Displaying publications 861 - 880 of 1883 in total

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  1. Shavani, Abirami, Adil Hussein, Wan-Hazabbah W.H.
    MyJurnal
    To report a rare case of an elderly gentleman who presented with herpes zoster ophthalmicus, complicated with persistent hyphema and orbital apex syndrome. A 75-year-old Malay gentleman presented with left herpes zoster ophthalmicus that was complicated with complete ophthalmoplegia and ptosis. He developed total hyphema in the affected eye with a secondary elevated intraocular pressure after a week. He was treated with oral acyclovir and topical corticosteroids. However, the total hyphema persisted that required an anterior chamber washout surgery. Herpes Zoster Ophthalmicus complicated with persistent hyphema and orbital apex syndrome is rare and very challenging to manage. Radiological imaging is important to exclude other causes of OAS. It is recommended to treat HZO with systemic acyclovir for a longer duration in view of ocular and neurological involvement.
    Matched MeSH terms: Intraocular Pressure
  2. Pei, Fang Neoh, Tai, Evelyn L.M., Liza-Sharmini A.T.
    MyJurnal
    A 65-year-old lady complained of occasional flashes of light over her left eye for 2 months. She was referred for ocular assessment after she underwent refractive assessment at the optometrist. On examination, best corrected visual acuity in both eyes was 6/9. Both eyes anterior segments were normal, with normal intraocular pressure. The pupils were equal with no relative afferent pupillary defect. Left eye fundus examination was normal. On the contrary, the "normal" right eye fundus examination revealed a huge, well-circumscribed hypo-pigmented elevated choroidal mass. B scan ultrasonography of the right eye showed a mushroom-shaped intraocular mass. Magnetic resonance imaging showed an intraocular lesion. Comprehensive systemic examination and investigations to rule out distant primary malignancy were unremarkable. A provisional diagnosis of right eye primary choroidal melanoma was made. Despite good vision in the affected eye, she underwent right eye enucleation in view of the large intraocular mass. The diagnosis was confirmed by histopathological examination.
    Matched MeSH terms: Intraocular Pressure
  3. Ofori-Boateng C, Lee KT
    Food Sci Nutr, 2013 05;1(3):209-221.
    PMID: 29387349 DOI: 10.1002/fsn3.22
    Oil palm (Elaeis guineensis Jacq.) fronds (OPF) are the most abundant oil palm solid wastes that are generated during oil palm agriculture and harvest. Palm oil and some other palm wastes have been reported to contain high concentrations of carotenoids with vital bioactive properties. However, the extraction and quantification of carotenoids from OPF have not been reported. In this study, ultrasonic-assisted extraction, HPLC-FLD for quantification, and response surface methodology (RSM) for optimization of β-carotene, lutein, and zeaxanthin from OPF extracts were investigated. The effects of extraction temperature (X1: 30-70°C), extraction time (X2: 10-50 min), and solvent-sample ratio (X3: 10-50 mL/g) on the recovery of β-carotene (Y1), lutein (Y2), and zeaxanthin (Y3) were investigated using three-level Box-Behnken design (BBD) experiment. At a desirability of 1, the optimum extraction conditions for β-carotene (30.14°C, 37.11 min, and 23.18 mL/g), lutein (30.00°C, 39.09 min, and 19.24 mL/g), and zeaxanthin (30.09°C, 36.76 min, and 22.38 mL/g) yielded carotenoid concentrations of 17.95 μg/g dry weight (DW), 261.99 μg/g DW, and 29.99 μg/g DW, respectively.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  4. Tang SS, Prodhan ZH, Biswas SK, Le CF, Sekaran SD
    Phytochemistry, 2018 Oct;154:94-105.
    PMID: 30031244 DOI: 10.1016/j.phytochem.2018.07.002
    Antimicrobial peptides (AMPs), the self-defence products of organisms, are extensively distributed in plants. They can be classified into several groups, including thionins, defensins, snakins, lipid transfer proteins, glycine-rich proteins, cyclotides and hevein-type proteins. AMPs can be extracted and isolated from different plants and plant organs such as stems, roots, seeds, flowers and leaves. They perform various physiological defensive mechanisms to eliminate viruses, bacteria, fungi and parasites, and so could be used as therapeutic and preservative agents. Research on AMPs has sought to obtain more detailed and reliable information regarding the selection of suitable plant sources and the use of appropriate isolation and purification techniques, as well as examining the mode of action of these peptides. Well-established AMP purification techniques currently used include salt precipitation methods, absorption-desorption, a combination of ion-exchange and reversed-phase C18 solid phase extraction, reversed-phase high-performance liquid chromatography (RP-HPLC), and the sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) method. Beyond these traditional methods, this review aims to highlight new and different approaches to the selection, characterisation, isolation, purification, mode of action and bioactivity assessment of a range of AMPs collected from plant sources. The information gathered will be helpful in the search for novel AMPs distributed in the plant kingdom, as well as providing future directions for the further investigation of AMPs for possible use on humans.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  5. Leman, A.M., Che Wan Izzudin, Md Zin Ibrahim, Dafit Feriyanto
    MyJurnal
    Brake pad apparatus is designed for help student and instructor in teaching and learning application. The objective
    of this research is to differentiate the pressure effect and braking temperature condition of different pad. This apparatus
    also aimed for learning the safety car and motorcycle braking system. This apparatus can to compare with theoretical
    calculation in order to approve that this apparatus is useful. The main concept in this apparatus is thermocouple use
    to detect the temperature gain while braking process. Speed motor controller used for set the angular velocity of the
    motor in braking process. Pressure applied at brake pedal detected by pressure gauge and data logger function as a
    connector. This apparatus also designed based on valid data for average of teenager in Malaysia which made on a
    sample university student. Result show that the apparatus can function effectively by defines the different temperature
    when applied the different pressure and different pad. Pad C shows the 880C for thermocouple 1 and 790C for
    thermocouple 2 at the 20 psi and infrared thermometer show 1130C for pad C. Graph from calculation shows that the
    pad A have 216.480C at 1000 rpm which have low temperature than pad B, C and D. high efficiency of friction and
    pressure applied will cause more heat generate than low coefficient of friction and pressure applied.
    Matched MeSH terms: Pressure
  6. Azizah, A.H., Wee, K.C., Azizah, O., Azizah, M.
    MyJurnal
    Effect of various cooking methods on antioxidant content and radical scavenging activity of pumpkin was evaluated. Pumpkin (Cucurbita moschata) was boiled and stir-fried for 2, 4 and 6 minutes respectively. Beta-carotene and lycopene were determined using HPLC and total phenolics measured using Folin-Ciocalteu method. The free radical scavenging activity of the samples was determined using 1, 1-diphenyl-2 picrylhydrazyl assay. Interestingly, result of the study showed an increase in both beta-carotene (2 to 4 times) and lycopene (17 to 40 times) content of pumpkin after cooking for 2, 4 and 6 minutes. However, the treatment resulted in 18 to 54% losses of total phenolics content of the pumpkin. Nevertheless, the free radical scavenging activity exhibited by cooked pumpkins was found to be high, in the range of 81.1% to 94.6% with IC50 of 1.41 to 1.62 mg ml-1
    .
    Matched MeSH terms: Chromatography, High Pressure Liquid
  7. Azrina, A., Abd Aziz, N., Khoo, H. E., Amin, I., Al-Sheraji, S. H., Muhammad Rizal, R.
    MyJurnal
    This study was conducted to determine the cholesterol and alpha-tocopherol contents of 20 marine fish and four other seafood from the Straits of Malacca. Cholesterol and alphatocopherol contents of the fish and other seafood were determined using high-performance liquid chromatography. The results showed that most of the fish contained low amounts of cholesterol, except sixbar grouper (Epinephelus fasciatus), long-tailed butterfly ray (Gymnura sp.), yellowstripe scad (Selaroides leptolepis), cuttlefish (Sepia officinalis), large-scale tongue sole (Cynoglossus arel), and longtail shad (Hilsa macrura) that contained high amounts of cholesterol (119.39-353.97 mg/100 g wet samples). Indian mackerel (Rastrelliger kanagurta), giant seaperch (Lates calcarifer), prawn (Metapenaeus affinis), and moonfish (Trachinotus blochii) had high alpha-tocopherol contents (462-989 μg/100 g wet sample). Regular consumption of fish and other seafood is highly recommended partly due to the high alphatocopherol content. Due to the high cholesterol in certain types of fish, consumption of the fish fillets of sixbar grouper, long-tailed butterfly ray, yellowstripe scad, cuttlefish, and large scale tongue sole should be < 100 g per day and < 50 per day for longtail shad. Validation of the analytical method also showed a high accuracy and reproducibility of the HPLC method.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  8. Abdullah R, Diaz LN, Wesseling S, Rietjens IM
    PMID: 27892830 DOI: 10.1080/19440049.2016.1266098
    After the incidences of induction of aristolochic acid nephropathy after consumption of herbal weight loss preparations that accidentally contained aristolochic acids (AAs), several countries defined national restrictions on the presence of AAs in food, including plant food supplements (PFS) and herbal products. This study investigates whether the risks associated with exposure to AAs via PFS and herbal products are at present indeed negligible. Data reported in literature on AA levels in PFS and other herbal products and also obtained from a new series of PFS in the present study were used to calculate the estimated daily intakes (EDIs) and corresponding margins of exposure (MOEs). Available literature data revealed that 206 out of 573 samples were found to contain aristolochic acid I (AAI) and/or aristolochic acid II (AAII). The results obtained from recently collected PFS revealed that both AAI and AAII were detected in three out of 18 analysed PFS at levels up to 594.8 and 235.3 µg g(-1), respectively, being in line with the levels reported in literature. The EDIs resulting from intake of these PFS resulted in MOEs that were generally below 10,000, corroborating the priority for risk management. Although these results refer to PFS collected by targeted sampling strategies, the data reveal that AA-containing PFS are still freely available. When considering that the use of these samples may be limited to shorter periods of time, the EDIs might be lower, but MOE values would still be lower than 10,000 for more than 50% of the AA-containing PFS and herbal products. In conclusion, the presence of AAs in PFS and herbal products even several years after instalment of the legal restrictions still raises concern, especially for people who frequently use the respective PFS and herbal products.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  9. Bivi MS, Paiko AS, Khairulmazmi A, Akhtar MS, Idris AS
    Plant Pathol J, 2016 Oct;32(5):396-406.
    PMID: 27721689
    Continuous supplementation of mineral nutrients and salicylic acid (SA) as foliar application could improve efficacy in controlling basal stem rot (BSR) disease in oil palm seedling. It is revealed from the results that the highest disease severity index (58.3%) was recorded in T8 treatments at 9 months after inoculation. The best disease control was achieved by T7 treatments (calcium/copper/SA [Ca/Cu/SA]) (5.0%) followed by T1 (5.5%), T5 (5.8%), T3 (8.3%), T6 (8.3%), T4 (13.3%), and T2 (15.8%) treatments. Continuous supplementation of Ca/Cu/SA was found to be the most effective in controlling the disease and the high performance liquid chromatography results showed the detection of ergosterol at very low concentration in the treated samples. Moreover, the transmission electron microscopy analysis results clearly indicated that T7 treatment was also enhancing lignification, which was responsible for the thickness of the secondary cell walls and middle lamella compared to untreated samples. It was therefore, concluded that continuous supplementation of minerals nutrients and SA could effectively suppress disease severity by reducing ergosterol activity and also improve the process of lignification in the treated plants. Furthermore, this treatment also managed to delay the onset of BSR symptoms and promote the growth of the seedlings and eventually suppress the BSR disease.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  10. Nurdianah, H.F., Ahmad Firdaus, A.H., Eshaifol Azam, O., Wan Adnan, W.O.
    MyJurnal
    Bee pollen is considered as one of the functional foods due to its complex biochemical
    properties. Bee pollen which is collected from pollen grains from various botanical sources
    contains almost a complete nutrition such as carbohydrates, proteins, amino acids, vitamins
    and minerals. Its beneficial effect on health is thought to be due to the presence of phenolic
    compounds with its antioxidant activity. Antioxidant activities of ethanolic bee pollen extract
    (BPE) from three species of Malaysian stingless bee; Trigona thoracica, Trigona itama and
    Trigona apicalis in this study were measured using DPPH-HPLC method and gallic acid (GA)
    as a standard reference. The percentage of DPPH inhibition by T. apicalis BPE at 1 mg/mL
    showed the highest inhibition (39%, GA equivalent to 0.3 mg/mL) compared with T. itama
    (14.3%, GA equivalent to 0.1 mg/mL) and T. thoracica (6.7%, GA equivalent to 0.05 mg/mL).
    Our result was the first in reporting antioxidant activity of BPE measured using DPPH-HPLC
    method from three different species of Malaysian stingless bee.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  11. 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
  12. Loh KS, Lee YH, Musa A, Salmah AA, Zamri I
    Sensors (Basel), 2008 Sep 18;8(9):5775-5791.
    PMID: 27873839
    Magnetic nanoparticles of Fe₃O₄ were synthesized and characterized using transmission electron microscopy and X-ray diffraction. The Fe₃O₄ nanoparticles were found to have an average diameter of 5.48 ±1.37 nm. An electrochemical biosensor based on immobilized alkaline phosphatase (ALP) and Fe₃O₄ nanoparticles was studied. The amperometric biosensor was based on the reaction of ALP with the substrate ascorbic acid 2-phosphate (AA2P). The incorporation of the Fe₃O₄ nanoparticles together with ALP into a sol gel/chitosan biosensor membrane has led to the enhancement of the biosensor response, with an improved linear response range to the substrate AA2P (5-120 μM) and increased sensitivity. Using the inhibition property of the ALP, the biosensor was applied to the determination of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D). The use of Fe₃O₄ nanoparticles gives a two-fold improvement in the sensitivity towards 2,4-D, with a linear response range of 0.5-30 μgL-1. Exposure of the biosensor to other toxicants such as heavy metals demonstrated only slight interference from metals such as Hg2+, Cu2+, Ag2+ and Pb2+. The biosensor was shown to be useful for the determination of the herbicide 2, 4-D because good recovery of 95-100 percent was obtained, even though the analysis was performed in water samples with a complex matrix. Furthermore, the results from the analysis of 2,4-D in water samples using the biosensor correlated well with a HPLC method.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  13. Chew BS, Ghazali R, Othman H, Ismail NAM, Othman AS, Laim NMST, et al.
    J Obstet Gynaecol Res, 2018 Oct 10.
    PMID: 30306675 DOI: 10.1111/jog.13836
    AIM: The aim of our study was to determine the endocan-1 expression in placenta of hypertensive women, and its association with maternal and fetal outcomes.

    METHODS: This was a cross-sectional study consisted of 21 pregnant women with hypertension and 23 without hypertension. The gestational age ranged from 28 to 39 weeks (hypertensive) and 32 to 40 weeks (normotensive). The paraffin embedded formalin fixed placenta tissue blocks were retrieved from the pathology archives. Endocan immunohistochemistry was performed on tissue sections of full thickness and maternal surface of the placenta. The endocan expression was determined in fetal endothelial cells, maternal endothelial cells, cytotrophoblasts, syncytiotrophoblasts and decidual cells. The differences in endocan expression in placenta between hypertensive and normotensive subjects were evaluated by Pearson chi-square test and t-test were used in the statistical analysis.

    RESULTS: The endocan expression was significantly higher in fetal endothelial cells (P

    Matched MeSH terms: Blood Pressure
  14. Tan CH, Tan KY, Tan NH
    Methods Mol Biol, 2019;1871:83-92.
    PMID: 30276733 DOI: 10.1007/978-1-4939-8814-3_5
    Snake venoms are complex mixtures of proteins and peptides that play vital roles in the survival of venomous snakes. As with their diverse pharmacological activities, snake venoms can be highly variable, hence the importance of understanding the compositional details of different snake venoms. However, profiling venom protein mixtures is challenging, in particular when dealing with the diversity of protein subtypes and their abundances. Here we described an optimized strategy combining a protein decomplexation method with in-solution trypsin digestion and mass spectrometry of snake venom proteins. The approach involves the integrated use of C18 reverse-phase high-performance liquid chromatography (RP-HPLC), sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and nano-electrospray ionization tandem mass spectrometry (nano-ESI-LC-MS/MS).
    Matched MeSH terms: Chromatography, High Pressure Liquid
  15. Kow FP, Adlina B, Sivasangari S, Punithavathi N, Ng KK, Ang AH, et al.
    Med J Malaysia, 2018 08;73(4):233-238.
    PMID: 30121686 MyJurnal
    INTRODUCTION: As pharmacological treatment of hypertension has become a burden worldwide, the study looked into nonpharmacological ways of reducing blood pressure. The objective was to determine if music guided, slow and deep breathing will reduce the blood pressure among patients with hypertension in eight weeks.

    METHODS: A participant blinded, multi-centre, randomised controlled trial was conducted in which the participants in the intervention group (IG) practiced deep breathing exercise guided by sound cues and those in the control group (CG) listened to the music. The primary end point was reduction in blood pressure at eight weeks.

    RESULTS: 87 patients, 46 males and 41 females with mean age of 61.1 years were recruited and 93.1% of them successfully completed the study. There was significant reduction in systolic and diastolic Blood Pressure from baseline by 8 weeks in both groups. The reduction in Mean systolic blood pressure (SBP) in the control arm was 10.5mmHg compared to 8.3mmHg (p<0.001) in intervention group. Diastolic blood pressure (DBP) reduction in control and intervention groups were 5.2 mmHg (p<0.001) and 5.6 mmHg (p<0.001) respectively. The absolute difference in SBP reduction from baseline in IG & CG was -2.2 (95%CI: -7.8 to 3.5) and DBP was -0.4 (95%CI: -2.9 to 3.6). However, blood pressure reduction between the two groups was not significant.

    CONCLUSIONS: Both listening to music and deep breathing exercise were associated with a clinically significant reduction in SBP and DBP. However, deep breathing exercise did not augment the benefit of music in reducing BP.

    Matched MeSH terms: Blood Pressure
  16. Al-Juhaimi F, Ghafoor K, Özcan MM, Jahurul MHA, Babiker EE, Jinap S, et al.
    J Food Sci Technol, 2018 Oct;55(10):3872-3880.
    PMID: 30228385 DOI: 10.1007/s13197-018-3370-0
    Bioactive compounds from plant sources are generally categorized as natural antioxidants with well-known health benefits. The health-promoting characteristics of natural antioxidants include anti-inflammatory, anti-diabetic, and hepatic effects as well as free radical scavenging. Herein, a comprehensive and comparative review are presented about the effects of conventional (thermal and mechanical) and relatively new (non-thermal) processing methods on phytochemicals and discussed the importance of implementing the use of those methods that could be of very helpful retaining the quality of the bioactive compounds in plant-based foods. Plant-based foods rich in phenolics, vitamin C, carotenoids, and other compounds undergo a range of processing operations before they are consumed. Most of these methods involve thermal treatments of fruits, stems, leaves, and roots. These techniques have varying effects on bioactive compounds and their activities, and the magnitude of these effects depends on process parameters such as temperature, time, and the food matrix. Thermal processing can be detrimental to bioactive compounds while nonthermal procedures may not cause significant deterioration of important health-promoting phytochemicals and in some cases can improve their bio-activity and bio-availability. The detrimental effects of conventional processing on the quality of natural antioxidants have been compared to the effects of innovative nonthermal food treatments such as gamma and ultraviolet irradiation, ultraviolet light, pulsed electric fields, and high hydrostatic pressure.
    Matched MeSH terms: Hydrostatic Pressure
  17. Mohd Ali, A., Jahidin, A.H., Abdul Wahab, I., Mohsin, H.F., Mizaton, H.H.
    MyJurnal
    In this study, the unprecedented extraction of the Vitex pouch was performed. The compounds from
    methanolic and chloroform extracts were isolated by using thin layer chromatography (TLC). The
    compound of interest was investigated by using 1H-Nuclear Magnetic Resonance (NMR, 500 MHz)
    spectroscopy. From the NMR spectral examination, the compound from the methanolic extract was
    suggested as glucononitol. Indeed, there are some parameters that could enhance the attainment of this
    research, which include high performance liquid chromatographic supplies. Nevertheless, more
    information and understanding on the pharmaceutical and chemical analysis of the Vitex species were
    obtained. To sum up, it is anticipated that incoming research with advanced technology for this
    natural product could be explored in the future.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  18. Mohammad Rashedi Ismail-Fitry, Safiullah Jauhar, Chong, Gun Hean, Mahmud Ab Rashid NorKhaizura, Wan Zunairah Wan Ibadullah
    MyJurnal
    Recently natural polyphenol compounds (PCs) of plants, gained wide consideration of
    scientists, companies and public people because of its unique pharmaceutical and
    preservative benefits in the physiological system. They can prevent mortal and serious
    diseases such as cancer, cardiovascular and Alzheimer. However, defining a suitable
    source of PCs and their proper, economic and efficient extraction method are still a
    challenge. The aim of this study was to review PCs as an important antioxidant, the
    significance of pomegranate as a source of natural PCs and its application in meat and
    meat product. This study also covers different types of PCs extraction methods such as
    solid-liquid extraction (SLE) method as a conventional extraction which using Soxhlet
    apparatus and several solvents and advanced methods such as microwave-assisted
    extraction (MAE), supercritical fluid extraction (SFE), accelerated solvent extraction
    (ASE), ultrasound-assisted extraction (UAE) and high hydrostatic pressure extraction
    (HHPE). Simple and developed analytical method of PCs is also reviewed in the study.
    SLE method is an easy and simple method but, it uses lots of chemicals and is not
    suitable for all kinds of PCs extraction. UAE is using for quick extraction PCs, SFE is green
    extraction method uses less solvent and have a good result but it needs high
    technology. ASE method is a proper alternative for Soxhlet extraction method for its
    quick result. MAE method has high extraction result but is not suitable for some
    thermolabile PCs. Several parts of pomegranate showed antioxidant and antimicrobial
    traits for shelf life extension of meat and meat product. Pomegranate peel is the
    strongest antioxidant followed by pomegranate juice and seed. Pomegranate peel
    prolonged chilled chicken meat shelf live up to three weeks.
    Matched MeSH terms: Hydrostatic Pressure
  19. Che Hussian CHA, Raja Abd Rahman RNZ, Thean Chor AL, Salleh AB, Mohamad Ali MS
    PeerJ, 2018;6:e5833.
    PMID: 30479887 DOI: 10.7717/peerj.5833
    T1 Lipase is a thermostable secretary protein of Geobacillus zalihae strain previously expressed in a prokaryotic system and purified using three-step purification: affinity 1, affinity 2, and ion exchange chromatography (IEX). This approach is time consuming and offers low purity and recovery yield. In order to enhance the purification strategy of T1 lipase, affinity 2 was removed so that after affinity 1, the cleaved Glutathione S-transferase (GST) and matured T1 lipase could be directly separated through IEX. Therefore, a rational design of GST isoelectric point (pI) was implemented by prediction using ExPASy software in order to enhance the differences of pI values between GST and matured T1 lipase. Site-directed mutagenesis at two locations flanking the downstream region of GST sequences (H215R and G213R) was successfully performed. Double point mutations changed the charge on GST from 6.10 to 6.53. The purified lipase from the new construct GST tag mutant-T1 was successfully purified using two steps of purification with 6,849 U/mg of lipase specific activity, 33% yield, and a 44-fold increase in purification. Hence, the increment of the pI values in the GST tag fusion T1 lipase resulted in a successful direct separation through IEX and lead to successful purification.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  20. Kar SS, Bhat VG, Shenoy VP, Bairy I, Shenoy GG
    Chem Biol Drug Des, 2019 01;93(1):60-66.
    PMID: 30118192 DOI: 10.1111/cbdd.13379
    In our efforts to develop druggable diphenyl ethers as potential antitubercular agents, a series of novel diphenyl ether derivatives (5a-f, 6a-f) were designed and synthesized. The representative compounds showed promising in vitro activity against drug-susceptible, isoniazid-resistant, and multidrug-resistant strains of Mycobacterium tuberculosis with MIC values of 1.56 μg/ml (6b), 6.25 μg/ml (6a-d), and 3.125 μg/ml (6b-c), respectively. All the synthesized compounds exhibited satisfactory safety profile (CC50  > 300 μg/ml) against Vero and HepG2 cells. Reverse phase HPLC method was used to probe the physicochemical properties of the synthesized compounds. This series of compounds demonstrated comparatively low logP values. pKa values of representative compounds indicated that they were weak acids. Additionally, in vitro human liver microsomal stability assay confirmed that the synthesized compounds possessed acceptable stability under study conditions. The present study thus establishes compound 6b as the most promising antitubercular agent with acceptable drug-likeness.
    Matched MeSH terms: Chromatography, High Pressure Liquid
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