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Publication Metadata only Insights into antioxidant activity of 1-adamantylthiopyridine analogs using multiple linear regression(2014-02-12) Apilak Worachartcheewan; Chanin Nantasenamat; Wiwat Owasirikul; Teerawat Monnor; Orapan Naruepantawart; Sayamon Janyapaisarn; Supaluk Prachayasittikul; Virapong Prachayasittikul; Mahidol University(QSAR) models. Molecular structures were geometrically optimized at B3LYP/6-31g(d) level and subjected for further molecular descriptor calculation using Dragon software. Multiple linear regression (MLR) was employed for the development of QSAR models....3440, respectively, while QExtand RMSEExtof external test set corresponded to 0.7353 and 4.2721, respectively. Furthermore, QCVand RMSECVvalues of the LOO-CV set for predicting SOD activity were 0.7549 and 5.6380, respectively. The QSAR model's equation was then usedPublication Metadata only Synthesis, anticancer activity and QSAR study of 1,4-naphthoquinone derivatives(2014-09-12) Veda Prachayasittikul; Ratchanok Pingaew; Apilak Worachartcheewan; Chanin Nantasenamat; Supaluk Prachayasittikul; Somsak Ruchirawat; Virapong Prachayasittikul; Mahidol University; Srinakharinwirot University; Chulabhorn Research Institute; Chulabhorn Graduate Institute; Ministry of Educationactivities were predicted using equations obtained from the previously constructed QSAR models. Interpretation of informative descriptors from QSAR models revealed pertinent knowledge on physicochemical properties governing the cytotoxic activities of tested... cytotoxic activity against the MOLT-3 cell line with an IC50of 2.118 μM. Quantitative structure-activity relationship (QSAR) investigations provided good predictive performance as observed from cross-validated R of 0.9177-0.9753 and RMSE of 0.0614-0Publication Open Access Modeling the LPS neutralization activity of anti-endotoxins(2009) Chadinee Thippakorn; Thummaruk Suksrichavalit; Chanin Nantasenamat; Tanawut Tantimongcolwat; Chartchalerm Isarankura-Na-Ayudhya; Thanakorn Naenna; Virapong PrachayasittikulBacterial lipopolysaccharides (LPS), also known as endotoxins, are major structural components of the outer membrane of Gram-negative bacteria that serve as a barrier and protective shield between them and their surrounding environment. LPS... is considered to be a major virulence factor as it strongly stimulates the secretion of proinflammatory cytokines which mediate the host immune response and culminating in septic shock. Quantitative structure-activity relationship studies of the LPSPublication Open Access Discovery of novel 1,2,3-triazole derivatives as anticancer agents using QSAR and in silico structural modification(2015-10-05) Veda Prachayasittikul; Ratchanok Pingaew; Nuttapat Anuwongcharoen; Apilak Worachartcheewan; Chanin Nantasenamat; Supaluk Prachayasittikul; Somsak Ruchirawat; Virapong Prachayasittikul; Mahidol University. Faculty of Medical Technology. Department of Clinical Microbiology and Applied Technology; Mahidol University. Faculty of Medical Technology. Center of Data Mining and Biomedical Informaticsused for QSAR analysis. Four QSAR models were successfully constructed with acceptable predictive performance affording RCV ranging from 0.5958 to 0.8957 and RMSE CV ranging from 0.2070 to 0.4526. An additional set of 64 structurally modified triazole.... Structural modification on the privileged structures is noted as an effective strategy towards successful design and development of novel drugs. The quantitative structure–activity relationships (QSAR) is well-known as a powerful computational toolPublication Open Access Molecular modeling of the human hemoglobin-haptoglobin complex sheds light on the protective mechanisms of haptoglobin.(Mahidol University, 2013-04) Chanin Nantasenamat; Virapong Prachayasittikul; Leif Bulow; Mahidol University. Faculty of Medical Technologyprotein that scavenges Hb and the resulting Hb-Hp complex is subjected to CD163-mediated endocytosis by macrophages. The interaction between Hb and Hp is extraordinarily strong and largely irreversible. As the structural details of the human Hb-Hp complex... identified by computational alanine scanning mutagenesis. Results revealed that the surface of the binding interface of Hb-Hp is not flat and protrudes into each binding partner. It was also observed that the secondary structures at the Hb-Hp interfacePublication Open Access Copper Complexes of Nicotinic-Aromatic Carboxylic Acids as Superoxide Dismutase Mimetics(Mahidol University, 2008) Thummaruk Suksrichavalit; Supaluk Prachayasittikul; Theeraphon Piacham; Chartchalerm Isarankura-Na-Ayudhya; Chanin Nantasenamat; Virapong PrachayasittikulNicotinic acid (also known as vitamin B3) is a dietary element essential for physiological and antihyperlipidemic functions. This study reports the synthesis of novel mixed ligand complexes of copper with nicotinic and other select carboxylic acids (phthalic, salicylic and anthranilic acids). The tested copper complexes exhibited superoxide dismutase (SOD) mimetic activity and antimicrobial activity against Bacillus subtilis ATCC 6633, with a minimum inhibition concentration of 256 μg/mL. Copper complex of nicotinic-phthalic acids (CuNA/Ph) was the most potent with a SOD mimetic activity of IC50 34.42 μM. The SOD activities were observed to correlate well with the theoretical parameters as calculated using density functional theory (DFT) at the B3LYP/LANL2DZ level of theory. Interestingly, the SOD activity of the copper complex CuNA/Ph was positively correlated with the electron affinity (EA) value. The two quantum chemical parameters, highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO), were shown to be appropriate for understanding the mechanism of the metal complexes as their calculated energies show good correlation with the SOD activity. Moreover, copper complex with the highest SOD activity were shown to possess the lowest HOMO energy. These findings demonstrate a great potential for the development of value-added metallovitamin-based therapeutics.Publication Open Access Classification of P-glycoprotein-interacting compounds using machine-learning methods(2015-07) Watshara Shoombuatong; Apilak Worachartcheewan; Veda Prachayasittikul; Chanin Nantasenamat; Virapong Prachayasittikul; Mahidol University. Faculty of Medical Technology. Center of Data Mining and Biomedical Informatics-interacting compounds (i.e., 1341 inhibitors, 913 non-inhibitors, 197 substrates and 26 non-substrates) was performed using several machine learning methods (i.e., decision tree induction, artificial neural network modelling and support vector machine) as a... function of their physicochemical properties. The models provided good predictive performance, producing MCC values in the range of 0.739-1 for internal cross-validation and 0.665-1 for external validation. The study provided simple and interpretable modelsPublication Open Access Elucidating the structure-activity relationships of the vasorelaxation and antioxidation properties of thionicotinic acid derivatives(2010) Supaluk Prachayasittikul; Orapin Wongsawatkul; Apilak Worachartcheewan; Chanin Nantasenamat; Somsak Ruchirawat; Virapong Prachayasittikul(as discerned from DPPH assay). Molecular modeling was also used to provide mechanistic insights into the vasorelaxant and antioxidative activities. The findings reveal that the thionicotinic acid analogs are a novel class of vasorelaxant and antioxidantPublication Open Access Synthesis and theoretical study of molecularly imprinted nanospheres for recognition of tocopherols(2009) Theeraphon Piacham; Chanin Nantasenamat; Thummaruk Suksrichavalit; Charoenchai Puttipanyalears; Tippawan Pissawong; Supanee Maneewas; Chartchalerm Isarankura-Na-Ayudhya; Virapong PrachayasittikulMolecular imprinting is a technology that facilitates the production of artificial receptors toward compounds of interest. The molecularly imprinted polymers act as artificial antibodies, artificial receptors, or artificial enzymes with the added benefit over their biological counterparts of being highly durable. In this study, we prepared molecularly imprinted polymers for the purpose of binding specifically to tocopherol (vitamin E) and its derivative, tocopherol acetate. Binding of the imprinted polymers to the template was found to be two times greater than that of the control, non-imprinted polymers, when using only 10 mg of polymers. Optimization of the rebinding solvent indicated that ethanol-water at a molar ratio of 6:4 (v/v) was the best solvent system as it enhanced the rebinding performance of the imprinted polymers toward both tocopherol and tocopherol acetate with a binding capacity of approximately 2 mg/g of polymer. Furthermore, imprinted nanospheres against tocopherol was successfully prepared by precipitation polymerization with ethanol-water at a molar ratio of 8:2 (v/v) as the optimal rebinding solvent. Computer simulation was also performed to provide mechanistic insights on the binding mode of template-monomer complexes. Such polymers show high potential for industrial and medical applications, particularly for selective separation of tocopherol and derivatives.