Screening Of Herbicidal Potential Of Crude Extract Of Isolated Fungal Strains Against Some Noxious Weeds Of India: A Preliminary Evaluation

The diversity of symbiotic fungi derived from two marine sponges and sediment collected off Obhur, Jeddah (Saudi Arabia), was investigated in the current study. A total of 23 isolates were purified using a culture-dependent approach. Using the morphological properties combined with internal transcribed spacer-rDNA (ITS-rDNA) sequences, 23 fungal strains (in the majority Penicillium and Aspergillus) were identified from these samples. The biological screening (cytotoxic and antimicrobial activities) of small-scale cultures of these fungi yielded several target fungal strains which produced bioactive secondary metabolites. Amongst these isolates, the crude extract of Aspergillus terreus strain S020, which was cultured in fermentation static broth, 21 L, for 40 days at room temperature on potato dextrose broth, displayed strong antimicrobial activities against Pseudomonas aeruginosa and Staphylococcus aureus and significant antiproliferative effects on human carcinoma cells. Chromatographic separation of the crude extract by silica gel column chromatography indicated that the S020 isolate could produce a series of chemical compounds. Among these, pure crystalline terrein was separated with a high yield of 537.26 ± 23.42 g/kg extract, which represents the highest fermentation production of terrein to date. Its chemical structure was elucidated on the basis of high-resolution electrospray ionization mass spectrometry (HRESIMS) or high-resolution mass spectrometry (HRMS), 1D, and 2D NMR spectroscopic analyses and by comparison with reported data. The compound showed strong cytotoxic activity against colorectal carcinoma cells (HCT-116) and hepatocellular carcinoma cells (HepG2), with IC50 values of 12.13 and 22.53 µM, respectively. Our study highlights the potential of A. terreus strain S020 for the industrial production of bioactive terrein on a large scale and the importance of future investigations of these strains to identify the bioactive leads in these fungal extracts.

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SPECTROSCOPIC CHARACTERIZATION OF PHYTOCONSTITUENTS ISOLATED FROM A RARE MANGROVE AEGIALITIS ROTUNDIFOLIA ROXB., LEAVES AND EVALUATION OF ANTIMICROBIAL ACTIVITY OF THE CRUDE EXTRACT

Asian Journal of Pharmaceutical and Clinical Research ◽

10.22159/ajpcr.2019.v12i9.29986 ◽

2019 ◽

pp. 220-224

Author(s):

DEBJIT GHOSH ◽

SUMANTA MONDAL ◽

K. RAMAKRISHNA

Keyword(s):

Nuclear Magnetic Resonance ◽

Antimicrobial Activity ◽

Magnetic Resonance ◽

Benzoic Acid ◽

Ethyl Acetate ◽

Crude Extract ◽

Diffusion Method ◽

Fungal Strains ◽

Aegialitis Rotundifolia ◽

Nuclear Magnetic

Objective: The aim of the study is to isolate and characterize the phytochemicals from the leaves of a rare and unexplored mangrove Aegialitis rotundifolia and evaluate the antimicrobial properties of the crude extract. Methods: The dried powdered plant material was extracted with ethanol, and the ethanol extract obtained was dissolved in distilled water and partitioned using n-hexane first and then ethyl acetate. The ethyl acetate fraction was subjected to column chromatography for isolation of phytocompounds. The isolated compounds were characterized using infrared (IR), carbon-13 nuclear magnetic resonance (13C NMR), proton nuclear magnetic resonance (1H NMR), mass spectroscopy, and thin-layer chromatography (TLC). Antimicrobial activity of the crude extracts was performed using the well diffusion method against four bacterial strains and two fungal strains. Results: Three pure compounds were isolated from the leaves of Aegialitis rotundifolia, namely, 3,4-dimethyl benzoic acid, 3’-methoxy-4’-hydroxy-flavan-3-ol, and 3’,7-dimethoxy-dimethyl-4’,3,5-trihydroxy flavone which were confirmed by spectroscopic studies. Strong antibacterial activity was shown by the test extract against Staphylococcus aureus and Pseudomonas aeruginosa, whereas Escherichia coli and Bacillus cereus showed average and nil activity, respectively. The antifungal activity of the test extract was found to be strong for both the fungal strains, namely, Candida albicans and Aspergillus niger. Conclusion: The results of the present study show that the isolated compounds were confirmed to be 3,4-dimethyl benzoic acid, 3’-methoxy-4’- hydroxy-flavan-3-ol, and 3’,7-dimethoxy-dimethyl-4’,3,5-trihydroxy flavone and the test extracts showed potent antimicrobial activity for all the bacterial and fungal strains except E. coli and B. cereus which showed average and nil activity, respectively.

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Phytochemical Analysis, Antibacterial and Antifungal Activities of Different Crude Extracts of Marine Red Alga Gracilaria corticata From The Gulf of Mannar South Coast, Navaladi, South India

International Journal of Pharmaceutical Sciences and Drug Research ◽

10.25004/ijpsdr.2017.090203 ◽

2017 ◽

Vol 9 (2) ◽

Author(s):

Manivachagam Chandrasekaran ◽

Gnanaprakasam Adaikala Raj ◽

Sakthivel Jegan ◽

Venugopalan G. Venkatesalu

Keyword(s):

Antifungal Activity ◽

Ethyl Acetate ◽

Crude Extract ◽

Ethyl Acetate Extract ◽

The Other ◽

Disc Diffusion ◽

Antibacterial And Antifungal Activity ◽

Fungal Strains ◽

Gracilaria Corticata ◽

Antibacterial And Antifungal

To investigate the antibacterial and antifungal activity of hexane, chloroform, ethyl acetate, acetone and methanol extracts of Gracilaria corticata J. Ag against bacterial and fungal strains viz., Bacillus subtilis, Streptococcus pyogenes, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella typhimurium, Vibrio cholerae, Shigella flexneri, Proteus mirabilis and Proteus vulgaris. Fungal strains Candida albicans, Candida krusei, Candida guilliermondi, Candida parapsilosis, Candida tropicalis, Candida glabrata, four dermatophytes viz., Trichophyton rubrum, Trichophyton mentagrophytes, Microsporum gypseum and Epidermophyton flocossum. The extracts of G. corticata were extracted with different solvents viz., hexane, chloroform, ethyl acetate and methanol against bacterial and fungal strains by using disc diffusion method, MIC, MBC and MFC were determined. The ethyl acetate extract of G. corticata showed the highest antibacterial and antifungal activity against all the bacterial and fungal strains tested than the other extracts. The mean zones of inhibition produced by the extracts in agar disc diffusion assays were from 7.1 to 16.0 mm. The Minimum Inhibitory Concentrations (MIC) was between 125 and 500?g/ml, while the Minimum Bactericidal Concentrations and Minimum Fungicidal Concentrations (MFC) were between 250 and 500?g/ml. The highest mean zone of inhibition (16.0 mm) was observed in ethyl acetate extract of G. corticata against B. subtilis. The lowest MIC (125?g/ml), MBC and MFC (250?g/ml) values was observed in ethyl acetate extract of G. corticata against B. subtilis. The results suggest that the effective ethyl acetate crude extract of G. corticata showed the presence of phytochemical, terpenoids, tannins and phenolic compounds strongly than the other solvent extracts. These finding suggest that ethyl acetate crude extract of G. corticata have potential antimicrobial activity are under going further analysis to identify the active compounds currently progress.

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Phytochemical Analysis and Antifungal Activity of Aqueous Leaf Extract of Trema guineensis (Ulmaceae), A Plant from the Ivoirian Pharmacopoeia

Journal of Advances in Microbiology ◽

10.9734/jamb/2020/v20i830271 ◽

2020 ◽

pp. 14-20

Author(s):

Lacinan Ouattara ◽

M’boh Epi Reine Elisabeth N’gou ◽

Issa Bagré ◽

Andrée Emmanuelle Sika ◽

Karamoko Ouattara

Keyword(s):

Antifungal Activity ◽

Crude Extract ◽

Fungal Growth ◽

Pathogenic Fungi ◽

Dilution Method ◽

Phytochemical Analysis ◽

Traditional Use ◽

Fungal Strains ◽

Aqueous Leaf Extract ◽

Tube Dilution Method

Trema guineensis is a woody plant distributed in tropical forest of which leaf and bark extracts are traditionally used for the treatment of various diseases including fever, bronchitis, and gastrointestinal disorders. Previous studies have highlighted their antibacterial activity. So, present work was designed to examine the phytochemical and antifungal properties of aqueous crude extract of T. guineensis leaves. The bioactive components extracted from leaves were tested against pathogenic fungi using the agar tube dilution method. Antifungal activity of aqueous leaves extracts was carried out against selected pathogenic fungal strains as Aspergillus fumigatus, Cryptococcus neoformans and Candida albicans. The phytochemical analysis of the aqueous crude extract revealed the presence of secondary metabolites widely reported as antifungal such as flavonoids, saponins, quinones, alkaloids, polyphenols. The results showed that the aqueous crude leaves extract of T. guineensis was effective in inhibiting the fungal growth and were active against A. fumigatus, C. neoformans and C. albicans with MIC and MFC ranged from 20 to 200 mg/mL and 100 to 400 mg/mL, respectively. The efficient antifungal activity of T. guineensis from the present investigation revealed that aqueous leaf crude extract of the selected plant had a moderate potential to inhibit the growth of pathogenic fungal strains. This finding showed that the aqueous extract of T. guineensis exerted an antifungal effect on C. albicans, A. fumigatus and C. neoformans and supports its traditional use in herbal medicine.

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Preliminary Evaluation of a Weibull Function for Fitting Slow-Component Eye Velocity over the Time Course of Caloric-Induced Nystagmus

Journal of Speech Language and Hearing Research ◽

10.1044/jshr.3203.681 ◽

1989 ◽

Vol 32 (3) ◽

pp. 681-687 ◽

Cited By ~ 1

Author(s):

C. Formby ◽

B. Albritton ◽

I. M. Rivera

Keyword(s):

Time Course ◽

Slow Component ◽

Weibull Function ◽

Preliminary Evaluation ◽

Mathematical Function ◽

Before And After ◽

Best Fitting ◽

Eye Velocity ◽

Fitting Parameters ◽

Weibull Equation

We describe preliminary attempts to fit a mathematical function to the slow-component eye velocity (SCV) over the time course of caloric-induced nystagmus. Initially, we consider a Weibull equation with three parameters. These parameters are estimated by a least-squares procedure to fit digitized SCV data. We present examples of SCV data and fitted curves to show how adjustments in the parameters of the model affect the fitted curve. The best fitting parameters are presented for curves fit to 120 warm caloric responses. The fitting parameters and the efficacy of the fitted curves are compared before and after the SCV data were smoothed to reduce response variability. We also consider a more flexible four-parameter Weibull equation that, for 98% of the smoothed caloric responses, yields fits that describe the data more precisely than a line through the mean. Finally, we consider advantages and problems in fitting the Weibull function to caloric data.

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