Melatonin charge transfer complex with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone: Molecular structure, DFT studies, thermal analyses, evaluation of biological activity and utility for determination of melatonin in pure and dosage forms.

A simple, accurate and fast spectrophotometric method for the quantitative determination of melatonin (ML) drug in its pure and pharmaceutical forms was developed based on the formation of its charge transfer complex with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) as an electron acceptor. The different conditions for this method were optimized accurately. The Lambert-Beer's law was found to be valid over the concentration range of 4-100µgmL-1 ML. The solid form of the CT complex was structurally characterized by means of different spectral methods. Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations were carried out. The different quantum chemical parameters of the CT complex were calculated. Thermal properties of the CT complex and its kinetic thermodynamic parameters were studied, as well as its antimicrobial and antifungal activities were investigated. Molecular docking studies were performed to predict the binding modes of the CT complex components towards E. coli bacterial RNA and the receptor of breast cancer mutant oxidoreductase.

Strong prediction of virological response to combination therapy by IL28B gene variants rs12979860 and rs8099917 in chronic hepatitis C genotype 4.

BACKGROUND: A strong association between single nucleotide polymorphisms (SNPs) of IL28B and treatment outcomes of pegylated interferon-α (PEG IFNα) and ribavirin (RBV) has been shown in chronic hepatitis C (CHC) patients with genotype 1. AIM: This study aimed to assess two SNPs of IL28B, rs12979860 and rs8099917, in predicting sustained virological responses (SVR) to treatment of CHC patients with genotype 4 (HCV-4). The value of rs8099917 was investigated in carriers of unfavourable genotypes of rs12979860. METHODS: This study included 119 CHC patients with HCV-4 receiving combination therapy. Both SNPs of IL28B were determined by real-time detection polymerase chain reaction. RESULTS: Genotypes CC/CT/TT of rs12979860 were found in 42 (35.3%), 56 (47.1%) and 21 (17.6%) and rs8099917 TT/TG/GG were found in 74 (62.2%), 40 (33.6%) and 5 (4.2%). In carriers of rs12979860 CC and rs8099917 TT, the rate of SVR was 87.5 and 65.7% respectively. In 54 patients heterozygous for the C allele of rs12979860, testing of rs8099917 revealed SVR in 42.3% of carriers of the TT genotype but no such responses in carriers of TG or GG (P < 0.0001, OR = 47.3, 95% CI: 2.33-767.2). By multivariate analysis, predictors of SVR were baseline ALT (P = 0.014, OR = 6.3, 95% CI: 1.45-27.33), rs12979860 CC (P = 0.001, OR = 13.48, 95% CI: 2.95-61.69) and rs8099917 TT (P = 0.027, OR = 7.5, 95% CI: 1.25-44.88). CONCLUSION: In CHC genotype 4 patients, favourable genotypes of both SNPs of IL28B are valuable for predicting SVR. Additional genotyping of rs8099917 in carriers of the heterozygous C allele of rs12979860 can improve the prediction of SVR.