scholarly journals Hansforesters A–M, polyesters from the sponge-associated fungusHansfordia sinuosaewith antibacterial activities

RSC Advances ◽  
2018 ◽  
Vol 8 (69) ◽  
pp. 39756-39768 ◽  
Author(s):  
Zehong Wu ◽  
Dong Liu ◽  
Jian Huang ◽  
Peter Proksch ◽  
Kui Zhu ◽  
...  
Keyword(s):  
Antibacterial Activities ◽  
Bacterial Strains ◽  
Potent Inhibition

Bioassay-guided separation of a sponge-derived fungusHansfordia sinuosaeafforded thirteen new polyesters namely hansforesters A–M. Hansforester A and ascotrichalactone A exhibited potent inhibition against a panel of bacterial strains.

Antioxidant and Antibacterial Activities of Artemisia herba-alba Asso Essential Oil from Middle Atlas, Morocco

2018 ◽  
Vol 16 (S1) ◽  
pp. S48-S54
Author(s):  
Y. Ez zoubi ◽  
S. Lairini ◽  
A. Farah ◽  
K. Taghzouti ◽  
A. El Ouali Lalami
Keyword(s):  
Antibacterial Activity ◽  
Essential Oil ◽  
Foodborne Pathogens ◽  
Food Systems ◽  
Antibacterial Activities ◽  
Culture Collection ◽  
Bornyl Acetate ◽  
Bacterial Strains ◽  
Disk Diffusion Assay ◽  
Different Strains

The purpose of this study was to determine the chemical composition and to evaluate the antioxidant and antibacterial effects of the Moroccan Artemisia herba-alba Asso essential oil against foodborne pathogens. The essential oil of Artemisia herba-alba was analyzed by gas chromatography coupled with mass spectroscopy. The antibacterial activity was assessed against three bacterial strains isolated from foodstuff and three bacterial strains referenced by the ATCC (American Type Culture Collection) using the disk diffusion assay and the macrodilution method. The antioxidant activity was evaluated using the DPPH (2, 2-diphenyl-1- picrylhydrazyl) method. The fourteen compounds of the Artemisia herba-alba essential oil were identified; the main components were identified as β-thujone, chrysanthenone, α-terpineol, α-thujone, α-pinene, and bornyl acetate. The results of the antibacterial activity obtained showed a sensitivity of the different strains to Artemisia herba-alba essential oil with an inhibition diameter of 8.50 to 17.00 mm. Concerning the MICs (minimum inhibitory concentrations), the essential oil exhibited much higher antibacterial activity with MIC values of 2.5 μl/ml against Bacillus subtilis ATCC and Lactobacillus sp. The essential oil was found to be active by inhibiting free radicals with an IC50 (concentration of an inhibitor where the response is reduced by half) value of 2.9 μg/ml. These results indicate the possible use of the essential oil on food systems as an effective inhibitor of foodborne pathogens, as a natural antioxidant, and for potential pharmaceutical applications. However, further research is needed in order to determine the toxicity, antibacterial, and antioxidant effects in edible products.

In the search for new secondary metabolites with biopesticidal properties

2015 ◽  
Vol 62 (4) ◽  
pp. 216-228 ◽  
Author(s):  
Carlos L. Céspedes ◽  
Julio E. Alarcon ◽  
Pedro Aqueveque ◽  
David S. Seigler ◽  
Isao Kubo
Keyword(s):  
Secondary Metabolites ◽  
Chemical Defense ◽  
Insect Pests ◽  
Sesquiterpene Lactones ◽  
Antibacterial Activities ◽  
Natural Compounds ◽  
Insect Growth Regulator ◽  
Bacterial Strains ◽  
Plant Chemical Defense ◽  
Insect Growth

Secondary metabolites are involved in diverse functions in plants, including defense and protective processes. Information concerning the biosynthesis of secondary metabolites in plants points at a constitutive or induced chemical defense, generated for protection against a variety of phytopathogenic attacks. Our phytochemical studies are aimed at finding biopesticides of botanical origin. Some plant taxa of American distribution are toxic to selected insects, fungi and bacterial strains, and their effect has been associated with the presence of phenolics, phenylpropanoids and terpenes. We have isolated some diterpenes, triterpenes, sesquiterpene lactones, flavonoids, and phenylpropanoids from members of the plant families Araucariaceae, Asteraceae, Calceolariaceae, Celastraceae, and Rhamnaceae. In addition, we have identified a number of chemical derivatives of these compound classes from the plants. A major finding indicates that compounds or their derivatives that possess antioxidant, antifungal, insect growth regulator or insecticidal activity and enzymatic inhibitors are natural compounds. Insecticidal activities were assayed against strains of lepidopteran, dipteran, and coleopteran insect pests that affect many crops. Antifungal and antibacterial activities were assayed against phytopathogenic species of filamentous fungi and bacterial strains that are pests on many crops. Our results indicate that the plant-derived compounds obtained from the abovementioned plants have excellent insect growth regulatory activity and a good potency as antifungal agents. However, little is known about the effects of these natural compounds and their derivatives on insect pests. The natural compounds that we have isolated represent a valuable resource for future studies of plant chemical defense and the role of these substances in chemical ecology.

scholarly journals ANTIBACTERIAL ACTIVITY OF METHANOLIC RHIZOME EXTRACT OF ALPINIA CALCARATA ROSC. (ZINGIBERACEAE)

2016 ◽  
Vol 3 (1) ◽  
pp. 65-66
Author(s):  
Arumugasamy K ◽  
Nantha Kumar R ◽  
Abdul Kaffoor H ◽  
Shalimol A
Keyword(s):  
Antibacterial Activity ◽  
Bacterial Species ◽  
Antibacterial Activities ◽  
Bacterial Activity ◽  
Proteus Vulgaris ◽  
Bacterial Strains ◽  
Zone Of Inhibition

The methanolic rhizome extract of A. calcarata was evaluated for its antibacterial activities against five bacterial strains Pseudomonas aeuroginosa, Proteus vulgaris, Salmonella paratyphi, Bacillus thurungiensis and Staphylococcus faccealis. The extract has inhibited all the tested bacterial species with different manner at various concentration. However the higher level zone of inhibition in 400 (mg/ml) is significant against all the above said bacterial strains of these Salmonella paratyphi. Based on the present study it can be conculuded that the plant rhizome possess potent anti bacterial activity.

Synthesis and Antibacterial Activities of Amidine Substituted Monocyclic β-Lactams

2021 ◽  
Vol 17 ◽  
Author(s):  
Lijuan Zhai ◽  
Lili He ◽  
Yuanbai Liu ◽  
Ko Ko Myo ◽  
Zafar Iqbal ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Bacterial Species ◽  
Antimicrobial Effect ◽  
Antibacterial Activities ◽  
Lead Target ◽  
Bacterial Strains ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Clinical Interest

Background: Mononcyclic β-lactams are regarded as the most resistant class of β-lactams against a series of β-lactamases though possess limited antibacterial activity. Aztreonam being the first clinically approved monobactam needs broad-spectrum efficacy through structural modification. Objective: We strive to synthesize a number of monocyclic β-lactams by varying the substituents at N1, C3 and C4 positions of azetidinone ring and study the antimicrobial effect on variable bacterial strains. Methods: Seven new monobactam derivatives 23a-g, containing substituted-amidine moieties linked to the azetidinone ring via thiazole linker, were synthesized through multistep synthesis. The final compounds were investigated for their in vitro antibacterial activities using broth microdilution method, against ten bacterial strains of clinical interest. The minimum inhibitory concentrations (MICs) of newly synthesized derivatives were compared with aztreonam, ceftazidime and meropenem, existing clinical antibiotics. Results: All compounds 23a-g showed higher antibacterial activities (MIC 0.25 µg/mL to 64 µg/mL) against tested strains as compared to aztreonam (MIC 16 µg/mL to >64 µg/mL) and ceftazidime (MIC >64 µg/mL). However all compounds, except 23d, exhibited lower antibacterial activity against all tested bacterial strains as compared to meropenem. Conclusion: Compound 23d showed comparable or improved antibacterial activity (MIC 0.25 µg/mL to 2 µg/mL) to meropenem (MIC 1 µg/mL to 2 µg/mL) in case of seven bacterial species. Therefore, compound 23d may be valuable lead target for further investigations against multi-drug resistant Gram-negative bacteria.

scholarly journals Antibacterial Potential of Aloe weloensis (Aloeacea) Leaf Latex against Gram-Positive and Gram-Negative Bacteria Strains

2019 ◽  
Vol 2019 ◽  
pp. 1-4
Author(s):  
Yohannes Kelifa Emiru ◽  
Ebrahim Abdela Siraj ◽  
Tekleab Teka Teklehaimanot ◽  
Gedefaw Getnet Amare
Keyword(s):  
Antibacterial Activity ◽  
Bacterial Infections ◽  
Inhibition Zone ◽  
Antibacterial Activities ◽  
Maximum Activity ◽  
New Drugs ◽  
Diffusion Method ◽  
Bacterial Strains ◽  
Gram Positive ◽  
Gram Negative

Objective. To evaluate the antibacterial effects of the leaf latex of Aloe weloensis against infectious bacterial strains. Methods. The leaf latex of A. weloensis at different concentrations (400, 500, and 600 mg/ml) was evaluated for antibacterial activities using the disc diffusion method against some Gram-negative species such as Escherichia coli (ATCC 14700) and Pseudomonas aeruginosa (ATCC 35619) and Gram-positive such as Staphylococcus aureus (ATCC 50080) and Enterococcus fecalis (ATCC 4623). Results. The tested concentrations of the latex ranging between 400 and 600 mg·mL−1 showed significant antibacterial activity against bacterial strain. The highest dose (600 mg/ml) of A. weloensis leaf latex revealed the maximum activity (25.93 ± 0.066 inhibition zone) followed by the dose 500 mg/ml against S. aureus. The lowest antibacterial activity was observed by the concentration 400 mg/ml (5.03 ± 0.03) against E. coli. Conclusion. The results of the present investigation suggest that the leaf latex of A. weloensis can be used as potential leads to discover new drugs to control some bacterial infections.

Characterization of Antibacterial Proanthocyanidins of Dalbergia monetaria, an Amazonian Medicinal Plant, by UHPLC-HRMS/MS

Planta Medica ◽  
2020 ◽  
Vol 86 (12) ◽  
pp. 858-866
Author(s):  
Patricia Homobono Brito de Moura ◽  
Amaryllis Almeida de Sousa ◽  
Andrea Porzel ◽  
Ludger A. Wessjohann ◽  
Ivana Correa Ramos Leal ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Pathogenic Bacteria ◽  
Neutral Loss ◽  
Antibacterial Activities ◽  
Quinone Methide ◽  
In Vitro Assays ◽  
Fragmentation Pattern ◽  
Bacterial Strains ◽  
Tract Infections

Abstract Dalbergia monetaria is an Amazonian plant whose bark is widely used to treat urinary tract infections. This paper describes a bio-guided study of ethanolic extracts from the bark and leaves of D. monetaria, in a search for metabolites active against human pathogenic bacteria. In vitro assays were performed against 10 bacterial strains, highlighting methicillin-sensitive Staphylococcus aureus and methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa. Fractioning of the extracts was performed using instrumental and classical techniques, and samples were characterized by UHPLC-HRMS/MS. Ethyl acetate fractions from bark and leaves showed similar antibacterial activities. EAFB is enriched in isoflavone C-glucosides and EAFL enriched in proanthocyanidins. Subfractions from EAFL presented higher activity and showed a complex profile of proanthocyanidins constructed by (epi)-cassiaflavan and (epi)-catechin units, including dimers, trimers and tetramers. The fragmentation pattern emphasized the neutral loss of cassiaflavan units by quinone-methide fission. Fraction SL7-6, constituted by (ent)-cassiaflavan-(ent)-cassiaflavan-(epi)-catechin isomers, showed the lowest MIC against the S. aureus and P. aeruginosa with values corresponding to 64 and 32 µg/mL, respectively. Cassiaflavan-proanthocyanidins have not been found previously in another botanical genus, except in Cassia, and the traditional medicinal use of D. monetaria might be related to the antibacterial activity of proanthocyanidins characterized in the species.

Antibacterial Activities of Antibacterial Proteins/Peptides Isolated from Organs and Mucus of Clarias Gariepinus Reared at High Stocking Density

2012 ◽  
Vol 455-456 ◽  
pp. 455-460 ◽  
Author(s):  
Xiao Mei Wang ◽  
Wei Dai ◽  
Ke Zhing Xing ◽  
Tian Jun Li ◽  
Xin Wang
Keyword(s):  
Molecular Weight ◽  
Antibacterial Activity ◽  
Crude Protein ◽  
Clarias Gariepinus ◽  
Gel Filtration ◽  
Stocking Density ◽  
Antibacterial Activities ◽  
Edwardsiella Tarda ◽  
Bacterial Strains ◽  
Sds Page

. Antibacterial proteins/peptides are important parts of the innate immune system in Clarias gariepinus. To examine potential antibacterial proteins/peptides in organs and mucus of C. gariepinus, crude protein/peptide extracts were isolated with ammonium sulfate precipitation from mucus, skin, gill, suprabranchial organ and intestine. Following further extraction using Sephadex G-50 gel filtration chromatography, the proteins/peptides associated with two absorption peaks (AP1 and AP2) were pooled, respectively, and assayed for their antibacterial activities against Escherichia coli, Aeromonas hydrophila and Edwardsiella tarda. The results showed that AP1 and AP2 from all the sampled tissues and mucus at concentration of 100 mg mL-1 exhibited antibacterial activity against the tested bacterial strains. Differences in antibacterial activity were observed among sample extracts. The protein profiles of AP1 obtained by Tricine-SDS-PAGE gel showed a broad range of peptides/proteins, and molecular weight of the mutual abundant peptide obtained was about 27 kDa. Antibacterial activity of AP2 extracted from intestine was due to peptide with molecular weight of 5.5 kDa.

QSAR analysis of 1,3-diaryl-2-propen-1-ones and their indole analogs for designing potent antibacterial agents

2009 ◽  
Vol 63 (4) ◽  
Author(s):  
Neela Bhatia ◽  
Kakasaheb Mahadik ◽  
Manish Bhatia
Keyword(s):  
Antibacterial Activity ◽  
Elemental Analysis ◽  
Antibacterial Agents ◽  
Structure Optimization ◽  
Antibacterial Activities ◽  
Bacterial Strains ◽  
Lower Toxicity ◽  
Qsar Analysis ◽  
Qsar Studies ◽  
Vlife Mds

AbstractA series of 1,3-diaryl-2-propen-1-ones and their indole analogs were synthesized and evaluated for antibacterial activity. Structures of newly synthesized compounds were confirmed by physicochemical, spectral and elemental analysis. All the compounds were screened for their antibacterial activities against four different bacterial strains. The QSAR studies were performed using Vlife MDS 3.5 software. QSAR equation revealed that selected electronic, steric and lipophilic parameters have good correlation with antibacterial activity. Best equations were selected on basis of the correlation coefficient (r 2) and the predictable ability of the equations. The present findings suggest that the 1,3-diaryl-2-propen-1-ones framework is an attractive template for structure optimization to achieve higher potency, lower toxicity, and a wider spectrum of antibacterial activity.

Two new zinc(II) and mercury(II) complexes based on N,N′-(cyclohexane-1,2-diylidene)bis(4-fluorobenzohydrazide): synthesis, crystal structures and antibacterial activities

2020 ◽  
Vol 76 (5) ◽  
pp. 476-482
Author(s):  
Al-Ameen Bariz OmarAli ◽  
Ahmed Jasim M. Al-Karawi ◽  
Adil A. Awad ◽  
Necmi Dege ◽  
Sevgi Kansız ◽  
...  
Keyword(s):  
Organic Ligand ◽  
Antibacterial Activities ◽  
Structural Features ◽  
Bacterial Strains ◽  
Tetrahedral Geometry ◽  
X Ray ◽  
X Ray Crystallography ◽  
Growth Inhibitory ◽  
The Difference

Reaction of N,N′-(cyclohexane-1,2-diylidene)bis(4-fluorobenzohydrazide), C20H18F2N4O2, (LF ), with zinc chloride and mercury(II) chloride produced different types and shapes of neutral coordination complexes, namely, dichlorido[N,N′-(cyclohexane-1,2-diylidene)bis(4-fluorobenzohydrazide)-κ2 N,O]zinc(II), [ZnCl2(C20H18F2N4O2)], (1), and dichlorido[N,N′-(cyclohexane-1,2-diylidene)bis(4-fluorobenzohydrazide)-κ4 O,N,N′,O′]mercury(II), [HgCl2(C20H18F2N4O2)], (2). The organic ligand and its metal complexes are characterized using various techniques: IR, UV–Vis and nuclear magnetic resonance (NMR) spectroscopies, in addition to powder X-ray diffraction (PXRD), single-crystal X-ray crystallography and microelemental analysis. Depending upon the data from these analyses and measurements, a typical tetrahedral geometry was confirmed for zinc complex (1), in which the ZnII atom is located outside the bis(benzhydrazone) core. The HgII atom in (2) is found within the core and has a common octahedral structure. The in vitro antibacterial activities of the prepared compounds were evaluated against two different bacterial strains, i.e. gram positive Bacillus subtilis and gram negative Pseudomonas aeruginosa bacteria. The prepared compounds exhibited differentiated growth-inhibitory activities against these two bacterial strains based on the difference in their lipophilic nature and structural features.

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