Displaying publications 41 - 60 of 680 in total

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  1. Trace monitoring of water-borne phenolics in the Klang River Basin
    Tan GH, Chong CL
    Environ Monit Assess, 1993 Feb;24(3):267-77.
    PMID: 24227384 DOI: 10.1007/BF00545983
    The Klang River Basin is located in the most densely populated region in Malaysia, with its heavy concentration of industries and population. A systematic study of the pollution to this river system caused by phenolic compounds have been carried out under this project. Analyses of water samples from the Klang River by high performance liquid chromatography (HPLC) with an ultraviolet (UV) detector at 280 nm have shown the presence of some priority phenolic pollutants.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  2. Quantification of atovaquone from amorphous solid dispersion formulation using HPLC: An in vitro and ex vivo investigation
    Teoh XY, Goh CF, Aminu N, Chan SY
    J Pharm Biomed Anal, 2021 Jan 05;192:113631.
    PMID: 33011581 DOI: 10.1016/j.jpba.2020.113631
    Atovaquone (ATQ) is a poorly soluble drug. Therefore, formulating ATQ into its supersaturated state through solid dispersion for bioavailability enhancement can be of great value. However, due to fast crystallising properties of ATQ, the quantification of ATQ in a supersaturated solid dispersion system can be complicated. Therefore, in pursuit of accurate quantification of such sample, a simple HPLC analytical method utilising a C18 column (250 × 4.6 mm ID, 5 μm) for the quantitation of ATQ has been developed and validated. Atovaquone elution using the proposed method demonstrated a retention time around 7.6 min with good linearity (R2 > 0.999). The system suitability is also detailed with the tailing factor at 1.365 ± 0.002. The addition of solubilising agent as sample treatment step aided in ensuring the accurate quantitation of the fast crystallising ATQ. The developed HPLC quantitation method has been successfully employed in the analysis of ATQ from solid dispersion samples in in vitro dissolution as well as ex vivo permeation studies for formulation development.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  3. Toxicity of xylene in occupationally exposed workers: A high-performance liquid chromatography analysis
    Rajan ST, Narasimhan M, Rao KB, Jacob TE
    J Oral Maxillofac Pathol, 2019 9 14;23(2):303.
    PMID: 31516245 DOI: 10.4103/jomfp.JOMFP_297_18
    Background: Xylene is one of the most commonly used solvents in industrial and medical technologies. Several health hazards of xylene have been documented in literature. Workers in certain forces appear to have the greatest potential for exposure to high concentrations of xylene - histopathology technicians and painters are two such groups. This study was undertaken with the aim to determine the level of xylene exposure and the various systemic health effects among these groups.

    Methodology: The study was performed by analyzing the urine samples of the participants for methylhippuric acid, the established biomarker of xylene with the aid of high-performance liquid chromatography.

    Results and Conclusion: The work hours per week of the occupationally exposed participants were statistically analyzed with that of the excretory values of the metabolites of xylene, and the P value was found to be highly significant. Various side effects of xylene including respiratory, dermatological, neurological and gastrointestinal symptoms were observed among the study groups.

    Matched MeSH terms: Chromatography, High Pressure Liquid
  4. Effects of different cooking methods on isoflavone content in Malaysian soy-based dishes
    Hasnah Haron, Tasneem Shaari, Chan BK
    Sains Malaysiana, 2016;45:1329-1335.
    Soy-based products are one of famous raw ingredients used in the preparation of Asian cuisines. These soy-based products are good source of isoflavones. This study was carried out to observe the effects of different cooking methods on isoflavone content in soy-based products. A total of eight Malaysian dishes prepared using soy-based products with different cooking methods was selected as samples for this study. Daidzein and genestein contents in raw and cooked soy-based products were both quantified using high performance liquid chromatography (HPLC). The results showed that dishes containing tempe as ingredients had significantly higher (p<0.05) amount of isoflavone content, in both raw and cooked forms, as compared to those prepared from other types of soy-based products when based on dry and wet. In conclusion, the isoflavone content was significantly reduced (p<0.05) in some cooked soy-based products (tempe (TSS and ML), fu jook (ML) and firm tofu (FTC)) based on dry weight as compared with the raw ones. However, the correlations between isoflavone content with cooking methods, durations and temperatures were not significant (p>0.05) in this study.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  5. Advancements in the preparation and application of monolithic silica columns for efficient separation in liquid chromatography
    Khoo HT, Leow CH
    Talanta, 2021 Mar 01;224:121777.
    PMID: 33379011 DOI: 10.1016/j.talanta.2020.121777
    Fast and efficient separation remains a big challenge in high performance liquid chromatography (HPLC). The need for higher efficiency and resolution in separation is constantly in demand. To achieve that, columns developed are rapidly moving towards having smaller particle sizes and internal diameters (i.d.). However, these parameters will lead to high back-pressure in the system and will burden the pumps of the HPLC instrument. To address this limitation, monolithic columns, especially silica-based monolithic columns have been introduced. These columns are being widely investigated for fast and efficient separation of a wide range of molecules. The present article describes the current methods developed to enhance the column efficiency of particle packed columns and how silica monolithic columns can act as an alternative in overcoming the low permeability of particle packed columns. The fundamental processes behind the fabrication of the monolith including the starting materials and the silica sol-gel process will be discussed. Different monolith derivatization and end-capping processes will be further elaborated and followed by highlights of the performance such monolithic columns in key applications in different fields with various types of matrices.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  6. Fulltext A comparative UHPLC-Q/TOF-MS-based eco-metabolomics approach reveals temperature adaptation of four Nepenthes species
    Wong C, Ling YS, Wee JLS, Mujahid A, Müller M
    Sci Rep, 2020 12 14;10(1):21861.
    PMID: 33318532 DOI: 10.1038/s41598-020-78873-3
    Nepenthes, as the largest family of carnivorous plants, is found with an extensive geographical distribution throughout the Malay Archipelago, specifically in Borneo, Philippines, and Sumatra. Highland species are able to tolerate cold stress and lowland species heat stress. Our current understanding on the adaptation or survival mechanisms acquired by the different Nepenthes species to their climatic conditions at the phytochemical level is, however, limited. In this study, we applied an eco-metabolomics approach to identify temperature stressed individual metabolic fingerprints of four Nepenthes species: the lowlanders N. ampullaria, N. rafflesiana and N. northiana, and the highlander N. minima. We hypothesized that distinct metabolite regulation patterns exist between the Nepenthes species due to their adaptation towards different geographical and altitudinal distribution. Our results revealed not only distinct temperature stress induced metabolite fingerprints for each Nepenthes species, but also shared metabolic response and adaptation strategies. The interspecific responses and adaptation of N. rafflesiana and N. northiana likely reflected their natural habitat niches. Moreover, our study also indicates the potential of lowlanders, especially N. ampullaria and N. rafflesiana, to produce metabolites needed to deal with increased temperatures, offering hope for the plant genus and future adaption in times of changing climate.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  7. Fulltext The effect of tocotrienol-rich fraction supplementation on the ovarian metabolome and the quality of oocyte in aging mice
    Norrabiátul Adawiyah, A., Teh, L.K., Fathimah, M., Nuraliza, A.S.
    Medicine & Health, 2020;15(1):54-69.
    MyJurnal
    Penuaan ovari telah dikaitkan dengan tekanan oksidatif dan kehilangan fungsi ovari. Tokotrienol telah dibuktikan dapat memberi kesan yang baik terhadap sistem pembiakan wanita. Walau bagaimanapun, peranan tokotrienol ke atas metabolisma ovari dan seterusnya peningkatan kualiti oosit dalam mencit tua masih tidak diketahui. Oleh itu, hubungan antara perubahan aktiviti metabolik dalam ovari dan kualiti oosit dalam mencit tua selepas suplementasi fraksi kaya tokotrienol (TRF) telah dikaji. Mencit betina berusia enam minggu digunakan sebagai kumpulan Muda. Mencit betina berusia enam bulan dibahagikan kepada empat kumpulan iaitu kumpulan pertama yang diberikan minyak jagung-bebas tokoferol (kawalan) manakala tiga kumpulan yang lain diberi suplimen TRF pada dos 90, 120, dan 150 mg/kg. Rawatan diberikan secara oral selama dua bulan. Pada akhir rawatan, mencit dari semua kumpulan disuperovulasi dan kemudian dikorbankan. Kualiti oosit dinilai dan analisis metabolomik secara tidak disasarkan, pada tisu ovari dijalankan dengan menggunakan 'liquid chromatography tandem mass spectrometry of quadrupole time-of-flight' (LC-MS Q-TOF). Peratusan oosit normal adalah lebih tinggi (p
    Matched MeSH terms: Chromatography, High Pressure Liquid
  8. New Determination Method of Two Bioactive Saponins in Lysimachia capillipes Hemsl. by Quantitative Analysis of Multi-Components by Single-Marker
    Zhang X, Chen X, Jin J, Gong M, He Q, Li S, et al.
    J Chromatogr Sci, 2021 Oct 29;59(10):941-948.
    PMID: 33728454 DOI: 10.1093/chromsci/bmab028
    Capilliposide B (CPS-B) and Capilliposide C (CPS-C), as the key components in Lysimachia capillipes Hemsl., increasingly aroused the interest and research concern of many researchers due to the good bioactivities. Nowadays, the reference standards of CPS-B and CPS-C yield were very limited. Due to the deficit of reference standards, the determination could be difficult to carry out, and the quality control and evaluation would be restrained afterwards. To solve this urgent problem, a quantitative analysis of multi-components by single-marker (QAMS) method was proposed and established based on high-performance liquid-chromatography tandem evaporative light-scattering detector. In this QAMS method, the content of the two bioactive components could be calculated by buddlejasaponin IV, which is applied as an external standard and readily obtained. And the methodological experiments were evaluated and indicated accuracy, stability and feasibility of this QAMS method. Therefore, in this study, this built method would properly meet the requirement of determination of CPS-B, CPS-C and quality control of the L. capillipes Hemsl. plant.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  9. An overview of techniques and strategies for isolation of flavonoids from the genus Erythrina
    Rahmawati R, Hartati YW, Latip JB, Herlina T
    J Sep Sci, 2023 Jun;46(12):e2200800.
    PMID: 36715692 DOI: 10.1002/jssc.202200800
    Plants in the genus Erythrina is a potential source of chemical constituents, one of which is flavonoids, which have diverse bioactivities. To date, literature on the flavonoids from the genus Erythrina has only highlighted the phytochemical aspects, so this review article will discuss isolation techniques and strategies for the first time. More than 420 flavonoids have been reported in the Erythrina genus, which are grouped into 17 categories. These flavonoid compounds were obtained through isolation techniques and strategies using polar, semi-polar, and non-polar solvents. Various chromatographic techniques have been developed to isolate flavonoids using column flash chromatography, quick column chromatography, centrifugally accelerated thin-layer chromatography, radial chromatography, medium-pressure column chromatography, semi-preparative high-performance liquid chromatography, and preparative high-performance liquid chromatography. Chromatographic processes for isolating flavonoids can be optimized using multivariate statistical applications such as response surface methodology with central composite design, Box-Behnken design, Doehlert design, and mixture design.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  10. Fulltext Distribution of Flavonoids and Cyclohexenyl Chalcone Derivatives in Conventional Propagated and In Vitro-Derived Field-Grown Boesenbergia rotunda (L.) Mansf
    Tan BC, Tan SK, Wong SM, Ata N, Rahman NA, Khalid N
    Evid Based Complement Alternat Med, 2015;2015:451870.
    PMID: 25883671 DOI: 10.1155/2015/451870
    The distribution patterns of flavonoids and cyclohexenyl chalcone derivatives in conventional propagated (CP) and in vitro-derived (CPA) field-grown plants of an important medicinal ginger, Boesenbergia rotunda, are described. A total of eight compounds were extracted from six organs (rootlet, rhizome, shoot base, maroon stem, stalk, and leaf) of the CP and CPA plants. Five major chromatographic peaks, namely, alpinetin, pinocembrin, pinostrobin, 4-hydroxypanduratin A, and panduratin A, were consistently observed by high performance liquid chromatography. Nonaerial organs had higher levels of flavonoids than the aerial ones for all types of samples. Among the compounds detected, pinostrobin and 4-hydroxypanduratin A were the most abundant flavonoid and cyclohexenyl chalcone derivative, respectively. The distribution and abundance of the bioactive compounds suggested that the shoot base could be more potentially useful for medicinal application than other organs of the plant and may be the site of storage or occurrence of biosynthetic enzymatic activities.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  11. Application of continual injection liquid-phase microextraction method coupled with liquid chromatography to the analysis of organophosphorus pesticides
    Raharjo Y, Sanagi MM, Ibrahim WA, Naim AA, Aboul-Enein HY
    J Sep Sci, 2009 Feb;32(4):623-9.
    PMID: 19165835 DOI: 10.1002/jssc.200800566
    A liquid-phase microextraction coupled with LC method has been developed for the determination of organophosphorus pesticides (methidation, quinalphos and profenofos) in drinking water samples. In this method, a small amount (3 microL) of isooctane as the acceptor phase was introduced continually to fill-up the channel of a 1.5 cm polypropylene hollow fiber using a microsyringe while the hollow fiber was immersed in an aqueous donor solution. A portion of the acceptor phase (ca. 0.4 microL) was first introduced into the hollow fiber and additional amounts (ca. 0.2 microL) of the acceptor phase were introduced to replenish at intervals of 3 min until set end of extraction (40 min). After extraction, the acceptor phase was withdrawn and transferred into a 2 mL vial for a drying step prior to injection into a LC system. Parameters that affect the extraction efficiency were studied including the organic solvent, length of fiber, volume of acceptor and donor phase, stirring rate, extraction time, and effect of salting out. The proposed method provided good enrichment factors of up to 189.50, with RSD ranging from 0.10 to 0.29%, analyte recoveries of over 79.80% and good linearity ranging from 10.0 to 1.25 mg/L. The LOD ranged from 2.86 to 82.66 microg/L. This method was applied successfully to the determination of organophosphorus pesticides in selected drinking water samples.
    Matched MeSH terms: Chromatography, High Pressure Liquid/instrumentation*; Chromatography, High Pressure Liquid/methods*
  12. Analysis of tocotrienols in different sample matrixes by HPLC
    Sundram K, Nor RM
    Methods Mol Biol, 2002;186:221-32.
    PMID: 12013770
    Matched MeSH terms: Chromatography, High Pressure Liquid/instrumentation; Chromatography, High Pressure Liquid/methods*
  13. Determination of the antifilarial drug UMF-078 and its metabolites UMF-060 and flubendazole in whole blood using high-performance liquid chromatography
    Ramanathan S, Nair NK, Mansor SM, Navaratnam V
    J Chromatogr B Biomed Appl, 1994 May 13;655(2):269-73.
    PMID: 8081473
    A rapid and selective high-performance liquid chromatographic (HPLC) method for the simultaneous determination of the antifilarial drug UMF-078 (I) and its metabolites UMF-060 (II) and flubendazole (III) is described. After a simple extraction from whole blood, the compounds were determined by HPLC using a C18 Inertsil ODS-2 reversed-phase column with methanol-0.05M ammonium acetate (pH 4.0) as the mobile phase and ultraviolet detection at 291 nm. The average recoveries of I, II and III over the concentration range 20-500 ng ml-1 were 69.9 +/- 4.7, 85.6 +/- 4.4 and 85.1 +/- 6.0%, respectively. The minimum detectable concentrations in whole blood for I, II and III were 10, 7 and 7 ng ml-1, respectively. This method was found to be suitable for pharmacokinetic studies.
    Matched MeSH terms: Chromatography, High Pressure Liquid/methods*; Chromatography, High Pressure Liquid/statistics & numerical data
  14. Evaluation of dynamics of derivatization and development of RP-HPLC method for the determination of amikacin sulphate
    Shehzadi N, Hussain K, Khan MT, Salman M, Islam M
    Pak J Pharm Sci, 2017 Sep;30(5):1767-1777.
    PMID: 29084700
    The absence of chromophore and/or conjugated system, prerequisite for UV and florescent light detection, or absorbance at very low wavelength necessitates the development of simple and reliable methods for the determination of amikacin sulphate. Therefore, the present study describes for the first time dynamics of the drug derivatization using ninhydrin reagent and development and validation of a simple RP-HPLC method, using diode array detector (DAD). The variables such as heating time, heating type, drug-reagent ratio, reagent composition and storage temperature of the derivative were optimized. The analyte and aqueous ninhydrin solution upon heating for 2.00-5.00 min produced the colored drug-derivative which was stable for one month at refrigeration. The derivatized drug (20.00μL) was eluted through a column - Eclipse DB-C18 (5.00 µm, 4.60×150.00 mm), maintained at 25°C- using isocratic mobile phase comprising water and acetonitrile (70:30, v/v) at a flow rate of 1.00 mL/min, and detected at 400 nm. The method was found to be reliable (98.08-100.72% recovery), repeatable (98.02-100.72% intraday accuracy) and reproducible (98.47-101.27% inter day accuracy) with relative standard deviation less than 5%. The results of the present study indicate that the method is easy to perform, specific and sensitive, and suitable to be used for the determination of amikacin sulphate in bulk and pharmaceutical preparations using less expensive/laborious derivatization.
    Matched MeSH terms: Chromatography, High Pressure Liquid/methods*; Chromatography, High Pressure Liquid/standards
  15. Method development and validation of repaglinide in human plasma by HPLC and its application in pharmacokinetic studies
    Ruzilawati AB, Wahab MS, Imran A, Ismail Z, Gan SH
    J Pharm Biomed Anal, 2007 Apr 11;43(5):1831-5.
    PMID: 17240100
    In this study, the development and validation of a high-performance liquid chromatography (HPLC) assay for determination of repaglinide concentration in human plasma for pharmacokinetic studies is described. Plasma samples containing repaglinide and an internal standard, indomethacin were extracted with ethylacetate at pH 7.4. The recovery of repaglinide was 92%+/-55.31. Chromatographic separations were performed on Purospher STAR C-18 analytical column (4.8 mm x 150 mm; 5 microm particle size). The mobile phase composed of acetonitrile-ammonium formate (pH 2.7; 0.01 M) (60:40, v/v). The flow rate was 1 ml/min. The retention time for repaglinide and indomethacin were approximately 6.2 and 5.3 min, respectively. Calibration curves of repaglinide were linear in the concentration range of 20-200 ng/ml in plasma. The limits of detection and quantification were 10 ng/ml and 20 ng/ml, respectively. The inter-day precision was from 5.21 to 11.84% and the intra-day precision ranged from 3.90 to 6.67%. The inter-day accuracy ranged 89.95 to 105.75% and intra-day accuracy ranged from 92.37 to 104.66%. This method was applied to determine repaglinide concentration in human plasma samples for a pharmacokinetic study.
    Matched MeSH terms: Chromatography, High Pressure Liquid/instrumentation; Chromatography, High Pressure Liquid/methods*
  16. A rapid MCM-41 dispersive micro-solid phase extraction coupled with LC/MS/MS for quantification of ketoconazole and voriconazole in biological fluids
    Yahaya N, Sanagi MM, Abd Aziz N, Wan Ibrahim WA, Nur H, Loh SH, et al.
    Biomed Chromatogr, 2017 Feb;31(2).
    PMID: 27474795 DOI: 10.1002/bmc.3803
    A rapid dispersive micro-solid phase extraction (D-μ-SPE) combined with LC/MS/MS method was developed and validated for the determination of ketoconazole and voriconazole in human urine and plasma samples. Synthesized mesoporous silica MCM-41 was used as sorbent in d-μ-SPE of the azole compounds from biological fluids. Important D-μ-SPE parameters, namely type desorption solvent, extraction time, sample pH, salt addition, desorption time, amount of sorbent and sample volume were optimized. Liquid chromatographic separations were carried out on a Zorbax SB-C18 column (2.1 × 100 mm, 3.5 μm), using a mobile phase of acetonitrile-0.05% formic acid in 5 mm ammonium acetate buffer (70:30, v/v). A triple quadrupole mass spectrometer with positive ionization mode was used for the determination of target analytes. Under the optimized conditions, the calibration curves showed good linearity in the range of 0.1-10,000 μg/L with satisfactory limit of detection (≤0.06 μg/L) and limit of quantitation (≤0.3 μg/L). The proposed method also showed acceptable intra- and inter-day precisions for ketoconazole and voriconazole from urine and human plasma with RSD ≤16.5% and good relative recoveries in the range 84.3-114.8%. The MCM-41-D-μ-SPE method proved to be rapid and simple and requires a small volume of organic solvent (200 μL); thus it is advantageous for routine drug analysis.
    Matched MeSH terms: Chromatography, High Pressure Liquid/economics; Chromatography, High Pressure Liquid/methods
  17. Fulltext Palm-based medium-and-long-chain triacylglycerol (P-MLCT): production via enzymatic interesterification and optimization using response surface methodology (RSM)
    Lee YY, Tang TK, Phuah ET, Karim NA, Alwi SM, Lai OM
    J Food Sci Technol, 2015 Feb;52(2):685-96.
    PMID: 25694677 DOI: 10.1007/s13197-013-1065-0
    Structured lipid such as medium-and long-chain triacylglycerol (MLCT) is claimed to be able to suppress body fat accumulation and be used to manage obesity. Response surface methodology (RSM) with four factors and three levels (+1,0,-1) faced centered composite design (FCCD) was employed for optimization of the enzymatic interesterification conditions of palm-based MLCT (P-MLCT) production. The effect of the four variables namely: substrate ratio palm kernel oil: palm oil, PKO:PO (40:60-100:0 w/w), temperature (50-70 °C), reaction time (0.5-7.5 h) and enzyme load (5-15 % w/w) on the P-MLCT yield (%) and by products (%) produced were investigated. The responses were determined via acylglycerol composition obtained from high performance liquid chromatography. Well-fitted models were successfully established for both responses: P-MLCT yield (R (2) = 0.9979) and by-products (R (2) = 0.9892). The P-MLCT yield was significantly (P  0.05). Substrate ratio PKO: PO (100:0 w/w) gave the highest yield of P-MLCT (61 %). Nonetheless, substrate ratio of PKO: PO (90:10w/w) was chosen to improve the fatty acid composition of the P-MLCT. The optimized conditions for substrate ratio PKO: PO (90:10 w/w) was 7.26 h, 50 °C and 5 % (w/w) Lipozyme TLIM lipase, which managed to give 60 % yields of P-MLCT. Up scaled results in stirred tank batch reactor gave similar yields as lab scale. A 20 % increase in P-MLCT yield was obtained via RSM. The effect of enzymatic interesterification on the physicochemical properties of PKO:PO (90:10 w/w) were also studied. Thermoprofile showed that the P-MLCT oil melted below body temperature of 37 °C.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  18. Influence of step increases in hydraulic retention time on (RS)-MCPP degradation using an anaerobic membrane bioreactor
    Yuzir A, Chelliapan S, Sallis PJ
    Bioresour Technol, 2011 Oct;102(20):9456-61.
    PMID: 21862323 DOI: 10.1016/j.biortech.2011.07.083
    The effects of different hydraulic retention time (HRT) on (RS)-MCPP utilisation was investigated by decreasing the feed flow rate in an anaerobic membrane bioreactor (AnMBR). Results showed an average COD removal efficiency of 91.4%, 96.9% and 94.4% when the reactor was operated at HRT 3, 7 and 17 d, respectively. However, when the HRT was reduced to 1d, the COD removal efficiency declined to just only 60%, confirming the AnMBR is stable to a large transient hydraulic shock loads. The (RS)-MCPP removal efficiency fluctuated from 6% to 39% at HRT 3 d, however when it was increased to 7 and 17 d, the removal efficiency increased to an average of 60% and 74.5%. In addition, (RS)-MCPP specific utilisation rates (SUR) were dependent on the HRT and gradually improved from 18 to 43 μg mg VSS(-1) d(-1) as flow rate increased.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  19. Natural occurrence of ochratoxin A contamination in commercial black and white pepper products
    Jalili M, Jinap S, Radu S
    Mycopathologia, 2010 Oct;170(4):251-8.
    PMID: 20526682 DOI: 10.1007/s11046-010-9320-7
    The concentration of ochratoxin A (OTA) in 120 commercial pepper (84 pre-packed and 36 bulk samples), which consist of local and imported white and black pepper in powder and seed form in Malaysia were determined. The objective of the study was to investigate and compare OTA concentration in black pepper and white pepper being commercialized in Malaysia. Determination method was based on HPLC with fluorescence detection coupled with immunoaffinity column clean-up step. Mobile phase consisted of acetonitrile-water-acetic acid (49.5:49.5:1.0, v/v/v), and flow rate was 1 ml/min. The LOD was 0.02 ng/g, and the average recovery values of OTA ranged from 79.5 to 92.0% in black pepper and 81.2-90.3% in white pepper. A total of 57 samples (47.5%) were contaminated with OTA ranging from 0.15 to 13.58 ng/g. The results showed that there was a significant difference between type of pepper and brands. OTA concentration in black pepper was significantly higher than white pepper (p < 0.05). The highest concentration of ochratoxin, 13.58 ng/g, was detected in a sample of black pepper seed followed by 12.64 ng/g in a sample of black pepper powder, both were bulk samples purchased from open market.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  20. The Production of 9-methoxycanthin-6-one from Callus Cultures of (Eurycoma longifolia Jack) Tongkat Ali
    Maziah M, Rosli N
    Methods Mol Biol, 2009;547:359-69.
    PMID: 19521859 DOI: 10.1007/978-1-60327-287-2_29
    Plant cell culture technology is potentially useful in producing high-valued secondary metabolites. Eurycoma longifolia root extracts are consumed as a health tonic but more popularly used as an aphrodisiac. Studies on the aphrodisiac properties and the possible compounds involved have been widely studied. There are many potentially useful compounds reported from the root extracts of E. longifolia. However, studies on the in vitro production of useful compounds from this plant have not been reported. This chapter will describe methods of callus induction and extraction of 9-methoxycanthin-6-one from E. longifolia Jack explants with emphasis on the tap and fibrous roots. This compound, known to have anti-tumour activity, is present in intact plant parts and in callus tissues of different explants.
    Matched MeSH terms: Chromatography, High Pressure Liquid
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