MyMedR

Displaying publications 61 - 68 of 68 in total

Abstract:

Sort:

Fulltext Design, synthesis and therapeutic potential of 3-(2-(1H-benzo[d]imidazol-2-ylthio)acetamido)-N-(substituted phenyl)benzamide analogues

Tahlan S, Ramasamy K, Lim SM, Shah SAA, Mani V, Narasimhan B

Chem Cent J, 2018 Dec 19;12(1):139.
PMID: 30569392 DOI: 10.1186/s13065-018-0513-3

BACKGROUND: The emergence of bacterial resistance is a major public health problem. It is essential to develop and synthesize new therapeutic agents with better activity. The mode of actions of certain newly developed antimicrobial agents, however, exhibited very limited effect in treating life threatening systemic infections. Therefore, the advancement of multi-potent and efficient antimicrobial agents is crucial to overcome the increased multi-drug resistance of bacteria and fungi. Cancer, which remains as one of the primary causes of deaths and is commonly treated by chemotherapeutic agents, is also in need of novel and efficacious agents to treat resistant cases. As such, a sequence of novel substituted benzamides was designed, synthesized and evaluated for their antimicrobial and anticancer activities.
METHODOLOGY: All synthesized compounds were characterized by IR, NMR, Mass and elemental analysis followed by in vitro antimicrobial studies against Gram-positive (Staphylococcus aureus), Gram-negative (Salmonella typhi and Klebsiella pneumoniae) bacterial and fungal (Candida albicans and Aspergillus niger) strains by the tube dilution method. The in vitro anticancer evaluation was carried out against the human colorectal carcinoma cell line (HCT116), using the Sulforhodamine B assay.
RESULTS, DISCUSSION AND CONCLUSION: Compound W6 (MICsa, st, kp = 5.19 µM) emerged as a significant antibacterial agent against all tested bacterial strains i.e. Gram-positive (S. aureus), Gram-negative (S. typhi, K. pneumoniae) while compound W1 (MICca, an = 5.08 µM) was most potent against fungal strains (A. niger and C. albicans) and comparable to fluconazole (MIC = 8.16 µM). The anticancer screening demonstrated that compound W17 (IC50 = 4.12 µM) was most potent amongst the synthesized compounds and also more potent than the standard drug 5-FU (IC50 = 7.69 µM).

Matched MeSH terms: Aspergillus niger
Phytochemical and biological evaluation of Defatted seeds of Jatropha Curcas

Ul Haq MN, Wazir SM, Ullah F, Khan RA, Shah MS, Khatak A

Sains Malaysiana, 2016;45:1435-1442.

In this study, the antimicrobial, antioxidant, phytotoxic and phytochemical properties of defatted seeds of Jatropha curcas were evaluated. A crude methanolic extract of defatted seeds was tested against three fungal strains - Aspergillus niger, Aspergillus flavus and Aspergillus fumigatus - and five bacteria: Escherichia coli and Klebsiella pneumoniae (Gram negative) and Micrococcus luteus, Bacillus subtilis and Staphylococcus aureus (Gram positive). The methanolic extract was diluted in dimethylsulfoxide to final concentrations of 1, 2, 3, 4 and 5 mg/10 mL. The largest zones of inhibition against K. pneumoniae, M. luteus and B. subtilis were achieved using the concentration of 5 mg/10 mL. The concentration of 1 mg/10 mL was most effective against S. aureus and E. coli. In a 1, 1-diphenyl-2-picrylahydrazyl (DPPH) radical scavenging assay, the 5 mg/10 mL concentration of the Jatropha seed extract showed the strongest activity. Higher concentrations of the Jatropha seed extract (10 mg/50 mL and 5 mg/50 mL) significantly inhibited the germination of radish seeds and had negative effects on radish seedling relative water content, shoot length, root length, seedling fresh weight and seedling dry weight (p<0.05). Phytochemical analyses of the defatted seeds detected alkaloids (7.3%), flavonoids (0.39%) and soluble phenolics (mg gallic acid equivalents/g extract). Based on these results, it was inferred that J. curcas seeds contain active ingredients that are effective against pathogenic microbes and therefore could be used to formulate drugs to treat various diseases.

Matched MeSH terms: Aspergillus niger
Initial screening of mangrove endophytic fungi for antimicrobial compounds and heavy metal biosorption potential

Ling Onn M, Teen Lim P, Aazani Mujahid, Proksch P, Müller M

Sains Malaysiana, 2016;45:1063-1071.

Endophytic fungi provide protection to their host plant and the fungi often produce antimicrobial compounds to aid the host
fighting off pathogens. These bioactive compounds were secondary metabolites which were often produced as waste- or
by-products. In the present study, endophytic fungi isolated from mangrove plants and soils were characterized and their
antimicrobial production and bioremediation potential of heavy metals copper (Cu) and zinc (Zn) were assessed. Twelve
(12) isolated and identified endophytic fungi belonged to seven species; Penicillium, Curvularia, Diaporthe, Aspergillus,
Guignardia, Neusartorya and Eupenicillium. Antimicrobial activities of these 12 fungal endophytes were tested against
Gram negative bacteria; Bacillus subtilis, Staphylococcus aureus, Gram positive bacteria; Escherichia coli and fungi;
Candida albicans and Aspergillus niger among others. Two isolates (related to Guignardia sp. and Neusartoya sp.) showed
strong antimicrobial (and antifungal) activity whereas the rest showed no activity. Compounds were isolated from both
isolates and screened using HPLC. Both isolates displayed chemically very interesting chromatograms as they possessed a
high diversity of basic chemical structures and peaks over a wide range of polarities, with structures similar to Trimeric
catechin and Helenalin among others. For bioremediation assessment, the results showed maximum biosorption capacity
for two isolates related to Curvularia sp. and Neusartorya sp., with the former removing 25 mg Cu/g biomass and the
latter removing 24 mg Zn/g biomass. Our results indicated the potential of mangrove endophytic fungi in producing
bioactive compounds and also highlighted their potential for the treatment of heavy metal-contaminated wastewater.

Matched MeSH terms: Aspergillus niger
Fulltext Production of citric acid from sugarcane molasses by Aspergillus niger using submerged fermentation

Almakki, Asma, Mirghani, Mohamed E.S., Kabbashi, Nassereldeen A.

Biological and Natural Resources Engineering Journal, 2019;2(1):47-55.
MyJurnal

Citric acid (CA) has a high demand due to its various uses in the food and pharmaceutical industries. However, the natural supply of CA is minimal compared to its growing industrial demand. The increasing demand for CA can be fulfilled by using biotechnological processes. This study utilized liquid state bioconversion by Aspergillus niger for CA production using sugarcane molasses as the primary substrate. Sugarcane molasses which is agricultural waste consists of significant proportion of organic matters such as lipids and carbohydrates. This makes sugarcane molasses as a potential and alternative source of producing CA at a lower cost. In this study, statistical optimization was applied to improve CA production using submerged fermentation in shake flasks. Aspergillus niger was cultured in potato dextrose agar. Then, inoculum spores were introduced into the fermentation media for a specific duration according to the experimental design from Central Composite Design (CCD) tool under Response Surface Methodology (RSM) in Design Expert 6.0 software. Three parameters were chosen to be optimized at 32⁰C i.e.agitation rate (160, 80, 200 rpm), substrate concentration (47, 60, 73%) and fermentation time (24, 72, 120 h). High Performance Liquid Chromatography (HPLC)and Fourier-transform infrared spectroscopy(FTIR) analyses were conducted to measure CA yield. The optimization study showed that the media incubated for 72 hours with a substrate concentration of 60% and an agitation speed of 180 rpm produced the highest CA yield(21.2 g/L).The analysis of variance (ANOVA) also showed that CCD quadratic model was significant with P-value< 0.0104 and R2is0.8964.

Matched MeSH terms: Aspergillus niger
Synthesis, Characterization, Antimicrobial and Anticancer Studies of Metal Complexes of 2-methoxy-4-((3-methylpyridin-2-ylimino)methyl)phenol

Mishra A, Tahlan S, Ramasamy K, Lim SM, Shah SAA, Narasimhan B

Mini Rev Med Chem, 2020;20(13):1311-1317.
PMID: 32368977 DOI: 10.2174/1389557520666200505124125

BACKGROUND: Being derived from primary amine and aromatic aldehyde, Schiff base and their complexes have an imperative role in the improvement of inorganic chemistry, which are broadly studied as coordination compounds and are gradually becoming more important in biochemical and analytical applications.
METHODS: They have also been used for antibacterial, antifungal, anticancer, antitubercular activities. Novel synthesised Schiff's base 2-methoxy-4-((3-methylpyridin-2-ylimino)methyl)phenol (SB) and its metal complexes (Zn[II], Cu[II], Co[II] and Ni[II]) were characterised by UV, IR and NMR spectroscopy. Formation of the Schiff base and the metal (Zn[II], Cu[II], Co[II] and Ni[II]) chelates was supported by spectral and analytical data. The ligand and metal complexes have been screened for their antibacterial activity against Staphylococcus aureus, Salmonella typhi, Escherichia coli, Klebsiella pneumoniae and antifungal activity against the fungi Candida albicans and Aspergillus niger. Further, the synthesised compounds were also screened for antiproliferative activity against the human colorectal carcinoma (HCT116) cell line using the Sulforhodamine B assay.
RESULT: Metal complexes formed were found to enhance the potency of the Schiff base due to coordination with a copper complex, showing better activity than others.
CONCLUSION: Copper complex was observed to be more potent than other complexes against all the pathogenic microbes and cancer cell line (HCT116).

Matched MeSH terms: Aspergillus niger
Fulltext Screening antimicrobial activity of tropical edible medicinal plant extracts against five standard microorganisms for natural food preservative

Rukayadi, Y., Lau, K.Y., Zainin, N.S., Zakaria, M., Abas, F.

International Food Research Journal, 2013;20(5):2905-2910.
MyJurnal

Edible medicinal plants are often used in the treatment of various ailments and spice in traditional food preparation. In this study, 45 of tropical edible medicinal plants extracts from Indonesia, Malaysia, and Thailand were screened for their antimicrobial activity against five standard microorganisms for food preservative namely Aspergillus niger, Candida albicans, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. The methanol extracts of Piper nigrum L. seed, Piper cubeba L. seed, and the root of Ligusticum acutilobum Siebold and Zucc. showed antimicrobial activity against five species of standard microorganisms. Among them, P. cubeba L. extract demonstrated the most susceptible against all tested microorganisms. Minimal inhibitory concentration (MIC) and minimal bactericidal or fungicidal concentration (MBC or MFC) were performed by the broth microdilution techniques as described by the Clinical and Laboratory Standard Institute. MIC values of P. cubeba L. extract to A. niger, C. albicans, E. coli, P. aeruginosa and S. aureus were 12.8, 1.6, 3.2, 6.4, and 1.6 mg/ml, respectively. P. cubeba extract killed A. niger, C. albicans, E. coli, P. aeruginosa and S. aureus with MBC values of 25.6, 3.2, 6.4, 12.8, and 3.2 mg/ml, respectively. The potent antimicrobial activity of P. cubeba L. extract may support its use for natural food preservative.

Matched MeSH terms: Aspergillus niger
Fulltext Antifungal effect of Malaysian neem leaf extract on selected fungal species causing otomycosis in in-vitro culture medium

Puvan Arul Arumugam, Irfan Mohamad, Rosdan Salim, Zeehaida Mohamed

Malaysian Journal of Medicine and Health Sciences, 2015;11(2):69-84.
MyJurnal

Azadirachta indica (neem) has been used for a long time in agricultural and alternative medicine. Neem
had been proved effective against certain fungi that could infect human body. This pilot study aims to
demonstrate the antifungal effect of Malaysian neem leaf extracts on the pathogenic fungi in otomycosis,
Aspergillus niger and Candida albicans. This is a laboratory-controlled prospective study conducted at
Universiti Sains Malaysia. The powder form of Malaysian neem leaf was prepared. Ethanol and aqueous
extracts of the neem leaf was diluted with sterile water to establish five different concentrations of 50 g/
ml, 25 g/ml, 12.5 g/ml, 6.25 g/ml and 3.125g/ml. The extract was tested on Sabouraud Dextrose Agar
suspended with Candida albicans and Aspergillus niger respectively. Well diffusion method was used
and zone of inhibition was measured. Growth of the fungi was inhibited in both alcohol and aqueous
extract concentrations. The minimum inhibitory concentration (MIC) of Malaysian neem aqueous extract
against Candida albicans was 11.91 g/ml, neem ethanol extract against Candida albicans was 5.16 g/
ml, neem aqueous extract against Aspergillus niger was 7.73 g/ml and neem ethanol extract against
Aspergillus niger was 9.25 g/ml. Statistical analysis showed that the antifungal activity of Candida
albicans is better in alcohol neem than aqueous extract (p

Matched MeSH terms: Aspergillus niger
Fulltext Hydroxypropylcellulose as a novel green reservoir for the synthesis, stabilization, and storage of silver nanoparticles

Hussain MA, Shah A, Jantan I, Shah MR, Tahir MN, Ahmad R, et al.

Int J Nanomedicine, 2015;10:2079-88.
PMID: 25844038 DOI: 10.2147/IJN.S75874

Polysaccharides are attracting the vigil eye of researchers in order to design the green synthesis of silver nanoparticles (Ag NPs) of diverse size, shape, and application. We report an environmentally friendly method to synthesize Ag NPs where no physical reaction conditions were employed. Hydroxypropylcellulose (HPC) was used as a template nanoreactor, stabilizer, and capping agent to obtain Ag NPs. Different concentrations of AgNO3 solutions (50 mmol, 75 mmol, and 100 mmol) were mixed with a concentrated aqueous solution of HPC and the progress of the reaction was monitored by noting color changes of the reaction mixture at different reaction times for up to 24 hours. Characteristic ultraviolet-visible spectroscopy (UV/Vis) absorption bands of Ag NPs were observed in the range of 388-452 nm. The morphology of the Ag NPs was studied by scanning electron microscopy, transmission electron microscopy (TEM), and atomic force microscopy. The TEM images confirmed that the size of the Ag NPs was in the range of 25-55 nm. Powder X-ray diffraction studies showed that the crystal phase of the Ag NPs was face-centered cubic. The as-prepared Ag NPs were found to be stable, and no changes in size and morphology were observed after storage in HPC thin films over 1 year, as indicated by UV/Vis spectra. So, the present work furnishes a green and economical strategy for the synthesis and storage of stable Ag NPs. As-synthesized Ag NPs showed significant antimicrobial activity against different bacterial (Escherichia coli, Staphylococcus epidermidis, S. aureus, Bacillus subtilis, Pseudomonas aeruginosa) and fungal strains (Actinomycetes and Aspergillus niger).

Matched MeSH terms: Aspergillus niger/drug effects