Displaying publications 3961 - 3980 of 10390 in total

Abstract:
Sort:
  1. Natural diterpene pyrones: chemistry and biology
    Al-Khdhairawi AAQ, Cordell GA, Thomas NF, Shivanagere Nagojappa NB, Weber JF
    Org Biomol Chem, 2019 10 28;17(40):8943-8957.
    PMID: 31482157 DOI: 10.1039/c9ob01501a
    Diterpene pyrones (DTPs) are a group of well-known, mainly fungal, natural products, first isolated in 1966. As the name indicates, they are composed of two main structural features: a diterpenyl moiety and a pyrone ring. Various names have been given to this class of metabolites; however, biogenetic evidence indicates that they originate through the same metabolic pathway. Based on their biosynthesis, which leads to differences in their structural architecture, the DTPs can be classified into three main types. In addition to their intriguing chemistry, these compounds demonstrate a wide range of biological activities rendering them a desirable target for total synthesis. To date, sixty-seven DTPs have been isolated from various fungal species, with one example originating from the plant kingdom. This review aims at unifying the classification of these compounds, in addition to presenting a detailed description of their isolation, bioactivities, biosynthesis, and total synthesis.
    Matched MeSH terms: Biological Products/chemistry*; Diterpenes/chemistry*; Pyrones/chemistry*
  2. Effects of tourism-derived sewage on coral reefs: Isotopic assessments identify effective bioindicators
    Lachs L, Johari NAM, Le DQ, Safuan CDM, Duprey NN, Tanaka K, et al.
    Mar Pollut Bull, 2019 Nov;148:85-96.
    PMID: 31422307 DOI: 10.1016/j.marpolbul.2019.07.059
    Pulau Redang and Pulau Tioman have experienced huge tourism growth over the last two decades, but minimal sewage treatment may threaten the resilience of their coral reefs. This study uses stable isotope techniques to identify suitable bioindicators of sewage nutrients (δ15N) at these islands by measuring macroalgae (Lobophora spp.), gastropods (Drupella spp.), scleractinian coral (Acropora spp.), and leather coral (Sinularia spp.). At tourist hubs using seepage septic tank systems, enrichment of Acropora δ15N (Redang, +0.7‰) and Sinularia δ15N (Tioman, +0.4‰) compared to pristine background levels indicate enhanced sewage nutrient discharge. Carbon isotopes and survey data suggest that sedimentation did not confound these δ15N trends. Potential damaging effects of sewage discharge on the coral reef communities at both islands are highlighted by strong correlations between Acropora δ15N and regional variation in coral reef community structure, and exclusive occurrence of degraded reefs at regions of high sewage influence.
    Matched MeSH terms: Sewage/chemistry*; Geologic Sediments/chemistry; Anthozoa/chemistry*
  3. A DNA based visual and colorimetric aggregation assay for the early growth factor receptor (EGFR) mutation by using unmodified gold nanoparticles
    Ramanathan S, Gopinath SCB, Arshad MKM, Poopalan P, Anbu P
    Mikrochim Acta, 2019 07 18;186(8):546.
    PMID: 31321546 DOI: 10.1007/s00604-019-3696-y
    A genomic DNA-based colorimetric assay is described for the detection of the early growth factor receptor (EGFR) mutation, which is the protruding reason for non-small cell lung cancer. A DNA sequence was designed and immobilized on unmodified gold nanoparticles (GNPs). The formation of the respective duplex indicates the presence of an EGFR mutation. It is accompanied by the aggregation of the GNPs in the presence of monovalent ions, and it indicates the presence of an EGFR mutation. This is accompanied by a color change from red (520 nm) to purple (620 nm). Aggregation was evidenced by transmission electron microscopy, scanning electron microscopy and atomic force microscopy. The limit of detection is 313 nM of the mutant target strand. A similar peak shift was observed for 2.5 μM concentrations of wild type target. No significant peak shift was observed with probe and non-complementary DNA. Graphical abstract Schematic representation of high-specific genomic DNA sequence on gold nanoparticle (GNP) aggregation with sodium chloride (NaCl). It illustrates the detection method for EGFR mutation on lung cancer detection. Red and purple colors of tubes represent dispersed and aggregated GNP, respectively.
    Matched MeSH terms: DNA, Single-Stranded/chemistry*; Gold/chemistry*; Metal Nanoparticles/chemistry*
  4. Constituents of the Edible Leaves of Melicope pteleifolia with Potential Analgesic Activity
    Lee BW, Park JG, Ha TKQ, Pham HTT, An JP, Noh JR, et al.
    J Nat Prod, 2019 08 23;82(8):2201-2210.
    PMID: 31393125 DOI: 10.1021/acs.jnatprod.9b00224
    Melicope pteleifolia has long been consumed as a popular vegetable and tea in Southeast Asian countries, including Malaysia and southern mainland China, and is effective in the treatment of colds and inflammation. In the search for active metabolites that can explain its traditional use as an antipyretic, six new phloroacetophenone derivatives (3-8) along with seven known compounds (1, 2, and 9-13) were isolated from the leaves of M. pteleifolia. Their chemical structures were confirmed by extensive spectroscopic analysis including NMR, IR, ECD, and HRMS. All compounds isolated from the leaves of M. pteleifolia (1-13) have a phloroacetophenone skeleton. Notably, the new compound 8 contains an additional cyclobutane moiety in its structure. The bioactivities of the isolated compounds were evaluated, and compounds 1, 6, and 7 inhibited tumor necrosis factor-α-induced prostaglandin E2. Moreover, the major constituent, 3,5-di-C-β-d-glucopyranosyl phloroacetophenone (1), was found to be responsible for the antipyretic activity of M. pteleifolia based on in vivo experiments.
    Matched MeSH terms: Plants, Edible/chemistry; Plant Leaves/chemistry*; Rutaceae/chemistry*
  5. Exploring ligand-protein interaction: A laboratory exercise on herbicide binding to plasma transport protein
    Roslan AA, Tayyab S
    Biochem Mol Biol Educ, 2019 03;47(2):156-160.
    PMID: 30629781 DOI: 10.1002/bmb.21207
    A laboratory exercise on the interaction between the herbicide pendimethalin (PM) and goat serum albumin (GSA), a carrier protein present in mammalian blood circulation, is described. Fluorescence spectroscopy was used to study the binding reaction between PM and GSA. Titration of a constant amount of the protein (GSA) with increasing ligand (PM) concentrations produced a consecutive decrease in the protein's fluorescence. Treatment of the fluorescence quenching data according to the Stern-Volmer equation yielded the values of the Stern-Volmer constant (Ksv ) and bimolecular quenching rate constant (kq ), whereas values of the binding constant (Ka ) and number of binding sites (n) were obtained from the double logarithmic plot. This experiment provides an exciting opportunity for undergraduate students to independently perform ligand binding studies with a protein, in addition to providing the means for the determination of their binding parameters. © 2019 International Union of Biochemistry and Molecular Biology, 47(2): 156-160, 2019.
    Matched MeSH terms: Aniline Compounds/chemistry*; Herbicides/chemistry*; Serum Albumin/chemistry*
  6. Nanomedicines for cancer therapy: current status, challenges and future prospects
    Bor G, Mat Azmi ID, Yaghmur A
    Ther Deliv, 2019 02;10(2):113-132.
    PMID: 30678550 DOI: 10.4155/tde-2018-0062
    The emergence of nanomedicine as an innovative and promising alternative technology shows many advantages over conventional cancer therapies and provides new opportunities for early detection, improved treatment, and diagnosis of cancer. Despite the cancer nanomedicines' capability of delivering chemotherapeutic agents while providing lower systemic toxicity, it is paramount to consider the cancer complexity and dynamics for bridging the translational bench-to-bedside gap. It is important to conduct appropriate investigations for exploiting the tumor microenvironment, and achieving a more comprehensive understanding of the fundamental biological processes in cancer and their roles in modulating nanoparticle-protein interactions, blood circulation, and tumor penetration. This review provides an overview of the current cancer nanomedicines, the major challenges, and the future opportunities in this research area.
    Matched MeSH terms: Antineoplastic Agents/chemistry; Drug Carriers/chemistry; Nanoparticles/chemistry
  7. Optimisation of human VH domain antibodies specific to Mycobacterium tuberculosis heat shock protein (HSP16.3)
    Soong JX, Chan SK, Lim TS, Choong YS
    J Comput Aided Mol Des, 2019 03;33(3):375-385.
    PMID: 30689080 DOI: 10.1007/s10822-019-00186-z
    Mycobacterium tuberculosis (Mtb) 16.3 kDa heat shock protein 16.3 (HSP16.3) is a latency-associated antigen that can be targeted for latent tuberculosis (TB) diagnostic and therapeutic development. We have previously developed human VH domain antibodies (dAbs; clone E3 and F1) specific against HSP16.3. In this work, we applied computational methods to optimise and design the antibodies in order to improve the binding affinity with HSP16.3. The VH domain antibodies were first docked to the dimer form of HSP16.3 and further sampled using molecular dynamics simulation. The calculated binding free energy of the HSP16.3-dAb complexes showed non-polar interactions were responsible for the antigen-antibody association. Per-residue free energy decomposition and computational alanine scanning have identified one hotspot residue for E3 (Y391) and 4 hotspot residues for F1 (M394, Y396, R397 and M398). These hotspot residues were then mutated and evaluated by binding free energy calculations. Phage ELISA assay was carried out on the potential mutants (E3Y391W, F1M394E, F1R397N and F1M398Y). The experimental assay showed improved binding affinities of E3Y391W and F1M394E against HSP16.3 compared with the wild type E3 and F1. This case study has thus showed in silico methods are able to assist in optimisation or improvement of antibody-antigen binding.
    Matched MeSH terms: Antibodies/chemistry*; Bacterial Proteins/chemistry*; Chaperonins/chemistry*
  8. Comparative analysis of antioxidant and antiproliferative activities of Rhodomyrtus tomentosa extracts prepared with various solvents
    Abd Hamid H, Mutazah R, Yusoff MM, Abd Karim NA, Abdull Razis AF
    Food Chem Toxicol, 2017 Oct;108(Pt B):451-457.
    PMID: 27725206 DOI: 10.1016/j.fct.2016.10.004
    Rhodomyrtus tomentosa (Aiton) Hassk. has a wide spectrum of pharmacological effects and has been used to treat wounds, colic diarrhoea, heartburns, abscesses and gynaecopathy. The potential antiproliferative activities of R. tomentosa extracts from different solvents were evaluated in vitro on HepG2, MCF-7 and HT 29 cell lines while antioxidant activity was monitored by radical scavenging assay (DPPH), copper reducing antioxidant capacity (CUPRAC) and β-carotene bleaching assay. Extracts from R. tomentosa show the viability of the cells in concentration-dependent manner. According to the IC50 obtained, the ethyl acetate extracts showed significant antiproliferative activity on HepG2 (IC50 11.47 ± 0.280 μg/mL), MCF-7 (IC50 2.68 ± 0.529 μg/mL) and HT 29 (IC50 16.18 ± 0.538 μg/mL) after 72 h of treatment. Bioassay guided fractionation of the ethyl acetate extract led to the isolation of lupeol. Methanol extracts show significant antioxidant activities in DPPH (EC50 110.25 ± 0.005 μg/ml), CUPRAC (EC50 53.84 ± 0.004) and β-carotene bleaching (EC50 58.62 ± 0.001) due to the presence of high total flavonoid and total phenolic content which were 110.822 ± 0.017 mg butylated hydroxytoluene (BHT)/g and 190.467 ± 0.009 mg gallic acid (GAE)/g respectively. Taken together, the results extracts show the R. tomentosa as a potential source of antioxidant and antiproliferative efficacy.
    Matched MeSH terms: Plant Extracts/chemistry; Solvents/chemistry*; Myrtaceae/chemistry*
  9. Bougainvillea glabra (choisy): A comprehensive review on botany, traditional uses, phytochemistry, pharmacology and toxicity
    Saleem H, Usman A, Mahomoodally MF, Ahemad N
    J Ethnopharmacol, 2021 Feb 10;266:113356.
    PMID: 32956758 DOI: 10.1016/j.jep.2020.113356
    ETHNOPHARMACOLOGICAL RELEVANCE: Bougainvillea glabra (Choisy). (Family: Nyctinaginacea) is a valuable ornamental plant with culinary uses and also utilized in traditional medicine for treating common ailments. It is traditionally employed against several diseases such as diarrhoea, hypotension, intestinal disorders, stomachache, nausea, inflammation-related ailments, and in pain management. Though widely validated via in vitro and in vivo models, to date no endeavour has been made to compile in a single review the traditional, phytochemistry and pharmacological properties of B. glabra.

    AIMS: To provide an up-to-date, authoritative review with respect to the traditional uses, chemical composition, in vitro and in vivo pharmacological properties, and toxicological estimations accomplished either utilizing the crude extracts or, wherever applicable, the bioactive compounds isolated from B. glabra. Besides, a critical evaluation of the published literature has been undertaken with regards to the current biochemical and toxicological data.

    MATERIALS AND METHODS: Key databases per se, Ovid, Pubmed, Science Direct, Scopus, and Google scholar amongst others were probed for a systematic search using keywords to retrieve relevant publications on this plant. A total of 52 articles were included for the review depending on Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

    RESULTS: The studies conducted on either crude extracts, solvent fractions or isolated pure compounds from B. glabra had reported a varied range of biological effects comprising antibacterial, antifungal, antidiabetic, cytotoxic, analgesic, antipyretic, anti-inflammatory, and antioxidant activities. Phytochemical analysis of different parts of B. glabra unveiled 105 phytochemicals, belonging to phenolic, flavonoid, betacyanin, terpenoid, glycoside and essential oils classes of secondary metabolites.

    CONCLUSION: Most of the pharmacological activities of crude extracts from this plant have been reported. A very few studies have reported the isolation of compounds responsible for observed biological potential of this plant. Moreover, the toxicity studies of this plant still need to be explored comprehensively to ensure its safety parameters. Additional investigations are recommended to transmute the ethnopharmacological claims of this plant species in folklore medicines into scientific rationale-based information.

    Matched MeSH terms: Plant Extracts/chemistry; Nyctaginaceae/chemistry*; Phytochemicals/chemistry
  10. Cysteine-rich antimicrobial peptides from plants: The future of antimicrobial therapy
    Srivastava S, Dashora K, Ameta KL, Singh NP, El-Enshasy HA, Pagano MC, et al.
    Phytother Res, 2021 Jan;35(1):256-277.
    PMID: 32940412 DOI: 10.1002/ptr.6823
    There has been a spurt in the spread of microbial resistance to antibiotics due to indiscriminate use of antimicrobial agents in human medicine, agriculture, and animal husbandry. It has been realized that conventional antibiotic therapy would be less effective in the coming decades and more emphasis should be given for the development of novel antiinfective therapies. Cysteine rich peptides (CRPs) are broad-spectrum antimicrobial agents that modulate the innate immune system of different life forms such as bacteria, protozoans, fungi, plants, insects, and animals. These are also expressed in several plant tissues in response to invasion by pathogens, and play a crucial role in the regulation of plant growth and development. The present work explores the importance of CRPs as potent antimicrobial agents, which can supplement and/or replace the conventional antibiotics. Different plant parts of diverse plant species showed the presence of antimicrobial peptides (AMPs), which had significant structural and functional diversity. The plant-derived AMPs exhibited potent activity toward a range of plant and animal pathogens, protozoans, insects, and even against cancer cells. The cysteine-rich AMPs have opened new avenues for the use of plants as biofactories for the production of antimicrobials and can be considered as promising antimicrobial drugs in biotherapeutics.
    Matched MeSH terms: Cysteine/chemistry*; Plants/chemistry*; Pore Forming Cytotoxic Proteins/chemistry
  11. Biological evaluation of curcumin and related diarylheptanoids
    Abas F, Hui LS, Ahmad S, Stanslas J, Israf DA, Shaari K, et al.
    Z Naturforsch C J Biosci, 2006 12 2;61(9-10):625-31.
    PMID: 17137104
    Nine derivatives of three natural diarylheptanoids, curcumin, demethoxycurcumin and bisdemethoxycurcumin, were prepared. Their antioxidant, free radical scavenging, nitric oxide (NO) inhibitory and cytotoxic activities were evaluated and compared with those of the respective natural compounds. Curcumin (1), demethoxycurcumin (2), demethyldemethoxy-curcumin (C3), diacetyldemethoxycurcumin (AC2) and triacetyldemethylcurcumin (AC5) exhibited higher antioxidant activity than quercetin while products from demethylation of 1 and 2 exhibited higher free radical scavenging activity. Compounds AC2 and AC5 were found to be most active in inhibiting breast cancer cells (MCF-7) proliferation with IC50 values of 6.7 and 3.6 microM, respectively. The activity of AC2 is almost doubled and of AC5 almost tripled as compared to curcumin. Their selectivity towards different cell lines is also more noticeable. Compounds AC2 and AC5 also showed increased activity against a human prostate cancer cell line (DU-145) and non-small lung cancer cell line (NCI-H460) with IC50 values of 20.4, 16.3 and 18.3, 10.7 microM, respectively.
    Matched MeSH terms: Curcumin/chemistry; Quercetin/chemistry; Diarylheptanoids/chemistry
  12. Analysis and physicochemical properties of cellulose nanowhiskers from Pennisetum purpureum via different acid hydrolysis reaction time
    Sucinda EF, Abdul Majid MS, Ridzuan MJM, Sultan MTH, Gibson AG
    Int J Biol Macromol, 2020 Jul 15;155:241-248.
    PMID: 32240733 DOI: 10.1016/j.ijbiomac.2020.03.199
    Cellulose nanowhisker (NWC) was extracted by hydrolysing Pennisetum purpureum (PP) fibres with acid and alkali. They were subjected to different periods of acid hydrolysis; 30, 45, and 60 min. NWC morphology and physicochemical properties were characterised by transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), particle size analyser, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and thermogravimetric analysis. NWC3, which underwent the longest hydrolysis time, showed the smallest width and length, under TEM. All samples presented a needle-like shape under TEM and AFM; uneven lengths and irregular shapes under FESEM; and a broad range of distribution, with the particle size analyser. All samples exhibited a good crystallinity index (CrI)-72.0 to 74.6%. The highest CrI% corresponded to 60 min of acid hydrolysis. Thermogravimetric analysis showed thermal stability between 310.72 °C and 336.28 °C. Thus, cellulose nanowhisker from PP fibres, have high potential as bio-nanocomposites.
    Matched MeSH terms: Cellulose/chemistry*; Pennisetum/chemistry*; Nanocomposites/chemistry*
  13. Fulltext Enhancement of β-Mannanase Production by Bacillus subtilis ATCC11774 through Optimization of Medium Composition
    Norizan NABM, Halim M, Tan JS, Abbasiliasi S, Mat Sahri M, Othman F, et al.
    Molecules, 2020 Jul 31;25(15).
    PMID: 32752106 DOI: 10.3390/molecules25153516
    Palm kernel cake (PKC) has been largely produced in Malaysia as one of the cheap and abundant agro-waste by-products from the palm oil industry and it contains high fiber (mannan) content. The present study aimed to produce β-mannanase by Bacillus subtilis ATCC11774 via optimization of the medium composition using palm kernel cake as substrate in semi-solid fermentation. The fermentation nutrients such as PKC, peptone, yeast extract, sodium chloride, magnesium sulphate (MgSO2), initial culture pH and temperature were screened using a Plackett-Burman design. The three most significant factors identified, PKC, peptone and NaCl, were further optimized using central composite design (CCD), a response surface methodology (RSM) approach, where yeast extract and MgSO2 were fixed as a constant factor. The maximum β-mannanase activity predicted by CCD under the optimum medium composition of 16.50 g/L PKC, 19.59 g/L peptone, 3.00 g/L yeast extract, 2.72 g/L NaCl and 0.2 g/L MgSO2 was 799 U/mL. The validated β-mannanase activity was 805.12 U/mL, which was close to the predicted β-mannanas activity. As a comparison, commercial media such as nutrient broth, M9 and Luria bertani were used for the production of β-mannanase with activities achieved at 204.16 ± 9.21 U/mL, 50.32 U/mL and 88.90 U/mL, respectively. The optimized PKC fermentation medium was four times higher than nutrient broth. Hence, it could be a potential fermentation substrate for the production of β-mannanase activity by Bacillus subtilis ATCC11774.
    Matched MeSH terms: Culture Media/chemistry*; Magnesium Sulfate/chemistry; Sodium Chloride/chemistry
  14. Characterization of microcrystalline cellulose extracted from olive fiber
    Kian LK, Saba N, Jawaid M, Fouad H
    Int J Biol Macromol, 2020 Aug 01;156:347-353.
    PMID: 32278601 DOI: 10.1016/j.ijbiomac.2020.04.015
    Olive fiber is a renewable natural fiber which has potential as an alternative biomass for extraction of microcrystalline cellulose (MCC). MCC has been widely applied in various industries owing to its small dimensional size for ease of reactive fabrication process. At present study, a serial treatments of bleaching, alkaline and acid hydrolysis was employed to extract OL-BLF, OL-PUF, and OL-MCC respectively from olive stem fiber. In morphology examination, a feature of short micro-crystallite particles was obtained for OL-MCC. The particle size was found gradually reducing from OL-PUF (305.31 μm) to OL-MCC (156.06 μm) due to the disintegration of cellulose fibrils. From physicochemical analysis, most lignin and hemicellulose components had been removed from OL-BLF to form OL-PUF with individually fibril structure. The elemental analysis revealed that highly pure cellulose component was obtained for OL-MCC. Also, the rigidity had been improved from OL-BLF to OL-PUF, while with the highest for OL-MCC with 74.2% crystallinity, endowing it as a reliable load-bearing agent. As for thermal analysis, OL-MCC had the most stable heat resistance in among the chemically-treated fibers. Therefore, olive MCC could act as a promising reinforcing agent to withstand harsh conditions for variety fields of composite applications.
    Matched MeSH terms: Cellulose/chemistry*; Fruit/chemistry; Olea/chemistry*
  15. Fulltext The Role of Surface Exposed Lysine in Conformational Stability and Functional Properties of Lipase from Staphylococcus Family
    Ahmad NN, Ahmad Kamarudin NH, Leow ATC, Rahman RNZRA
    Molecules, 2020 Aug 25;25(17).
    PMID: 32854267 DOI: 10.3390/molecules25173858
    Surface charge residues have been recognized as one of the stability determinants in protein. In this study, we sought to compare and analyse the stability and conformational dynamics of staphylococcal lipase mutants with surface lysine mutation using computational and experimental methods. Three highly mutable and exposed lysine residues (Lys91, Lys177, Lys325) were targeted to generate six mutant lipases in silico. The model structures were simulated in water environment at 25 °C. Our simulations showed that the stability was compromised when Lys177 was substituted while mutation at position 91 and 325 improved the stability. To illustrate the putative alterations of enzyme stability in the stabilising mutants, we characterized single mutant K325G and double mutant K91A/K325G. Both mutants showed a 5 °C change in optimal temperature compared to their wild type. Single mutant K325G rendered a longer half-life at 25 °C (T1/2 = 21 h) while double mutant K91A/K325G retained only 40% of relative activity after 12 h incubation. The optimal pH for mutant K325G was shifted from 8 to 9 and similar substrate preference was observed for the wild type and two mutants. Our findings indicate that surface lysine mutation alters the enzymatic behaviour and, thus, rationalizes the functional effects of surface exposed lysine in conformational stability and activity of this lipase.
    Matched MeSH terms: Bacterial Proteins/chemistry*; Lipase/chemistry*; Lysine/chemistry
  16. Synthesis of symmetrical bis-Schiff base-disulfide hybrids as highly effective anti-leishmanial agents
    Taha M, Sain AA, Ali M, Anouar EH, Rahim F, Ismail NH, et al.
    Bioorg Chem, 2020 06;99:103819.
    PMID: 32325334 DOI: 10.1016/j.bioorg.2020.103819
    Leishmaniasis has affected a wider part of population around the globe. Most often, the existing regiments to battle against leishmaniasis are inadequate and limited. In our ongoing efforts to develop new leishmanicidal agents, we have synthesized a series of novel and symmetrical bis-Schiff base-disulfide hybrids 1-27. Intermediate disulfide was synthesized from corresponding 2-aminothiol followed by reacting the coupled adduct with various aromatic aldehydes. All these compounds showed outstanding inhibition when compared with standard (Table 1). Out of twenty seven analogues, twenty two analogues i.e. 1-5, 7-13, 17-21, 23-27 analogues showed excellent inhibitory potential with EC50 values ranging from 0.010 ± 0.00 to 0.096 ± 0.01 μM while five compounds i.e. 6, 14-16, and 22 showed good inhibitory potential with EC50 values ranging from 0.10 ± 0.00 to 0.137 ± 0.01 μM when compared with the standard Amphotericin B. Structure-activity relationship has been established while molecular docking studies were performed to pin the binding interaction of active molecules. This study will help to develop new antileishmanial lead compounds.
    Matched MeSH terms: Antiprotozoal Agents/chemistry; Disulfides/chemistry; Schiff Bases/chemistry
  17. Fulltext Simultaneous quantification of ten key Kratom alkaloids in Mitragyna speciosa leaf extracts and commercial products by ultra-performance liquid chromatography-tandem mass spectrometry
    Sharma A, Kamble SH, León F, Chear NJ, King TI, Berthold EC, et al.
    Drug Test Anal, 2019 Aug;11(8):1162-1171.
    PMID: 30997725 DOI: 10.1002/dta.2604
    Kratom (Mitragyna speciosa) is a psychoactive plant popular in the United States for the self-treatment of pain and opioid addiction. For standardization and quality control of raw and commercial kratom products, an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for the quantification of ten key alkaloids, namely: corynantheidine, corynoxine, corynoxine B, 7-hydroxymitragynine, isocorynantheidine, mitragynine, mitraphylline, paynantheine, speciociliatine, and speciogynine. Chromatographic separation of diastereomers, or alkaloids sharing same ion transitions, was achieved on an Acquity BEH C18 column with a gradient elution using a mobile phase containing acetonitrile and aqueous ammonium acetate buffer (10mM, pH 3.5). The developed method was linear over a concentration range of 1-200 ng/mL for each alkaloid. The total analysis time per sample was 22.5 minutes. The analytical method was validated for accuracy, precision, robustness, and stability. After successful validation, the method was applied for the quantification of kratom alkaloids in alkaloid-rich fractions, ethanolic extracts, lyophilized teas, and commercial products. Mitragynine (0.7%-38.7% w/w), paynantheine (0.3%-12.8% w/w), speciociliatine (0.4%-12.3% w/w), and speciogynine (0.1%-5.3% w/w) were the major alkaloids in the analyzed kratom products/extracts. Minor kratom alkaloids (corynantheidine, corynoxine, corynoxine B, 7-hydroxymitragynine, isocorynantheidine) were also quantified (0.01%-2.8% w/w) in the analyzed products; however mitraphylline was below the lower limit of quantification in all analyses.
    Matched MeSH terms: Plant Extracts/chemistry*; Plant Leaves/chemistry*; Mitragyna/chemistry*
  18. Development of active agents filled polylactic acid films for food packaging application
    Mohamad N, Mazlan MM, Tawakkal ISMA, Talib RA, Kian LK, Fouad H, et al.
    Int J Biol Macromol, 2020 Nov 15;163:1451-1457.
    PMID: 32738328 DOI: 10.1016/j.ijbiomac.2020.07.209
    The growing global awareness for environmental protection has inspired the exploration on producing active packaging films from bio-based materials. In present work, three types of active agents were studied by incorporating thymol(T), kesum(K), and curry(C) (10% wt.) into polylactic acid (PLA) to produce PLA-10T, PLA-10K, and PLA10-C packaging films via solvent casting method. The morphology, functional chemistry, thermal stability, permeability, and antimicrobial properties were evaluated for PLA films. Functional chemical analysis confirmed the presence of interfacial bonding between aromatic groups of active agents and PLA carbonyl group. PLA-10K exhibited the highest thermal resistance comparing to PLA-10T and PLA-10C while water vapor barrier was enhanced after incorporation of active agents. Qualitative observation had indicated that chicken meat could be preserved in the active films until 15 days, while odourless and firm texture properties retained in food sample. For disc diffusion assay (in vitro), it showed positive results against Gram-positive bacteria (Staphylococcus aureus) whereas with negative results against Gram-negative bacteria (Escherichia coli) and Aspergillus Brasiliensis due to embedded active agents within PLA matrix. We concluded that produced active agents filled PLA films potential to use in food packaging application to enhance the shelf life of meats, fruits and vegetables product.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry; Polyesters/chemistry*; Thymol/chemistry
  19. Chemical characterization, antioxidant, enzyme inhibitory and cytotoxic properties of two geophytes: Crocus pallasii and Cyclamen cilicium
    Zengin G, Mahomoodally MF, Sinan KI, Picot-Allain MCN, Yildiztugay E, Cziáky Z, et al.
    Food Res Int, 2020 07;133:109129.
    PMID: 32466933 DOI: 10.1016/j.foodres.2020.109129
    The Crocus and Cyclamen genus have been reported to possess diverse biological properties. In the present investigation, two geophytes from these genus, namely Crocus pallasi and Cyclamen cilicium have been studied. The in vitro antioxidant, enzyme inhibitory, and cytotoxic effects of the methanol extracts of Crocus pallasii and Cyclamen cilicium aerial and underground parts were investigated. Antioxidant abilities of the extracts were investigated via different antioxidant assays (metal chelating, radical quenching (ABTS and DPPH), reducing power (CUPRAC and FRAP) and phosphomolybdenum). Cholinesterases, amylase, tyrosinase, and glucosidase were used as target enzymes for detecting enzyme inhibitory abilities of the samples. Regarding the cytotoxic abilities, breast cancer cell lines (MDA-MB 231 and MCF-7) and prostate cancer cell lines (DU-145) were used. The flowers extracts of Crocus pallasii and C. cilicium possessed the highest flavonoid content. The highest phenolic content was recorded from C. cilicium root extract (47.62 mg gallic acid equivalent/g extract). Cyclamen cilicium root extract showed significantly (p 
    Matched MeSH terms: Crocus/chemistry*; Cyclamen/chemistry*; Flowers/chemistry
  20. Fulltext In Vitro Evaluation of Curcumin-Encapsulated Chitosan Nanoparticles against Feline Infectious Peritonitis Virus and Pharmacokinetics Study in Cats
    Ng SW, Selvarajah GT, Hussein MZ, Yeap SK, Omar AR
    Biomed Res Int, 2020;2020:3012198.
    PMID: 32596292 DOI: 10.1155/2020/3012198
    Feline infectious peritonitis (FIP) is an important feline viral disease, causing an overridden inflammatory response that results in a high mortality rate, primarily in young cats. Curcumin is notable for its biological activities against various viral diseases; however, its poor bioavailability has hindered its potential in therapeutic application. In this study, curcumin was encapsulated in chitosan nanoparticles to improve its bioavailability. Curcumin-encapsulated chitosan (Cur-CS) nanoparticles were synthesised based on the ionic gelation technique and were spherical and cuboidal in shape, with an average particle size of 330 nm and +42 mV in zeta potential. The nanoparticles exerted lower toxicity in Crandell-Rees feline kidney (CrFK) cells and enhanced antiviral activities with a selective index (SI) value three times higher than that of curcumin. Feline-specific bead-based multiplex immunoassay and qPCR were used to examine their modulatory effects on proinflammatory cytokines, including tumour necrosis factor (TNF)α, interleukin- (IL-) 6, and IL-1β. There were significant decrements in IL-1β, IL-6, and TNFα expression in both curcumin and Cur-CS nanoparticles. Based on the multiplex immunoassay, curcumin and the Cur-CS nanoparticles could lower the immune-related proteins in FIP virus (FIPV) infection. The single- and multiple-dose pharmacokinetics profiles of curcumin and the Cur-CS nanoparticles were determined by high-performance liquid chromatography (HPLC). Oral delivery of the Cur-CS nanoparticles to cats showed enhanced bioavailability with a maximum plasma concentration (Cmax) value of 621.5 ng/mL. Incorporating chitosan nanoparticles to deliver curcumin improved the oral bioavailability and antiviral effects of curcumin against FIPV infection. This study provides evidence for the potential of Cur-CS nanoparticles as a supplementary treatment of FIP.
    Matched MeSH terms: Drug Carriers/chemistry; Chitosan/chemistry*; Nanoparticles/chemistry*
Related Terms
Filters
Contact Us

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

External Links