Displaying publications 761 - 780 of 962 in total

Abstract:
Sort:
  1. Ceesay A, Nor Shamsudin M, Aliyu-Paiko M, Ismail IS, Nazarudin MF, Mohamed Alipiah N
    Biomed Res Int, 2019;2019:2640684.
    PMID: 31119160 DOI: 10.1155/2019/2640684
    The aim of the present study was to extract and characterize bioactive components from separate body organs of Holothuria leucospilota. Preliminary qualitative assessment of the crude extracts was positive for phenols, terpenoids, carbohydrates, flavonoids, saponins, glycosides, cardiac glycosides, steroids, phlobatannins, and tannins in all body organs evaluated. Phenolics were the most abundant group of bioactives accounting for approximately 80%. The extraction solvent mixtures that yielded most compounds evaluated were methanol/acetone (3:1, v:v) and methanol/distilled water (3:1, v:v). In other analyses, GC-MS data revealed diverse metabolic and biologically active compounds, where those in high concentrations included 2-Pentanone, 4-hydroxy-4-methyl- among the ketones; phenol- 2,4-bis(1,1-dimethylethyl)-, a phenol group; and 2-Chlorooctane, a hydrocarbon. Among FA and their methyl/ethyl esters, n-hexadecanoic acid, 5,8,11,14-eicosatetraenoic acid ethyl ester (arachidonic acid), and 5,8,11,14,17-eicosapentaenoic acid methyl ester (EPA) were among the most abundant FAMEs accounting for approximately 50% of the subgroups measured. Data from GC-FID analysis revealed methyl laurate (C12:0), methyl myristate (C14:0), methyl palmitate (C16:0), and methyl stearate (18:0) methyl esters as the most abundant saturated FA, whereas cis-9-oleic methyl ester (C18:1) and methyl linoleate (C18:2) were found as the major monounsaturated FA and PUFA FAMEs, respectively, in the body wall of the species. Taken together, the extraction and characterization of different categories of metabolically and biologically active compounds in various organ extracts of H. leucospilota suggest that the species is potentially a rich source of cholesterol-lowering, antioxidant, antimicrobial, and anticancer agents. These substances are known to benefit human health and assist in disease prevention. These findings justify the use of sea cucumbers in traditional folklore medication and the current interest and attention focused on the species to mine for bioactives in new drugs research.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
  2. Nayan N, van Erven G, Kabel MA, Sonnenberg AS, Hendriks WH, Cone JW
    J Sci Food Agric, 2019 Jun;99(8):4054-4062.
    PMID: 30737799 DOI: 10.1002/jsfa.9634
    BACKGROUND: White rot fungi have been used to improve the nutritive value of lignocellulose for ruminants. In feed analysis, the Van Soest method is widely used to determine the cell wall contents. To assess the reliability of this method (Method A) for determination of cell wall contents in fungal-treated wheat straw, we compared a combined monosaccharide analysis and pyrolysis coupled to gas chromatography with mass spectrometry (Py-GC/MS) (Method B). Ruminal digestibility, measured as in vitro gas production (IVGP), was subsequently used to examine which method explains best the effect of fungal pretreatment on the digestibility of wheat straw.

    RESULTS: Both methods differed considerably in the mass recoveries of the individual cell wall components, which changed on how we assess their degradation characteristics. For example, Method B gave a higher degradation of lignin (61.9%), as compared to Method A (33.2%). Method A, however, showed a better correlation of IVGP with the ratio of lignin to total structural carbohydrates, as compared to Method B (Pearson's r of -0.84 versus -0.69). Nevertheless, Method B provides a more accurate quantification of lignin, reflecting its actual modification and degradation. With the information on the lignin structural features, Method B presents a substantial advantage in understanding the underlying mechanisms of lignin breakdown. Both methods, however, could not accurately quantify the cellulose contents - among others, due to interference of fungal biomass.

    CONCLUSION: Method A only accounts for the recalcitrant residue and therefore is more suitable for evaluating ruminal digestibility. Method B allows a more accurate quantification of cell wall, required to understand and better explains the actual modification of the cell wall. The suitability of both methods, therefore, depends on their intended purposes. © 2019 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
  3. Chua LYW, Chua BL, Figiel A, Chong CH, Wojdyło A, Szumny A, et al.
    Molecules, 2019 Apr 24;24(8).
    PMID: 31022967 DOI: 10.3390/molecules24081625
    The preservation of active constituents in Cassia alata through the removal of moisture is crucial in producing a final product with high antioxidant activity. This study aims to determine the influences of various drying methods and drying conditions on the antioxidant activity, volatiles and phytosterols content of C. alata. The drying methods used were convective drying (CD) at 40 °C, 50 °C and 60 °C; freeze drying; vacuum microwave drying (VMD) at 6, 9 and 12 W/g; and two-stage convective pre-drying followed by vacuum microwave finish drying (CPD-VMFD) at 50 °C and 9 W/g. The drying kinetics of C. alata are best described by the thin-layer model (modified Page model). The highest antioxidant activity, TPC and volatile concentration were achieved with CD at 40 °C. GC-MS analysis identified the presence of 51 volatiles, which were mostly present in all samples but with quantitative variation. The dominant volatiles in fresh C. alata are 2-hexenal (60.28 mg 100 g-1 db), 1-hexanol (18.70 mg 100 g-1 db) and salicylic acid (15.05 mg 100 g-1 db). The concentration of phytosterols in fresh sample was 3647.48 mg 100 g-1 db, and the major phytosterols present in fresh and dried samples were β-sitosterol (1162.24 mg 100 g-1 db). CPD-VMFD was effective in ensuring the preservation of higher phytosterol content in comparison with CD at 50 °C. The final recommendation of a suitable drying method to dehydrate C. alata leaves is CD at 40 °C.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
  4. Auwal SM, Zainal Abidin N, Zarei M, Tan CP, Saari N
    PLoS One, 2019;14(5):e0197644.
    PMID: 31145747 DOI: 10.1371/journal.pone.0197644
    Stone fish is an under-utilized sea cucumber with many health benefits. Hydrolysates with strong ACE-inhibitory effects were generated from stone fish protein under the optimum conditions of hydrolysis using bromelain and fractionated based on hydrophobicity and isoelectric properties of the constituent peptides. Five novel peptide sequences with molecular weight (mw) < 1000 daltons (Da) were identified using LC-MS/MS. The peptides including Ala-Leu-Gly-Pro-Gln-Phe-Tyr (794.44 Da), Lys-Val-Pro-Pro-Lys-Ala (638.88 Da), Leu-Ala-Pro-Pro-Thr-Met (628.85 Da), Glu-Val-Leu-Ile-Gln (600.77 Da) and Glu-His-Pro-Val-Leu (593.74 Da) were evaluated for ACE-inhibitory activity and showed IC50 values of 0.012 mM, 0.980 mM, 1.310 mM, 1.440 mM and 1.680 mM, respectively. The ACE-inhibitory effects of the peptides were further verified using molecular docking study. The docking results demonstrated that the peptides exhibit their effect mainly via hydrogen and electrostatic bond interactions with ACE. These findings provide evidence about stone fish as a valuable source of raw materials for the manufacture of antihypertensive peptides that can be incorporated to enhance therapeutic relevance and commercial significance of formulated functional foods.
    Matched MeSH terms: Tandem Mass Spectrometry
  5. Ezzat SM, Ezzat MI, Okba MM, Hassan SM, Alkorashy AI, Karar MM, et al.
    PMID: 31275418 DOI: 10.1155/2019/7543460
    Eurycoma longifolia Jack (Fam.: Simaroubaceae), known as Tongkat Ali (TA), has been known as a symbol of virility and sexual power for men. Metabolic profiling of the aqueous extract of E. longifolia (AEEL) using UPLC-MS/MS in both positive and negative modes allowed the identification of seventeen metabolites. The identified compounds were classified into four groups: quassinoids, alkaloids, triterpenes, and biphenylneolignans. AEEL is considered safe with oral LD50 cut-off >5000 mg/kg. Oral administration of 50, 100, 200, 400, or 800 mg/kg of AEEL for 10 consecutive days to Sprague-Dawley male rats caused significant reductions in mounting, intromission, and ejaculation latencies and increased penile erection index. AEEL increased total body weight and relative weights of seminal vesicles and prostate. Total and free serum testosterone and brain cortical and hippocampal dopamine content was significantly elevated in treated groups with no significant effects on serotonin or noradrenaline content.
    Matched MeSH terms: Tandem Mass Spectrometry
  6. Gan CY, Zainuddin Z, Muhamad Noh H, Rahmat R, Mohd Akir F, Mahad NH, et al.
    Forensic Sci Int, 2019 Sep;302:109865.
    PMID: 31279278 DOI: 10.1016/j.forsciint.2019.06.023
    Consumption of curry containing poppy seeds has raised an issue concerning the opiate content in the urine that might exceed the cut-off value (300ng/mL). The main objective of this study was to examine the morphine and codeine contents in the urine of the consumers after partaking poppy seed-enriched curry in. The volunteers were asked to partake: (a) a single meal and their urines were collected within 24h, or (b) Two meals a day for three consecutive days and their urines were collected within 72h. Two different dosages were also tested in this study: (a) low dosage: 1g/100ml curry (containing 138μg of morphine and 66μg of codeine) and (b) high dosage: 5g/100ml curry (containing 690μg of morphine and 330μg of codeine). The subjects were randomised into the groups using the method of stratified randomization with age and gender groups as covariates. A total of 6 subjects was allocated for each group and placebos were used as control. Results showed that all subjects who consumed low dosage of poppy seeds either in single meal or multiple meals experiment were found negative. However, 1 out of 6high dosage subjects was confirmed positive at a period of 3-6h after the consumption of curry in the single meal study. This outlier maybe due to the lack of water consumption after consuming the curry, thus the low volume of urine was collected and the opiate was concentrated in the urine. On the other hand, 5 out of 6high dosage subjects in the multiple meals experiment were found positive. Majority of these subjects were found positive on the second and third day of the experiment after the second curry meal was consumed. The outlier (negative) in this group might be due to the high consumption of water throughout the experiment and the subject's urine volumes and frequency of urine collection were much higher compared to other subjects. From the result of this study, it can be concluded that partaking high dosages of poppy seed in curry could give a positive response (>300ng/ml+uncertainty of measurement) in the urine, and the water consumption after partaking curry has significant influence for the opiate contents in the urine.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
  7. Nafeesa K, Aziz-Ur-Rehman -, Abbasi MA, Siddiqui SZ, Rasool S, Ali Shah SA, et al.
    Pak J Pharm Sci, 2019 Nov;32(6):2651-2658.
    PMID: 31969298
    A series of 1, 2, 4-triazole derivatives bearing piperidine moiety has been introduced as new anti-diabetic drug candidates with least cytotoxicity. p-Chlorophenylsulfonyl chloride (1) and ethyl nipecotate (2) were the starting reagents that resulted into corresponding 3,4,5-trisubstituted-1,2,4-triazole (6) through a series of steps. A series of electrophiles, 9a-e, were synthesized by reacting 4-bromobutyryl chloride (7) with differently substituted aromatic amines (8a-e) under basic aqueous medium. Target derivatives, 10a-e, were synthesized by the reaction of compound 6 with N-aryl-4-bromobutanamides (9a-e) in an aprotic solvent. Structures of all the derivatives were verified by spectroscopic analysis using IR, 1H-NMR, 13C-NMR and EIMS. Most of the derivatives revealed moderate to good α-glucosidase inhibitory activity with reference to acarbose. The moderate hemolytic potential demonstrated least toxicity.
    Matched MeSH terms: Mass Spectrometry
  8. Mahmod II, Ismail IS, Alitheen NB, Normi YM, Abas F, Khatib A, et al.
    BMC Complement Med Ther, 2020 Oct 22;20(1):320.
    PMID: 33092571 DOI: 10.1186/s12906-020-03067-3
    BACKGROUND: Clinacanthus nutans (C. nutans) Lind. locally known as Belalai Gajah or Sabah snake grass is a medicinal plant belonging to Acanthaceae family. In Asia, this plant is traditionally used for treating skin rashes, insects and snake bites, diabetes mellitus, fever and for diuretic effect. C. nutans has been reported to possess biological activities including anti-oxidant, anti-inflammation, anti-cancer, anti-diabetic and anti-viral activities.

    METHODS: Proton Nuclear Magnetic Resonance (1H NMR) and Liquid Chromatography Mass Spectroscopy (LCMS) coupled with multivariate data analysis were employed to characterize the metabolic variations of intracellular metabolites and the compositional changes of the corresponding culture media in rat renal proximal tubular cells (NRK-52E).

    RESULTS: NMR and LCMS analysis highlighted choline, creatine, phosphocholine, valine, acetic acid, phenylalanine, leucine, glutamic acid, threonine, uridine and proline as the main metabolites which differentiated the cisplatin-induced group of NRK-52E from control cells extract. The corresponding media exhibited lactic acid, glutamine, glutamic acid and glucose-1-phosphate as the varied metabolites. The altered pathways perturbed by cisplatin nephrotoxic on NRK-52E cells included changes in amino acid metabolism, lipid metabolism and glycolysis.

    CONCLUSION: The C. nutans aqueous extract (1000 μg/mL) exhibited the most potential nephroprotective effect against cisplatin toxicity on NRK-52E cell lines at 89% of viability. The protective effect could be seen through the changes of the metabolites such as choline, alanine and valine in the C. nutans pre-treated samples with those of the cisplatin-induced group.

    Matched MeSH terms: Mass Spectrometry
  9. Abdullah R, Wesseling S, Spenkelink B, Louisse J, Punt A, Rietjens IMCM
    J Appl Toxicol, 2020 12;40(12):1647-1660.
    PMID: 33034907 DOI: 10.1002/jat.4024
    Aristolochic acid I (AAI) is a well-known genotoxic kidney carcinogen. Metabolic conversion of AAI into the DNA-reactive aristolactam-nitrenium ion is involved in the mode of action of tumor formation. This study aims to predict in vivo AAI-DNA adduct formation in the kidney of rat, mouse and human by translating the in vitro concentration-response curves for AAI-DNA adduct formation to the in vivo situation using physiologically based kinetic (PBK) modeling-based reverse dosimetry. DNA adduct formation in kidney proximal tubular LLC-PK1 cells exposed to AAI was quantified by liquid chromatography-electrospray ionization-tandem mass spectrometry. Subsequently, the in vitro concentration-response curves were converted to predicted in vivo dose-response curves in rat, mouse and human kidney using PBK models. Results obtained revealed a dose-dependent increase in AAI-DNA adduct formation in the rat, mouse and human kidney and the predicted DNA adduct levels were generally within an order of magnitude compared with values reported in the literature. It is concluded that the combined in vitro PBK modeling approach provides a novel way to define in vivo dose-response curves for kidney DNA adduct formation in rat, mouse and human and contributes to the reduction, refinement and replacement of animal testing.
    Matched MeSH terms: Tandem Mass Spectrometry
  10. Jairoun AA, Shahwan M, Zyoud SH
    Sci Rep, 2020 11 02;10(1):18824.
    PMID: 33139833 DOI: 10.1038/s41598-020-76000-w
    A specific safety concern is the possibility that a dietary supplement could be contaminated with heavy metals. This research was undertaken to investigate the daily exposure levels of heavy metals in dietary supplements available in the UAE and to explore the factors associated with the contamination of dietary supplements with heavy metals. A total of 277 dietary supplement samples were collected from the UAE market and prepared for the analysis of selected heavy metal contamination. Inductively coupled plasma mass spectrometry (ICP-MS) was used to determine the presence of heavy metals. The average daily intake of cadmium was 0.73 μg [95% CI 0.61-0.85], compared to the acceptable daily intake (ADI) of 6 μg; the daily intake of lead was 0.85 μg [95% CI 0.62-1.07], compared to the acceptable daily intake (ADI) of 20 μg; and the daily intake of arsenic was 0.67 μg [95% CI 0.57-0.78], compared to the acceptable daily intake of 10 μg. Although the dietary supplements available in the UAE have low levels of heavy metal contamination, numerous individuals are consuming a number of different dietary supplements every day and thereby may experience a cumulative level of toxic exposure. Dietary supplements formulations (Categories), dosage forms and country of origin are strong determents of heavy metal contamination in dietary supplements products.
    Matched MeSH terms: Mass Spectrometry
  11. Stepien M, Keski-Rahkonen P, Kiss A, Robinot N, Duarte-Salles T, Murphy N, et al.
    Int J Cancer, 2021 Feb 01;148(3):609-625.
    PMID: 32734650 DOI: 10.1002/ijc.33236
    Hepatocellular carcinoma (HCC) development entails changes in liver metabolism. Current knowledge on metabolic perturbations in HCC is derived mostly from case-control designs, with sparse information from prospective cohorts. Our objective was to apply comprehensive metabolite profiling to detect metabolites whose serum concentrations are associated with HCC development, using biological samples from within the prospective European Prospective Investigation into Cancer and Nutrition (EPIC) cohort (>520 000 participants), where we identified 129 HCC cases matched 1:1 to controls. We conducted high-resolution untargeted liquid chromatography-mass spectrometry-based metabolomics on serum samples collected at recruitment prior to cancer diagnosis. Multivariable conditional logistic regression was applied controlling for dietary habits, alcohol consumption, smoking, body size, hepatitis infection and liver dysfunction. Corrections for multiple comparisons were applied. Of 9206 molecular features detected, 220 discriminated HCC cases from controls. Detailed feature annotation revealed 92 metabolites associated with HCC risk, of which 14 were unambiguously identified using pure reference standards. Positive HCC-risk associations were observed for N1-acetylspermidine, isatin, p-hydroxyphenyllactic acid, tyrosine, sphingosine, l,l-cyclo(leucylprolyl), glycochenodeoxycholic acid, glycocholic acid and 7-methylguanine. Inverse risk associations were observed for retinol, dehydroepiandrosterone sulfate, glycerophosphocholine, γ-carboxyethyl hydroxychroman and creatine. Discernible differences for these metabolites were observed between cases and controls up to 10 years prior to diagnosis. Our observations highlight the diversity of metabolic perturbations involved in HCC development and replicate previous observations (metabolism of bile acids, amino acids and phospholipids) made in Asian and Scandinavian populations. These findings emphasize the role of metabolic pathways associated with steroid metabolism and immunity and specific dietary and environmental exposures in HCC development.
    Matched MeSH terms: Mass Spectrometry
  12. Soopramanien M, Khan NA, Sagathevan K, Siddiqui R
    Int Microbiol, 2021 Jan;24(1):47-56.
    PMID: 32737845 DOI: 10.1007/s10123-020-00139-9
    Pollution, unhygienic conditions and organic waste are detrimental to human health. On the contrary, animals living in polluted environments, feeding on organic waste and exposed to noxious agents such as heavy metals must possess remarkable properties against contracting diseases. Species such as cockroaches and water monitor lizards thrive in unhygienic conditions and feed on decaying matter. Here, we investigated the antitumour properties of metabolites produced by gut bacteria isolated from Varanus salvator (Asian water monitor lizard). An adult water monitor lizard and a juvenile water monitor lizard were acquired, and dissected. Their aerobic gut bacteria were isolated and identificated through 16S rDNA sequencing. Next, bacterial conditioned media (CM) were prepared and utilised for subsequent assays. Growth inhibition, MTT 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide cell viability assay, cytotoxicity and cell survival assays were accomplished against a panel of cancer cells as well as a normal cell line. Furthermore, liquid chromatography-mass spectrometry (LC-MS) was employed to identify potential antitumour molecules. A plethora of bacteria were isolated from the gut of juvenile and adult V. salvator respectively. Moreover, CM prepared from selected bacteria exhibited antitumour activity. Of note, LC-MS results indicated the presence of several molecules with reported antitumour activity, namely, 3-butylidene-7-hydroxyphthalide, C75, enigmol, estrone 16-oxime, proglumide and S-allyl-L-cysteine. Furthermore, 356 potentially novel molecules from juvenile V. salvator and 184 from adult V. salvator were depicted. Thus, the gut microbiota of V. salvator might be considered as a great niche of antitumour molecules; however, further in vitro and in vivo studies are needed to assess the antitumour properties of these molecules.
    Matched MeSH terms: Mass Spectrometry
  13. Wei J, Ren W, Wang L, Liu M, Tian X, Ding G, et al.
    J Sci Food Agric, 2020 Dec;100(15):5627-5636.
    PMID: 32712996 DOI: 10.1002/jsfa.10690
    BACKGROUND: Serofluid dish, a traditional Chinese fermented food, possesses unique flavors and health beneficial effects. These properties are likely due to the sophisticated metabolic networks during fermentation, which are mainly driven by microbiota. However, the exact roles of metabolic pathways and the microbial community during this process remain equivocal.

    RESULTS: Here, we investigated the microbial dynamics by next-generation sequencing, and outlined a differential non-targeted metabolite profiling in the process of serofluid dish fermentation using the method of hydrophilic interaction liquid chromatography column with ultra-high-performance liquid chromatography-quadruple time-of-flight mass spectrometry. Lactobacillus was the leading genus of bacteria, while Pichia and Issatchenkia were the dominant fungi. They all accumulated during fermentation. In total, 218 differential metabolites were identified, of which organic acids, amino acids, sugar and sugar alcohols, fatty acids, and esters comprised the majority. The constructed metabolic network showed that tricarboxylic acid cycle, urea cycle, sugar metabolism, amino acids metabolism, choline metabolism, and flavonoid metabolism were regulated by the fermentation. Furthermore, correlation analysis revealed that the leading fungi, Pichia and Issatchenkia, were linked to organic acids, amino acid and sugar metabolism, flavonoids, and several other flavor and functional components. Antibacterial tests indicated the antibacterial effect of serofluid soup against Salmonella and Staphylococcus.

    CONCLUSION: This work provides new insights into the complex microbial and metabolic networks during serofluid dish fermentation, and a theoretical basis for the optimization of its industrial production. © 2020 Society of Chemical Industry.

    Matched MeSH terms: Mass Spectrometry
  14. Ashhar Z, Yusof NA, Ahmad Saad FF, Mohd Nor SM, Mohammad F, Bahrin Wan Kamal WH, et al.
    Molecules, 2020 Jun 09;25(11).
    PMID: 32526838 DOI: 10.3390/molecules25112668
    Early diagnosis of bone metastases is crucial to prevent skeletal-related events, and for that, the non-invasive techniques to diagnose bone metastases that make use of image-guided radiopharmaceuticals are being employed as an alternative to traditional biopsies. Hence, in the present work, we tested the efficacy of a gallium-68 (68Ga)-based compound as a radiopharmaceutical agent towards the bone imaging in positron emitting tomography (PET). For that, we prepared, thoroughly characterized, and radiolabeled [68Ga]Ga-NODAGA-pamidronic acid radiopharmaceutical, a 68Ga precursor for PET bone cancer imaging applications. The preparation of NODAGA-pamidronic acid was performed via the N-Hydroxysuccinimide (NHS) ester strategy and was characterized using liquid chromatography-mass spectrometry (LC-MS) and tandem mass spectrometry (MSn). The unreacted NODAGA chelator was separated using the ion-suppression reverse phase-high performance liquid chromatography (RP-HPLC) method, and the freeze-dried NODAGA-pamidronic acid was radiolabeled with 68Ga. The radiolabeling condition was found to be most optimum at a pH ranging from 4 to 4.5 and a temperature of above 60 °C. From previous work, we found that the pamidronic acid itself has a good bone binding affinity. Moreover, from the analysis of the results, the ionic structure of radiolabeled [68Ga]Ga-NODAGA-pamidronic acid has the ability to improve the blood clearance and may exert good renal excretion, enhance the bone-to-background ratio, and consequently the final image quality. This was reflected by both the in vitro bone binding assay and in vivo animal biodistribution presented in this research.
    Matched MeSH terms: Mass Spectrometry
  15. Salahuddin MAH, Ismail A, Kassim NK, Hamid M, Ali MSM
    Food Chem, 2020 Nov 30;331:127240.
    PMID: 32585546 DOI: 10.1016/j.foodchem.2020.127240
    The present study focused on the phytochemical profiling along with evaluation of in vitro antioxidant, α-glucosidase and α-amylase inhibitory activities of various crudes and fractions obtained from Lepisanthes fruticosa (Roxb) Leenh fruit. Ethanolic seed crude extract exhibited the strongest radical scavenging, β-carotene bleaching activity, α-glucosidase inhibition and the highest total phenolic content (TPC). Column chromatography afforded various fractions with fraction M4 being the most potent due to the strongest radical scavenging, β-carotene bleaching, α-glucosidase inhibition and greatest amount of TPC. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis of ethanolic seed crude extract and fraction M4 showed the presence of various phytochemicals with antioxidant and antidiabetic properties, which include mostly flavonoids and tannins. The results may suggest that the ethanolic crude seed extract and its fraction could be an excellent source of bioactive phytochemicals with antioxidant and antidiabetic potential.
    Matched MeSH terms: Tandem Mass Spectrometry
  16. Quintero-Yanes A, Lee CM, Monson R, Salmond G
    Environ Microbiol, 2020 07;22(7):2921-2938.
    PMID: 32352190 DOI: 10.1111/1462-2920.15048
    Serratia sp. ATCC 39006 produces intracellular gas vesicles to enable upward flotation in water columns. It also uses flagellar rotation to swim through liquid and swarm across semi-solid surfaces. Flotation and motility can be co-regulated with production of a β-lactam antibiotic (carbapenem carboxylate) and a linear tripyrrole red antibiotic, prodigiosin. Production of gas vesicles, carbapenem and prodigiosin antibiotics, and motility are controlled by master transcriptional and post-transcriptional regulators, including the SmaI/SmaR-based quorum sensing system and the mRNA binding protein, RsmA. Recently, the ribose operon repressor, RbsR, was also defined as a pleiotropic regulator of flotation and virulence factor elaboration in this strain. Here, we report the discovery of a new global regulator (FloR; a DeoR family transcription factor) that modulates flotation through control of gas vesicle morphogenesis. The floR mutation is highly pleiotropic, down-regulating production of gas vesicles, carbapenem and prodigiosin antibiotics, and infection in Caenorhabditis elegans, but up-regulating flagellar motility. Detailed proteomic analysis using TMT peptide labelling and LC-MS/MS revealed that FloR is a physiological master regulator that operates through subordinate pleiotropic regulators including Rap, RpoS, RsmA, PigU, PstS and PigT.
    Matched MeSH terms: Tandem Mass Spectrometry
  17. Tan TK, Lim YAL, Chua KH, Chai HC, Low VL, Bathmanaban P, et al.
    Parasitol Res, 2020 Sep;119(9):2851-2862.
    PMID: 32651637 DOI: 10.1007/s00436-020-06790-5
    The field strain of Haemonchus contortus has a long history of anthelmintic resistance. To understand this phenomenon, the benzimidazole resistance profile was characterized from the Malaysian field-resistant strain by integrating phenotypic, genotypic and proteomic approaches. The faecal egg count reduction test (FECRT) demonstrated that benzimidazole resistance was at a critical level in the studied strain. The primary resistance mechanism was attributed to F200Y mutation in the isotype 1 β-tubulin gene as revealed by AS-PCR and direct sequencing. Furthermore, the protein response of the resistant strain towards benzimidazole (i.e., albendazole) treatment was investigated via two-dimensional difference gel electrophoresis (2D-DIGE) and tandem liquid chromatography-mass spectrometry (LC-MS/MS). These investigations illustrated an up-regulation of antioxidant (i.e., ATP-binding region and heat-shock protein 90, superoxide dismutase) and metabolic (i.e., glutamate dehydrogenase) enzymes and down-regulation of glutathione S-transferase, malate dehydrogenase, and other structural and cytoskeletal proteins (i.e., actin, troponin T). Findings from this study are pivotal in updating the current knowledge on anthelmintic resistance and providing new insights into the defence mechanisms of resistant nematodes towards drug treatment.
    Matched MeSH terms: Tandem Mass Spectrometry
  18. Abdul Satar NM, Ogawa S, Parhar IS
    Sci Rep, 2020 11 09;10(1):19361.
    PMID: 33168887 DOI: 10.1038/s41598-020-75777-0
    The habenula is a phylogenetically conserved epithalamic structure, which conveys negative information via inhibition of mesolimbic dopamine neurons. We have previously shown the expression of kisspeptin (Kiss1) in the habenula and its role in the modulation of fear responses in the zebrafish. In this study, to investigate whether habenular Kiss1 regulates fear responses via dopamine neurons in the zebrafish, Kiss1 peptides were intracranially administered close to the habenula, and the expression of dopamine-related genes (th1, th2 and dat) were examined in the brain using real-time PCR and dopamine levels using LC-MS/MS. th1 mRNA levels and dopamine levels were significantly increased in the telencephalon 24-h and 30-min after Kiss1 administration, respectively. In fish administered with Kiss1, expression of neural activity marker gene, npas4a and kiss1 gene were significantly decreased in the ventral habenula. Application of neural tracer into the median raphe, site of habenular Kiss1 neural terminal projections showed tracer-labelled projections in the medial forebrain bundle towards the telencephalon where dopamine neurons reside. These results suggest that Kiss1 negatively regulates its own neuronal activity in the ventral habenula via autocrine action. This, in turn affects neurons of the median raphe via interneurons, which project to the telencephalic dopaminergic neurons.
    Matched MeSH terms: Tandem Mass Spectrometry
  19. Munusamy K, Loke MF, Vadivelu J, Tay ST
    Microb Pathog, 2021 Mar;152:104614.
    PMID: 33202254 DOI: 10.1016/j.micpath.2020.104614
    Candidiasis is the most common fungal infection associated with high morbidity and mortality among immunocompromised patients. The ability to form biofilm is essential for Candida albicans pathogenesis and drug resistance. In this study, the planktonic cell and biofilm proteomes of C. albicans SC5314 strain analyzed using Liquid Chromatography-Mass Spectrometry (LC-MS) were compared. In total, 280 and 449 proteins are annotated from the planktonic cell and biofilm proteomes, respectively. The biofilm proteome demonstrated significantly higher proportion of proteins associated with the endomembrane system, mitochondrion and cytoplasm than planktonic proteome. Among proteins detected, 143 and 207 biological processes are annotated, of which, 38 and 102 are specific to the planktonic cell and biofilm proteomes, respectively, while 105 are common biological processes. The specific biological processes of C. albicans planktonic cell proteome are associated with cell polarity, energy metabolism and nucleotide (purine) metabolism, oxido-reduction coenzyme metabolic process, monosaccharide and amino acid (methionine) biosynthesis, regulation of anatomical structure morphogenesis and cell cycling, and single organism reproduction. Meanwhile, regulation of cellular macromolecule biosynthesis and metabolism, transcription and gene expression are major biological processes specifically associated with C. albicans biofilm proteome. Biosynthesis of leucine, isoleucine, and thiocysteine are highlighted as planktonic-related pathways, whereas folate metabolism, fatty acid metabolism and biosynthesis of amino acids (lysine, serine and glycine) are highlighted as biofilm-related pathways. In summary, LC-MS-based proteomic analysis reveals different adaptative strategies of C. albicans via specific biological and metabolic processes for planktonic cell and biofilm lifestyles. The mass spectrometry data are available via ProteomeXchange with identifiers PXD007830 (for biofilm proteome) and PXD007831 (for planktonic cell proteome).
    Matched MeSH terms: Tandem Mass Spectrometry
  20. Abdullah S, Oh YS, Kwak MK, Chong K
    J Microbiol, 2021 Feb;59(2):164-174.
    PMID: 33355891 DOI: 10.1007/s12275-021-0551-8
    There have been relatively few studies which support a link between Ganoderma boninense, a phytopathogenic fungus that is particularly cytotoxic and pathogenic to plant tissues and roots, and antimicrobial compounds. We previously observed that liquid-liquid extraction (LLE) using chloroformmethanol-water at a ratio (1:1:1) was superior at detecting antibacterial activities and significant quantities of antibacterial compounds. Herein, we demonstrate that antibacterial secondary metabolites are produced from G. boninense mycelia. Antibacterial compounds were monitored in concurrent biochemical and biophysical experiments. The combined methods included high performance thin-layer chromatography (HPTLC), gas chromatography-mass spectrometry (GC-MS), high-performance liquid chromatography (HPLC), fourier transform infrared (FTIR), and nuclear magnetic resonance (NMR) spectroscopy. The antibacterial compounds derived from mycelia with chloroform-methanol extraction through LLE were isolated via a gradient solvent elution system using HPTLC. The antibacterial activity of the isolated compounds was observed to be the most potent against Staphylococcus aureus ATCC 25923 and multidrug-resistant S. aureus NCTC 11939. GC-MS, HPLC, and FTIR analysis confirmed two antibacterial compounds, which were identified as 4,4,14α-trimethylcholestane (m/z = 414.75; lanostane, C30H54) and ergosta-5,7,22-trien-3β-ol (m/z = 396.65; ergosterol, C28H44O). With the aid of spectroscopic evaluations, ganoboninketal (m/z = 498.66, C30H42O6), which belongs to the 3,4-seco-27-norlanostane triterpene family, was additionally characterized by 2D-NMR analysis. Despite the lack of antibacterial potential exhibited by lanostane; both ergosterol and ganoboninketal displayed significant antibacterial activities against bacterial pathogens. Results provide evidence for the existence of bioactive compounds in the mycelia of the relatively unexplored phytopathogenic G. boninense, together with a robust method for estimating the corresponding potent antibacterial secondary metabolites.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links