Time filter

Source Type

Chulabhorn, Thailand

Chulabhorn Research Institute is a biomedical and chemistry research institute in Bangkok, Thailand. Initiated by Princess Chulabhorn in 1987, the institute was established as an independent agency funded by the Thai government.Today, the institute operates 9 laboratories in biochemistry, biotechnology, medicinal chemistry, chemical carcinogenesis, environmental toxicology, immunology, natural products, organic synthesis and pharmacology. Besides research, the institute also offers various trainings as well as master's and doctoral degree programs in Environmental Toxicology, Technology and Management.In addition to the existing units and programs, the Chulabhorn Cancer Center and Chulabhorn Graduate School are scheduled to open in 2007. Wikipedia.

Courant T.,CNRS Natural Product Chemistry Institute | Kumarn S.,Chulabhorn Research Institute | Kumarn S.,Mahidol University | He L.,CNRS Natural Product Chemistry Institute | And 2 more authors.
Advanced Synthesis and Catalysis | Year: 2013

An enantioselective aza-Friedel-Crafts reaction of indoles with γ-hydroxy-γ-lactams using a chiral phosphoric acid catalyst is reported. The approach described herein provides an efficient access to 5-indolylpyrrolidinones in good to quantitative yields and excellent enantioselectivities (up to >99% ee). The results suggest that the reaction may proceed via N-acyliminium intermediates associated with the chiral phosphoric acid anion. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Fearnley S.P.,City University of New York | Thongsornkleeb C.,Chulabhorn Research Institute
Journal of Organic Chemistry | Year: 2010

Intramolecular Diels-Alder cycloaddition of N-substituted oxazolone triene I allows direct entry to the functionalized octahydroquinoline II. Further manipulation of this framework by stereo- and regioselective introduction of the 5-methyl substituent, followed by excision of the carbamate, yields (±)-2-epi-pumiliotoxin C. © 2009 American Chemical Society.

Au W.W.,University of Texas Medical Branch | Giri A.K.,Indian Institute of Chemical Technology | Ruchirawat M.,Chulabhorn Research Institute
International Journal of Hygiene and Environmental Health | Year: 2010

A variety of biomarkers have been used to monitor exposed populations to determine potential health hazards from their exposure to environmental toxic agents. However, the majority of these biomarkers have been focused onto the identification of biological damage from the exposure. Therefore, there is a need to develop functional biomarkers that can identify exposure-induced functional deficiencies. More importantly, these deficiencies should be positioned along pathways that are responsible for the development of specific diseases. One of such pathways belongs to the extensive and complex DNA-repair machinery. The machinery thus becomes a large target for damage from environmental toxic agents. The hypothesis is that damage to any component of a repair pathway will interfere with the pathway-specific repair activities. Therefore, when cells from exposed populations are challenged with a DNA-damaging agent in vitro, the in vivo exposure-induced repair deficiency will be dramatically amplified and the deficiency will be detectable in a challenge assay as increased chromosome aberrations, micronuclei or un-repaired DNA strand breaks. The challenge assay has been used in different laboratories to show that a variety of exposed populations (with exposure to air pollutants, arsenic, benzene, butadiene, cigarette smoke, incense smoke, lead, mercury, pesticides, uranium or xylene but not to low concentrations of air pollutants or butadiene) expressed abnormal challenge response. The predicted health consequences of some of these studies have also been validated. Therefore, the challenge assay is a useful functional biomarker for population studies. Details of the challenge assay and its application will be presented in this review. © 2009 Elsevier GmbH. All rights reserved.

Prapagdee B.,Mahidol University | Chanprasert M.,Mahidol University | Mongkolsuk S.,Mahidol University | Mongkolsuk S.,Chulabhorn Research Institute
Chemosphere | Year: 2013

Micrococcus sp. MU1 and Klebsiella sp. BAM1, the cadmium-resistant plant growth-promoting rhizobacteria (PGPR), produce high levels of indole-3-acetic acid (IAA) during the late stationary phase of their growth. The ability of PGPR to promote root elongation, plant growth and cadmium uptake in sunflowers (Helianthus annuus) was evaluated. Both species of bacteria were able to remove cadmium ions from an aqueous solution and enhanced cadmium mobilization in contaminated soil. Micrococcus sp. and Klebsiella sp. use aminocyclopropane carboxylic acid as a nitrogen source to support their growth, and the minimum inhibitory concentrations of cadmium for Micrococcus sp. and Klebsiella sp. were 1000 and 800. mM, respectively. These bacteria promoted root elongation in H. annuus seedlings in both the absence and presence of cadmium compared to uninoculated seedlings. Inoculation with these bacteria was found to increase the root lengths of H. annuus that had been planted in cadmium-contaminated soil. An increase in dry weight was observed for H. annuus inoculated with Micrococcus sp. Moreover, Micrococcus sp. enhanced the accumulation of cadmium in the root and leaf of H. annuus compared to untreated plants. The highest cadmium accumulation in the whole plant was observed when the plants were treated with EDTA following the treatment with Micrococcus sp. In addition, the highest translocation of cadmium from root to the above-ground tissues of H. annuus was found after treatment with Klebsiella sp. in the fourth week after planting. Our results show that plant growth and cadmium accumulation in H. annuus was significantly enhanced by cadmium-resistant PGPRs, and these bacterial inoculants are excellent promoters of phytoextraction for the rehabilitation of heavy metal-polluted environments. © 2013 Elsevier Ltd.

Sandee D.,University of California at San Francisco | Sandee D.,Chulabhorn Research Institute | Miller W.L.,University of California at San Francisco
Endocrinology | Year: 2011

P450 oxidoreductase (POR) is a two-flavin protein that reduces microsomal P450 enzymes and some otherproteins. Preparation of active bacterially expressed human POR for biochemical studies has been difficult because membrane-bound proteins tend to interact with column matrices. To reduce column-protein interactions and permit more vigorous washing, human POR lacking 27 N-terminal residues (N-27 POR) was modified to carry a C-terminal Gly3His6-tag (N-27 POR-G3H6). When expressed in Escherichia coli, N-27 POR-G3H6 could be purified to apparent homogeneity by a modified, single-step nickel-nitrilotriacetic acid affinity chromatography, yielding 31 mg POR per liter of culture, whereas standard purification of native N-27 POR required multiple steps, yielding 5 mg POR per liter. Both POR proteins had absorption maxima at 375 and 453 nm and both reduced cytochrome c with indistinguishable specific activities. Using progesterone as substrate for bacterially expressed purified human P450c17, the Michaelis constant for 17α-hydroxylase activity supported by N-27 POR or N-27 POR-G3H6 were 1.73 or 1.49 μM, and the maximal velocity was 0.029 or 0.026 pmol steroids per picomole P450 per minute, respectively. Using 17-hydroxypregnenolone as the P450c17 substrate, the Michaelis constant for 17,20 lyase activity using N-27 POR or N-27 POR-G3H6 was 1.92 or 1.89 μM and the maximal velocity was 0.041 or 0.042 pmol steroid per picomole P450 per minute, respectively. Thus, N-27 POR-G3H6 is equally active as native N-27 POR. This expression and purification system permits the rapid preparation of large amounts of highly pure, biologically active POR and may be generally applicable for the preparation of membrane-bound proteins. Copyright © 2011 by The Endocrine Society.

Discover hidden collaborations