Chulabhorn Graduate Institute

Kamphaeng Phet, Thailand

Chulabhorn Graduate Institute

Kamphaeng Phet, Thailand
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Athikomkulchai S.,Srinakharinwirot University | Awale S.,University of Toyama | Ruangrungsi N.,Chulalongkorn University | Ruchirawat S.,Chulabhorn Research Institute | And 2 more authors.
Fitoterapia | Year: 2013

Phytochemical investigation on the constituents of Thai propolis led the isolation of a new phenylallylflavanone, (7″S)-8-[1-(4′-hydroxy- 3′-methoxyphenyl)prop-2-en-1-yl]-(2S)-pinocembrin (1) and (E)-cinnamyl-(E)-cinnamylidenate (2) from methanolic extract of Thai propolis. Their structures were determined on the basis of extensive NMR spectroscopic analysis. In addition to this, 19 compounds (3-21) belonging to flavonoids and phenolic esters were isolated and identified. © 2013 Elsevier B.V.

Pingaew R.,Srinakharinwirot University | Prachayasittikul S.,Srinakharinwirot University | Ruchirawat S.,Chulabhorn Research Institute | Ruchirawat S.,Chulabhorn Graduate Institute
Molecules | Year: 2010

Thiosemicarbazone analogs of papaveraldine and related compounds 1-6 were synthesized and evaluated for cytotoxic and antimalarial activities. The cytotoxic activity was tested against HuCCA-1, HepG2, A549 and MOLT-3 human cancer cell lines. Thiosemicarbazones 1-5 displayed cytotoxicity toward all the tested cell lines, while compounds 2-5 selectively showed potent activity against the MOLT-3 cell lines. Significantly, N(4)-phenyl-2-benzoylpyridine thiosemicarbazone 4 exhibited the most potent activity against HuCCA-1, HepG2, A549 and MOLT-3 cell lines with IC50 values of 0.03, 4.75, 0.04 and 0.004 μg/mL, respectively. In addition, 2-benzoylpyridine thiosemicarbazones 3 and 4 showed antimalarial activity against Plasmodium falciparum with IC 50 of 10-7 to < 10-6 M. The study demonstrates the quite promising activity of analog 4 as a lead molecule for further development. © 2010 by the authors.

Pornmuttakun D.,Mahidol University | Pornmuttakun D.,Queen Saovabha Memorial Institute | Ratanabanangkoon K.,Chulabhorn Research Institute | Ratanabanangkoon K.,Chulabhorn Graduate Institute
Toxicon | Year: 2014

An in vitro potency assay of antivenom against Malayan pit viper (Calloselasma rhodostoma, CR) has been developed. The assay is based on the neutralizing activity of the antivenom against the coagulant activity of the venom. The minimum coagulant dose (MCD) of CR venom was 22.12 ± 0.25 μg/ml. The coagulation time induced by 2MCD of the venom was used as the control for calculating the neutralizing activity of each batch of antivenom. The in vitro potency of antivenom, expressed as effective dose (ED), was the antivenom/venom ratio at which the coagulation time was increased three fold of that induced by 2MCD of the venom. Eleven batches of the antivenom were assayed for their lethality neutralizing activity (ED50) by the in vivo assay using mice as well as the developed in vitro assay. The correlation coefficient (r) between the in vitro neutralizing activities (ED) and in vivo neutralizing activities (ED50) was 0.957, (p value < 0.001). This simple and rapid in vitro assay of C. rhodostoma antivenom should be a good alternative method for the assessment of antivenom potency during the immunization program and fractionation process. The assay should be adaptable for use with antivenoms against other similar procoagulant venoms. © 2013 Elsevier Ltd. All rights reserved.

Tummatorn J.,Chulabhorn Research Institute | Ruchirawat S.,Chulabhorn Research Institute | Ruchirawat S.,Chulabhorn Graduate Institute | Ploypradith P.,Chulabhorn Research Institute | Ploypradith P.,Chulabhorn Graduate Institute
Chemistry - A European Journal | Year: 2010

(Figure Presented) Five and six: 3, 4-Cyclopentyl- and cyclohexyl-fused 2-arylchromans could be readily prepared from the intramolecular hetero-Diels-Alder reactions of the corresponding ortho-quinone methide (o-QM) precursors tethered to the styrenes under mild reaction conditions. The products were obtained with good to excellent diastereoselectivity (up to > 99:1 dr; see scheme; MOM = methoxymethyl). © 2010 Wiley-VCH Verlag GmbH & Co. KGaA.

Chaiyawat P.,Chulabhorn Graduate Institute | Netsirisawan P.,Chulabhorn Graduate Institute | Svasti J.,Chulabhorn Graduate Institute | Svasti J.,Chulabhorn Research Institute | And 2 more authors.
Frontiers in Endocrinology | Year: 2014

Increasing glucose consumption is thought to provide an evolutionary advantage to cancer cells. Alteration of glucose metabolism in cancer influences various important metabolic pathways including the hexosamine biosynthesis pathway (HBP), a relatively minor branch of glycolysis. Uridine diphosphate N-acetylglucosamine (UDP-GlcNAc), an end product of HBP, is a sugar substrate used for classical glycosylation and O-GlcNAcylation, a post-translational protein modification implicated in a wide range of effects on cellular functions. Emerging evidence reveals that certain cellular proteins are abnormally O-GlcNAc modified in many kinds of cancers, indicating O-GlcNAcylation is associated with malignancy. Since O-GlcNAc rapidly on and offmodifies in a similar time scale as in phosphorylation and these modifications may occur on proteins at either on the same or adjacent sites, it suggests that both modifications can work to regulate the cellular signaling pathways. This review describes the metabolic shifts related to the HBP, which are commonly found in most cancers. It also describes O-GlcNAc modified proteins identified in primary breast and colorectal cancer, as well as in the related cancer cell lines. Moreover, we also discuss the potential use of aberrant O-GlcNAcylated proteins as novel biomarkers of cancer. © 2014 Chaiyawat, Netsirisawan, Svasti and Champattanachai.

Robinson L.N.,Harvard-MIT Division of Health Sciences and Technology | Artpradit C.,Chulabhorn Graduate Institute | Raman R.,Harvard-MIT Division of Health Sciences and Technology | Shriver Z.H.,Harvard-MIT Division of Health Sciences and Technology | And 3 more authors.
Electrophoresis | Year: 2012

Glycans, or complex carbohydrates, are a ubiquitous class of biological molecule which impinge on a variety of physiological processes ranging from signal transduction to tissue development and microbial pathogenesis. In comparison to DNA and proteins, glycans present unique challenges to the study of their structure and function owing to their complex and heterogeneous structures and the dominant role played by multivalency in their sequence-specific biological interactions. Arising from these challenges, there is a need to integrate information from multiple complementary methods to decode structure-function relationships. Focusing on acidic glycans, we describe here key glycomics technologies for characterizing their structural attributes, including linkage, modifications, and topology, as well as for elucidating their role in biological processes. Two cases studies, one involving sialylated branched glycans and the other sulfated glycosaminoglycans, are used to highlight how integration of orthogonal information from diverse datasets enables rapid convergence of glycan characterization for development of robust structure-function relationships. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Tummatorn J.,Chulabhorn Research Institute | Thongsornkleeb C.,Chulabhorn Research Institute | Thongsornkleeb C.,Chulabhorn Graduate Institute | Ruchirawat S.,Chulabhorn Research Institute | And 2 more authors.
Organic and Biomolecular Chemistry | Year: 2013

A convenient synthesis of 2,4-unsubstituted quinoline-3-carboxylic acid ethyl esters via a domino process is described. The synthesis employs arylmethyl azides as the precursor which undergoes an acid-promoted rearrangement to give an N-aryl iminium ion. Following the addition with ethyl 3-ethoxyacrylate, intramolecular electrophilic aromatic substitution, elimination and subsequent oxidation, the quinoline products were obtained in moderate to excellent yields. This journal is © 2013 The Royal Society of Chemistry.

Radomkit S.,Chulabhorn Graduate Institute | Sarnpitak P.,Chulabhorn Graduate Institute | Tummatorn J.,Chulabhorn Research Institute | Batsomboon P.,Chulabhorn Research Institute | And 3 more authors.
Tetrahedron | Year: 2011

Novel intermolecular and intramolecular generations of ortho-quinone methides and their formal [4+2]-cycloaddition reactions with olefins catalyzed by PtCl 4 and AuCl 3 under mild conditions have been developed. Good to excellent yields (up to 99%) and diastereoselectivity (up to >99:1) of the chromans were obtained. PtCl 4 was found to be effective and compatible with various functional groups present in the substrates. A mechanism accounting for its catalytic cycle is proposed and discussed. © 2011 Elsevier Ltd. All rights reserved.

Bensulong S.,Chulabhorn Graduate Institute | Boonsombat J.,Chulabhorn Research Institute | Ruchirawat S.,Chulabhorn Research Institute | Ruchirawat S.,Chulabhorn Graduate Institute
Tetrahedron | Year: 2013

The regioselective cyclization/dehydration sequence of ortho diketo phenoxyethers induced by DBU has been explored. The results demonstrated a high degree of selectivity with preference for 6-exo-trig cyclization leading to the formation of γ-benzopyranone derivatives in good yield. © 2013 Elsevier Ltd. All rights reserved.

Ngok-Ngam P.,Chulabhorn Graduate Institute | Watcharasit P.,Chulabhorn Graduate Institute | Watcharasit P.,Chulabhorn Research Institute | Thiantanawat A.,Chulabhorn Graduate Institute | And 3 more authors.
Cellular and Molecular Biology Letters | Year: 2013

Glycogen synthase kinase-3 (GSK3) and p53 play crucial roles in the mitochondrial apoptotic pathway and are known to interact in the nucleus. However, it is not known if GSK3 has a regulatory role in the mitochondrial translocation of p53 that participates in apoptotic signaling following DNA damage. In this study, we demonstrated that lithium and SB216763, which are pharmacological inhibitors of GSK3, attenuated p53 accumulation and caspase-3 activation, as shown by PARP cleavage induced by the DNA-damaging agents doxorubicin, etoposide and camptothecin. Furthermore, each of these agents induced translocation of p53 to the mitochondria and activated the mitochondrial pathway of apoptosis, as evidenced by the release of cytochrome C from the mitochondria. Both mitochondrial translocation of p53 and mitochondrial release of cytochrome C were attenuated by inhibition of GSK3, indicating that GSK3 promotes the DNA damage-induced mitochondrial translocation of p53 and the mitochondrial apoptosis pathway. Interestingly, the regulation of p53 mitochondrial translocation by GSK3 was only evident with wild-type p53, not with mutated p53. GSK3 inhibition also reduced the phosphorylation of wild-type p53 at serine 33, which is induced by doxorubicin, etoposide and camptothecin in the mitochondria. Moreover, inhibition of GSK3 reduced etoposide-induced association of p53 with Bcl2 and Bax oligomerization. These findings show that GSK3 promotes the mitochondrial translocation of p53, enabling its interaction with Bcl2 to allow Bax oligomerization and the subsequent release of cytochrome C. This leads to caspase activation in the mitochondrial pathway of intrinsic apoptotic signaling. © 2012 Versita Warsaw and Springer-Verlag Wien.

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