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Aibrohim Dramae Sutichai Nithithanasilp Wilunda Choowong Pranee Rachtawee Samran Prabpai Palangpon Kongsaeree Pattama Pittayakhajonwut 《Tetrahedron》2013
Two new natural products, samroiyotmycins A (1) and B (2), along with two naturally new novclobiocin 101 (3) and 4-hydroxy-3-(3-methylbut-2-enyl)benzamide (5), and five known substances including neoantimycin, clorobiocin (4), 29-O-methylabierixin, daidzein, and 1-(3-indolyl)-2,3-dihydroxypropan-1-one have been isolated from Streptomyces sp. BCC33756. Their chemical structures were determined based on NMR spectral information and the relative stereochemistry of compound 1 was determined by X-ray crystallographic data. Both samroiyotmycins A and B exhibited antimalarial activity against Plasmodium falciparum K1—multi-drug resistant strain, with IC50 values of 3.65 and 3.16 μg/mL, respectively. Compound 1 was inactive against both cancerous (MCF-7, KB) and non-cancerous (Vero) cells, while compound 2 displayed cytotoxicity against Vero cell with IC50 value of 29.57 μg/mL. 相似文献
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Jakapun Soponpong Kulvadee Dolsophon Chawanee Thongpanchang Anthony Linden Tienthong Thongpanchang 《Tetrahedron letters》2019,60(6):497-500
The structure of a constrained bicyclic chiral derivatizing agent (CDA), 1,2,3,4-tetrahydro-1,4-epoxynaphthalene-1-carboxylic acid, THENA 1, was modified by replacing both exo-methylene protons with deuterium atoms. The modified CDA, THENA-d22, could be used to assign the absolute configuration of chiral secondary alcohols with good reliability. Compared with THENA, the multiplicity of the methylene proton signals in the 1H NMR spectra of THENA-d2 derivatives is less complicated and the new CDA thus offers simpler NMR spectra for data interpretation. 相似文献
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Siriporn Saepua Jittra Kornsakulkarn Wiwat Somyong Pattiyaa Laksanacharoen Masahiko Isaka Chawanee Thongpanchang 《Tetrahedron》2018,74(8):859-866
Eleven new compounds, including two quinone derivatives of bioxanthracene, conoideocrellones A (1) and B (2), two bioxanthracenes 3 and 4, four isocoumarins and isocoumarin glycosides 7–10, two phenolic compounds 16 and 17, and a diterpenoid compound, conoideocin A (18), were isolated from culture of the scale-insect pathogenic fungus Conoideocrella tenuis BCC 44534. Seventeen known compounds, compounds 5 and 6, ES-242-2 and its atropisomer, isocoumarins and isocoumarin glycosides 11–15, 3,4,6-trihydroxymellein, cis-4,6-dihydroxymellein, metarhizins A (19) and B (20), BR-050 (21), 5α,8α-epidioxy-24(R)-methylcholesta-6,22-dien-3β-ol, zeorin, and conoideocrellide A, were also isolated from this fungus. Structures of these compounds were elucidated by NMR and MS data analyses. Compound 4 was active against Plasmodium falciparum K1 (IC50 6.6?μg/mL), while it did not show cytotoxicity. Conoideocrellone A (1) and compounds 3 and 7 exhibited cytotoxic activity, while conoideocin A (18) showed broad range of biological activities including antimalarial, antibacterial, and cytotoxic activities. 相似文献
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J Lertvorachon Y Thebtaranonth T Thongpanchang P Thongyoo 《The Journal of organic chemistry》2001,66(13):4692-4694
Stereospecific deprotonation of the epoxy proton at the beta-position of the alpha,beta-epoxy esters 5 and 6 yielded oxiranyl "remote" anions 7 and 8, which could then be used for alkylation. The anions 7 and 8 underwent a consecutive aldol lactonization to give, respectively, epoxy lactones 11 and 13 with high stereoselectivity. Generation of the remote anions as well as their stereoselective reactions served as a new synthetic route to the naturally occurring alpha-methylenebis-gamma-butyrolactones, 1. 相似文献
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Charun Yafa Sirinapha Srithongtim Pranee Phukphatthanachai Araya Thiparuk Nittaya Sudsiri Laddawan Rojanapantip Mayuree Uraroongroj Panawan Kluengklangdon Preeyaporn Jaengkarnkit Kittipong Sirisuthanant Chamoy Thonglue Thanida Pimma Paramee Pengpreecha Tippaya Julwee Fortune Ratirot Zwicker Vorapot Permnamtip Sirinart Laoharojanaphnad Boonlert Suanmamuang Juwadee Shiowatana Weerawan Waiyawat Atitaya Siripinyanond Kunchit Judprasong Benjawan Boonsong Suwaluck Talaluck Chainarong Cherdchu 《Accreditation and quality assurance》2010,15(4):223-231
Reference materials play an important role for evaluating the accuracy of analytical results, and are essential parts of good laboratory practice. They represent a key tool for quality control of chemical analyses. In Thailand, the demand of food and environmental reference materials is constantly increasing, and the National Institute of Metrology (NIMT, Thailand) is responding to the urgent needs for affordable materials, which require collaborative efforts at the national level. This paper describes the preparation of a new glutinous rice reference material, along with homogeneity and stability studies and the analytical work carried out for the certification of the contents of inorganic elements. The incurred material was collected from an actual rice paddy field. Material preparation along with homogeneity and stability testing were carried out at the Environmental Research Training Centre (ERTC). The homogeneity study was designed to have three experimental conditions; (A) 10 bottles of candidate materials being analyzed each with 2 replicates, (B) 20 bottles with 2 replicates, (C) 10 bottles with 7 replicates, in order to study the suitable treatments for homogeneity testing in the reference material production. It was shown that a minimum number of 10 bottles with duplicate analyses are enough to demonstrate the homogeneity of candidate reference material. Certification of a candidate reference material in a single laboratory using reference method was confirmed with an interlaboratory comparison participated by a certain number of well recognized testing laboratories in Thailand. Further elaborative results will be discussed. 相似文献
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Thidarath Rattanaburee Patpanat Sermmai Kornthip Tangthana-umrung Tienthong Thongpanchang Potchanapond Graidist 《Molecules (Basel, Switzerland)》2022,27(23)
This study aimed to investigate the cytotoxicity and anticancer activity of (±)-kusunokinin derivatives ((±)-TTPG-A and (±)-TTPG-B). The cytotoxicity effect was performed on human cancer cells, including breast cancer, cholangiocarcinoma, colon and ovarian cancer-cells, compared with normal cells, using the MTT assay. Cell-cycle arrest and apoptosis were detected using flow-cytometry analysis. We found that (±)-TTPG-B exhibited the strongest cytotoxicity on aggressive breast-cancer (MDA-MB-468 and MDA-MB-231) and cholangiocarcinoma (KKU-M213), with an IC50 value of 0.43 ± 0.01, 1.83 ± 0.04 and 0.01 ± 0.001 µM, respectively. Interestingly, (±)-TTPG-A and (±)-TTPG-B exhibited less toxicity than (±)-kusunokinin (9.75 ± 0.39 µM) on L-929 cells (normal fibroblasts). Moreover, (±)-TTPG-A predominated the ell-cycle arrest at the S phase, while (±)-TTPG-B caused cell arrest at the G0/G1 phase, in the same way as (±)-kusunokinin in KKU-M213 cells. Both (±)-TTPG-A and (±)-TTPG-B induced apoptosis and multi-caspase activity more than (±)-kusunokinin. Taken together, we conclude that (±)-TTPG-A and (±)-TTPG-B have a strong anticancer effect on cholangiocarcinoma. Moreover, (±)-TTPG-B could be a potential candidate compound for breast cancer and cholangiocarcinoma in the future. 相似文献
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Jittra Kornsakulkarn Siriporn Saepua Rapheephat Suvannakad Sumalee Supothina Nattawut Boonyuen Masahiko Isaka Samran Prabpai Palangpon Kongsaeree Chawanee Thongpanchang 《Tetrahedron》2017,73(25):3505-3512
Twelve new compounds, including nine tropolones, nemanolones A?I (1–9), three 7-isochromenones, nemanecins A?C (10–12), and a new naturally isolated 4-isochromanone (13), along with two known compounds, 7,8-dihydroxy-3-methyl isochroman-4-one (XJP), and chaetoquadrin F, were isolated from culture broth of the fungus Nemania sp. BCC 30850. Structures of these compounds were elucidated by NMR and MS spectroscopic analyses. Nemanolones exhibited cytotoxic activities and two of them, compounds 1 and 2, also showed antibacterial activity against Bacillus cereus and antifungal activity against Candida albicans. 相似文献
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Jittra Kornsakulkarn Siriporn SaepuaSomjit Komwijit Pranee RachtaweeChawanee Thongpanchang 《Tetrahedron》2014
Five new compounds, phthalide 1, dihydroisocoumarin 2, and 3, pyrone 4, and benzophenone 5, together with nine known compounds, 3,4-dihydro-4,5,8-trihydroxy-3-methylisocoumarin, sclerotinin A, methyl-8-hydroxy-6-methylxanthone-1-carboxylate, sydowinin A, conioxanthone A, 1,3,8-trihydroxy-6-methylxanthone, 1,8-dihydroxy-3-methoxy-6-methylxanthone, coniochaetone B, and xylaranol B, were isolated from the fungus Astrocystis sp. BCC 22166. Structures of these compounds were elucidated using NMR spectroscopic and MS spectrometric analyses. Compound 1 exhibited antibacterial activity against Bacillus cereus (IC50=12.5 μg/mL) while compound 2 showed cytotoxicity to KB and Vero cells (IC50=22.6 and 48.2 μg/mL). 相似文献
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Suttipun Sungsuwan Samran Prabpai Tienthong Thongpanchang 《Tetrahedron letters》2010,51(38):4965-4967
A new chiral derivatizing agent, tetrahydro-1,4-epoxynaphthalene-1-carboxylic acid (THENA), with a represented syn-periplanar disposition of O-Cα-CO as a part of the bicyclic system to lock the aromatic residue conformation and the availability of an internal reference proton for 1H NMR spectral alignment, is introduced. In the determination of the absolute configuration of chiral secondary alcohols, THENA offered good uniformity of Δδ with high reliability, resulting in unambiguous assignment of the absolute configuration. 相似文献