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Item Metadata only Land suitability for salt mining in environmental protection aspect : a case study on the Amphoe Khamthaleso, Nakorn Ratchasima province(Mahidol University. Mahidol University Library and Knowledge Center, 2024) Ramate Sukpum; Thanakorn Uan-On; Sansanee Choowaew; Pichai Wichaidit; Surin VivajsirinPublication Open Access Predicting the Oligomeric States of Fluorescent Proteins(2015) Saw Simeon; Watshara Shoombuatong; Likit Preeyanon; Virapong Prachayasittikul; Chanin Nantasenamat; Mahidol University. Faculty of Medical Technology. Center of Data Mining and Biomedical Informatics; Mahidol University. Faculty of Medical Technology. Department of Clinical Microbiology and Applied TechnologyCurrently, monomeric fluorescent proteins (FP) are ideal markers for protein tagging. The prediction of oligomeric states is helpful for enhancing live biomedical imaging. Computational prediction of FP oligomeric states can accelerate the effort of protein engineering to create monomeric FPs by saving time and money. To the best of our knowledge, this study represents the first computational model for predicting and analyzing FP oligomerization directly from their amino acid sequences. An exhaustive dataset consisting of 397 unique FP oligomeric states was compiled from the literature. FP were described by 3 classes of protein descriptors including amino acid composition, dipeptide composition and physicochemical properties. The oligomeric states of FP was predicted using decision tree (DT) algorithm and results demonstrated that DT provided robust performance with accuracies in ranges of 79.97-81.72% and 80.76-82.63% for the internal (e.g. 10-fold cross-validation) and external sets, respectively. This approach was also benchmarked with other common machine learning algorithms such as artificial neural network, support vector machine and random forest. A thorough analysis of amino acid sequence features was conducted to provide informative insights into FP oligomerization, which may aid in engineering novel monomeric fluorescent proteins. The following differentiating characteristics of monomeric and oligomeric fluorescent proteins were derived from DT: (i) substitution of any amino acid to Glu led to the reduction of aggregated proteins and (ii) oligomerization of FP appears to be stabilized by several hydrophobic contacts.Publication Open Access Antimicrobial and cytotoxic acetogenin from Polyalthia debilis(2015-03) Somchai Boonpangrak; Rungrot Cherdtrakulkiat; Ratchanok Pingaew; Patumporn Manam; Supaluk Prachayasittikul; Somsak Ruchirawat; Virapong Prachayasittikul; Mahidol University. Faculty of Medical Technology. Center for Innovation Development and Technology Transfer; 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 InformaticsObjective: To isolate bioactive acetogenin compound and to investigate antimicrobial, antioxidant as well as cytotoxic activities of the isolate, fractions and extracts of Polyalthia debilis. Methods: The P. debilis (roots) extracts and isolated compound were tested for their antimicrobial (agar dilution method) against twenty-seven strains of microorganisms (gram positive and gram negative bacteria, and diploid fungus), antioxidant (DPPH assay) and cytotoxic activities. The plant extracts were isolated by column chromatography and structure of compound was confirmed by spectral data . Result: The plant extracts and isolated fractions exhibited antioxidant and cytotoxic activities. The isolated acetogenin 1 (debilisome E) displayed antimicrobial activity against Morexella catarrhalis with the MIC of 64 microgram/mL, Corynebacterium diphtheriae NCTC 10356 and Streptococcus pyogenes with partial inhibition (50-75%) at 128 microgram/mL. The compound 1 exerted cytotoxic activity against 5 cancer cells (HepG2, A549, HCC-S102,HL-60 and P388) with IC50 values 18.4 - 40.3 microgram/mL. Conclusion: The results demonstrate novel bioactivities of P. debilis as antimicrobials and anticancer agents.Publication Open Access Investigation of aromatase inhibitory activity of metal complexes of 8-hydroxyquinoline and uracil derivatives(2014-08-14) Veda Prachayasittikul; Ratchanok Pingaew; Virapong Prachayasittikul; Chanin Nantasenamat; Somsak Ruchirawat; Supaluk 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 InformaticsPurpose: Estrogens play important roles in the pathogenesis and progression of breast cancer as well as estrogen-related diseases. Aromatase is a key enzyme in the rate-limiting step of estrogen production, in which its inhibition is one strategy for controlling estrogen levels to improve prognosis of estrogen-related cancers and diseases. Herein, a series of metal (Mn, Cu, and Ni) complexes of 8-hydroxyquinoline (8HQ) and uracil derivatives (4–9) were investigated for their aromatase inhibitory and cytotoxic activities. Methods: The aromatase inhibition assay was performed according to a Gentest™ kit using CYP19 enzyme, wherein ketoconazole and letrozole were used as reference drugs. The cytotoxicity was tested on normal embryonic lung cells (MRC-5) using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Results: Only Cu complexes (6 and 9) exhibited aromatase inhibitory effect with IC50 0.30 and 1.7 µM, respectively. Cytotoxicity test against MRC-5 cells showed that Mn and Cu complexes (5 and 6), as well as free ligand 8HQ, exhibited activity with IC50 range 0.74–6.27 µM. Conclusion: Cu complexes (6 and 9) were found to act as a novel class of aromatase inhibitor. Our findings suggest that these 8HQ–Cu–uracil complexes are promising agents that could be potentially developed as a selective anticancer agent for breast cancer and other estrogen-related diseases.Publication Open Access Synthesis of a “clickable” Angiopep-conjugated p-coumaric acid for brain-targeted delivery(2014-08-19) Thummaruk Suksrichavalit; Supaluk Prachayasittikul; Virapong Prachayasittikul; Chartchalerm Isarankura Na Ayudhya; Mahidol University. Faculty of Medical Technology. Center of Data Mining and Biomedical Informatics; Mahidol University. Faculty of Medical Technology. Department of Clinical Chemistry; Mahidol University. Faculty of Medical Technology. Department of Clinical Microbiology and Applied TechnologyOverexpression of free radicals in the brain is emerging as important markers in the etiology of neurodegenerative diseases including Parkinson’s disease, Alzheimer’s disease, and stroke. Numerous antioxidants with protective effect on neuronal injuries under oxidative stress are often limited to penetrate the blood–brain barrier (BBB). Angiopep-2 is the ligand of low-density lipoprotein receptor-related protein expressed on the BBB possessing high transcytosis capacity and parenchymal accumulation. In this study, novel Angiopep-conjugated p-coumaric acid (3) was synthesized, using the Click chemistry, as a potential antioxidant for the protection of the brain under oxidative stress. The clickable Angiopep (3) was synthesized by Cu(I)-catalyzed 1,3-dipolar cycloaddition reaction of the terminal acetylene-modified Angiopep and azide of p-coumaric acid. The Angiopep-conjugated compound (3) showed antioxidant potency and non-cytotoxic effect toward brain endothelial cells (BECs). Obviously, the penetration and BECs protection of 3 were higher than that of the unconjugated p-coumaric acid. The results establish the bio-conjugation of antioxidant and Angiopep with enhanced protective effect on the BECs under oxidative stress. The findings provide great potential for the development of neurotherapeutics with increased brain penetration.Publication Open Access Origin of aromatase inhibitory activity via proteochemometric modeling(2016-04) Saw Simeon; Ola Spjuth; Maris Lapins; Chanin Nantasenamat; Jarl ES Wikberg; Virapong Prachayasittikul; Mahidol University. Faculty of Medical Technology. Center of Data Mining and Biomedical InformaticsAromatase, the rate-limiting enzyme that catalyzes the conversion of androgen to estrogen, plays an essential role in the development of estrogen-dependent breast cancer. Side effects due to aromatase inhibitors (AIs) necessitate the pursuit of novel inhibitor candidates with high selectivity, lower toxicity and increased potency. Designing a novel therapeutic agent against aromatase could be achieved computationally by means of ligand-based and structure-based methods. For over a decade, we have utilized both approaches to design potential AIs for which quantitative structure-activity relationships and molecular docking were used to explore inhibitory mechanisms of AIs towards aromatase. However, such approaches do not consider the effects that aromatase variants have on different AIs. In this study, proteochemometrics modeling was applied to analyze the interaction space between AIs and aromatase variants as a function of their substructural and amino acid features. Good predictive performance was achieved, as rigorously verified by 10-fold cross-validation, external validation, leave-one-compound-out cross-validation, leave-one-protein-out cross-validation and Y-scrambling tests. The investigations presented herein provide important insights into the mechanisms of aromatase inhibitory activity that could aid in the design of novel potent AIs as breast cancer therapeutic agents.Publication Open Access The role of short-chain dehydrogenase/ oxidoreductase, induced by salt stress, on host interaction of B. pseudomallei(2014) Pornpan Pumirat; Usa Boonyuen; Muthita Vanaporn; Peechanika Pinweha; Sarunporn Tandhavanant; Sunee Korbsrisate; Narisara Chantratita; Mahidol University. Faculty of Tropical Medicine. Department of Microbiology and ImmunologyBackground: Burkholderia pseudomallei is the causative agent of melioidosis, a frequently occurring disease in northeastern Thailand, where soil and water high in salt content are common. Using microarray analysis, we previously showed that B.... pseudomallei up-regulated a short-chain dehydrogenase/oxidoreductase (SDO) under salt stress. However, the importance of SDO in B. pseudomallei infection is unknown. This study aimed to explore the function of B. pseudomallei SDO, and to investigate its rolePublication Open Access การศึกษาเปรียบเทียบหมวดหินที่ประกอบด้วยชั้นเกลือหินและโพแทชของประเทศไทยและลาว(2554-10) ปกรณ์ สุวานิช; Parkorn Suwanich; มหาวิทยาลัยมหิดล. คณะสิ่งแวดล้อมและทรัพยากรศาสตร์A comparison of the rock formation composed of rock salt and potash layers between Thailand and Lao PDR determines the relationships of each layer found in both countries. The result of rock salt and potash formations could be correlatedPublication Open Access An overview of American Buddhist poetry: its genesis and typical features and differences from Asian Buddhist poetry(2014) Somboon Pojprasat; Mahidol University. Faculty of Liberal ArtsAmerican Buddhist poetry is an interesting genre which has enjoyed its increased readership since the early nineties. However, it is more perplexing than clarifying, especially when read in juxtaposition with Asian Buddhist poetry. One might experience difficulties in the interpretation of underlying spiritual message which is to a large degree americanised, the unconventional poetic form that even complicates its meaning, and its remarkable divergence from the Asian counterpart. This paper then aims to discuss three main issues, namely the development of Buddhism in America together with typical, complicated features of American Buddhism, the salient characteristics of Asian Buddhist poetry, and the comparison between the two cultures of Buddhist poetry, in the hope of shedding brighter light on this special genre.Publication Open Access Biology of culex sitiens, a predominant mosquito in PhangNga, Thailand after a tsunami(2012) Samrerng Prummongkol; Chotechuang Panasoponkul; Chamnarn Apiwathnasorn; Usa Lek-Uthai; อุษา เล็กอุทัย; Mahidol university. Faculty of Public Health. Department of Parasitology and Entomology; Mahidol university. Faculty of Graduate Studies; Mahidol university. Faculty of Tropical Medicine. Department of Medical EntomologyA tsunami affected area in Phang Nga province, Thailand was explored randomly as some freshwater sites had changed into brackish-water sites. A survey of four areas found Culex sitiens to be the most dominant mosquito species.This mosquito prefers to breed in putrefied water with garbage and it was found in almost every stagnant, brackish-water site in full sunlight. The larval density was more than 300 larvae/dip/250 ml water. Its biting cycle, determined by human landing catch, was nocturnal, with a single peak at 19.00-20.00 hr. The maximum rate was 108 mosquitoes per person/hour. The biology of the mosquito was studied by colonization in natural water under laboratory conditions. The mean number of eggs per raft was 158.1 ± 31.7, hatchability 96.6 ± 4.1%, development from 1st instar larvae to adult was 8.8-11.7 days, and longevity of adult males was 7.3-41.3 days and females 11.0-52.7 days. The ratio of adult males to adult females was 1:1.1 ± 0.2.