Displaying publications 41 - 60 of 681 in total

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  1. Akowuah GA, Zhari I, Mariam A
    Food Chem Toxicol, 2008 Dec;46(12):3616-20.
    PMID: 18824206 DOI: 10.1016/j.fct.2008.09.008
    A simple high-performance liquid chromatography (HPLC) method was developed to determine the content of andrographolide (AP) and 14-deoxy-11,12-dideoxyandrographolide (DIAP) in a pooled urine of rat obtained within 24h after an oral dose of Andrographis paniculata leaf extract at 1g/kg body weight. Cumulative urinary excretion of AP and DIAP in 24h after oral administration of the extract was 0.88% and 1.61% of oral dose administered, respectively. The extract showed significant reduction (p<0.05) of MDA levels and elevation of total antioxidant status in rat urine samples collected in 24 after oral administration.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  2. Al Azzam KM, Makahleah A, Saad B, Mansor SM
    J Chromatogr A, 2010 Jun 4;1217(23):3654-9.
    PMID: 20409552 DOI: 10.1016/j.chroma.2010.03.055
    A three-phase hollow fiber liquid-phase microextraction (HF-LPME) coupled either with capillary electrophoresis (CE) or high performance liquid chromatography (HPLC) with UV detection methods was successfully developed for the determination of trace levels of the anti-diabetic drug, rosiglitazone (ROSI) in biological fluids. The analyte was extracted into dihexyl ether that was immobilized in the wall pores of a porous hollow fiber from 10 mL of aqueous sample, pH 9.5 (donor phase), and was back extracted into the acceptor phase that contained 0.1M HCl located in the lumen of the hollow fiber. Parameters affecting the extraction process such as type of extraction solvent, HCl concentration, donor phase pH, extraction time, stirring speed, and salt addition were studied and optimized. Under the optimized conditions (extraction solvent, dihexyl ether; donor phase pH, 9.5; acceptor phase, 0.1M HCl; stirring speed, 600 rpm; extraction time, 30 min; without addition of salt), enrichment factor of 280 was obtained. Good linearity and correlation coefficients of the analyte was obtained over the concentration ranges of 1.0-500 and 5.0-500 ng mL(-1) for the HPLC (r(2)=0.9988) and CE (r(2)=0.9967) methods, respectively. The limits of detection (LOD) and limits of quantitation (LOQ) for the HPLC and CE methods were (0.18, 2.83) and (0.56, 5.00) ng mL(-1), respectively. The percent relative standard deviation (n=6) for the extraction and determination of three concentration levels (10, 250, 500 ng mL(-1)) of ROSI using the HPLC and CE methods were less than 10.9% and 13.2%, respectively. The developed methods are simple, rapid, sensitive and are suitable for the determination of trace amounts of ROSI in biological fluids.
    Matched MeSH terms: Chromatography, High Pressure Liquid/methods*
  3. Al Madfai F, Zaidi STR, Ming LC, Wanandy T, Patel RP
    Eur J Hosp Pharm, 2018 Oct;25(e2):e115-e119.
    PMID: 31157080 DOI: 10.1136/ejhpharm-2017-001221
    Background: Severe infections such as endocarditis and osteomyelitis require long-term treatment with parenteral antibiotics and hence prolonged hospitalisation. Continuous infusion of ceftaroline through elastomeric devices can facilitate early hospital discharge by managing parenteral antibiotics in patient's home. Therefore, the purpose of this study was to investigate the stability of ceftaroline in a commonly used elastomeric device.

    Method: A total of 24 elastomeric devices were prepared, and six elastomeric devices containing 6mg/mL of ceftaroline (three in each type of diluents) were stored at one of the following conditions: 4°C for 6 days, 25°C for 24hours, 30°C for 24hours or 35°C for 24hours. An aliquot was withdrawn before storage and at different time points. Chemical stability was measured using a stability indicating high-performance liquid chromatography, and physical stability was assessed as change in pH, colour and particle content.

    Results: Ceftaroline, when admixed with both diluents, was stable for 144, 24 and 12hours at 4°C, 25°C and 30°C, respectively. At 35°C, ceftaroline admixed with normal saline (NS) and glucose 5% was stable for 12hours and for 6hours, respectively. No evidence of particle formation, colour change or pH change was observed throughout the study period.

    Conclusions: Our findings support 12 or 24hours continuous elastomeric infusion of ceftaroline-NS admixture, and bulk preparation of elastomeric pumps containing ceftaroline solution in advance. This would facilitate early hospital discharge of patients eligible for the elastomeric-based home therapy and avoid the need for patient's caregivers travelling to the hospital on a daily basis.

    Matched MeSH terms: Chromatography, High Pressure Liquid
  4. Al'Abri AM, Abdul Halim SN, Abu Bakar NK, Saharin SM, Sherino B, Rashidi Nodeh H, et al.
    J Environ Sci Health B, 2019;54(12):930-941.
    PMID: 31407615 DOI: 10.1080/03601234.2019.1652072
    This article demonstrates the first application of a copper-based porous coordination polymer (BTCA-P-Cu-CP) as a carbon paste electrode (CPE) modifier for the detection of malathion. The electrochemical behavior of BTCA-P-Cu-CP/CPE was explored using cyclic voltammetry (CV) while chrono-amperometry methods were applied for the analytical evaluation of the sensor performance. Under optimized conditions, the developed sensor exhibited high reproducibility, stability, and wide dynamic range (0.6-24 nM) with the limits of detection and sensitivity equal to 0.17 nM and 5.7 µAnMcm-1, respectively, based on inhibition signal measurement. Furthermore, the presence of common coexisting interfering species showed a minor change in signals (<4.4%). The developed sensor has been applied in the determination of malathion in spiked vegetable extracts. It exhibited promising results in term of fast and sensitive determination of malathion in real samples at trace level with recoveries of 91.0 to 104.4%. (RSDs < 5%, n = 3). A comparison of the two studied techniques showed that the HPLC technique is unable to detect malathion when the concentration is lower than 1.8 µM while 0.006 µM is detected with appropriate RSDs 0.2-5.2% (n = 3) by amperometric method. Due to the high sensitivity and selectivity, this new electrochemical sensor will be useful for monitoring trace malathion in real samples.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  5. Al-Jaal B, Latiff A, Salama S, Hussain HM, Al-Thani NA, Al-Naimi N, et al.
    Toxins (Basel), 2021 04 08;13(4).
    PMID: 33917988 DOI: 10.3390/toxins13040267
    Mycotoxins are naturally occurring food toxins worldwide that can cause serious health effects. The measurement of mycotoxin biomarkers in biological fluids is needed to assess individuals' exposure. The aim of this study was to investigate the incidence of mycotoxins in the Qatari population. Serum samples from 412 adults and urinary samples from 559 adults were analyzed for the presence of mycotoxin biomarkers. Multimycotoxin approaches have been applied, using liquid chromatography mass spectrometry methods. Samples were further analyzed for the oxidative stress markers and compared with regard to the incidence of mycotoxins. The presence of mycotoxins was identified in 37% of serum samples and in less than 20% of urine samples. It was found that 88% of positive of the samples were positive for only one mycotoxin, while 12% of positive samples had two or more mycotoxins. Trichothecenes and zearalenone metabolites were most commonly detected mycotoxins, followed by aflatoxins, roquefortine C and mycophenolic acid. The presence of mycotoxins was found to positively correlate with oxidative stress markers. The obtained results illustrate the importance of mycotoxin biomonitoring studies in humans and the need to elucidate the underlying mechanisms of mycotoxin-induced toxicity.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  6. Al-Khateeb A, Zahri MK, Mohamed MS, Sasongko TH, Ibrahim S, Yusof Z, et al.
    BMC Med Genet, 2011;12:40.
    PMID: 21418584 DOI: 10.1186/1471-2350-12-40
    Familial hypercholesterolemia is a genetic disorder mainly caused by defects in the low-density lipoprotein receptor gene. Few and limited analyses of familial hypercholesterolemia have been performed in Malaysia, and the underlying mutations therefore remain largely unknown.We studied a group of 154 unrelated FH patients from a northern area of Malaysia (Kelantan). The promoter region and exons 2-15 of the LDLR gene were screened by denaturing high-performance liquid chromatography to detect short deletions and nucleotide substitutions, and by multiplex ligation-dependent probe amplification to detect large rearrangements.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  7. Al-Qaim FF, Abdullah MP, Othman MR, Latip J, Zakaria Z
    J Chromatogr A, 2014 Jun 6;1345:139-53.
    PMID: 24768127 DOI: 10.1016/j.chroma.2014.04.025
    An analytical method that facilitated the analysis of 11 pharmaceuticals residue (caffeine, prazosin, enalapril, carbamazepine, nifedipine, levonorgestrel, simvastatin, hydrochlorothiazide, gliclazide, diclofenac-Na, and mefenamic acid) with a single pre-treatment protocol was developed. The proposed method included an isolation and concentration procedure using solid phase extraction (Oasis HLB), a separation step using high-performance liquid chromatography, and a detection procedure that applies time-of-flight mass spectrometry. The method was validated for drinking water (DW), surface water (SW), sewage treatment plant (STP) influent and effluent, and hospital (HSP) influent and effluent. The limits of quantification were as low as 0.4, 1.6, 5, 3, 2.2 and 11 ng/L in DW, SW, HSP influent and effluent, STP effluent, and STP influent, respectively. On average, good recoveries higher than 75% were obtained for most of the target analytes in all matrices. Matrix effect was evaluated for all samples matrices. The proposed method successfully determined and quantified the target compounds in raw and treated wastewater of four STPs and three hospitals in Malaysia, as well as in two SW sites. The results showed that a number of the studied compounds pose moderate to high persistency in sewage treatment effluents as well as in the recipient rivers, namely; caffeine, simvastatin, and hydrochlorothiazide. Ten out of 11 compounds were detected and quantified in 13 sampling points. Caffeine was detected with the highest level, with concentrations reaching up to 9099 ng/L in STP influent.
    Matched MeSH terms: Chromatography, High Pressure Liquid/methods*
  8. Al-Salahi OS, Kit-Lam C, Majid AM, Al-Suede FS, Mohammed Saghir SA, Abdullah WZ, et al.
    Microvasc Res, 2013 Nov;90:30-9.
    PMID: 23899415 DOI: 10.1016/j.mvr.2013.07.007
    Targeting angiogenesis could be an excellent strategy to combat angiogenesis-dependent pathophysiological conditions such as cancer, rheumatoid arthritis, obesity, systemic lupus erythematosus, psoriasis, proliferative retinopathy and atherosclerosis. Recently a number of clinical investigations are being undertaken to assess the potential therapeutic application of various anti-angiogenic agents. Many of these angiogenesis inhibitors are directed against the functions of endothelial cells, which are considered as the building blocks of blood vessels. Similarly, roots of a traditional medicinal plant, Eurycoma longifolia, can be used as an alternative treatment to prevent and treat the angiogenesis-related diseases. In the present study, antiangiogenic potential of partially purified quassinoid-rich fraction (TAF273) of E. longifolia root extract was evaluated using ex vivo and in vivo angiogenesis models and the anti-angiogenic efficacy of TAF273 was investigated in human umbilical vein endothelial cells (HUVEC). TAF273 caused significant suppression in sprouting of microvessels in rat aorta with IC50 11.5μg/ml. TAF273 (50μg/ml) showed remarkable inhibition (63.13%) of neovascularization in chorioallantoic membrane of chick embryo. Tumor histology also revealed marked reduction in extent of vascularization. In vitro, TAF273 significantly inhibited the major angiogenesis steps such as proliferation, migration and differentiation of HUVECs. Phytochemical analysis revealed high content of quassinoids in TAF273. Specially, HPLC characterization showed that TAF273 is enriched with eurycomanone, 13α(21)-epoxyeurycomanone and eurycomanol. These results demonstrated that the antiangiogenic activity of TAF273 may be due to its inhibitory effect on endothelial cell proliferation, differentiation and migration which could be attributed to the high content of quassinoids in E. longifolia.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  9. Al-Wajeeh AS, Salhimi SM, Al-Mansoub MA, Khalid IA, Harvey TM, Latiff A, et al.
    PLoS One, 2020;15(1):e0227404.
    PMID: 31945087 DOI: 10.1371/journal.pone.0227404
    BACKGROUND: Breast cancer is the fifth most prevalent cause of death among women worldwide. It is also one of the most common types of cancer among Malaysian women. This study aimed to characterize and differentiate the proteomics profiles of different stages of breast cancer and its matched adjacent normal tissues in Malaysian breast cancer patients. Also, this study aimed to construct a pertinent protein pathway involved in each stage of cancer.

    METHODS: In total, 80 samples of tumor and matched adjacent normal tissues were collected from breast cancer patients at Seberang Jaya Hospital (SJH) and Kepala Batas Hospital (KBH), both in Penang, Malaysia. The protein expression profiles of breast cancer and normal tissues were mapped by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The Gel-Eluted Liquid Fractionation Entrapment Electrophoresis (GELFREE) Technology System was used for the separation and fractionation of extracted proteins, which also were analyzed to maximize protein detection. The protein fractions were then analyzed by tandem mass spectrometry (LC-MS/MS) analysis using LC/MS LTQ-Orbitrap Fusion and Elite. This study identified the proteins contained within the tissue samples using de novo sequencing and database matching via PEAKS software. We performed two different pathway analyses, DAVID and STRING, in the sets of proteins from stage 2 and stage 3 breast cancer samples. The lists of molecules were generated by the REACTOME-FI plugin, part of the CYTOSCAPE tool, and linker nodes were added in order to generate a connected network. Then, pathway enrichment was obtained, and a graphical model was created to depict the participation of the input proteins as well as the linker nodes.

    RESULTS: This study identified 12 proteins that were detected in stage 2 tumor tissues, and 17 proteins that were detected in stage 3 tumor tissues, related to their normal counterparts. It also identified some proteins that were present in stage 2 but not stage 3 and vice versa. Based on these results, this study clarified unique proteins pathways involved in carcinogenesis within stage 2 and stage 3 breast cancers.

    CONCLUSIONS: This study provided some useful insights about the proteins associated with breast cancer carcinogenesis and could establish an important foundation for future cancer-related discoveries using differential proteomics profiling. Beyond protein identification, this study considered the interaction, function, network, signaling pathway, and protein pathway involved in each profile. These results suggest that knowledge of protein expression, especially in stage 2 and stage 3 breast cancer, can provide important clues that may enable the discovery of novel biomarkers in carcinogenesis.

    Matched MeSH terms: Chromatography, High Pressure Liquid
  10. Alafiatayo AA, Lai KS, Syahida A, Mahmood M, Shaharuddin NA
    PMID: 30949217 DOI: 10.1155/2019/3807207
    Curcuma longa L. is a rhizome plant often used as traditional medicinal preparations in Southeast Asia. The dried powder is commonly known as cure-all herbal medicine with a wider spectrum of pharmaceutical activities. In spite of the widely reported therapeutic applications of C. longa, research on its safety and teratogenic effects on zebrafish embryos and larvae is still limited. Hence, this research aimed to assess the toxicity of C. longa extract on zebrafish. Using a reflux flask, methanol extract of C. longa was extracted and the identification and quantification of total flavonoids were carried out with HPLC. Twelve fertilized embryos were selected to test the embryotoxicity and teratogenicity at different concentration points. The embryos were exposed to the extract in the E3M medium while the control was only exposed to E3M and different developmental endpoints were recorded with the therapeutic index calculated using the ratio of LC50/EC50. C. longa extract was detected to be highly rich in flavonoids with catechin, epicatechin, and naringenin as the 3 most abundant with concentrations of 3,531.34, 688.70, and 523.83μg/mL, respectively. The toxicity effects were discovered to be dose-dependent at dosage above 62.50μg/mL, while, at 125.0μg/mL, mortality of embryos was observed and physical body deformities of larvae were recorded among the hatched embryos at higher concentrations. Teratogenic effect of the extract was severe at higher concentrations producing physical body deformities such as kink tail, bend trunk, and enlarged yolk sac edema. Finally, the therapeutic index (TI) values calculated were approximately the same for different concentration points tested. Overall, the result revealed that plants having therapeutic potential could also pose threats when consumed at higher doses especially on the embryos. Therefore, detailed toxicity analysis should be carried out on medicinal plants to ascertain their safety on the embryos and its development.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  11. Alam N, Hossain M, Khalil MI, Moniruzzaman M, Sulaiman SA, Gan SH
    PMID: 21854608 DOI: 10.1186/1472-6882-11-65
    Withania somnifera is an important medicinal plant traditionally used in the treatment of many diseases. The present study was carried out to characterize the phenolic acids, flavonoids and 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) scavenging activities in methanolic extracts of W. somnifera fruits, roots and leaves (WSFEt, WSREt and WSLEt).
    Matched MeSH terms: Chromatography, High Pressure Liquid
  12. Alauddin H, Mohamad Nasir S, Ahadon M, Raja Sabudin RZ, Ithnin A, Hussin NH, et al.
    Malays J Pathol, 2015 Dec;37(3):287-92.
    PMID: 26712677
    Haemoglobin (Hb) Lepore is a variant Hb consisting of two α-globin and two δβ-globin chains. In a heterozygote, it is associated with clinical findings of thalassaemia minor, but interactions with other haemoglobinopathies can lead to various clinical phenotypes and pose diagnostic challenges. We reported a pair of siblings from a Malay family, who presented with pallor and hepatosplenomegaly at the ages of 21 months and 14 months old. The red cell indices and peripheral blood smears of both patients showed features of thalassaemia intermedia. Other laboratory investigations of the patients showed conflicting results. However, laboratory investigation results of the parents had led to a presumptive diagnosis of compound heterozygote Hb Lepore/β-thalassaemia and co-inheritance α+-thalassaemia (-α3.7). Hb Lepore has rarely been detected in Southeast Asian countries, particularly in Malaysia. These two cases highlight the importance of family studies for accurate diagnosis, hence appropriate clinical management and genetic counseling.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  13. Ali F, Ranneh Y, Ismail A, Esa NM
    J Food Sci Technol, 2015 Apr;52(4):2103-11.
    PMID: 25829590 DOI: 10.1007/s13197-013-1187-4
    The antioxidant components of cocoa powder, which is rich in polyphenols, were isolated using column chromatography and high performance liquid chromatography. Polyphenolic compounds were then characterized by high-performance liquid chromatography/Ultraviolet and electronspray ionization-tandem mass spectrometry (HPLC-UV-/ESI-MS-MS). As a result, five phenolic compounds were detected. In this study we also investigated scavenging or the total antioxidant capacity (%) of cocoa polyphenol (CP) fractionated from cocoa powder extract. 114.0 mg/g of gallic acid -equivalent phenolics and 94.3 mg/g catechin- equivalent flavonoids were quantified in this extract. Their free radical-scavenging activity was assessed by 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) assay, β-carotene bleaching test, and xanthine oxidase inhibitory activity (OX). Total antioxidant capacity (TAC) was further assessed against the myoglobin-induced oxidation of 6-hydroxy-2, 5, 7, 8-tetramethylchroman-2-carboxylic acid (ABTS) and expressed as Trolox equivalent. A high correlation between TAC and phenolic contents indicated that phenolic compounds from cocoa were a major contributor of antioxidant activity (0.967 ≤ r ≤ 1.00). CP extract had significantly (P 
    Matched MeSH terms: Chromatography, High Pressure Liquid
  14. Ali N, Hashim NH, Shuib NS
    PMID: 25658149 DOI: 10.1080/19440049.2015.1011712
    The analysis of aflatoxins (B1, B2, G1 and G2) and ochratoxin A (OTA) was performed in processed spices marketed in Penang, Malaysia, using immunoaffinity columns and HPLC equipped with fluorescence detector (HPLC-FD). The processed powdered spices analysed include dried chilli, fennel, cumin, turmeric, black and white pepper, poppy seed, coriander, 'garam masala', and mixed spices for fish, meat and chicken curry. Two different studies were carried out. The limit of detection (LOD) was 0.01 ng g(-1) for each aflatoxin (AF) and 0.10 ng g(-1) for OTA (signal-to-noise ratio = 3:1). In the first study, 34 commercial processed spices analysed with a mean level, range and incidence of positive samples for total AF were 1.61 ng g(-1), 0.01-9.34 ng g(-1) and 85%, respectively, and for AFB1 were 1.38 ng g(-1), 0.01-7.68 ng g(-1) and 85%, respectively. The mean level, range and incidence of positive samples for OTA were 2.21 ng g(-1), 0.14-20.40 ng g(-1) and 79%, respectively. Natural co-occurrence of AF and OTA was found in 25 (74%) samples. In the second study of 24 commercial processed spices, the mean level, range and incidence of positive samples for total AF were 8.38 ng g(-1), 0.32-31.17 ng g(-1) and 88%, respectively, and for AFB1 were 7.31 ng g(-1), 0.32-28.43 ng g(-1) and 83%, respectively. Fifteen positive samples for total AF and two positive samples for OTA exceeded the permissible Malaysian limit of 5 ng g(-1). Contamination of both mycotoxins in spices may represent another route of exposure to consumers due to their frequent and prolonged consumption, as spices are common ingredients in popular dishes among Asian countries.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  15. Ali N, Hashim NH, Yoshizawa T
    Food Addit Contam, 1999 Jul;16(7):273-80.
    PMID: 10656052
    For application to the analysis of aflatoxins (AF) in commercial peanut and corn products, the ISOLUTE multimode column (IMC, solid phase multifunctional column) method was validated by comparing with the modified Florisil column (MFC) method. Twenty-two peanut and eight corn products from Malaysia and the Philippines were analysed for AFB1, AFB2, AFG1 and AFG2 firstly by the MFC method and then by the IMC method. For peanut products, 14 out of 22 samples were positive by the two methods in the range of 1-378 micrograms/kg of AF, and correlation coefficients (r) for AFB1 and AFB2 were 0.987 and 0.997, respectively. For corn and corn products, all the samples were positive in the range of 1-130 micrograms/kg, and r values were 0.992 and 0.805 for AFB1 and AFB2 respectively. Thus, the results were significantly (p < 0.01) in close agreement, particularly for lower range of 1-50 micrograms/kg of AF concentrations in all the samples. For the occurrence of AF, 11 (65%) of peanut products from Malaysia were contaminated with AF at a mean level of 50 micrograms/kg (maximum 180 micrograms/kg) and two (40% products from the Philippines were contaminated with as high as 375 micrograms/kg and 177 micrograms/kg of AF, respectively. All the corn products from the Philippines were contaminated with AF at a mean level of 44 micrograms/kg (maximum 130 micrograms/kg). Contamination of commercial foods with high levels of AF is a very important issue to both the countries since these foods are very popular among children.
    Matched MeSH terms: Chromatography, High Pressure Liquid/methods
  16. Ali N, Hashim NH, Saad B, Safan K, Nakajima M, Yoshizawa T
    Food Chem Toxicol, 2005 Dec;43(12):1763-72.
    PMID: 16019122
    Traditional herbal medicines, popularly known as 'jamu' and 'makjun' in Malaysia and Indonesia, are consumed regularly to promote health. In consideration of their frequent and prolonged consumption, the natural occurrence of aflatoxins (AF) in these products was determined using immunoaffinity column clean-up and high-performance liquid chromatography with pre-column derivatization. The evaluated method, which entails dilution of sample extracts with Tween 20-phosphate buffered saline (1:9, v/v) and a chromatographic system using isocratic mobile phase composed of water-methanol-acetonitrile (70:20:10, v/v/v), was effective in separating AFB1, AFG1 and AFG2 from interference at their retention times. Results were confirmed using post-column derivatization with photochemical reactor. For 23 commercial samples analyzed, mean levels (incidence) of AFB(1), AFB(2) and AFG1 in positive samples were 0.26 (70%), 0.07 (61%) and 0.10 (30%) microg/kg, respectively; one sample was positive for AFG2 at a level of 0.03 (4%) microg/kg. In contrast to the high levels of AF in crude herbal drugs and medicinal plants reported previously by other researchers, the low contamination levels reported in this study may be attributed to the higher selectivity to AF of the method applied. Based on the AFB1 levels and the daily consumption of positive samples, a mean probable daily intake of 0.022 ng/kg body weight was calculated.
    Matched MeSH terms: Chromatography, High Pressure Liquid/methods
  17. Alkhatib H, Mawazi SM, Al-Mahmood SMA, Zaiter A, Doolaanea AA
    J Pharm Bioallied Sci, 2020 07 18;12(3):284-288.
    PMID: 33100788 DOI: 10.4103/jpbs.JPBS_208_20
    Thymoquinone (TQ) is the major active compound in black seed oil (BSO). Many pharmacological effects of TQ, such as anti-inflammatory, hypoglycemic, antioxidant, immune stimulator, and anticancer, have been reported. TQ can be considered as a biomarker for BSO, but its content in the commercial products is rarely reported. TQ content varies based on the oil source and extraction method. This study aimed to quantify the TQ content in the commercial BSO products in Malaysia and to evaluate whether the products can be used as a source of TQ for therapeutic benefits. TQ was quantified using an established high-performance liquid chromatography (HPLC) method. TQ human equivalent dose (HED) was calculated based on reported animal studies from literature, and theoretical BSO amount containing the TQ dose was calculated based on the HPLC analysis. TQ content in the commercial BSO products ranged from 0.07% wt/wt to 1.88% wt/wt. The product with the highest TQ concentration is approximately 27-fold higher than the product with the lowest TQ concentration. Consequently, theoretical BSO amounts needed for specific diseases varied and some products cannot provide practical amount of TQ. This study recommends the regulation of TQ content in BSO and suggests that the BSO might be fortified with extra TQ to be effectively used in some diseases.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  18. Almakki, Asma, Mirghani, Mohamed E.S., Kabbashi, Nassereldeen A.
    MyJurnal
    Citric acid (CA) has a high demand due to its various uses in the food and pharmaceutical industries. However, the natural supply of CA is minimal compared to its growing industrial demand. The increasing demand for CA can be fulfilled by using biotechnological processes. This study utilized liquid state bioconversion by Aspergillus niger for CA production using sugarcane molasses as the primary substrate. Sugarcane molasses which is agricultural waste consists of significant proportion of organic matters such as lipids and carbohydrates. This makes sugarcane molasses as a potential and alternative source of producing CA at a lower cost. In this study, statistical optimization was applied to improve CA production using submerged fermentation in shake flasks. Aspergillus niger was cultured in potato dextrose agar. Then, inoculum spores were introduced into the fermentation media for a specific duration according to the experimental design from Central Composite Design (CCD) tool under Response Surface Methodology (RSM) in Design Expert 6.0 software. Three parameters were chosen to be optimized at 32⁰C i.e.agitation rate (160, 80, 200 rpm), substrate concentration (47, 60, 73%) and fermentation time (24, 72, 120 h). High Performance Liquid Chromatography (HPLC)and Fourier-transform infrared spectroscopy(FTIR) analyses were conducted to measure CA yield. The optimization study showed that the media incubated for 72 hours with a substrate concentration of 60% and an agitation speed of 180 rpm produced the highest CA yield(21.2 g/L).The analysis of variance (ANOVA) also showed that CCD quadratic model was significant with P-value< 0.0104 and R2is0.8964.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  19. Alshaibani M, Zin NM, Jalil J, Sidik N, Ahmad SJ, Kamal N, et al.
    J Microbiol Biotechnol, 2017 07 28;27(7):1249-1256.
    PMID: 28535606 DOI: 10.4014/jmb.1608.08032
    In our search for new sources of bioactive secondary metabolites from Streptomyces sp., the ethyl acetate extracts from endophytic Streptomyces SUK 25 afforded five active diketopiperazine (DKP) compounds. The aim of this study was to characterize the bioactive compounds isolated from endophytic Streptomyces SUK 25 and evaluate their bioactivity against multiple drug resistance (MDR) bacteria such as Enterococcus raffinosus, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumanii, Pseudomonas aeruginosa, and Enterobacter spp., and their cytotoxic activities against the human hepatoma (HepaRG) cell line. The production of secondary metabolites by this strain was optimized through Thornton's medium. Isolation, purification, and identification of the bioactive compounds were carried out using high-performance liquid chromatography, high-resolution mass liquid chromatography-mass spectrometry, Fourier transform infrared spectroscopy, and nuclear magnetic resonance, and cryopreserved HepaRG cells were selected to test the cytotoxicity. The results showed that endophytic Streptomyces SUK 25 produces four active DKP compounds and an acetamide derivative, which were elucidated as cyclo-(L-Val-L-Pro), cyclo-(L-Leu-L-Pro), cyclo-(L-Phe-L-Pro), cyclo-(L-Val-L-Phe), and N-(7-hydroxy-6-methyl-octyl)-acetamide. These active compounds exhibited activity against methicillin-resistant S. aureus ATCC 43300 and Enterococcus raffinosus, with low toxicity against human hepatoma HepaRG cells. Endophytic Streptomyces SUK 25 has the ability to produce DKP derivatives biologically active against some MDR bacteria with relatively low toxicity against HepaRG cells line.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  20. Alshishani A, Makahleh A, Yap HF, Gubartallah EA, Salhimi SM, Saad B
    Talanta, 2016 Dec 01;161:398-404.
    PMID: 27769423 DOI: 10.1016/j.talanta.2016.08.067
    A new sample preparation method, ion-pair vortex assisted liquid-liquid microextraction (VALLME-BE), for the determination of a highly polar anti-diabetic drug (metformin) in plasma sample was developed. The VALLME-BE was performed by diluting the plasma in borate buffer and extracted to 150µL 1-octanol containing 0.2M di-(2-ethylhexyl)phosphoric acid as intermediate phase. The drug was next back-extracted into 20µL of 0.075M HCl solution. The effects of pH, ion-pair concentration, type of organic solvent, volume of extraction phases, ionic strength, vortexing and centrifugation times on the extraction efficiency were investigated. The optimum conditions were at pH 9.3, 60s vortexing and 2min centrifugation. The microextract, contained metformin and buformin (internal standard), was directly injected into a HPLC unit using C1 column (250mm×4.6mm×10µm) and detected at 235nm. The method was validated and calibration curve was linear with r2>0.99 over the range of 20-2000µgL-1. The limits of detection and quantitation were 1.4 and 4.1µgL-1, respectively. The accuracy was within 94.8-108% of the nominal concentration. The relative standard deviation for inter- and intra-day precision was less than 10.8%. The method was conveniently applied for the determination of metformin in plasma samples.
    Matched MeSH terms: Chromatography, High Pressure Liquid/methods
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