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Background: Serotype coxsackievirus B (CVB) infection has been linked to viral myocarditis, dilated cardiomyopathy, meningitis, and pancreatitis in children and young adults. As of yet, no antiviral drug has been authorized for the treatment of coxsackievirus infection. Therefore, there is perpetual demand for new therapeutic agents and the improvement of existing ones. Benzo[g]quinazolines, the subject of several well-known heterocyclic systems, have risen to prominence and played a significant role in the development of antiviral agents, particularly those for anti-coxsackievirus B4 infection. Methods: This study investigated the cytotoxicity of the target benzo[g]quinazolines (1–16) in the BGM cells line as well as their anti-coxsackievirus B4 activity.Determination of CVB4 titers using a plaque assay. Results: Most of the target benzoquinazolines exhibited antiviral activity, however, compounds 1–3appeared to be the most effective (reduction percentages of 66.7, 70, and 83.3%, respectively). The binding mechanisms and interactions of the three most active 1–3with the constitutive amino acids in the active site of the multi-target of coxsackievirus B4 (3Clpro and RdRp) targets were also investigated using molecular docking. Conclusion: The anti coxsackievirus B4 activity has resulted, and the top three active benzoquinazolines (1–3) have bonded to and interacted with the constitutive amino acids in the active region of the multi-target coxsackievirus B4 (RdRp and 3Clpro). Further research is required in the lab. to determine the exact benzoquinazolines mechanism of action.

C27H19N5O5S, monoclinic, P21/c(no. 14), a= 14.2789(4) Å, b= 27.3722(9) Å, c= 13.0126(4) Å, β= 101.805(2)°, V= 4978.3(3) Å3, Z= 8, Rgt(F) = 0.0809, wRref(F2) = 0.1705.

C40H45BN2O, monoclinic, P21/c(No. 14), a= 14.4148(6) Å, b= 16.7684(7) Å, c= 13.7178(5), β= 102.791(1)°, V= 3233.5(2) Å3, Z= 4, Rgt(F)= 0.0424, wRref(F2) = 0.1128, T= 100 K.

C32H31BN2S, monoclinic, P21/c(no. 14), a= 8.7214(4) Å, b= 15.4388(7) Å, c= 20.1249(10) Å, β= 92.176(2)°, V= 2707.8 (2) Å3, Z= 4, Rgt(F)= 0.0586, wRref(F2)= 0.1588, T= 296 K.

C17H22N2S, orthorhombic, Pbca(no. 61), a= 12.0579(7) Å, b= 11.12133(5) Å, c= 21.9741(13) Å, V= 2946.7(3) Å3, Z= 8, Rgt(F)= 0.0470, wRref(F2)= 0.1125, T= 100 K.

A new sensitive chromogenic reagent, 9,10-phenanthaquinone monoethylthiosemicarbazone (PET), has been synthesized and used in the spectrophotometric determination of Tl(III). In HNO3, H2SO4or H3PO4acids, PET can react immediately at room temperature with Tl(III) to form a red 2:1 complex with a maximum absorption at 516 nm. The different analytical parameters affecting the extraction and determination processes have been examined. The calibration curve was found to be linear over the range 0.2–10 µg cm–3with a molar absorptivity of 2.2 × 104dm3mol–1cm–1. Sandell’s sensitivity was found to be 0.0093 µg cm–2. No interference from macroamounts of foreign ions was detected, except for Pd(II). However, Pd(II) does not affect the determination process, because its complex with PET has its λmaxat 625 nm. The proposed method has been applied to the determination of Tl(I and III) in synthetic and natural samples after separation by flotation (in oleic acid/kerosene) and solid-phase extraction (on polyurethane foam) techniques. The two methods were found to be accurate and not subject to random error, but solid-phase extraction was preferred because it is cheap, simpler and there is no contamination risk coming from flotation reagents.

Controlled-pore silica glass modified with N-propylsalicylaldimine (SCPSG) has been investigated as a surface-active matrix for the separation of some metal ions. The porous silica glass base was confirmed to have better stability towards hydrolysis in aqueous solution buffered at pH = 9 in comparison to silica gel, which showed twice the surface area of controlled-pore silica glass. The different analytical parameters affecting the batch mode separation and preconcentration of trace Al(III), Ag(I) and Hg(II) in environmental samples using SCPSG, prior to their determination using inductively coupled plasma mass spectrometry (ICP-MS), were studied. The optimum conditions are pH 9.0 ± 0.1, time of stirring 30 min and the eluent concentration 0.5 mol dm–3HNO3. The ion-exchange capacity of SCPSG with respect to Al(III), Ag(I) and Hg(II) was 0.27, 0.18 and 0.23 mmol g–1, respectively. The recovery values for the metal ions were 96.8 ± 0.86, 98.1 ± 0.60 and 96.2 ± 1.06%, and the analytical detection limits were 26.1, 1.49 and 0.44 pg cm–3, respectively, for a preconcentration factor of 100. The method has been applied to the determination of the investigated metal ions in natural water samples as well as certified and reported samples and the results were found to be accurate.

A novel cetylpyridinium chloride-selective membrane sensor consisting of cetylpyridinium-ferric thiocyanate ion pairs dispersed in a PVC matrix placticized with dioctylphthalate is described. The electrode shows a stable, near-Nernstian response for 1 × 10–3–1 × 10–6mol l–1cetylpyridinium chloride (CPC) at 25°C over the pH range 1–6 with a cationic slope of 57.5 ± 0.4. The lower detection limit is 8 × 10–7mol l–1and the response time is 30–60 s. Selectivity coefficients for CPC relative to a number of interfering substances were investigated. There is negligible interference from many cations, anions and pharmaceutical excipients; however, cetyltrimethylammonim bromide (CTMAB) interfered significantly. The determination of 0.5–350 μg/ml of CPC in aqueous solutions shows an average recovery of 98.5% and a mean relative standard deviation of 1.6% at 56.0 μg/ml. The direct determination of CPC in Ezafluor mouthwash gave results that compare favorably with those obtained by the British Pharmacopoeia method. Precipitation titrations involving CPC as titrant are monitored with a CP sensor. The CP electrode has been utilized as an end point indicator electrode for the determination of anionic surfactants in some commercial detergents.