Displaying publications 361 - 367 of 367 in total

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  1. Permana D, Lajis NH, Mackeen MM, Ali AM, Aimi N, Kitajima M, et al.
    J Nat Prod, 2001 Jul;64(7):976-9.
    PMID: 11473441
    Two new prenylated compounds, the benzoquinone atrovirinone (1) and the depsidone atrovirisidone (2), were isolated from the roots of Garcinia atroviridis. Their structures were determined on the basis of the analysis of spectroscopic data. While compound 2 showed some cytotoxicity against HeLa cells, both compounds 1 and 2 were only mildly inhibitory toward Bacillus cereus and Staphylococcus aureus.
    Matched MeSH terms: Bacillus cereus/drug effects
  2. Jaafar NR, Khoiri NM, Ismail NF, Mahmood NAN, Abdul Murad AM, Abu Bakar FD, et al.
    Enzyme Microb Technol, 2020 Oct;140:109625.
    PMID: 32912685 DOI: 10.1016/j.enzmictec.2020.109625
    Endo-β-1,3-glucanase from alkalophilic bacterium, Bacillus lehensis G1 (Blg32) composed of 284 amino acids with a predicted molecular mass of 31.6 kDa is expressed in Escherichia coli and purified to homogeneity. Herein, Blg32 characteristics, substrates and product specificity as well as structural traits that might be involved in the production of sugar molecules are analysed. This enzyme functions optimally at the temperature of 70 °C, pH value of 8.0 with its catalytic activity strongly enhanced by Mn2+. Remarkably, the purified enzyme is highly stable in high temperature and alkaline conditions. It exhibits the highest activity on laminarin (376.73 U/mg) followed by curdlan and yeast β-glucan. Blg32 activity increased by 62% towards soluble substrate (laminarin) compared to insoluble substrate (curdlan). Hydrolytic products of laminarin were oligosaccharides with degree of polymerisation (DP) of 1 to 5 with the main product being laminaritriose (DP3). This suggests that the active site of Blg32 could recognise up to five glucose units. High concentration of Blg32 mainly produces glucose whilst low concentration of Blg32 yields oligosaccharides with different DP (predominantly DP3). A theoretical structural model of Blg32 was constructed and structural analysis revealed that Trp156 is involved in multiple hydrophobic stacking interactions. The amino acid was predicted to participate in substrate recognition and binding. It was also exhibited that catalytic groove of Blg32 has a narrow angle, thus limiting the substrate binding reaction. All these properties and knowledge of the subsites are suggested to be related to the possible mode of action of how Blg32 produces glucooligosaccharides.
    Matched MeSH terms: Bacillus/enzymology*
  3. Chan KK, Wong RS, Mohamed SM, Ibrahim TA, Abdullah M, Nadarajah VD
    PMID: 22591286
    Bacillus thuringiensis (Bt) parasporal proteins with selective anticancer activity have recently garnered interest. This study determines the efficacy and mode of cell death of Bt 18 parasporal proteins against 3 leukemic cell lines (CEM-SS, CCRF-SB and CCRF-HSB-2).Cell-based biochemical analysis aimed to determine cell viability and the percentage of apoptotic cell death in treated cell lines; ultrastructural analysis to study apoptotic changes and Western blot to identify the parasporal proteins' binding site were performed. Bt 18 parasporal proteins moderately decreased viability of leukemic cells but not that of normal human T lymphocytes. Further purification of the proteins showed changes in inhibition selectivity. Phosphatidylserine externalization, active caspase-3, cell cycle, and ultrastructural analysis confirmed apoptotic activity and S-phase cell-cycle arrest. Western blot analysis demonstrated glyceraldehyde 3-phosphate dehydrogenase as a binding protein. We suggest that Bt 18 parasporal proteins inhibit leukemic cell viability by cell-cycle arrest and apoptosis and that glyceraldehyde 3-phosphate dehydrogenase binding initiates apoptosis.
    Matched MeSH terms: Bacillus thuringiensis*
  4. NA Bahaman, Raha Ahmad Raus, Yusilawati Ahmad Nor, Al Mamun, Abdullah, Noor Suhana Adzahar, Dayang Fredalina Basri
    MyJurnal
    Introduction: Traditionally, Mallotus paniculatus (Balik Angin) plant is used in the treatment of various
    diseases in rural areas such as remedy after childbirth, wound healing and fever. In this present study, four
    medicinal properties of the plant were investigated which included antibacterial, antifungal, anticancer and
    antioxidant activities. Materials and Methods: Potential medicinal compounds were extracted from the plant
    leaves by sonication with 3 different solvents namely ethanol, ethyl acetate and hexane respectively. The
    antibacterial and antifungal properties were determined using disc diffusion agar and broth dilution assay,
    the antioxidant activity by DPPH scavenging assay and the anticancer effect by MTT assay. Results: From the
    screening of the medicinal properties, M. paniculatus leave extracts were shown to possess antibacterial,
    antioxidant and anticancer properties but not antifungal properties. Ethanolic and ethyl acetate extracts of
    the leave were active against gram positive bacteria (Staphylococcus aureus and Bacillus subtilis) but not
    gram negative bacteria (Pseudomonas aeruginosa and Escherichia coli). The antioxidant activity of the
    ethanolic crude extract was high; with IC50 of 30 μg/ml comparable with the positive controls; ascorbic acid
    and butylated hydroxytoluene (BHT). Both ethanolic and ethyl acetate extracts were cytotoxic against breast
    cancer (MCF7), colon cancer (HT-29), cervix cancer (Hela) cell lines. Conclusion: M. paniculatus leave
    extract has many potential medicinal values for further studies.
    Matched MeSH terms: Bacillus subtilis
  5. Kumari M, Tahlan S, Narasimhan B, Ramasamy K, Lim SM, Shah SAA, et al.
    BMC Chem, 2021 Jan 21;15(1):5.
    PMID: 33478538 DOI: 10.1186/s13065-020-00717-y
    BACKGROUND: Triazole is an important heterocyclic moiety that occupies a unique position in heterocyclic chemistry, due to its large number of biological activities. It exists in two isomeric forms i.e. 1,2,4-triazole and 1,2,3-triazole and is used as core molecule for the design and synthesis of many medicinal compounds. 1,2,4-Triazole possess broad spectrum of therapeutically interesting drug candidates such as analgesic, antiseptic, antimicrobial, antioxidant, anti-urease, anti-inflammatory, diuretics, anticancer, anticonvulsant, antidiabetic and antimigraine agents.

    METHODS: The structures of all synthesized compounds were characterized by physicochemical properties and spectral means (IR and NMR). The synthesized compounds were evaluated for their in vitro antimicrobial activity against Gram-positive (B. subtilis), Gram-negative (P. aeruginosa and E. coli) bacterial and fungal (C. albicans and A. niger) strains by tube dilution method using ciprofloxacin, amoxicillin and fluconazole as standards. In-vitro antioxidant and anti-urease screening was done by DPPH assay and indophenol method, respectively. The in-vitro anticancer evaluation was carried out against MCF-7 and HCT116 cancer cell lines using 5-FU as standards.

    RESULTS, DISCUSSION AND CONCLUSION: The biological screening results reveal that the compounds T5 (MICBS, EC = 24.7 µM, MICPA, CA = 12.3 µM) and T17 (MICAN = 27.1 µM) exhibited potent antimicrobial activity as comparable to standards ciprofloxacin, amoxicillin (MICCipro = 18.1 µM, MICAmo = 17.1 µM) and fluconazole (MICFlu = 20.4 µM), respectively. The antioxidant evaluation showed that compounds T2 (IC50 = 34.83 µg/ml) and T3 (IC50 = 34.38 µg/ml) showed significant antioxidant activity and comparable to ascorbic acid (IC50 = 35.44 µg/ml). Compounds T3 (IC50 = 54.01 µg/ml) was the most potent urease inhibitor amongst the synthesized compounds and compared to standard thiourea (IC50 = 54.25 µg/ml). The most potent anticancer activity was shown by compounds T2 (IC50 = 3.84 μM) and T7 (IC50 = 3.25 μM) against HCT116 cell lines as compared to standard 5-FU (IC50 = 25.36 μM).

    Matched MeSH terms: Bacillus subtilis
  6. Chin, Yow-Wen, Loh, Li-Cher, Wong, Thim-Fatt, Abdul Razak Muttalif
    MyJurnal
    Introduction: To review the sputum bacteriology and its in-vitro antibiotic susceptibility in patients hospitalized with community-acquired pneumonia (CAP) in a state tertiary-referral Hospital (Penang hospital, Malaysia) in order to determine the most appropriate empiric antibiotics.
    Methods: From September 2006 to May 2007, 68 immunocompetent adult patients [mean age: 52 years (range 16-89); 69% male] admitted to respiratory wards for CAP with positive sputum isolates within 48 hours of admission were retrospectively identified and reviewed.
    Results: 62 isolates were Gram(-) bacilli (91%) & 6 were Gram(+) cocci (9%). The two commonest pathogens isolated were Pseudomonas aeruginosa (n=20) and Klebsiella pneumoniae (n=19) together constituted 57% of all positive isolates. Among the Pseudomonas isolates, 84.2% were fully sensitive to cefoperazone and cefoperazon/sulbactam; 95% to ceftazidime, cefepime, piperacillin/tazobactam, ciprofloxacin and amikacin, and 100% to gentamycin, netilmycin, imipenem and meropenem. Among the Klebsiella isolates, 5.3% were fully sensitive to ampicillin; 84.2% to amoxicillin, ampicllin/sulbactam, cefuroxime and ceftriazone; 89.5% to piperacillin/ tazobactam; 93.3% to cefoperazon/sulbactam and 100% sensitive to ceftazidime, cefepime, ciprofloxacin, all aminoglycosides and carbopenems.
    Conclusion: In view of the high prevalence of respiratory Pseudomonas aeruginosa, ampicillin/ sulbactam, currently the most prescribed antibiotic to treat CAP in our respiratory wards, may not be the most appropriate empiric choice. Higher generation cephalosporins with or without beta-lactamase inhibitors, ciprofloxacin or carbapenem may be the more appropriate choices. The lack of information on patients’ premorbidities such as recent hospitalization and prior antibiotic exposure, limits the interpretation of our findings and may have biased our results towards higher rates of Gram negative organisms.
    Matched MeSH terms: Bacillus
  7. Murugan K, Suresh U, Panneerselvam C, Rajaganesh R, Roni M, Aziz AT, et al.
    Environ Sci Pollut Res Int, 2018 Apr;25(11):10456-10470.
    PMID: 28913784 DOI: 10.1007/s11356-017-0074-3
    The development of novel mosquito control tools is a key prerequisite to build effective and reliable Integrated Vector Management strategies. Here, we proposed a novel method using cigarette butts for the synthesis of Ag nanostructures toxic to young instars of the malaria vector Anopheles stephensi, chloroquine (CQ)-resistant malaria parasites Plasmodium falciparum and microbial pathogens. The non-target impact of these nanomaterials in the aquatic environment was evaluated testing them at sub-lethal doses on the predatory copepod Mesocyclops aspericornis. Cigarette butt-synthesized Ag nanostructures were characterized by UV-vis and FTIR spectroscopy, as well as by EDX, SEM and XRD analyses. Low doses of cigarette butt extracts (with and without tobacco) showed larvicidal and pupicidal toxicity on An. stephensi. The LC50 of cigarette butt-synthesized Ag nanostructures ranged from 4.505 ppm (I instar larvae) to 8.070 ppm (pupae) using smoked cigarette butts with tobacco, and from 3.571 (I instar larvae) to 6.143 ppm (pupae) using unsmoked cigarette butts without tobacco. Smoke toxicity experiments conducted against adults showed that unsmoked cigarette butts-based coils led to mortality comparable to permethrin-based positive control (84.2 and 91.2%, respectively). A single treatment with cigarette butts extracts and Ag nanostructures significantly reduced egg hatchability of An. stephensi. Furthermore, the antiplasmodial activity of cigarette butt extracts (with and without tobacco) and synthesized Ag nanostructures was evaluated against CQ-resistant (CQ-r) and CQ-sensitive (CQ-s) strains of P. falciparum. The lowest IC50 values were achieved by cigarette butt extracts without tobacco, they were 54.63 μg/ml (CQ-s) and 63.26 μg/ml (CQ-r); while Ag nanostructure IC50 values were 72.13 μg/ml (CQ-s) and 77.33 μg/ml (CQ-r). In MIC assays, low doses of the Ag nanostructures inhibited the growth of Bacillus subtilis, Klebsiella pneumoniae and Salmonella typhi. Finally, the predation efficiency of copepod M. aspericornis towards larvae of An. stephensi did not decrease in a nanoparticle-contaminated environment, if compared to control predation assays. Overall, the present research would suggest that an abundant hazardous waste, such as cigarette butts, can be turned to an important resource for nanosynthesis of highly effective antiplasmodials and insecticides.
    Matched MeSH terms: Bacillus subtilis
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