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Fulltext Pentocin MQ1: A Novel, Broad-Spectrum, Pore-Forming Bacteriocin From Lactobacillus pentosus CS2 With Quorum Sensing Regulatory Mechanism and Biopreservative Potential

Wayah SB, Philip K

Front Microbiol, 2018;9:564.
PMID: 29636737 DOI: 10.3389/fmicb.2018.00564

Micrococcus luteus, Listeria monocytogenes, and Bacillus cereus are major food-borne pathogenic and spoilage bacteria. Emergence of antibiotic resistance and consumer demand for foods containing less of chemical preservatives led to a search for natural antimicrobials. A study aimed at characterizing, investigating the mechanism of action and regulation of biosynthesis and evaluating the biopreservative potential of pentocin from Lactobacillus pentosus CS2 was conducted. Pentocin MQ1 is a novel bacteriocin isolated from L. pentosus CS2 of coconut shake origin. The purification strategy involved adsorption-desorption of bacteriocin followed by RP-HPLC. It has a molecular weight of 2110.672 Da as determined by MALDI-TOF mass spectrometry and a molar extinction value of 298.82 M-1 cm-1. Pentocin MQ1 is not plasmid-borne and its biosynthesis is regulated by a quorum sensing mechanism. It has a broad spectrum of antibacterial activity, exhibited high chemical, thermal and pH stability but proved sensitive to proteolytic enzymes. It is potent against M. luteus, B. cereus, and L. monocytogenes at micromolar concentrations. It is quick-acting and exhibited a bactericidal mode of action against its targets. Target killing was mediated by pore formation. We report for the first time membrane permeabilization as a mechanism of action of the pentocin from the study against Gram-positive bacteria. Pentocin MQ1 is a cell wall-associated bacteriocin. Application of pentocin MQ1 improved the microbiological quality and extended the shelf life of fresh banana. This is the first report on the biopreservation of banana using bacteriocin. These findings place pentocin MQ1 as a potential biopreservative for further evaluation in food and medical applications.

Matched MeSH terms: Chromatography, High Pressure Liquid
Fulltext Occurrence of Aflatoxins in Edible Vegetable Seeds and Oil Samples Available in Pakistani Retail Markets and Estimation of Dietary Intake in Consumers

Waqas M, Iqbal SZ, Abdull Razis AF, Pervaiz W, Ahmad T, Usman S, et al.

Int J Environ Res Public Health, 2021 07 29;18(15).
PMID: 34360308 DOI: 10.3390/ijerph18158015

Aflatoxins (AFs) are secondary metabolites toxic to humans as well as animals. The environmental conditions, conventional agricultural practices, and illiteracy are the main factors which favor the production of AFs in food and feed. In the current study 744 samples of vegetable seeds and oils (soybean, sunflower, canola, olive, corn, and mustard) were collected and tested for the presence of aflatoxin B1 (AFB1) and total AFs. Liquid-liquid extraction was employed for the extraction of AFs from seeds and oil samples. Reverse phase high performance liquid chromatography equipped with fluorescence detection was used for the analysis. The results have shown that 92 (56.7%) samples of imported and 108 (57.0%) samples of local edible seeds were observed to be contaminated with AFs. All samples of edible seeds have AFB1 levels greater than the proposed limit set by the European Union (EU, 2 µg/kg) and 12 (7.40%) samples of imported seeds and 14 (7.40%) samples of local seeds were found in the range ≥ 50 µg/kg. About 78 (43.3%) samples of imported edible oil and 103 (48.3%) sample of local edible oil were observed to be positive for AFs. Furthermore, 16 (8.88%) and six (3.33%) samples of imported vegetable oil have levels of total AFs in a range (21-50 µg/kg) and greater than 50 µg/kg, respectively. The findings indicate significant differences in AFs levels between imported and local vegetable oil samples (t = 22.27 and p = 0.009) at α = 0.05 and a significant difference in AFs levels were found between vegetable seeds and oil samples (t = -17.75, p = 0.009) at α = 0.05. The highest dietary intake was found for a local sunflower oil sample (0.90 µg/kg/day) in female individuals (16-22 age group). The results have shown considerably high levels of AFB1 and total AFs in seeds and oil samples and emphasise the need to monitor carefully the levels of these toxic substances in food and feed on regular basis.

Matched MeSH terms: Chromatography, High Pressure Liquid
Fulltext Perilla frutescens Leaf Extract and Fractions: Polyphenol Composition, Antioxidant, Enzymes (α-Glucosidase, Acetylcholinesterase, and Tyrosinase) Inhibitory, Anticancer, and Antidiabetic Activities

Wang Z, Tu Z, Xie X, Cui H, Kong KW, Zhang L

Foods, 2021 Feb 03;10(2).
PMID: 33546380 DOI: 10.3390/foods10020315

This study aims to evaluate the bioactive components, in vitro bioactivities, and in vivo hypoglycemic effect of P. frutescens leaf, which is a traditional medicine-food homology plant. P. frutescens methanol crude extract and its fractions (petroleum ether, chloroform, ethyl acetate, n-butanol fractions, and aqueous phase residue) were prepared by ultrasound-enzyme assisted extraction and liquid-liquid extraction. Among the samples, the ethyl acetate fraction possessed the high total phenolic (440.48 μg GAE/mg DE) and flavonoid content (455.22 μg RE/mg DE), the best antioxidant activity (the DPPH radical, ABTS radical, and superoxide anion scavenging activity, and ferric reducing antioxidant power were 1.71, 1.14, 2.40, 1.29, and 2.4 times higher than that of control Vc, respectively), the most powerful α-glucosidase inhibitory ability with the IC50 value of 190.03 μg/mL which was 2.2-folds higher than control acarbose, the strongest proliferative inhibitory ability against MCF-7 and HepG2 cell with the IC50 values of 37.92 and 13.43 μg/mL, which were considerable with control cisplatin, as well as certain inhibition abilities on acetylcholinesterase and tyrosinase. HPLC analysis showed that the luteolin, rosmarinic acid, rutin, and catechin were the dominant components of the ethyl acetate fraction. Animal experiments further demonstrated that the ethyl acetate fraction could significantly decrease the serum glucose level, food, and water intake of streptozotocin-induced diabetic SD rats, increase the body weight, modulate their serum levels of TC, TG, HDL-C, and LDL-C, improve the histopathology and glycogen accumulation in liver and intestinal tissue. Taken together, P. frutescens leaf exhibits excellent hypoglycemic activity in vitro and in vivo, and could be exploited as a source of natural antidiabetic agent.

Matched MeSH terms: Chromatography, High Pressure Liquid
Fulltext Haemoglobin A1c: comparing performance of two point of care devices with laboratory analyser

Wan Mohd Zin RM, Ahmad Kamil ZI, Tuan Soh TR, Embong M, Wan Mohamud WN

BMC Res Notes, 2013 Dec 18;6:540.
PMID: 24344903 DOI: 10.1186/1756-0500-6-540

BACKGROUND: Measurement of HbA1c has been widely used for long-term monitoring and management of diabetes control. There is increasing use of point-of-care (POC) devices for measuring HbA1c where quicker results would allow immediate clinical management decisions to be made. Therefore, it is important to evaluate and compare the performance of such devices to the reference laboratory method.
FINDINGS: A total of 274 venous blood was collected from normal healthy adults during the community screening programmes. The performance of POC devices, Afinion and Quo-test were compared to central laboratory HPLC method; Adams A1c HA 8160. Both POC devices showed good correlation to HA 8160 with r = 0.94 (p < 0.001) and r = 0.95 (p < 0.001) for Afinion and Quo-test respectively. The means difference were statistically higher between POC and HA 8160 with 0.23% (95% CI 0.19-0.26, p < 0.001) and 0.29% (95% CI 0.24-0.34, p < 0.001) for Afinion and Quo-test respectively.
CONCLUSIONS: Both POC devices could be considered in health clinics for diabetes management but not to be used for the diagnostic purposes.

Matched MeSH terms: Chromatography, High Pressure Liquid
Fulltext Potential use of cord blood for Hb E hemoglobinopathy screening programme using capillary electrophoresis

Wan Mohd Saman WA, Hassan R, Mohd Yusoff S, Che Yaakob CA, Abdullah NA, Ghazali S, et al.

Malays J Pathol, 2016 Dec;38(3):235-239.
PMID: 28028293 MyJurnal

BACKGROUND: Thalassemia and hemoglobinopathies are inherited red blood cell disorders found worldwide. Hemoglobin (Hb) E disorder is one of the hemoglobinopathies known to have the high prevalence in South East Asia. Most of transfusion-dependent thalassemias were genotypically compound heterozygous Hb E/ β-thalassemia. In Malaysia, the national screening program for thalassemia was implemented for early pregnancy or secondary school girls; however many participants do not turn-up and missed the screening test. Screening for thalassemia using samples from cord blood is an alternative choice as it is a readily available source of blood and hence early detection of the disease. The purpose of this study was to determine the potential use of cord blood for the screening of HbE hemoglobinopathy by using capillary electrophoresis (CE).
METHODS: Cord blood samples were collected from 300 newborns of healthy mothers. Hematological parameters were determined and hemoglobin quantitation for all cord blood samples were performed using capillary electrophoresis system (CES) and high performance liquid chromatography (HPLC).
RESULTS: Majority of cord blood samples (63%) revealed Hb AF followed by Hb AFA2 (20%). Hb AFE was detected in 10.7% with the mean value of Hb E ranging from 2.3%-11.1%.
CONCLUSION: Hemoglobin E was detected in cord blood using capillary electrophoresis system. It can be recommended in areas where Hb E/β is prevalent. Implementation of a screening strategy using CE on cord blood sampling will identify the disease early. With regular follow-up on these patients, the status of their disease can be determined earlier and appropriate management implemented.

Matched MeSH terms: Chromatography, High Pressure Liquid
Guinea pig genital tract lipidome reveals in vivo and in vitro regulation of phosphatidylcholine 16:0/18:1 and contribution to Chlamydia trachomatis serovar D infectivity

Wali S, Gupta R, Yu JJ, Mfuh A, Gao X, Guentzel MN, et al.

Metabolomics, 2016 Apr;12(4).
PMID: 27642272

INTRODUCTION: Chlamydia trachomatis (Ct), is the leading cause of sexually transmitted infections worldwide. Host transcriptomic- or proteomic profiling studies have identified key molecules involved in establishment of Ct infection or the generation of anti Ct-immunity. However, the contribution of the host metabolome is not known.
OBJECTIVES: The objective of this study was to determine the contribution of host metabolites in genital Ct infection.
METHODS: We used high-performance liquid chromatography-mass spectrometry, and mapped lipid profiles in genital swabs obtained from female guinea pigs at days 3, 9, 15, 30 and 65 post Ct serovar D intravaginal infection.
RESULTS: Across all time points assessed, 13 distinct lipid species including choline, ethanolamine and glycerol were detected. Amongst these metabolites, phosphatidylcholine (PC) was the predominant phospholipid detected from animals actively shedding bacteria i.e., at 3, 9, and 15 days post infection. However, at days 30 and 65 when the animals had cleared the infection, PC was observed to be decreased compared to previous time points. Mass spectrometry analyses of PC produced in guinea pigs (in vivo) and 104C1 guinea pig cell line (in vitro) revealed distinct PC species following Ct D infection. Amongst these, PC 16:0/18:1 was significantly upregulated following Ct D infection (p < 0.05, >twofold change) in vivo and in vitro infection models investigated in this report. Exogenous addition of PC 16:0/18:1 resulted in significant increase in Ct D in Hela 229 cells.
CONCLUSION: This study demonstrates a role for host metabolite, PC 16:0/18:1 in regulating genital Ct infection in vivo and in vitro.

Matched MeSH terms: Chromatography, High Pressure Liquid
Fulltext Characterisation of potential antidiabetic-related proteins from Pleurotus pulmonarius (Fr.) Quél. (grey oyster mushroom) by MALDI-TOF/TOF mass spectrometry

Wahab NA, Abdullah N, Aminudin N

Biomed Res Int, 2014;2014:131607.
PMID: 25243114 DOI: 10.1155/2014/131607

Pleurotus pulmonarius has been reported to have a potent remedial effect on diabetic property and considered to be an alternative for type 2 diabetes mellitus treatment. This study aimed to investigate the antidiabetic properties of ammonium sulphate precipitated protein fractions from P. pulmonarius basidiocarps. Preliminary results demonstrated that 30% (NH4)2SO4 precipitated fraction (F30) inhibited Saccharomyces cerevisiae α-glucosidase activity (24.18%), and 100% (NH4)2SO4 precipitated fraction (F100) inhibited porcine pancreatic α-amylase activity (41.80%). Following RP-HPLC purification, peak 3 from F30 fraction demonstrated inhibition towards α-glucosidase at the same time with meagre inhibition towards α-amylase activity. Characterisation of proteins using MALDI-TOF/TOF MS demonstrated the presence of four different proteins, which could be implicated in the regulation of blood glucose level via various mechanisms. Therefore, this study revealed the presence of four antidiabetic-related proteins which are profilin-like protein, glyceraldehyde-3-phosphate dehydrogenase-like protein, trehalose phosphorylase-like (TP-like) protein, and catalase-like protein. Hence, P. pulmonarius basidiocarps have high potential in lowering blood glucose level, reducing insulin resistance and vascular complications.

Matched MeSH terms: Chromatography, High Pressure Liquid
Fulltext Antimicrobial Potential of Aqueous Extract of Giant Sword Fern and Ultra-High-Performance Liquid Chromatography-High-Resolution Mass Spectrometry Analysis

Venmathi Maran BA, Palaniveloo K, Mahendran T, Chellappan DK, Tan JK, Yong YS, et al.

Molecules, 2023 Aug 15;28(16).
PMID: 37630329 DOI: 10.3390/molecules28166075

Vibriosis and parasitic leech infestations cause the death of various farmed fish, such as groupers, hybrid groupers, sea bass, etc., in Malaysia and other Southeast Asian countries. In the absence of natural control agents, aquaculture operators rely on toxic chemicals to control Vibrio infections and parasitic leeches, which can have a negative impact on the environment and health. In the present study, we investigated the antivibrio and antiparasitic activities of the aqueous extract of giant sword fern (GSF) (Nephrolepis biserrata, Nephrolepidaceae, locally known as "Paku Pedang") against four Vibrio spp. and the parasitic leech Zeylanicobdella arugamensis, as well as its metabolic composition using the ultra-high-performance liquid chromatography-high-resolution mass spectrometry system (UHPLC-HRMS). The data show that the aqueous extract of GSF at a concentration of 100 mg/mL exhibits potent bactericidal activity against V. parahaemolyticus with a zone of inhibition of 19.5 mm. In addition, the extract showed dose-dependent activity against leeches, resulting in the complete killing of the parasitic leeches within a short period of 11-43 min when tested at concentrations ranging from 100 to 25 mg/mL. The UHPLC-HRMS analysis detected 118 metabolites in the aqueous extract of GSF. Flavonoids were the primary metabolites, followed by phenolic, aromatic, fatty acyl, terpenoid, vitamin and steroidal compounds. Notably, several of these metabolites possess antibacterial and antiparasitic properties, including cinnamaldehyde, cinnamic acid, apigenin, quercetin, cynaroside, luteolin, naringenin, wogonin, 6-gingerol, nicotinamide, abscisic acid, daidzein, salvianolic acid B, etc. Overall, our study shows the significant antibacterial and antiparasitic potential of the GSF aqueous extract, which demonstrates the presence of valuable secondary metabolites. Consequently, the aqueous extract is a promising natural alternative for the effective control of Vibrio infections and the treatment of parasitic leeches in aquaculture systems.

Matched MeSH terms: Chromatography, High Pressure Liquid
Permeability of atenolol and propranolol in the presence of dimethyl sulfoxide in rat single-pass intestinal perfusion assay with liquid chromatography/UV detection

Venkatesh G, Ramanathan S, Nair NK, Mansor SM, Sattar MA, Khan MA, et al.

Biomed Chromatogr, 2007 May;21(5):484-90.
PMID: 17294505

A simple and sensitive RP-HPLC-UV method was developed and validated for simultaneous determination of atenolol and propranolol and subsequently applied to investigate the effect of dimethyl sulfoxide in rat in situ intestinal permeability studies. Atenolol (400 microm) and propranolol (100 microm) were perfused in the small intestine of anaesthetized (pentobarbitone sodium 60 mg/kg, i.p.) male Sprague-Dawley rats either in the presence (1, 3 and 5%) or in the absence of dimethyl sulfoxide. There was no significant alteration (p > 0.05) in the permeability of atenolol and propranolol, which indicated there was no effect of various concentrations of dimethyl sulfoxide (1-5%) on the membrane integrity of the rat intestinal tissues. The analytical method was validated on a C(4) column with a mobile phase comprising ammonium acetate buffer (pH 3.5, 0.02 m) and acetonitrile in the ratio of 30:70 (v/v) at a flow rate of 1.0 mL/min. The validated method was found to be accurate and precise and stability studies were carried out at different storage conditions and both analytes were found to be stable. These findings are applicable for determining the absorbability of water-insoluble drugs and new chemical entities for the purpose of classifying them in the biopharmaceutical classification system.

Matched MeSH terms: Chromatography, High Pressure Liquid/methods*
Development and validation of RP-HPLC-UV method for simultaneous determination of buparvaquone, atenolol, propranolol, quinidine and verapamil: a tool for the standardization of rat in situ intestinal permeability studies

Venkatesh G, Ramanathan S, Mansor SM, Nair NK, Sattar MA, Croft SL, et al.

J Pharm Biomed Anal, 2007 Mar 12;43(4):1546-51.
PMID: 17157469

A simple, sensitive and specific reversed phase high performance liquid chromatographic (RP-HPLC) method with UV detection at 251 nm was developed for simultaneous quantitation of buparvaquone (BPQ), atenolol, propranolol, quinidine and verapamil. The method was applicable in rat in situ intestinal permeability study to assess intestinal permeability of BPQ, a promising lead compound for Leishmania donovani infections. The method was validated on a C-4 column with mobile phase comprising ammonium acetate buffer (0.02 M, pH 3.5) and acetonitrile in the ratio of 30:70 (v/v) at a flow rate of 1.0 ml/min. The retention times for atenolol, quinidine, propranolol, verapamil and BPQ were 4.30, 5.96, 6.55, 7.98 and 8.54 min, respectively. The calibration curves were linear (correlation coefficient > or =0.996) in the selected range of each analyte. The method is specific and sensitive with limit of quantitation of 15 microg/ml for atenolol, 0.8 microg/ml for quinidine, 5 microg/ml for propranolol, 10 microg/ml for verapamil and 200 ng/ml for BPQ. The validated method was found to be accurate and precise in the working calibration range. Stability studies were carried out at different storage conditions and all the analytes were found to be stable. This method is simple, reliable and can be routinely used for accurate permeability characterization.

Matched MeSH terms: Chromatography, High Pressure Liquid/methods*
Optimization and validation of RP-HPLC-UV method with solid-phase extraction for determination of buparvaquone in human and rabbit plasma: application to pharmacokinetic study

Venkatesh G, Majid MI, Ramanathan S, Mansor SM, Nair NK, Croft SL, et al.

Biomed Chromatogr, 2008 May;22(5):535-41.
PMID: 18205140 DOI: 10.1002/bmc.965

A simple, sensitive and specific reversed-phase high-performance liquid chromatographic method with UV detection at 251 nm was developed for quantitation of buparvaquone (BPQ) in human and rabbit plasma. The method utilizes 250 microL of plasma and sample preparation involves protein precipitation followed by solid-phase extraction. The method was validated on a C18 column with mobile phase consisting of ammonium acetate buffer (0.02 m, pH 3.0) and acetonitrile in the ratio of 18:82 (v/v) at a flow rate of 1.1 mL/min. The calibration curves were linear (correlation coefficient>or=0.998) in the selected range. The method is specific and sensitive with limit of quantitation of 50 ng/mL for BPQ. The validated method was found to be accurate and precise in the working calibration range. Stability studies were carried out at different storage conditions and BPQ was found to be stable. Partial validation studies were carried out using rabbit plasma and intra- and inter-day precision and accuracy were within 7%. This method is simple, reliable and can be routinely used for preclinical pharmacokinetic studies for BPQ.

Matched MeSH terms: Chromatography, High Pressure Liquid/methods*
Fulltext A classical genetic solution to enhance the biosynthesis of anticancer phytochemicals in Andrographis paniculata Nees

Valdiani A, Talei D, Tan SG, Abdul Kadir M, Maziah M, Rafii MY, et al.

PLoS One, 2014;9(2):e87034.
PMID: 24586262 DOI: 10.1371/journal.pone.0087034

Andrographolides, the diterpene lactones, are major bioactive phytochemicals which could be found in different parts of the medicinal herb Andrographis paniculata. A number of such compounds namely andrographolide (AG), neoandrographolide (NAG), and 14-deoxy-11,12-didehydroandrographolide (DDAG) have already attracted a great deal of attention due to their potential therapeutic effects in hard-to-treat diseases such as cancers and HIV. Recently, they have also been considered as substrates for the discovery of novel pharmaceutical compounds. Nevertheless, there is still a huge gap in knowledge on the genetic pattern of the biosynthesis of these bioactive compounds. Hence, the present study aimed to investigate the genetic mechanisms controlling the biosynthesis of these phytochemicals using a diallel analysis. The high performance liquid chromatography analysis of the three andrographolides in 210 F1 progenies confirmed that the biosynthesis of these andrographolides was considerably increased via intraspecific hybridization. The results revealed high, moderate and low heterosis for DDAG, AG and NAG, respectively. Furthermore, the preponderance of non-additive gene actions was affirmed in the enhancement of the three andrographolides contents. The consequence of this type of gene action was the occurrence of high broad-sense and low narrow-sense heritabilities for the above mentioned andrographolides. The prevalence of non-additive gene action suggests the suitability of heterosis breeding and hybrid seed production as a preferred option to produce new plant varieties with higher andrographolide contents using the wild accessions of A. paniculata. Moreover, from an evolutionary point of view, the occurrence of population bottlenecks in the Malaysian accessions of A. paniculata was unveiled by observing a low level of additive genetic variance (VA ) for all the andrographolides.

Matched MeSH terms: Chromatography, High Pressure Liquid/methods
HPLC profiling of phenolics and flavonoids of Adonidia merrillii fruits and their antioxidant and cytotoxic properties

Vafaei A, Bin Mohamad J, Karimi E

Nat Prod Res, 2019 Sep;33(17):2531-2535.
PMID: 29527930 DOI: 10.1080/14786419.2018.1448810

In this study the antioxidant and cytotoxicity activity of the Adonidia merrillii fruits were investigated using different solvent polarities (methanol, ethyl acetate and water). The results showed that the total phenolic and flavonoid contents of the methanolic extract was higher compare with other extract with respective values of 17.80 ± 0.45 mg gallic acid equivalents/g dry weight (DW) and 5.43 ± 0.33 mg rutin equivalents/g DW. Beside that The RP-HPLC analyses indicated the presence of gallic acid, pyrogallol, caffeic acid, vanillic acid, syringic acid, naringin and rutin. In the DPPH, NO2 and ABTS scavenging assays, the methanolic extract exhibited higher antioxidant activity as compared to the ethyl acetate and water extracts. The extracts exhibited moderate to weak cytotoxic activity in the assays using human hepatocytes (Chang liver cells) and NIH/3T3 (fibroblasts cell) cell lines. The findings showed the Adonidia merrillii fruit extracts to possess considerable antioxidant and cytotoxicity properties. The fruit, therefore, is a potential candidate for further work to discover antioxidant and cytotoxic drugs from natural sources.

Matched MeSH terms: Chromatography, High Pressure Liquid
Growth and toxin production of the toxic dinoflagellate Pyrodinium bahamense var. compressum in laboratory cultures

Usup G, Kulis DM, Anderson DM

Nat. Toxins, 1994;2(5):254-62.
PMID: 7866660

Toxin production of a Malaysian isolate of the toxic red tide dinoflagellate Pyrodinium bahamense var. compressum was investigated at various stages of the batch culture growth cycle and under growth conditions affected by temperature, salinity, and light intensity variations. In all the experiments conducted, only 5 toxins were ever detected. Neosaxitoxin (NEO) and gonyautoxin V (GTX5) made up 80 mole percent or more of the cellular toxin content and saxitoxin (STX), GTX6 and decarbamoylsaxitoxin (dcSTX) made up the remainder. No gonyautoxins I-IV or C toxins were ever detected. In nutrient-replete batch cultures, toxin content rapidly peaked during early exponential phase and just as rapidly declined prior to the onset of plateau phase. Temperature had a marked effect on toxin content, which increased 3-fold as the temperature decreased from the optimum of 28 degrees C to 22 degrees C. Toxin content was constant at salinities of 24% or higher, but increased 3-fold at 20%. Toxin content decreased 2-fold and chlorophyll content increased 3-fold when light intensity was reduced from 90 to 15 microE m-2 s-1. This accompanied a 30% decrease in growth rate. Toxin composition (mole % individual toxin cell-1) remained constant throughout the course of the nutrient-replete culture and during growth at various salinities, but varied significantly with temperature and light intensity changes. At 22 degrees C, GTX5 was 25 mole % and NEO was 65 mole %, while at 34 degrees C, GTX5 increased to 55 mole % and NEO decreased proportionally to 40 mole %. When light intensity was reduced from 90 to 15 microE m-2 s-1, NEO decreased from 55 to 38 mole %, while GTX5 increased from 40 to 58 mole %. These data suggest that low light and high temperature both somehow enhance sulfo-transferase activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Matched MeSH terms: Chromatography, High Pressure Liquid
Fulltext Engineering the production of major catechins by Escherichia coli carrying metabolite genes of Camellia sinensis

Umar KM, Abdulkarim SM, Radu S, Abdul Hamid A, Saari N

ScientificWorldJournal, 2012;2012:529031.
PMID: 22645428 DOI: 10.1100/2012/529031

A mimicked biosynthetic pathway of catechin metabolite genes from C. sinensis, consisting of flavanone 3 hydroxylase (F3H), dihydroflavonol reductase (DFR), and leucoanthocyanidin reductase (LCR), was designed and arranged in two sets of constructs: (a) single promoter in front of F3H and ribosome-binding sequences both in front of DFR and LCR; (b) three different promoters with each in the front of the three genes and ribosome-binding sequences at appropriate positions. Recombinant E. coli BL (DE3) harbouring the constructs were cultivated for 65 h at 26 °C in M9 medium consisting of 40 g/L glucose, 1 mM IPTG, and 3 mM eriodictyol. Compounds produced were extracted in ethyl acetate in alkaline conditions after 1 h at room temperature and identified by HPLC. Two of the four major catechins, namely, (-)-epicatechin (0.01) and (-)-epicatechin gallate (0.36 mg/L), and two other types ((+)-catechin hydrate (0.13 mg/L) and (-)-catechin gallate (0.04 mg/L)) were successfully produced.

Matched MeSH terms: Chromatography, High Pressure Liquid/methods
Fulltext Suppression of Cisplatin-Induced Vomiting byCannabis sativain Pigeons: Neurochemical Evidences

Ullah I, Subhan F, Alam J, Shahid M, Ayaz M

Front Pharmacol, 2018;9:231.
PMID: 29615907 DOI: 10.3389/fphar.2018.00231

Cannabis sativa
(CS, familyCannabinaceae) has been reported for its anti-emetic activity against cancer chemotherapy-induced emesis in animal models and in clinics. The current study was designed to investigateCSfor potential effectiveness to attenuate cisplatin-induced vomiting in healthy pigeons and to study the impact on neurotransmitters involved centrally and peripherally in the act of vomiting. High-performance liquid chromatography system coupled with electrochemical detector was used for the quantification of neurotransmitters 5-hydroxytryptamine (5HT), dopamine (DA) and their metabolites; Di-hydroxy Phenyl Acetic acid (Dopac), Homovanillic acid (HVA), and 5-hydroxy indole acetic acid (5HIAA) centrally in specific brain areas (area postrema and brain stem) while, peripherally in small intestine. Cisplatin (7 mg/kg i.v.) induce emesis without lethality across the 24 h observation period.CShexane fraction (CS-HexFr; 10 mg/kg) attenuated cisplatin-induced emesis ∼ 65.85% (P< 0.05); the reference anti-emetic drug, metoclopramide (MCP; 30 mg/kg), produced ∼43.90% reduction (P< 0.05). At acute time point (3rdh), CS-HexFr decreased (P< 0.001) the concentration of 5HT and 5HIAA in the area postrema, brain stem and intestine, while at 18thh (delayed time point) CS-HexFr attenuated (P< 0.001) the upsurge of 5HT caused by cisplatin in the brain stem and intestine and dopamine in the area postrema.CS-HexFr treatment alone did not alter the basal neurotransmitters and their metabolites in the brain areas and intestine except 5HIAA and HVA, which were decreased significantly. In conclusion the anti-emetic effect ofCS-HexFr is mediated by anti-serotonergic and anti-dopaminergic components in a blended manner at the two different time points, i.e., 3rdand 18thh in pigeons.

Matched MeSH terms: Chromatography, High Pressure Liquid
Flavonoids of Piper sarmentosum and its cytoprotective effects against oxidative stress

Ugusman A, Zakaria Z, Hui CK, Nordin NA, Mahdy ZA

EXCLI J, 2012;11:705-714.
PMID: 27847456

Abnormalities in endothelial cell structure and function may lead to diseases such as thrombosis and atherosclerosis. Oxidative stress plays an important role in the pathogenesis of various cardiovascular diseases including atherosclerosis. Previous studies have shown a relationship between a diet rich in flavonoid and a reduced incidence of cardiovascular diseases. Piper sarmentosum (PS) is a plant with high flavonoid content and it possesses antioxidant and anti-atherosclerotic activities. Therefore this study aimed to investigate the flavonoids present in aqueous extract of PS (AEPS) and its cytoprotective effects in oxidative stress-induced human umbilical vein endothelial cells (HUVEC). AEPS contained high total phenolic content (91.02 ± 0.02 mg QE/g DM) and total flavonoid content (48.57 ± 0.03 mg GAE/g DM). Screening using high performance liquid chromatography (HPLC) technique showed the presence of rutin and vitexin as the main flavonoids in AEPS. HUVEC were exposed to 180 µM H2O2 and treated with various concentrations of rutin or vitexin (10 to 400 µM) for 24 hours. Both rutin and vitexin at the concentration of 150-400 µM significantly increased the viability of H2O2-induced HUVEC as denoted by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Therefore rutin and vitexin as the main flavonoids present in PS may be involved in the protective effects of PS against oxidative stress.

Matched MeSH terms: Chromatography, High Pressure Liquid
Differential expression and geographic variation of the venom phospholipases A2 of Calloselasma rhodostoma and Trimeresurus mucrosquamatus

Tsai IH, Chen YH, Wang YM, Liau MY, Lu PJ

Arch Biochem Biophys, 2001 Mar 15;387(2):257-64.
PMID: 11370849

To investigate the geographic variations in venoms of two medically important pitvipers, we have purified and characterized the phospholipases A2 (PLA2s) from the pooled venoms of Calloselasma rhodostoma from Malaysia, Thailand, Indonesia, and Vietnam, as well as the individual venom of Trimeresurus mucrosquamatus collected from both North and South Taiwan. Enzymatic and pharmacological activities of the purified PLA2s were also investigated. The complete amino acid sequences of the purified PLA2s were determined by sequencing the corresponding cDNAs from the venom gland and shown to be consistent with their molecular weight data and the N-terminal sequences. All the geographic venom samples of C. rhodostoma contain a major noncatalytic basic PLA2-homolog and two or three acidic PLA2s in different proportions. These acidic PLA2s contain Glu6-substitutions and show distinct inhibiting specificities toward the platelets from human and rabbit. We also found that the T. mucrosquamatus venoms from North Taiwan but not those from South Taiwan contain an Arg6-PLA2 designated as TmPL-III. Its amino acid sequence is reported for the first time. This enzyme is structurally almost identical to the low- or nonexpressed Arg6-PLA2 from C. rhodostoma venom gland, and thus appears to be a regressing venom component in both of the Asian pitvipers.

Matched MeSH terms: Chromatography, High Pressure Liquid
Fulltext Endophytic Diaporthe sp. ED2 Produces a Novel Anti-Candidal Ketone Derivative

Tong WY, Leong CR, Tan WN, Khairuddean M, Zakaria L, Ibrahim D

J Microbiol Biotechnol, 2017 Jun 28;27(6):1065-1070.
PMID: 28297749 DOI: 10.4014/jmb.1612.12009

This study aimed to examine the anti-candidal efficacy of a novel ketone derivative isolated from Diaporthe sp. ED2, an endophytic fungus residing in medicinal herb Orthosiphon stamieus Benth. The ethyl acetate extract of the fungal culture was separated by open column and reverse phase high-performance liquid chromatography (HPLC). The eluent at retention time 5.64 min in the HPLC system was the only compound that exhibited anti-candidal activity on Kirby-Bauer assay. The structure of the compound was also elucidated by nuclear magnetic resonance and spectroscopy techniques. The purified anti-candidal compound was obtainedas a colorless solid and characterized as 3-hydroxy-5-methoxyhex-5-ene-2,4-dione. On broth microdilution assay, the compound also exhibited fungicidal activity on a clinical strain of Candida albicans at a minimal inhibitory concentration of 3.1 μg/ml. The killing kinetic analysis also revealed that the compound was fungicidal against C. albicans in a concentration- and time-dependent manner. The compound was heat-stable up to 70°C, but its anti-candidal activity was affected at pH 2.

Matched MeSH terms: Chromatography, High Pressure Liquid
Selective magnetic nanographene oxide solid-phase extraction with high-performance liquid chromatography and fluorescence detection for the determination of zearalenone in corn samples

Thongprapai P, Cheewasedtham W, Chong KF, Rujiralai T

J Sep Sci, 2018 Dec;41(23):4348-4354.
PMID: 30267469 DOI: 10.1002/jssc.201800441

A magnetic nanographene oxide sorbent as a selective sorbent for the magnetic solid-phase extraction combined with high-performance liquid chromatography and fluorescence detection was developed and proved to be a robust method for zearalenone determination in corn samples. Optimum extraction of zearalenone (20 mg magnetic nanographene oxide sorbent, extraction for 15 min, desorption time of 15 min using 1 mL of 0.5% formic acid in methanol) resulted in low limits of detection (05 mg/L) and quantitation (0.13 mg/L) and good linearity range of 0.13-1.25 mg/L with the correlation coefficient of 0.9957. Acceptable recoveries (79.3-80.6%) with relative standard deviations below 4% and satisfactory intra- and interday precisions (2-7.4%) were achieved. Additionally, the proposed method has been proved to be good in several aspects: easily prepared sorbent with high affinity to zearalenone, convenient and fast procedure, and high extraction efficiency.

Matched MeSH terms: Chromatography, High Pressure Liquid

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