide, CHCl₃, toluene, and diesel, respectively.     

Comparative study of HPLC-DAD and HPTLC for the simultaneous determination of a new multitarget antidiabetic ternary mixture in combined tablets

Qternmet XR® (FDA approval, May 2019) is a multitarget anti-diabetic drug combination composed of metformin (MET), saxagliptin (SAX) and dapagliflozin (DAP). To our present knowledge, no analytical reports were found in the scientific databases for the simultaneous quantification of MET, SAX and DAP in their ternary combined tablets, moreover, no articles have attempted the simultaneous estimation of the cited drugs in any matrix using high-performance liquid chromatography with diode-array detection (HPLC–DAD) or high-performance thin-layer chromatography (HPTLC) technique. The current work represents a comparative study on two developed and validated chromatographic methods for the simultaneous determination of the ternary mixture (MET, SAX and DAP) in pure form and in combined tablet dosage form. The first method is reversed-phase HPLC using Agilent C18 column (4.6 × 250 mm, 5 μm p.s.) with a mobile phase consisting of acetonitrile and acidic aqueous phase pH 3 with a photodiode array detection at 230 nm. The second method is HPTLC in which drug solutions were applied to Merck HPTLC silica gel plates developed with a mixture of chloroform:methanol:water:acetic acid (7.4:2.6:0.5:0.01, v/v) and scanned at 224 nm. Both methods were fully validated following the ICH guidelines in terms of linearity, accuracy, precision, selectivity and robustness.

Representative HPLC (a) and HPTLC (b) chromatograms for a ternary mixture of metformin (MET), saxagliptin (SAX) and dapagliflozin (DAP)

     

Discovery of Bispecific Lead Compounds from Azadirachta indica against ZIKA NS2B-NS3 Protease and NS5 RNA Dependent RNA Polymerase Using Molecular Simulations

Zika virus (ZIKV) has been characterized as one of many potential pathogens and placed under future epidemic outbreaks by the WHO. However, a lack of potential therapeutics can result in an uncontrolled pandemic as with other human pandemic viruses. Therefore, prioritized effective therapeutics development has been recommended against ZIKV. In this context, the present study adopted a strategy to explore the lead compounds from Azadirachta indica against ZIKV via concurrent inhibition of the NS2B-NS3 protease (ZIKV^pro) and NS5 RNA dependent RNA polymerase (ZIKV^RdRp) proteins using molecular simulations. Initially, structure-based virtual screening of 44 bioflavonoids reported in Azadirachta indica against the crystal structures of targeted ZIKV proteins resulted in the identification of the top four common bioflavonoids, viz. Rutin, Nicotiflorin, Isoquercitrin, and Hyperoside. These compounds showed substantial docking energy (−7.9 to −11.01 kcal/mol) and intermolecular interactions with essential residues of ZIKV^pro (B:His⁵¹, B:Asp⁷⁵, and B:Ser¹³⁵) and ZIKV^RdRp (Asp⁵⁴⁰, Ile⁷⁹⁹, and Asp⁶⁶⁵) by comparison to the reference compounds, O7N inhibitor (ZIKV^pro) and Sofosbuvir inhibitor (ZIKV^RdRp). Besides, long interval molecular dynamics simulation (500 ns) on the selected docked poses reveals stability of the respective docked poses contributed by intermolecular hydrogen bonds and hydrophobic interactions. The predicted complex stability was further supported by calculated end-point binding free energy using molecular mechanics generalized born surface area (MM/GBSA) method. Consequently, the identified common bioflavonoids are recommended as promising therapeutic inhibitors of ZIKV^pro and ZIKV^RdRp against ZIKV for further experimental assessment.     

Synthesis and comparative study of reactivities of δ-lactone,estor group and oxazinone ring in coumarin derivatives towards carbon or nitrogen nucleophiles

Condensation of methyl 7-methylcoumarin-4-acetate ( 2 ) with primary amines and with anthranilic acid gave 7-methyl-2-oxo-N-aryl-2H-[1]-benzopyran-4-acetamide ( 4a—d ) and (7), respectively. Compound 7 underwent cyclization to give 2-(7-methyl-2-oxo-2H-[1]-benzopyran-4-yl)-methyl-4H-3,1-benzoxazin-4-one ( 3 ). The reaction of 3 with aromatic amines gave the corresponding quinazolone derivatives 5 which tautomerises to the thermodynamically more stable isomer 6 , whereas its reaction with Grignard reagents and aromatic aldehydes gave 8a, 8b , and 9a, 9b , respectively.