The antibacterial activity of some naturally occurring 2,5-dihydroxy-l,4-benzoquinones

1984 ◽  
Vol 30 (8) ◽  
pp. 1068-1072 ◽  
Author(s):  
D. Brewer ◽  
W.-C. Jen ◽  
G. A. Jones ◽  
A. Taylor
Keyword(s):  
Antibacterial Activity ◽  
Related Compound ◽  
Antibiotic Activity ◽  
Number Of Species ◽  
Naturally Occurring ◽  
Metabolic Products

Polyporic acid, atromentin, bovinone, and oosporein are common metabolic products of a number of species of fungi. The related compound cochliodinol and its congeners are produced by several Chaetomium spp. These quinonoid metabolites have been shown to inhibit the growth and metabolism of a range of bacterial genera. The antibiotic activity of the quinones depends on the substituents at the 3 and 6 positions of the 2,5-dihydroxy-1,4-benzoquinone ring; in aerobic systems the activity appears to be inversely proportional to the polarity of the metabolite. It has been shown that reduction of the quinone to the hydroquinone changes the antibiotic activity of these metabolites but does not abolish it. Contrary to previous reports, the activity of these hydroquinones is not reversed by cysteine.

scholarly journals Potentially Effective and Safe Anti-Helicobacter pylori Natural Products: Chemometric Study

2020 ◽  
Vol 71 (6) ◽  
pp. 267-273 ◽  
Author(s):  
Branislava D. Kocic ◽  
Dobrila M. Stankovic Dordevic ◽  
Marija V. Dimitrijevic ◽  
Marija S. Markovic ◽  
Dragoljub L. Miladinovic
Keyword(s):  
Helicobacter Pylori ◽  
Antibacterial Activity ◽  
Natural Products ◽  
Chemical Composition ◽  
Essential Oils ◽  
Principal Component ◽  
Synergistic Activity ◽  
Agglomerative Hierarchical Clustering ◽  
Naturally Occurring ◽  
H Pylori

The susceptibility of Helicobacter pylori to three essential oils (EOs), 12 naturally occurring monoterpene hydrocarbons, oxygenated and phenolic monoterpenes and three reference antibiotics were studied. Classification and comparison of essential oils and monoterpenes on the basis of their chemical composition and antibacterial activity were made by the utilization of principal component analyses (PCA) and agglomerative hierarchical clustering (AHC). The most abundant compound in the Thymus glabrescens Willd. and Thymus pulegioides L. EOs is geraniol (33.8% and 52.5%), while the main constituent in Satureja kitaibelii Wierzb. ex Heuff. EO is limonene (16,1%). The compound that was the most active against H. pylori was carvacrol. EOs of T. glabrescens and S. kitaibelii exhibit higher antibacterial ability in comparison with all monoterpenes, except carvacrol, probably based on the concept of synergistic activity of essential oil components. PCA separated essential oils based on chemical composition and explain 96.5% of the total variance in the first two principal components. Essential oils, phenolic monoterpenes and two antibiotics were classified in the same sub-cluster within AHC analyses. EOs of T. glabrescens and S. kitaibelii can be used to treat infections caused by H. pylori, as a potentially effective, cheap and safe natural products. Further research of antibacterial activity of selected monoterpenes, essential oils and standard antibiotic combinations, as well as clinical study are required.

The Structural Gene for Microcin H47 Encodes a Peptide Precursor with Antibiotic Activity

1999 ◽  
Vol 43 (9) ◽  
pp. 2176-2182 ◽  
Author(s):  
Eliana Rodríguez ◽  
Carina Gaggero ◽  
Magela Laviña
Keyword(s):  
Escherichia Coli ◽  
Gene Fusion ◽  
Genetic System ◽  
Antibiotic Activity ◽  
Peptide Antibiotic ◽  
Bifunctional Protein ◽  
Naturally Occurring ◽  
Hydrophobic Peptide ◽  
Peptide Precursor ◽  
Highly Hydrophobic

ABSTRACT Microcin H47 is a bactericidal antibiotic produced by a naturally occurring Escherichia coli strain isolated in Uruguay. The microcin genetic system is located in the chromosome and extends over a 10-kb DNA segment containing the genes required for microcin synthesis, secretion, and immunity. The smallest microcin synthesis gene,mchB, was sequenced and shown to encode a highly hydrophobic peptide. An mchB-phoA gene fusion, which directed the synthesis of a hybrid bifunctional protein with both PhoA and microcin H47-like activities, was isolated. The results presented herein lead us to propose that microcin H47 is indeed a ribosomally synthesized peptide antibiotic and that its peptide precursor already has antibiotic activity of the same specificity as that of mature microcin.

scholarly journals Conformation-dependent Antibacterial Activity of the Naturally Occurring Human Peptide LL-37

1998 ◽  
Vol 273 (6) ◽  
pp. 3718-3724 ◽  
Author(s):  
Jan Johansson ◽  
Gudmundur H. Gudmundsson ◽  
Martı́n E. Rottenberg ◽  
Kurt D. Berndt ◽  
Birgitta Agerberth
Keyword(s):  
Antibacterial Activity ◽  
Naturally Occurring

Antibacterial Activity of the Lactoperoxidase System: A Review

1993 ◽  
Vol 56 (10) ◽  
pp. 887-892 ◽  
Author(s):  
LISA M. WOLFSON ◽  
SUSAN S. SUMNER
Keyword(s):  
Antibacterial Activity ◽  
Shelf Life ◽  
Incubation Time ◽  
Raw Milk ◽  
Medium Ph ◽  
Gram Negative ◽  
System A ◽  
Naturally Occurring ◽  
Lactoperoxidase System ◽  
Storage Times

The lactoperoxidase (LP) system is a naturally occurring system which was first discovered in raw milk. Different groups of bacteria show a varying degree of resistance to the LP system. Gram-negative catalase-positive organisms, such as pseudomonads, coliforms, salmonellae, and shigellae, are inhibited by the LP system. Depending on the medium pH, temperature, incubation time, cell density, and the particular donor, these microorganisms may be killed. It has been shown that the LP system can increase storage times of raw milk by delaying growth of psychrotrophs; perhaps this method could be used to extend the shelf life of other foods.

scholarly journals Katanosin B and Plusbacin A3, Inhibitors of Peptidoglycan Synthesis in Methicillin-ResistantStaphylococcus aureus

2001 ◽  
Vol 45 (6) ◽  
pp. 1823-1827 ◽  
Author(s):  
Hideki Maki ◽  
Kenji Miura ◽  
Yoshinori Yamano
Keyword(s):  
Cell Wall ◽  
Antibacterial Activity ◽  
Whole Cells ◽  
Gram Positive Bacteria ◽  
Peptidoglycan Synthesis ◽  
Cyclic Depsipeptide ◽  
Naturally Occurring ◽  
Vancomycin Resistant Enterococci ◽  
Vancomycin Resistant

ABSTRACT Both katanosin B and plusbacin A3 are naturally occurring cyclic depsipeptide antibiotics containing a lactone linkage. They showed strong antibacterial activity against methicillin-resistantStaphylococcus aureus and VanA-type vancomycin-resistant enterococci, with MICs ranging from 0.39 to 3.13 μg/ml, as well as against other gram-positive bacteria. They inhibited the incorporation of N-acetylglucosamine, a precursor of cell wall synthesis, into peptidoglycan of S. aureus whole cells at concentrations close to their MICs. In vitro studies with a wall-membrane particulate fraction of S. aureus showed that katanosin B and plusbacin A3 inhibited the formation of lipid intermediates, with 50% inhibitory concentrations (IC50s) of 2.2 and 2.3 μg/ml, respectively, and inhibited the formation of nascent peptidoglycan, with IC50s of 0.8 and 0.4 μg/ml, respectively. Vancomycin, a well-known inhibitor of transglycosylation, did not inhibit the formation of lipid intermediates but did inhibit the formation of nascent peptidoglycan, with an IC50 of 4.1 μg/ml. Acetyl-Lys-d-Ala-d-Ala, an analog of the terminus of the lipid intermediates, effectively suppressed the inhibition of transglycosylation by vancomycin, but did not suppress those by katanosin B and plusbacin A3. These results indicate that the antibacterial activity of katanosin B and plusbacin A3 is due to blocking of transglycosylation and its foregoing steps of cell wall peptidoglycan synthesis via a mechanism differing from that of vancomycin.

scholarly journals Antibacterial Activity of Antibiotic-Impregnated Bone Cement Based Coatings Against Microorganisms with Different Antibiotic Resistance Levels

2018 ◽  
Vol 24 (4) ◽  
pp. 105-110
Author(s):  
D. V. Tapalski ◽  
P. A. Volotovski ◽  
A. I. Kozlova ◽  
A. Sitnik
Keyword(s):  
Antibacterial Activity ◽  
Bone Cement ◽  
Antibiotic Activity ◽  
Broth Microdilution ◽  
Antibiotic Resistant ◽  
Microdilution Method ◽  
Bactericidal Properties ◽  
Broth Microdilution Method ◽  
Marked Activity ◽  
Agar Method

Purpose — to evaluate the presence and duration of antibiotic activity of antibiotic-impregnated bone cement based coatings samples against antibiotic-sensitive and antibiotic-resistant microorganisms.Material and Methods. Bone cement based coatings impregnated with antibiotics (gentamycin, vancomycin, colistin, meropenem, fosfomycin) are formed on titanium (Ti) plates. A plate rinse was carried out; antibiotic concentrations in the rinsed solutions were estimated by a serial broth microdilution method. Antibacterial activity of the control and rinsed samples against the antibiotic-sensitive and multiple-antibiotic-resistant Staphylococcus aureus and Pseudomonas aeruginosa strains was estimated by a bilayer agar method.Results. The meropenem and fosfomycin concentrations in the rinsed solutions obtained at a one-fold (16 μg/ml for both antibiotics) and two-fold treatment (2 μg/ml for meropenem and 8 μg/ml for fosfomycin) were sufficient to suppress the growth of the control strains. One-fold rinse of samples with colistin eliminated their antibacterial activity completely. The marked activity of the samples with meropenem and fosfomycin persisted against the antibiotic-sensitive P. aeruginosa ATCC 27853 strain after 2 rinse cycles; single-rinsed samples with fosfomycin also maintained the activity against the extensively antibioticresistant P. aeruginosa BP-150 strain. Vancomycin-containing samples possessed the sufficient antibacterial activity against both methicillin-sensitive (MSSA) and methicillin-resistant (MRSA) S. aureus strains; two-fold rinse of the samples eliminated their bactericidal properties.Conclusion. Bone cement based coatings impregnated with fosfomycin and meropenem possess the most marked and long-lasting antibacterial activity, manifested mainly against the antibiotic-sensitive strains. 

scholarly journals Microbiological Studies on Naturally Present Bacteria in Camel and Buffalo Milk

2020 ◽  
pp. 562-570
Author(s):  
Amr M. Abdou ◽  
Riham H. Hedia ◽  
Shimaa T. Omara ◽  
Mai M. Kandil ◽  
M. A. Bakry ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Pathogenic Bacteria ◽  
Polymerase Chain Reaction Analysis ◽  
Buffalo Milk ◽  
Camel Milk ◽  
Lactobacillus Species ◽  
Milk Samples ◽  
Naturally Occurring ◽  
Polymerase Chain ◽  
Probiotic Lactobacilli

The aim of current study was to isolate and identify naturally occurring probiotic Lactobacillus species in buffalo milk, camel milk, and camel urine to investigate their susceptibility to antibiotics and their antibacterial activity against pathogenic bacteria. A total number of seven samples which included three milk samples from buffalo, three milk samples from camel, and one urine sample from camel were collected and used in this study. The samples were cultured, and 18 isolated strains were identified by using 16S rRNA multiplex Polymerase Chain Reaction analysis, which was performed following DNA extraction from the isolated bacteria. Buffalo and camel milk were different in their Lactobacilli content. All Lactobacilli strains that were found in both camel milk and camel urine, were also found in buffalo milk, Lactobacilli strains in camel milk and urine were generally more resistant to the antibiotic. Lactobacilli isolated from buffalo milk, camel milk, and also camel urine presented variable degrees of antibacterial activity against pathogenic bacteria. Further studies should be conducted with more samples to gain more information in the field of antibacterial activity of probiotic lactobacilli and to understand the mechanisms of their activity. Hopefully, they can be used as natural alternatives instead of synthetic antibiotics.

scholarly journals Phytochemical screening and synergistic interactions between aminoglycosides, selected antibiotics and extracts from the bryophyte Octoblepharum albidum Hedw (Calymperaceae)

2012 ◽  
Vol 64 (2) ◽  
pp. 465-470 ◽  
Author(s):  
C.A.S. Vidal ◽  
E.O. Sousa ◽  
Fabíola Rodrigues ◽  
Adriana Campos ◽  
S.R. Lacerda ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibacterial Activity ◽  
Klebsiella Pneumoniae ◽  
Synergistic Effect ◽  
Ethanolic Extract ◽  
Antibiotic Activity ◽  
Phytochemical Screening ◽  
Bacterial Strains ◽  
E Coli ◽  
Synergistic Interactions

This work is the first to describe the modulation of antibiotic activity of the bryophyte Octoblepharum albidum Hedw extract. The antibacterial activity of ethanolic extract of O. albidum (EEOa), alone and in association with aminoglycosides, was determined against six bacterial strains by a microdilution test. The results showed a similar inhibitory activity of EEOa against Escherichia coli ATCC 25922 and Klebsiella pneumoniae ATCC 33018 (MICs 512 ?g/mL). The synergistic effect of the extracts and aminoglycosides was also verified. The most pronounced effects were obtained with EEOa + gentamicin against E. coli and EEOa + kanamycin against K. pneumoniae with MICs reduction (128 to 32 ?g/mL). The data from this study are indicative of the antibacterial activity of the bryophyte O. albidum extracts and its potential in modifying the resistance of aminoglycosides analyzed.

scholarly journals SUBSTANSI ANTIBAKTERI JAMUR ENDOFIT PADA LAMUN ASAL PERAIRAN TONGKAINA

2017 ◽  
Vol 5 (3) ◽  
pp. 83
Author(s):  
Galih Prasetyo ◽  
Remmy Mangindaan ◽  
Robert Antonius Bara
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Endophytic Fungi ◽  
Fungal Endophytes ◽  
Antibiotic Activity ◽  
Thalassia Hemprichii ◽  
Enhalus Acoroides ◽  
Rice Medium ◽  
Partition Process

Seagrass is a part of Phanerogamae, commonly has a symbiotic relationship with microbial endophytes. The types of microbes those have ability to produce bioactive compounds with potentially exploited for medical, agriculture and industrial purposes. Antibacterial testing using the modified Kirby-Bauer method. The fungi show a strong antibiotic activity which cultivated statically and Staphylococcus aureus was induced in rice medium for 10 days. The purpose of inducing bacteria to the culture is to stimulate a strong antibiotic activity through Silence Biosynthesis Pathway. Fungal isolates were macerated with 96% of ethanol for 24 hours. Partition process was performed by adding solvents (ethyl acetate, n-hexane, ethanol and water) to get n-hexane, ethanol and water fractions. All fractions were tested their activity against clinical isolates bacteria S. aureus and Escherichia coli. Ten fungal endophytes were isolated from seagrass Thalassia hemprichii and Enhalus acoroides. Two isolates derived from the leaf of both seagrass specimens (E.D.1 and Th.D.1) showed strong antibacterial activity against S. aureus only. Antibacterial activity test of each fraction both active isolates show in water and ethanol fractions. This indicates the active antibacterial compounds of both endophytic fungi have semi-polar and polar characteristics. However, bacterial induction has no effect on their antibacterial activity.Keywords : Endophytic fungi, Thalassia hemprichii, Enhalus acoroides, antibacterial activity Staphylococcus aureus and Escherichia coli.Lamun merupakan tanaman tingkat tinggi yang mempunyai hubungan simbiosis dengan mikroba jamur endofit. Mikroba endofit ini mempunyai kemampuan untuk memproduksi senyawa-senyawa bioaktif dengan potensi yang besar untuk dieksploitasi dan menghasilkan yang bermanfaat di bidang medis, pertanian, dan industri. Isolasi jamur dilakukan mengacu pada penelitian Bara et al (2013). Pengujian antibakteri dilakukan berdasarkan metode Kirby-Bauer yang dimodifikasi. Jamur memperlihatkan aktivitas antibiotik yang kuat dikultivasi statis dan di induksikan bakteri S. aureus dalam media nasi selama 10 hari. Tujuan pemberian bakteri pada kultur yaitu untuk memicu adanya aktivitas antibiotik yang lebih kuat melalui jalur biosintesis senyap (Silence Biosintethic Pathway) pada jamur tersebut. Isolat jamur di maserasi dengan menambahkan etanol 96% selama 24 jam. Proses partisi dengan menambahkan pelarut (etil asetat, n-heksan, etanol dan air) untuk memperoleh fraksi n-heksan, etanol dan air. Tiap fraksi diuji kembali aktivitas antibiotiknya pada bakteri S. aureus dan Escherichia coli. Hasil penelitian ini diperoleh sepuluh isolat jamur dari lamun T. hemprichii dan E. acoroides. Dua isolat daun (E.D.1 dan Th.D.1) menunjukkan aktivitas yang kuat terhadap bakteri S. aureus. Pengujian aktivitas antibakteri tiap fraksi kedua isolat jamur memperlihatkan fraksi air dan etanol yang menunjukkan aktivitas penghambat. Hal ini menunjukkan bahwa senyawa aktif antibakteri kedua jamur endofit berisfat semi polar dan polar. Induksi bakteri tidak memberikan pengaruh terhadap aktivitas antibakteri.Kata Kunci : jamur endofit, Thalassia hemprichii, Enhalus acoroides, aktivitas antibakteri Staphylococcus aureus dan Escherichia coli.

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