scholarly journals Evaluation of Extracts of Qualea paraensis Ducke for their Antimicrobial, Toxic and Anticholinesterase Activities

2018 ◽  
Vol 10 (4) ◽  
Author(s):  
J. A. Melo1 ◽  
K. M. M. Aroucha1 ◽  
L. P. M. Santos ◽  
C. M. Moraes ◽  
J A. Takahashi ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antimalarial Activity ◽  
Biological Activities ◽  
Skin Lesions ◽  
Artemia Salina ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

Popularly known as red mandioqueira, ‘mandioqueira vermelha’, Qualea paraensis Ducke is a plant species belonging to the family Vochysiaceae, with a natural distribution in the Amazon region. It is used in traditional medicine, by native communities of the Amazon and Bolivia, for the treatment of skin lesions caused by microorganisms. Previous studies of the species have found antimalarial activity in vivo assays. However, studies involving the investigation of numerous biological activities of Q. paraensis are incipient. Biological assays already performed with plants of other species of the genus Qualea have shown promising biological activities. Therefore, this study describes the evaluation of the biological activities (bactericide, fungicide, toxicity, and anticholinesterase) of an ethanolic extract of the bark of Q. paraensis from the state of Roraima, Brazil. For the evaluation of the toxicity of the extract, a system with microcrustacean Artemia salina was used. Antimicrobial activity was tested for the pathogenic groups of fungi (Aspergillus flavus and Fusarium proliferatum), Gram-negative bacteria (Escherichia coli and Salmonella tiphymurium), and Gram-positive bacteria (Staphylococcus aureus and Streptococcus sanguinis). The potential of the extract for the inhibition of the enzyme acetylcholinesterase (AChE) was also evaluated. The assays for determining the antimicrobial activity for Gram-positive bacteria revealed satisfactory IC50 (29.98μg/mL) inhibition values for S. sanguinis strains, showing inhibition of 64.6% of their growth. The assay for S. aureus, however, presented low inhibition. For Gram-negative bacteria, there was moderate inhibition of E. coli strains. The extract showed low toxicity to A. salina and inhibition of 23.66% of the AChE enzyme.

Antimicrobial activity of Pycnarrhena cauliflora (Miers.) Diels. methanol extract

2021 ◽  
Vol 2 (2) ◽  
Author(s):  
Eti Nurwening Sholikhah ◽  
Maulina Diah ◽  
Mustofa ◽  
Masriani ◽  
Susi Iravati ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Methanolic Extract ◽  
Biological Activities ◽  
Positive Control ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Methanolic Extracts

Pycnarrhena cauliflora (Miers.) Diels., local name sengkubak, is one of indigenous plants from West Kalimantan that has been used as natural flavor. Pycnorrhena cauliflora is one of species of Menispermaceae family which is rich in bisbenzylisoquinoline alkaloids. This alkaloids are known to have various biological activities including antiprotozoal, antiplasmodial, antifungal and antibacterial activities. This study aimed to investigate antimicrobial activity of  the P. cauliflora (Miers.) Diels. methanolic extracts against gram-positive and gram-negative bacteria. The methanolic extract of P. cauliflora (Miers.) Diels., root, leaf and stem were prepared by maceration. The disk-diffusion method was then used to determine the antimicrobial activity of the extracts against Streptococcus pyogenes, S. mutants, Staphylococcus aureus, S. epidermidis, Salmonella typhi, Shigella flexneri, Pseudomonas aeruginosa and Escherichia coli after 18-24 h incubation at 37 oC. Amoxicillin was used as positive control for gram-positive bacteria and ciprofloxacin was used as gram-negative bacteria. The inhibition zones were then measured in mm. Analysis were conducted in duplicates. The results showed in general the methanolic extracts of P. cauliflora (Miers.) Diels. root (inhibition zone diameter= 10-23 mm) were more active than that leaf (0-15 mm) and stem (0-17 mm) extracts against gram-positive bacteria. The zone inhibition diameter of amoxicillin as positive control was 8-42 mm. In addition, the methanolic extracts of P. cauliflora (Miers.) Diels. root (12-17 mm) were also more active than that leaf (0-12 mm) and stem (0-12 mm) extracts against gram-negative bacteria. The zone inhibition diameter of ciprofloxacin as positive control was 33-36 mm. In conclusion, the methanolic extract of P. caulifloria (Miers.) Diels. root is the most extract active against both gram-positive and gram-negative bacteria. Further study will be focused to isolate active compounds in the methanolic extract of the root.

scholarly journals Enaminone-Derived Pyrazoles with Antimicrobial Activity

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Mashooq Ahmad Bhat ◽  
Mohamed A. Al-Omar ◽  
Ahmed M. Naglah ◽  
Abdul Arif Khan
Keyword(s):  
Antimicrobial Activity ◽  
Gram Negative Bacteria ◽  
Significant Activity ◽  
Disc Diffusion ◽  
Initial Screening ◽  
Gram Positive ◽  
Gram Negative ◽  
Disc Diffusion Assay ◽  
Gram Positive Bacteria ◽  
Diffusion Assay

A series of pyrazoles derived from the substituted enaminones were synthesized and were evaluated for antimicrobial activity. All the compounds were characterized by the spectral data and elemental analysis. The synthesized compounds were initially screened for their antimicrobial activity against ATCC 6538, NCTC 10400, NCTC 10418, and ATCC 27853. During initial screening, compounds (P1, P6, and P11) presented significant antimicrobial activity through disc diffusion assay. These compounds were further evaluated for antimicrobial activity at different time points against Gram-positive and Gram-negative bacteria and presented significant activity for 6 hours. The activity was found to be greater against Gram-positive bacteria. In contrast at 24 hours, the activity was found only against Gram-positive bacteria except compound (P11), showing activity against both types of bacteria. Compound (P11) was found to have highest activity against both Gram-positive and Gram-negative bacteria.

scholarly journals In Vitro and In Vivo Antibacterial Activities of DW-224a, a New Fluoronaphthyridone

2006 ◽  
Vol 50 (6) ◽  
pp. 2261-2264 ◽  
Author(s):  
Hee-Soo Park ◽  
Hyun-Joo Kim ◽  
Min-Jung Seol ◽  
Dong-Rack Choi ◽  
Eung-Chil Choi ◽  
...  
Keyword(s):  
Antibacterial Activities ◽  
The Other ◽  
Vitro Activity ◽  
Gram Negative Bacteria ◽  
In Vitro Activity ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

ABSTRACT DW-224a showed the most potent in vitro activity among the quinolone compounds tested against clinical isolates of gram-positive bacteria. Against gram-negative bacteria, DW-224a was slightly less active than the other fluoroquinolones. The in vivo activities of DW-224a against gram-positive bacteria were more potent than those of other quinolones.

ANTIMICROBIAL ACTIVITY OF COPPER KAOLINITE AND SURFACTANT MODIFIED COPPER KAOLINITE AGAINST GRAM POSITIVE AND GRAM NEGATIVE BACTERIA

2016 ◽  
Vol 78 (3-2) ◽  
Author(s):  
Nor Syafawani Sarah Md Saad ◽  
Nik Ahmad Nizam Nik Malek ◽  
Chun Shiong Chong
Keyword(s):  
Antimicrobial Activity ◽  
Synergistic Effects ◽  
Wide Spectrum ◽  
Copper Nitrate ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
X Ray ◽  
Gram Positive Bacteria ◽  
Diffusion Technique

The aim of this research was to determine the antimicrobial activity of kaolinite modified with antimicrobial compounds against Gram positive and Gram negative bacteria. Copper kaolinite (Cu-kaolinite) was prepared by loading raw kaolinite with copper nitrate trihydrate (CuNO3) while surfactant modified Cu-kaolinite (SM-Cu-kaolinite) was prepared by adding cationic surfactants hexadecyltrimethyl ammonium (HDTMA) on Cu-Kaolinite. Samples was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analyzer. The antimicrobial activity of the samples was tested against Gram negative bacteria (Escherichia coli ATCC 11229 and Pseudomonas aeruginosa ATCC 15442), and Gram positive bacteria (Staphylococcus aureus ATCC 6538 and Enterococcus faecalis ATCC 29212) through disc diffusion technique (DDT) and minimum inhibition concentration (MIC). The results showed that the antimicrobial activity of Cu-kaolinite increased after modified with HDTMA due to the synergistic effects of Cu ions and HDTMA molecules on the kaolinite. The antimicrobial activity for surfactant modified Cu-kaolinite was greater for Gram positive bacteria compared to Gram negative bacteria. In conclusion, the attachment of HDTMA on Cu-kaolinite contributed to the enhanced antimicrobial activity against wide spectrum of bacteria (Gram positive and Gram negative bacteria).

scholarly journals Analysis of Phytochemical Constituents and Biological Activity of Taxus Wallichiana Zucc. Dolakha District of Nepal

2018 ◽  
Vol 6 (2) ◽  
pp. 110-114
Author(s):  
Bimala Subba
Keyword(s):  
Biological Activities ◽  
Radical Scavenging ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Zone Of Inhibition ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Pharmacologically Active ◽  
Taxus Wallichiana

Phytochemical and biological activities of methanolic extract of Taxus wallichiana Zucc. (Leaf, stem) were carried out. The brine shrimp bioassay showed T. wallichiana is pharmacologically active. The antibacterial potential was studied against one gram positive bacteria (Staphylococcus aureus) and one gram negative bacteria (Escherichia Coli) using Agar Well Diffusion Method. Stem of T. wallichiana showed significant zone of inhibition against gram positive bacteria while the leaf of T. wallichiana did not show significant zone of inhibition against both gram positive and gram negative bacteria. Antioxidant activity was evaluated by 2, 2-diphenyl-1-picryl hydrazyl (DPPH) free radical scavenging activity and FRAP assay. Both assay showed that T. wallichiana leaves has high antioxidant activities.Int. J. Appl. Sci. Biotechnol. Vol 6(2): 110-114

scholarly journals Increases in Hydrophilicity and Charge on the Polar Face of Alyteserin 1c Helix Change its Selectivity towards Gram-Positive Bacteria

Antibiotics ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 238 ◽  
Author(s):  
Yamil Liscano ◽  
Constain H. Salamanca ◽  
Lina Vargas ◽  
Stefania Cantor ◽  
Valentina Laverde-Rojas ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Solid Phase ◽  
Structural Characteristics ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Mutant Derivative ◽  
Conventional Antibiotics ◽  
Carboxy Terminal

Recently, resistance of pathogens towards conventional antibiotics has increased, representing a threat to public health globally. As part of the fight against this, studies on alternative antibiotics such as antimicrobial peptides have been performed, and it has been shown that their sequence and structure are closely related to their antimicrobial activity. Against this background, we here evaluated the antibacterial activity of two peptides developed by solid-phase synthesis, Alyteserin 1c (WT) and its mutant derivative (ΔM), which shows increased net charge and reduced hydrophobicity. These structural characteristics were modified as a result of amino acid substitutions on the polar face of the WT helix. The minimum inhibitory concentration (MIC) of both peptides was obtained in Gram-positive and Gram-negative bacteria. The results showed that the rational substitutions of the amino acids increased the activity in Gram-positive bacteria, especially against Staphylococcus aureus, for which the MIC was one-third of that for the WT analog. In contrast to the case for Gram-positive bacteria, these substitutions decreased activity against Gram-negative bacteria, especially in Escherichia coli, for which the MIC was eight-fold higher than that exhibited by the WT peptide. To understand this, models of the peptide behavior upon interacting with membranes of E. coli and S. aureus created using molecular dynamics were studied and it was determined that the helical stability of the peptide is indispensable for antimicrobial activity. The hydrogen bonds between the His20 of the peptides and the phospholipids of the membranes should modulate the selectivity associated with structural stability at the carboxy-terminal region of the peptides.

scholarly journals Analysis of Phytoconstituents and Biological Activities on The Selected Medicinal Plants of Dolakha and Sindhualchowk District of Nepal

2018 ◽  
Vol 22 (2) ◽  
pp. 140-147 ◽  
Author(s):  
Bimala Subba ◽  
Susila Thapa
Keyword(s):  
Antioxidant Activities ◽  
Biological Activities ◽  
Radical Scavenging ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Antioxidant Power ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Pharmacologically Active

Phytochemical and biological activities of methanolic extract of seven plants viz. Scindapsus officinalis Schott. , Lepisorus loriformis, Nicotiana tabacum L., Clematis buchananiana DC., Astilbe rivularis D. Don, Potentilla fulgens Wall. ex Hook and Taxus wallichiana Zucc. were carried out. The brine shrimp bioassay showed that N. tabacum, A. rivularis, and P. fulgens were pharmacologically active. The antibacterial potential was studied against Staphylococcus aureus (gram positive bacteria) and Escherichia coli (gram negative bacteria) using Agar Well Diffusion Method. Roots of P. fulgens showed inhibition against gram positive bacteria while the rhizome of A. rivularis showed inhibition against both gram positive and gram negative bacteria. Antioxidant activity was evaluated by 2, 2-diphenyl-1-picryl hydrazyl (DPPH) free radical scavenging activity and ferric reducing antioxidant power FRAP assay. Both assays showed that P. fulgens has high antioxidant activities with (IC50 =15.57 ± 3.6) lower than standard ascorbic acid.  Journal of Institute of Science and TechnologyVolume 22, Issue 2, January 2018, Page: 140-147

scholarly journals Bacterial Induction of Beta Interferon in Mice Is a Function of the Lipopolysaccharide Component

2000 ◽  
Vol 68 (3) ◽  
pp. 1600-1607 ◽  
Author(s):  
Andreas Sing ◽  
Thomas Merlin ◽  
Hans-Peter Knopf ◽  
Peter J. Nielsen ◽  
Harald Loppnow ◽  
...  
Keyword(s):  
Mouse Strains ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Necrosis Factor Alpha ◽  
Gram Negative ◽  
Protein Levels ◽  
Gram Positive Bacteria ◽  
Beta Interferon

ABSTRACT We investigated the reason for the inability of lipopolysaccharide (LPS)-resistant (Lps-defective [Lpsd ]) C57BL/10ScCr mice to produce beta interferon (IFN-β) when stimulated with bacteria. For this purpose, the IFN-β and other macrophage cytokine responses induced by LPS and several killed gram-negative and gram-positive bacteria in LPS-sensitive (Lps-normal [Lpsn ]; C57BL/10ScSn and BALB/c) and Lpsd (C57BL/10ScCr and BALB/c/l) mice in vitro and in vivo were investigated on the mRNA and protein levels. In addition, double-stranded RNA (dsRNA) was used as a nonbacterial stimulus. LPS and all gram-negative bacteria employed induced IFN-β in the Lpsn mice but not in theLpsd mice. All gram-positive bacteria tested failed to induce significant amounts of IFN-β in all four of the mouse strains used. As expected, all other cytokines tested (tumor necrosis factor alpha, interleukin 1α [IL-1α], IL-6, and IL-10) were differentially induced by gram-negative and gram-positive bacteria. Stimulation with dsRNA induced IFN-β and all other cytokines mentioned above in all mouse strains, regardless of their LPS sensitivities. The results suggest strongly that LPS is the only bacterial component capable of inducing IFN-β in significant amounts that are readily detectable under the conditions used in this study. Consequently, in mice, IFN-β is inducible only by gram-negative bacteria, but not in C57BL/10ScCr or other LPS-resistant mice.

scholarly journals Small subunits of RNA polymerase: localization, levels and implications for core enzyme composition

Microbiology ◽  
2010 ◽  
Vol 156 (12) ◽  
pp. 3532-3543 ◽  
Author(s):  
Geoff P. Doherty ◽  
Mark J. Fogg ◽  
Anthony J. Wilkinson ◽  
Peter J. Lewis
Keyword(s):  
Fluorescent Protein ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
The Core ◽  
Bacterial Rna ◽  
Green Fluorescent

Bacterial RNA polymerases (RNAPs) contain several small auxiliary subunits known to co-purify with the core α, β and β′ subunits. The ω subunit is conserved between Gram-positive and Gram-negative bacteria, while the δ subunit is conserved within, but restricted to, Gram-positive bacteria. Although various functions have been assigned to these subunits via in vitro assays, very little is known about their in vivo roles. In this work we constructed a pair of vectors to investigate the subcellular localization of the δ and ω subunits in Bacillus subtilis with respect to the core RNAP. We found these subunits to be closely associated with RNAP involved in transcribing both mRNA and rRNA operons. Quantification of these subunits revealed δ to be present at equimolar levels with RNAP and ω to be present at around half the level of core RNAP. For comparison, the localization and quantification of RNAP β′ and ω subunits in Escherichia coli was also investigated. Similar to B. subtilis, β′ and ω closely associated with the nucleoid and formed subnucleoid regions of high green fluorescent protein intensity, but, unlike ω in B. subtilis, ω levels in E. coli were close to parity with those of β′. These results indicate that δ is likely to be an integral RNAP subunit in Gram-positives, whereas ω levels differ substantially between Gram-positives and -negatives. The ω subunit may be required for RNAP assembly and subsequently be turned over at different rates or it may play roles in Gram-negative bacteria that are performed by other factors in Gram-positives.

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