Polkit Sangvanich | Chulalongkorn University (original) (raw)
Papers by Polkit Sangvanich
Journal of Surfactants and Detergents, 2009
Sodium cardanol sulfonate surfactant was synthesized from cardanol from cashew nut shell liquid. ... more Sodium cardanol sulfonate surfactant was synthesized from cardanol from cashew nut shell liquid. Surfactant properties of cardanol sulfonate were determined and compared with dodecylbenzene sulfonate. Surface tension values were determined to be 32.25 mN/m for cardanol sulfonate at 20% w/v and 28.00 mN/m for dodecylbenzene sulfonate at 15% w/v. Critical micelle concentrations of dodecylbenzene sulfonate and cardanol sulfonate were found to be 0.435 and 0.372 mol/L, respectively. In comparison with dodecylbenzene sulfonate, the relative detergency of cardanol sulfonate was calculated to be 93.7% compared to dodecylbenzene sulfonate. Results suggest that cardanol sulfonate can be used as alternative anionic surfactant.
Biochimica et Biophysica Acta (BBA) - Molecular Basis of Disease, 2015
Cholangiocarcinoma (CCA), a common primary malignant tumor of bile duct epithelia, is highly prev... more Cholangiocarcinoma (CCA), a common primary malignant tumor of bile duct epithelia, is highly prevalent in Asian countries and unresponsive to chemotherapeutic drugs. Thus, a newly recognized biological entity for early diagnosis and treatment is highly needed. Exosomes are small membrane bound vesicles found in body fluids and released by most cell types including cancer cells. The vesicles contain specific subset of proteins and nucleic acids corresponding to cell types and play essential roles in pathophysiological processes. The present study aimed to assess the protein profiles of CCA-derived exosomes and their potential roles. We have isolated exosomes from CCA cells namely KKU-M213 and KKU-100 derived from Thai patients and their roles were investigated by incubation with normal human cholangiocyte (H69) cells. Exosomes were internalized into H69 cells and had no effects on viability or proliferation of the host cells. Interestingly, the exosomes from KKU-M213 cells only induced migration and invasion of H69 cells. Proteomic analysis of the exosomes from KKU-M213 cells disclosed multiple cancer related proteins that are not present in H69 exosomes. Consistent with the protein profile, treatment with KKU-M213 exosomes induced β-catenin and reduced E-cadherin expressions in H69 cells. Collectively, our results suggest that a direct cell-to-cell transfer of oncogenic proteins via exosomal pathway may be a novel mechanism for CCA progression and metastasis.
Cembranoid diterpenes, namely, crotocembraneic acid (1), neocrotocembraneic acid (2), poilaneic a... more Cembranoid diterpenes, namely, crotocembraneic acid (1), neocrotocembraneic acid (2), poilaneic acid , as well as their synthetic derivatives including methyl crotocembraneate (1a), crotocembranol (1b), crotocembranal (1c), methyl neocrotocembraneate (2a), neocrotocembranol (2b), neocrotocembranal (2c), methyl poilaneate (3a), poilaneol (3b) and poilanal (3c), were evaluated for their inhibitory activity against cAMP phosphodiesterase. Cembranoids with carboxylic acid functional groups showed higher inhibitory activity than those with other functionalities in the following order: carboxylic acid, hydroxyl, methyl ester and aldehyde.
Fems Microbiology Letters, 2007
An extracellular beta-glucosidase was purified from culture filtrates of the wood-decaying fungus... more An extracellular beta-glucosidase was purified from culture filtrates of the wood-decaying fungus Daldinia eschscholzii (Ehrenb.:Fr.) Rehm grown on 1.0% (w/v) carboxymethyl-cellulose using ammonium sulfate precipitation, ion-exchange, hydrophobic interaction and gel filtration chromatography. The enzyme is monomeric with a molecular weight of 64.2 kDa as estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and has a pI of 8.55. The enzyme catalyzes the hydrolysis of p-nitrophenyl-beta-D-glucopyranoside (PNPG) as the substrate, with a K(m) of 1.52 mM, and V(max) of 3.21 U min mg(-1) protein. Glucose competitively inhibited beta-glucosidase with a K(i) value of 0.79 mM. Optimal activity with PNPG as the substrate was at pH 5.0 and 50 degrees C. The enzyme was stable at pH 5.0 at temperatures up to 50 degrees C. The purified beta-glucosidase was active against PNPG, cellobiose, sophorose, laminaribiose and gentiobiose, but did not hydrolyze lactose, sucrose, Avicel or o-nitrophenyl-beta-d-galactopyranoside. The activity of beta-glucosidase was stimulated by Ca(2+), Co(2+), Mg(2+), Mn(2+), glycerol, dimethyl sulfoxide (DMSO), dithiothreitol and EDTA, and strongly inhibited by Hg(2+). The internal amino acid sequences of D. eschscholziibeta-glucosidase have similarity to the sequences of the family 3 beta-glucosyl hydrolase.
Journal of Surfactants and Detergents, 2009
Sodium cardanol sulfonate surfactant was synthesized from cardanol from cashew nut shell liquid. ... more Sodium cardanol sulfonate surfactant was synthesized from cardanol from cashew nut shell liquid. Surfactant properties of cardanol sulfonate were determined and compared with dodecylbenzene sulfonate. Surface tension values were determined to be 32.25 mN/m for cardanol sulfonate at 20% w/v and 28.00 mN/m for dodecylbenzene sulfonate at 15% w/v. Critical micelle concentrations of dodecylbenzene sulfonate and cardanol sulfonate were found to be 0.435 and 0.372 mol/L, respectively. In comparison with dodecylbenzene sulfonate, the relative detergency of cardanol sulfonate was calculated to be 93.7% compared to dodecylbenzene sulfonate. Results suggest that cardanol sulfonate can be used as alternative anionic surfactant.
European Journal of Pharmaceutics and Biopharmaceutics, 2014
Mucoadhesive thiolated chitosan suitable as a carrier for low water soluble drugs was designed an... more Mucoadhesive thiolated chitosan suitable as a carrier for low water soluble drugs was designed and synthesized by conjugating 5-amino-2-mercaptobenzimidazole (MBI) using methylacrylate (MA) as the linking agent. A 14.4% degree of substitution of MA, as determined by (1)H NMR analysis, and 11.86±0.01μmol thiol groups/g of polymer, as determined by Ellman's method, was obtained. The MBI-MA-chitosan had an 11-fold stronger mucoadhesive property compared to unmodified chitosan at pH 1.2, as determined by the periodic acid: Schiff colorimetric method. Chitosan, MA-chitosan and MBI-MA-chitosan were fabricated as well-formed microspheres using electrospray ionization, including an entrapment efficiency of simvastatin (SV) of over 80% for the MBI-MA-chitosan. The mucoadhesiveness of the SV-loaded MBI-MA-CS microspheres was still higher than that for SV-loaded chitosan at pH 1.2 and 6.4. The SV-loaded MBI-MA-CS microspheres revealed a reduced burst effect and an increased release rate (more than fivefold higher than pure SV) of SV over 12h.
Proteins involved during storage of Curcuma longa have not been investigated in detail. Proteins ... more Proteins involved during storage of Curcuma longa have not been investigated in detail. Proteins and nucleic acids are considered to be essential for the sprouting period. As numerous applications of proteomic ap- proaches have been reported in many areas of biology, biochemistry and biomedicine, we chose to use proteomic technology to study the protein expression of Curcuma longa (Khaminchun) rhizome during dor- mancy and sprouting. Microscale solution-phase iso- electric focusing (Zoom) was employed to enrich the low abundance proteins in the pH range of 5.4-10 and improve the separation of those proteins in the acidic range from 3-5.4. Samples were drawn at seven-day intervals from harvest until the commencement of sprouting. The proteomic patterns of the storage period (0, 14, 21, 42, and 70 days) were studied and identified by LC/MS/MS in these two pH ranges. High levels of glyceraldehyde-3-phosphate dehydrogenase, a glyco- lytic enzyme, were present and in glycosylated and pho...
Transactions of the Royal Society of Tropical Medicine and Hygiene, 2007
A new dihydroartemisinin (DHA) tablet formulation has been developed by the Thai Government Pharm... more A new dihydroartemisinin (DHA) tablet formulation has been developed by the Thai Government Pharmaceutical Organization (GPO). In this report, its in vitro dissolution and in vivo pharmacokinetics as well as its safety in healthy volunteers were evaluated, using the DHA tablet made by Dafra Pharma NV as a reference. A two-period crossover clinical study design was utilised. Twenty-four volunteers were randomly allocated to two sequences (12 volunteers in each) to receive a 200 mg single oral dose of either the GPO or Dafra formulation with a wash-out period of 5-7 days. In vitro, the GPO formulation dissolved more readily. In vivo, the GPO formulation had a higher maximum plasma concentration and approximately 149% (90% CI 125-179%) greater bioavailability. Both formulations were well tolerated. Interestingly, significant decreases in haemoglobin and haematocrit values (P < 0.001) were noted following administration of one dose of DHA (decrease of 0.73 g/dl haemoglobin and 2.0% haematocrit compared with baseline) or two doses of DHA (decrease of 0.95 g/dl haemoglobin and 3.3% haematocrit compared with baseline). The second dose was associated with additional toxicity compared with one dose with regard to haematocrit (P < 0.001) but not haemoglobin. This finding * Corresponding author.
The Analyst, 1995
ABSTRACT
Tetrahedron Letters, 2005
A series of novel conformationally rigid pyrrolidinyl peptide nucleic acids (PNA) based on D D-pr... more A series of novel conformationally rigid pyrrolidinyl peptide nucleic acids (PNA) based on D D-prolyl-2-aminocyclopentanecarboxylic acid (ACPC) backbones has been synthesized. Investigation of the binding properties of four stereoisomeric PNAs possessing different stereochemistry at the ACPC part with DNA revealed that a precise stereochemistry of the backbone is very important in determining the binding properties. Only the PNA containing (1S,2S)-ACPC can form a very stable 1:1 complex with the complementary DNA in a sequence-specific manner.
Sensors and Actuators B: Chemical, 2010
An immunosensor based on a quartz crystal microbalance (QCM) was developed for detection of Vibri... more An immunosensor based on a quartz crystal microbalance (QCM) was developed for detection of Vibrio harveyi (V. harveyi), a pathogenic bacteria causing morbidity and even a high level of fatality in commercial shrimp cultures, including Penaeus monodon. Immobilization of a monoclonal antibody (MAb) against V. harveyi onto the gold electrode of a QCM plate involved a three-step procedure: (1) the formation of a selfassembled monolayer (SAM) of a carboxyl-terminated alkanethiol, (2) activation of the carboxyl groups by N-hydroxysuccinimide (NHS) and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC), and (3) attachment of the MAb to the activated carboxyl groups. The developed QCM-based immunosensor could be used for the detection of V. harveyi in a working range of 10 3 -10 7 CFU/mL, with no detectable crossreactivity to Vibrio vulnificus and Vibrio parahaemolyticus. Controlling the density of surface-immobilized MAb, by the formation of mixed SAMs containing hydroxyl-terminated alkanethiol in combination with the treatment of 1% (w/v) bovine serum albumin (BSA) as a blocking reagent, can significantly improve the binding efficiency of the targeted bacteria.
PROTEOMICS, 2001
Identification of proteins from the mass spectra of peptide fragments generated by proteolytic cl... more Identification of proteins from the mass spectra of peptide fragments generated by proteolytic cleavage using database searching has become one of the most powerful techniques in proteome science, capable of rapid and efficient protein identification. Using computer simulation, we have studied how the application of chemical derivatisation techniques may improve the efficiency of protein identification from mass spectrometric data. These approaches enhance ion yield and lead to the promotion of specific ions and fragments, yielding additional database search information. The impact of three alternative techniques has been assessed by searching representative proteome databases for both single proteins and simple protein mixtures. For example, by reliably promoting fragmentation of singly-charged peptide ions at aspartic acid residues after homoarginine derivatisation, 82% of yeast proteins can be unambiguously identified from a single typical peptide-mass datum, with a measured mass accuracy of 50 ppm, by using the associated secondary ion data. The extra search information also provides a means to confidently identify proteins in protein mixtures where only limited data are available. Furthermore, the inclusion of limited sequence information for the peptides can compensate and exceed the search efficiency available via high accuracy searches of around 5 ppm, suggesting that this is a potentially useful approach for simple protein mixtures routinely obtained from two-dimensional gels.
Proteome Science, 2011
Background: The similarly in plant physiology and the difficulty of plant classification, in some... more Background: The similarly in plant physiology and the difficulty of plant classification, in some medicinal plant species, especially plants of the Zingiberaceae family, are a major problem for pharmacologists, leading to mistaken use. To overcome this problem, the proteomic base method was used to study protein profiles of the plant model, Curcuma comosa Roxb., which is a member of the Zingiberaceae and has been used in traditional Thai medicine as an anti-inflammatory agent for the treatment of postpartum uterine bleeding. Results: Due to the complexity of protein extraction from this plant, microscale solution-phase isoelectric focusing (MicroSol-IEF) was used to enrich and improve the separation of Curcuma comosa rhizomes phenol-soluble proteins, prior to resolving and analyzing by two-dimensional polyacrylamide gel electrophoresis and identification by tandem mass spectrometry. The protein patterns showed a high abundance of protein spots in the acidic range, including three lectin proteins. The metabolic and defense enzymes, such as superoxide dismutase (SOD) and ascorbate peroxidase, that are associated with antioxidant activity, were mainly found in the basic region. Furthermore, cysteine protease was found in this plant, as had been previously reported in other Zingiberaceae plants.
Preparative Biochemistry and Biotechnology, 2011
The objective of this study was to investigate the presence of antiproliferative activities again... more The objective of this study was to investigate the presence of antiproliferative activities against fungi, bacteria and human malignant cell lines in the cysteine protease obtained from Zingiber ottensii Valeton rhizomes. Rhizomes were extracted with 20 mM Tris-HCl pH 7.2 followed by 80% saturation (NH4)2SO4 salting out, dialysis and SPsepharose ion-exchange chromatography with four stepwise increments of NaCl (0-1.0 M) as the competing ionic eluting buffer. Protein purity was confirmed by non-denaturing and reducing SDS-PAGE. The cysteine protease, enriched to apparent homogeneity and initially designated F50, was assayed for antiproliferative activity against three plant pathogenic fungi species by the disc diffusion test, against four bacterial species by direct exposure in liquid culture and a dish diffusion test, and against five human malignant cell lines in tissue culture. A dose of 23.6 g F50/0.3 cm 2 disc showed the best inhibitory activity against Collectotrichum cassiicola and to a lesser extant against Exserohilum turicicum and Fusarium oxysporum, respectively. No inhibition of bacterial proliferation was detected in all studied bacterial strains. However, relatively strong anti-proliferative activities were found against the five human cell lines with IC50 values ranging from 1.13 g/ml (hepatoma cancer; HEP-G2) to 5.37 g/ml (colon cancer; SW620). Amino acid sequence analysis of tryptic peptides, obtained by GC tandem MS, suggested the likely identity of F50 as a homolog of Zingipain-1, a cysteine protease first discovered in Zingiber officinale, and supported by the presence of cysteine protease activity in F50. F50 is a glycoprotein, containing 26.301.01% (by weight) of carbohydrate and is potentially a heterotrimer or heterodimer composed of either two small (~13.8 and ~15.2 kDa) subunits, or these two plus a lager (~32.5 kDa) subunit.
Preparative Biochemistry and Biotechnology, 2013
Nitric oxide (NO) plays a key role in the pathogenesis of inflammation and has been implicated in... more Nitric oxide (NO) plays a key role in the pathogenesis of inflammation and has been implicated in endotoxin-induced tissue injury. Zingiberaceae is a family of indigenous plants of tropical regions, many of which have traditionally been used as anti-inflammatory agents. Here, the ability of crude protein extracts from the rhizomes of 15 Zingiberaceae species to inhibit NO production in the RAW 264.7 cell line after co-stimulation with lipopolysaccharide (LPS) and interferon-gamma (IFN-γ) was evaluated. The crude protein extract of Zingiber ottensii Valeton exhibited the highest inhibitory activity, with an IC(50) value of 38.6 ± 0.34 µg protein/mL, and also suppressed the LPS- and rm-interferon (IFN)-γ-mediated increase in the inducible nitric oxide synthase (iNOS), interleukin (IL)-6, and tumor necrosis factor (TNF)-α mRNA transcript expression levels, suggesting the interference was mediated at the transcriptional level. This strong anti-inflammatory activity may have the potential to be developed as a therapeutic compound. Analytical sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and mass spectrometry revealed four main protein bands, including a likely lectin, superoxide dismutase, and cysteine protease, in the fractions related to the antioxidant activity.
Polymer Degradation and Stability, 2003
This article describes a study on zinc hydroxystannate (ZHS) and zinc stannate (ZS) in combinatio... more This article describes a study on zinc hydroxystannate (ZHS) and zinc stannate (ZS) in combination with 1,2-bis(tribromophenoxy)ethane (BTBPE) for increasing flame retardancy and reduced smoke emission in an acrylonitrile-butadiene-styrene (ABS) copolymer. The combination between BTBPE, synergist and chlorinated polyethylene (CPE) yield a high value of LOI which for some proportions is higher than for commercial ABS. #
Planta Medica, 2002
A new furoclerodane, croblongifolin, together with one known clerodane, crovatin and one known la... more A new furoclerodane, croblongifolin, together with one known clerodane, crovatin and one known labdane, nidorellol, were isolated from the stem bark of Croton oblongifolius. Structures were established based on spectroscopic and X-ray analysis. Croblongifolin showed a significant cytotoxicity against various human tumor cell lines including HEP-G2, SW620, CHAGO, KATO3 and BT474.
Planta Medica, 2004
Three new halimane-type diterpenoids, crotohalimaneic acid ( 1), crotohalimoneic acid ( 2) and 12... more Three new halimane-type diterpenoids, crotohalimaneic acid ( 1), crotohalimoneic acid ( 2) and 12-benzoyloxycrotohalimaneic acid ( 3), were isolated from the stem bark of Croton oblongifolius Roxb. Their structures were established on the basis of spectroscopic and X-ray analysis. Compounds 1 and 2 showed non-specific strong cytotoxicity against a panel of human tumor cell lines; whereas 3 was inactive.
Petroleum Chemistry, 2009
Dinitrate compounds was prepared from alkane diols; 1,6-hexane diol, 1,8-octane diol, 1,10-decane... more Dinitrate compounds was prepared from alkane diols; 1,6-hexane diol, 1,8-octane diol, 1,10-decane diol, and 2-methyl-2,4-pentane diol using nitration reaction. These dinitrate compounds were used as cetane improver for diesel fuel. Results showed that the cetane number values has increased about 1 and 3 units for 0.05 and 0.10% by weight of dinitrate compounds, respectively, compared with base oil. Their efficiency is higher than commercial cetane improver, 2-ethylhexyl nitrate.
Odontology, 2013
Aloe vera is a traditional wound healing medicine. We hypothesized acemannan, a polysaccharide ex... more Aloe vera is a traditional wound healing medicine. We hypothesized acemannan, a polysaccharide extracted from Aloe vera gel, could affect bone formation. Primary rat bone marrow stromal cells (BMSCs) were treated with various concentrations of acemannan. New DNA synthesis, VEGF, BMP-2, alkaline phosphatase activity, bone sialoprotein, osteopontin expression, and mineralization were determined by [(3)H] thymidine incorporation assay, ELISA, biochemical assay, western blotting, and Alizarin Red staining, respectively. In an animal study, mandibular right incisors of male Sprague-Dawley rats were extracted and an acemannan treated sponge was placed in the socket. After 1, 2, and 4 weeks, the mandibles were dissected. Bone formation was evaluated by dual-energy X-ray absorptiometry and histopathological examination. The in vitro results revealed acemannan significantly increased BMSC proliferation, VEGF, BMP-2, alkaline phosphatase activity, bone sialoprotein and osteopontin expression, and mineralization. In-vivo results showed acemannan-treated groups had higher bone mineral density and faster bone healing compared with untreated controls. A substantial ingrowth of bone trabeculae was observed in acemannan-treated groups. These data suggest acemannan could function as a bioactive molecule inducing bone formation by stimulating BMSCs proliferation, differentiation into osteoblasts, and extracellular matrix synthesis. Acemannan could be a candidate natural biomaterial for bone regeneration.
Journal of Surfactants and Detergents, 2009
Sodium cardanol sulfonate surfactant was synthesized from cardanol from cashew nut shell liquid. ... more Sodium cardanol sulfonate surfactant was synthesized from cardanol from cashew nut shell liquid. Surfactant properties of cardanol sulfonate were determined and compared with dodecylbenzene sulfonate. Surface tension values were determined to be 32.25 mN/m for cardanol sulfonate at 20% w/v and 28.00 mN/m for dodecylbenzene sulfonate at 15% w/v. Critical micelle concentrations of dodecylbenzene sulfonate and cardanol sulfonate were found to be 0.435 and 0.372 mol/L, respectively. In comparison with dodecylbenzene sulfonate, the relative detergency of cardanol sulfonate was calculated to be 93.7% compared to dodecylbenzene sulfonate. Results suggest that cardanol sulfonate can be used as alternative anionic surfactant.
Biochimica et Biophysica Acta (BBA) - Molecular Basis of Disease, 2015
Cholangiocarcinoma (CCA), a common primary malignant tumor of bile duct epithelia, is highly prev... more Cholangiocarcinoma (CCA), a common primary malignant tumor of bile duct epithelia, is highly prevalent in Asian countries and unresponsive to chemotherapeutic drugs. Thus, a newly recognized biological entity for early diagnosis and treatment is highly needed. Exosomes are small membrane bound vesicles found in body fluids and released by most cell types including cancer cells. The vesicles contain specific subset of proteins and nucleic acids corresponding to cell types and play essential roles in pathophysiological processes. The present study aimed to assess the protein profiles of CCA-derived exosomes and their potential roles. We have isolated exosomes from CCA cells namely KKU-M213 and KKU-100 derived from Thai patients and their roles were investigated by incubation with normal human cholangiocyte (H69) cells. Exosomes were internalized into H69 cells and had no effects on viability or proliferation of the host cells. Interestingly, the exosomes from KKU-M213 cells only induced migration and invasion of H69 cells. Proteomic analysis of the exosomes from KKU-M213 cells disclosed multiple cancer related proteins that are not present in H69 exosomes. Consistent with the protein profile, treatment with KKU-M213 exosomes induced β-catenin and reduced E-cadherin expressions in H69 cells. Collectively, our results suggest that a direct cell-to-cell transfer of oncogenic proteins via exosomal pathway may be a novel mechanism for CCA progression and metastasis.
Cembranoid diterpenes, namely, crotocembraneic acid (1), neocrotocembraneic acid (2), poilaneic a... more Cembranoid diterpenes, namely, crotocembraneic acid (1), neocrotocembraneic acid (2), poilaneic acid , as well as their synthetic derivatives including methyl crotocembraneate (1a), crotocembranol (1b), crotocembranal (1c), methyl neocrotocembraneate (2a), neocrotocembranol (2b), neocrotocembranal (2c), methyl poilaneate (3a), poilaneol (3b) and poilanal (3c), were evaluated for their inhibitory activity against cAMP phosphodiesterase. Cembranoids with carboxylic acid functional groups showed higher inhibitory activity than those with other functionalities in the following order: carboxylic acid, hydroxyl, methyl ester and aldehyde.
Fems Microbiology Letters, 2007
An extracellular beta-glucosidase was purified from culture filtrates of the wood-decaying fungus... more An extracellular beta-glucosidase was purified from culture filtrates of the wood-decaying fungus Daldinia eschscholzii (Ehrenb.:Fr.) Rehm grown on 1.0% (w/v) carboxymethyl-cellulose using ammonium sulfate precipitation, ion-exchange, hydrophobic interaction and gel filtration chromatography. The enzyme is monomeric with a molecular weight of 64.2 kDa as estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and has a pI of 8.55. The enzyme catalyzes the hydrolysis of p-nitrophenyl-beta-D-glucopyranoside (PNPG) as the substrate, with a K(m) of 1.52 mM, and V(max) of 3.21 U min mg(-1) protein. Glucose competitively inhibited beta-glucosidase with a K(i) value of 0.79 mM. Optimal activity with PNPG as the substrate was at pH 5.0 and 50 degrees C. The enzyme was stable at pH 5.0 at temperatures up to 50 degrees C. The purified beta-glucosidase was active against PNPG, cellobiose, sophorose, laminaribiose and gentiobiose, but did not hydrolyze lactose, sucrose, Avicel or o-nitrophenyl-beta-d-galactopyranoside. The activity of beta-glucosidase was stimulated by Ca(2+), Co(2+), Mg(2+), Mn(2+), glycerol, dimethyl sulfoxide (DMSO), dithiothreitol and EDTA, and strongly inhibited by Hg(2+). The internal amino acid sequences of D. eschscholziibeta-glucosidase have similarity to the sequences of the family 3 beta-glucosyl hydrolase.
Journal of Surfactants and Detergents, 2009
Sodium cardanol sulfonate surfactant was synthesized from cardanol from cashew nut shell liquid. ... more Sodium cardanol sulfonate surfactant was synthesized from cardanol from cashew nut shell liquid. Surfactant properties of cardanol sulfonate were determined and compared with dodecylbenzene sulfonate. Surface tension values were determined to be 32.25 mN/m for cardanol sulfonate at 20% w/v and 28.00 mN/m for dodecylbenzene sulfonate at 15% w/v. Critical micelle concentrations of dodecylbenzene sulfonate and cardanol sulfonate were found to be 0.435 and 0.372 mol/L, respectively. In comparison with dodecylbenzene sulfonate, the relative detergency of cardanol sulfonate was calculated to be 93.7% compared to dodecylbenzene sulfonate. Results suggest that cardanol sulfonate can be used as alternative anionic surfactant.
European Journal of Pharmaceutics and Biopharmaceutics, 2014
Mucoadhesive thiolated chitosan suitable as a carrier for low water soluble drugs was designed an... more Mucoadhesive thiolated chitosan suitable as a carrier for low water soluble drugs was designed and synthesized by conjugating 5-amino-2-mercaptobenzimidazole (MBI) using methylacrylate (MA) as the linking agent. A 14.4% degree of substitution of MA, as determined by (1)H NMR analysis, and 11.86±0.01μmol thiol groups/g of polymer, as determined by Ellman&amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s method, was obtained. The MBI-MA-chitosan had an 11-fold stronger mucoadhesive property compared to unmodified chitosan at pH 1.2, as determined by the periodic acid: Schiff colorimetric method. Chitosan, MA-chitosan and MBI-MA-chitosan were fabricated as well-formed microspheres using electrospray ionization, including an entrapment efficiency of simvastatin (SV) of over 80% for the MBI-MA-chitosan. The mucoadhesiveness of the SV-loaded MBI-MA-CS microspheres was still higher than that for SV-loaded chitosan at pH 1.2 and 6.4. The SV-loaded MBI-MA-CS microspheres revealed a reduced burst effect and an increased release rate (more than fivefold higher than pure SV) of SV over 12h.
Proteins involved during storage of Curcuma longa have not been investigated in detail. Proteins ... more Proteins involved during storage of Curcuma longa have not been investigated in detail. Proteins and nucleic acids are considered to be essential for the sprouting period. As numerous applications of proteomic ap- proaches have been reported in many areas of biology, biochemistry and biomedicine, we chose to use proteomic technology to study the protein expression of Curcuma longa (Khaminchun) rhizome during dor- mancy and sprouting. Microscale solution-phase iso- electric focusing (Zoom) was employed to enrich the low abundance proteins in the pH range of 5.4-10 and improve the separation of those proteins in the acidic range from 3-5.4. Samples were drawn at seven-day intervals from harvest until the commencement of sprouting. The proteomic patterns of the storage period (0, 14, 21, 42, and 70 days) were studied and identified by LC/MS/MS in these two pH ranges. High levels of glyceraldehyde-3-phosphate dehydrogenase, a glyco- lytic enzyme, were present and in glycosylated and pho...
Transactions of the Royal Society of Tropical Medicine and Hygiene, 2007
A new dihydroartemisinin (DHA) tablet formulation has been developed by the Thai Government Pharm... more A new dihydroartemisinin (DHA) tablet formulation has been developed by the Thai Government Pharmaceutical Organization (GPO). In this report, its in vitro dissolution and in vivo pharmacokinetics as well as its safety in healthy volunteers were evaluated, using the DHA tablet made by Dafra Pharma NV as a reference. A two-period crossover clinical study design was utilised. Twenty-four volunteers were randomly allocated to two sequences (12 volunteers in each) to receive a 200 mg single oral dose of either the GPO or Dafra formulation with a wash-out period of 5-7 days. In vitro, the GPO formulation dissolved more readily. In vivo, the GPO formulation had a higher maximum plasma concentration and approximately 149% (90% CI 125-179%) greater bioavailability. Both formulations were well tolerated. Interestingly, significant decreases in haemoglobin and haematocrit values (P < 0.001) were noted following administration of one dose of DHA (decrease of 0.73 g/dl haemoglobin and 2.0% haematocrit compared with baseline) or two doses of DHA (decrease of 0.95 g/dl haemoglobin and 3.3% haematocrit compared with baseline). The second dose was associated with additional toxicity compared with one dose with regard to haematocrit (P < 0.001) but not haemoglobin. This finding * Corresponding author.
The Analyst, 1995
ABSTRACT
Tetrahedron Letters, 2005
A series of novel conformationally rigid pyrrolidinyl peptide nucleic acids (PNA) based on D D-pr... more A series of novel conformationally rigid pyrrolidinyl peptide nucleic acids (PNA) based on D D-prolyl-2-aminocyclopentanecarboxylic acid (ACPC) backbones has been synthesized. Investigation of the binding properties of four stereoisomeric PNAs possessing different stereochemistry at the ACPC part with DNA revealed that a precise stereochemistry of the backbone is very important in determining the binding properties. Only the PNA containing (1S,2S)-ACPC can form a very stable 1:1 complex with the complementary DNA in a sequence-specific manner.
Sensors and Actuators B: Chemical, 2010
An immunosensor based on a quartz crystal microbalance (QCM) was developed for detection of Vibri... more An immunosensor based on a quartz crystal microbalance (QCM) was developed for detection of Vibrio harveyi (V. harveyi), a pathogenic bacteria causing morbidity and even a high level of fatality in commercial shrimp cultures, including Penaeus monodon. Immobilization of a monoclonal antibody (MAb) against V. harveyi onto the gold electrode of a QCM plate involved a three-step procedure: (1) the formation of a selfassembled monolayer (SAM) of a carboxyl-terminated alkanethiol, (2) activation of the carboxyl groups by N-hydroxysuccinimide (NHS) and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC), and (3) attachment of the MAb to the activated carboxyl groups. The developed QCM-based immunosensor could be used for the detection of V. harveyi in a working range of 10 3 -10 7 CFU/mL, with no detectable crossreactivity to Vibrio vulnificus and Vibrio parahaemolyticus. Controlling the density of surface-immobilized MAb, by the formation of mixed SAMs containing hydroxyl-terminated alkanethiol in combination with the treatment of 1% (w/v) bovine serum albumin (BSA) as a blocking reagent, can significantly improve the binding efficiency of the targeted bacteria.
PROTEOMICS, 2001
Identification of proteins from the mass spectra of peptide fragments generated by proteolytic cl... more Identification of proteins from the mass spectra of peptide fragments generated by proteolytic cleavage using database searching has become one of the most powerful techniques in proteome science, capable of rapid and efficient protein identification. Using computer simulation, we have studied how the application of chemical derivatisation techniques may improve the efficiency of protein identification from mass spectrometric data. These approaches enhance ion yield and lead to the promotion of specific ions and fragments, yielding additional database search information. The impact of three alternative techniques has been assessed by searching representative proteome databases for both single proteins and simple protein mixtures. For example, by reliably promoting fragmentation of singly-charged peptide ions at aspartic acid residues after homoarginine derivatisation, 82% of yeast proteins can be unambiguously identified from a single typical peptide-mass datum, with a measured mass accuracy of 50 ppm, by using the associated secondary ion data. The extra search information also provides a means to confidently identify proteins in protein mixtures where only limited data are available. Furthermore, the inclusion of limited sequence information for the peptides can compensate and exceed the search efficiency available via high accuracy searches of around 5 ppm, suggesting that this is a potentially useful approach for simple protein mixtures routinely obtained from two-dimensional gels.
Proteome Science, 2011
Background: The similarly in plant physiology and the difficulty of plant classification, in some... more Background: The similarly in plant physiology and the difficulty of plant classification, in some medicinal plant species, especially plants of the Zingiberaceae family, are a major problem for pharmacologists, leading to mistaken use. To overcome this problem, the proteomic base method was used to study protein profiles of the plant model, Curcuma comosa Roxb., which is a member of the Zingiberaceae and has been used in traditional Thai medicine as an anti-inflammatory agent for the treatment of postpartum uterine bleeding. Results: Due to the complexity of protein extraction from this plant, microscale solution-phase isoelectric focusing (MicroSol-IEF) was used to enrich and improve the separation of Curcuma comosa rhizomes phenol-soluble proteins, prior to resolving and analyzing by two-dimensional polyacrylamide gel electrophoresis and identification by tandem mass spectrometry. The protein patterns showed a high abundance of protein spots in the acidic range, including three lectin proteins. The metabolic and defense enzymes, such as superoxide dismutase (SOD) and ascorbate peroxidase, that are associated with antioxidant activity, were mainly found in the basic region. Furthermore, cysteine protease was found in this plant, as had been previously reported in other Zingiberaceae plants.
Preparative Biochemistry and Biotechnology, 2011
The objective of this study was to investigate the presence of antiproliferative activities again... more The objective of this study was to investigate the presence of antiproliferative activities against fungi, bacteria and human malignant cell lines in the cysteine protease obtained from Zingiber ottensii Valeton rhizomes. Rhizomes were extracted with 20 mM Tris-HCl pH 7.2 followed by 80% saturation (NH4)2SO4 salting out, dialysis and SPsepharose ion-exchange chromatography with four stepwise increments of NaCl (0-1.0 M) as the competing ionic eluting buffer. Protein purity was confirmed by non-denaturing and reducing SDS-PAGE. The cysteine protease, enriched to apparent homogeneity and initially designated F50, was assayed for antiproliferative activity against three plant pathogenic fungi species by the disc diffusion test, against four bacterial species by direct exposure in liquid culture and a dish diffusion test, and against five human malignant cell lines in tissue culture. A dose of 23.6 g F50/0.3 cm 2 disc showed the best inhibitory activity against Collectotrichum cassiicola and to a lesser extant against Exserohilum turicicum and Fusarium oxysporum, respectively. No inhibition of bacterial proliferation was detected in all studied bacterial strains. However, relatively strong anti-proliferative activities were found against the five human cell lines with IC50 values ranging from 1.13 g/ml (hepatoma cancer; HEP-G2) to 5.37 g/ml (colon cancer; SW620). Amino acid sequence analysis of tryptic peptides, obtained by GC tandem MS, suggested the likely identity of F50 as a homolog of Zingipain-1, a cysteine protease first discovered in Zingiber officinale, and supported by the presence of cysteine protease activity in F50. F50 is a glycoprotein, containing 26.301.01% (by weight) of carbohydrate and is potentially a heterotrimer or heterodimer composed of either two small (~13.8 and ~15.2 kDa) subunits, or these two plus a lager (~32.5 kDa) subunit.
Preparative Biochemistry and Biotechnology, 2013
Nitric oxide (NO) plays a key role in the pathogenesis of inflammation and has been implicated in... more Nitric oxide (NO) plays a key role in the pathogenesis of inflammation and has been implicated in endotoxin-induced tissue injury. Zingiberaceae is a family of indigenous plants of tropical regions, many of which have traditionally been used as anti-inflammatory agents. Here, the ability of crude protein extracts from the rhizomes of 15 Zingiberaceae species to inhibit NO production in the RAW 264.7 cell line after co-stimulation with lipopolysaccharide (LPS) and interferon-gamma (IFN-γ) was evaluated. The crude protein extract of Zingiber ottensii Valeton exhibited the highest inhibitory activity, with an IC(50) value of 38.6 ± 0.34 µg protein/mL, and also suppressed the LPS- and rm-interferon (IFN)-γ-mediated increase in the inducible nitric oxide synthase (iNOS), interleukin (IL)-6, and tumor necrosis factor (TNF)-α mRNA transcript expression levels, suggesting the interference was mediated at the transcriptional level. This strong anti-inflammatory activity may have the potential to be developed as a therapeutic compound. Analytical sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and mass spectrometry revealed four main protein bands, including a likely lectin, superoxide dismutase, and cysteine protease, in the fractions related to the antioxidant activity.
Polymer Degradation and Stability, 2003
This article describes a study on zinc hydroxystannate (ZHS) and zinc stannate (ZS) in combinatio... more This article describes a study on zinc hydroxystannate (ZHS) and zinc stannate (ZS) in combination with 1,2-bis(tribromophenoxy)ethane (BTBPE) for increasing flame retardancy and reduced smoke emission in an acrylonitrile-butadiene-styrene (ABS) copolymer. The combination between BTBPE, synergist and chlorinated polyethylene (CPE) yield a high value of LOI which for some proportions is higher than for commercial ABS. #
Planta Medica, 2002
A new furoclerodane, croblongifolin, together with one known clerodane, crovatin and one known la... more A new furoclerodane, croblongifolin, together with one known clerodane, crovatin and one known labdane, nidorellol, were isolated from the stem bark of Croton oblongifolius. Structures were established based on spectroscopic and X-ray analysis. Croblongifolin showed a significant cytotoxicity against various human tumor cell lines including HEP-G2, SW620, CHAGO, KATO3 and BT474.
Planta Medica, 2004
Three new halimane-type diterpenoids, crotohalimaneic acid ( 1), crotohalimoneic acid ( 2) and 12... more Three new halimane-type diterpenoids, crotohalimaneic acid ( 1), crotohalimoneic acid ( 2) and 12-benzoyloxycrotohalimaneic acid ( 3), were isolated from the stem bark of Croton oblongifolius Roxb. Their structures were established on the basis of spectroscopic and X-ray analysis. Compounds 1 and 2 showed non-specific strong cytotoxicity against a panel of human tumor cell lines; whereas 3 was inactive.
Petroleum Chemistry, 2009
Dinitrate compounds was prepared from alkane diols; 1,6-hexane diol, 1,8-octane diol, 1,10-decane... more Dinitrate compounds was prepared from alkane diols; 1,6-hexane diol, 1,8-octane diol, 1,10-decane diol, and 2-methyl-2,4-pentane diol using nitration reaction. These dinitrate compounds were used as cetane improver for diesel fuel. Results showed that the cetane number values has increased about 1 and 3 units for 0.05 and 0.10% by weight of dinitrate compounds, respectively, compared with base oil. Their efficiency is higher than commercial cetane improver, 2-ethylhexyl nitrate.
Odontology, 2013
Aloe vera is a traditional wound healing medicine. We hypothesized acemannan, a polysaccharide ex... more Aloe vera is a traditional wound healing medicine. We hypothesized acemannan, a polysaccharide extracted from Aloe vera gel, could affect bone formation. Primary rat bone marrow stromal cells (BMSCs) were treated with various concentrations of acemannan. New DNA synthesis, VEGF, BMP-2, alkaline phosphatase activity, bone sialoprotein, osteopontin expression, and mineralization were determined by [(3)H] thymidine incorporation assay, ELISA, biochemical assay, western blotting, and Alizarin Red staining, respectively. In an animal study, mandibular right incisors of male Sprague-Dawley rats were extracted and an acemannan treated sponge was placed in the socket. After 1, 2, and 4 weeks, the mandibles were dissected. Bone formation was evaluated by dual-energy X-ray absorptiometry and histopathological examination. The in vitro results revealed acemannan significantly increased BMSC proliferation, VEGF, BMP-2, alkaline phosphatase activity, bone sialoprotein and osteopontin expression, and mineralization. In-vivo results showed acemannan-treated groups had higher bone mineral density and faster bone healing compared with untreated controls. A substantial ingrowth of bone trabeculae was observed in acemannan-treated groups. These data suggest acemannan could function as a bioactive molecule inducing bone formation by stimulating BMSCs proliferation, differentiation into osteoblasts, and extracellular matrix synthesis. Acemannan could be a candidate natural biomaterial for bone regeneration.