scholarly journals Antimicrobial Polyketide Metabolites from Penicillium bissettii and P. glabrum

Molecules ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 240
Author(s):  
Melissa M. Cadelis ◽  
Natasha S. L. Nipper ◽  
Alex Grey ◽  
Soeren Geese ◽  
Shara J. van de Pas ◽  
...  

Screening of several fungi from the New Zealand International Collection of Microorganisms from Plants identified two strains of Penicillium, P. bissettii and P. glabrum, which exhibited antimicrobial activity against Escherichia coli,Klebsiella pneumoniae, and Staphylococcus aureus. Further investigation into the natural products of the fungi, through extraction and fractionation, led to the isolation of five known polyketide metabolites, penicillic acid (1), citromycetin (2), penialdin A (3), penialdin F (4), and myxotrichin B (5). Semi-synthetic derivatization of 1 led to the discovery of a novel dihydro (1a) derivative that provided evidence for the existence of the much-speculated open-chained form of 1. Upon investigation of the antimicrobial activities of the natural products and derivatives, both penicillic acid (1) and penialdin F (4) were found to inhibit the growth of Methicillin-resistant S. aureus. Penialdin F (4) was also found to have some inhibitory activity against Mycobacterium abscessus and M. marinum along with citromycetin (2).

2002 ◽  
Vol 57 (5-6) ◽  
pp. 483-488 ◽  
Author(s):  
Moacir G. Pizzolatti ◽  
Andreia F. Venson ◽  
Artur Smânia Júnior ◽  
Elza de F. A. Smânia ◽  
Raimundo Braz-Filho

A mixture of flavalignan cinchonains Ia and Ib was isolated from the bark of Trichilia catigua. The structures were established on the basis of spectroscopic data of the natural products and their methylated derivatives including 2D NMR experiments, and compared with data in the literature. These flavalignans exhibited antibacterial activity against Bacillus cereus, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus.


2018 ◽  
Vol 42 (6) ◽  
pp. 332-336 ◽  
Author(s):  
Sayed K. Ramadan ◽  
Eman A. E. El-Helw

6-Chloro-3-((2-oxo-5-phenylfuran-3(2 H)-ylidene)methyl)-4 H-chromen-4-one was utilised for the construction of N-heterocycles. The proclivity of this furanone towards some nitrogen nucleophiles, i.e. glycine, thiosemicarbazide, thiocarbohydrazide, phenylhydrazine and o-phenylenediamine, was studied. The structures of all products obtained were established on the basis of their analytical and spectral data. All synthesised compounds were screened for their in vitro antibacterial (two strains of bacteria; Escherichia coli and Staphylococcus aureus) and antifungal (two fungus strains; Aspergillus flavus and Candida albicans) activities. Some products exhibited promising antimicrobial activities.


2008 ◽  
Vol 63 (1-2) ◽  
pp. 47-50 ◽  
Author(s):  
Ooko Selline Awino ◽  
Paul Chepkwony Kiprono ◽  
Kipkemboi Pius Keronei ◽  
Festus Kaberia ◽  
Andrew Ambogo Obala

Chromatographic separation of an ethyl acetate extract from Embelia schimperi led to the isolation of a new compound identified as 2,5-dihydroxy-3-methyl-1,4-benzoquinone (1) on the basis of spectroscopic and physical data. The plant’s crude extract and pure compound 1 were assayed for in vitro antimicrobial activity against clinical strains of Salmonella spp., Proteus spp., Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, Cryptococcus neoformans, Shigella dysentriae and Staphylococcus aureus. Disc diffusion method was used and zones of inhibition, after respective incubation periods, were used to quantify antimicrobial activity. Standard antibiotics namely: augmentin, cotrimoxazole, gentamycin, tetracycline and lyncomycin were used as controls. The crude extract was inactive while the pure compound 1 showed significant activities against Salmonella spp., Proteus spp., Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, Cryptococcus neoformans, Shigella dysentriae and Staphylococcus aureus with zones of inhibition ranging from 10−20 mm. The most sensitive microorganism was P. aeruginosa while C. neoformans was insensitive to both the crude extract and compound 1.


Medicina ◽  
2008 ◽  
Vol 44 (12) ◽  
pp. 977 ◽  
Author(s):  
Alvydas Pavilonis ◽  
Algirdas Baranauskas ◽  
Ligita Puidokaitė ◽  
Žaneta Maželienė ◽  
Arūnas Savickas ◽  
...  

Objective. To evaluate the antimicrobial activity of soft and purified propolis extracts. Study object and methods. Antimicrobial activity of soft and purified propolis extracts was determined with reference cultures of Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25922, Klebsiella pneumoniae ATCC 33499, Pseudomonas aeruginosa ATCC 27853, Proteus mirabilis ATCC 12459, Bacillus subtilis ATCC 6633, Bacillus cereus ATCC 8035, and fungus Candida albicans ATCC 60193. Microbiological tests were performed under aseptic conditions. Minimum inhibitory concentration (MIC) – the highest dilution of preparation (the lowest concentration of preparation) that suppresses growth of reference microorganisms – was determined. Results. Concentration of phenolic compounds in soft propolis extract that possesses antimicrobial activity against gram-positive (Staphylococcus aureus, Enterococcus faecalis) and gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa, and Proteus mirabilis) is 0.587±0.054 mg and 0.587±0.054–0.394±0.022 mg (P>0.05) and in purified propolis extract – 0.427±0.044 mg and 0.256±0.02 mg (P>0.05). Klebsiella pneumoniae is most resistant to soft propolis extract when the concentration of phenolic compounds is 1.119± 0.152 mg and to purified propolis extract when the concentration of phenolic compounds is 1.013±0.189 mg (P>0.05). Spore-forming Bacillus subtilis bacteria are more sensitive to soft and purified propolis extracts when the concentration of phenolic compounds is 0.134±0.002 mg and 0.075±0.025 mg, respectively, and Bacillus cereus – when the concentration is 0.394±0.022 mg and 0.256±0.02 mg (P>0.05). Sensitivity of fungus Candida albicans to soft and purified propolis extracts is the same as Bacillus subtilis. Encapsulated bacterium Klebsiella pneumoniae is most resistant to antimicrobial action of soft and purified propolis extracts as compared with gram-positive Staphylococcus aureus and Enterococcus faecalis bacteria (P<0.05), gram-negative Escherichia coli, Pseudomonas aeruginosa, and Proteus mirabilis (P<0.05), sporeforming Bacillus subtilis and Bacillus cereus bacteria (P<0.05), and fungus Candida albicans (P<0.05). There is no statistically significant difference between antimicrobial effect of soft propolis extract and purified propolis extract on gram-positive bacteria, gram-negative bacteria, spore-forming bacteria, encapsulated bacteria, and Candida fungus. Conclusions. Soft and purified propolis extracts possess antimicrobial activity. They could be recommended as natural preservatives in the manufacture of pharmaceutical products.


1994 ◽  
Vol 302 (2) ◽  
pp. 535-538 ◽  
Author(s):  
J Alvarez-Bravo ◽  
S Kurata ◽  
S Natori

Previously, we identified a core undecapeptide of sapecin B having antimicrobial activity. Based on the structure of this peptide, we systematically synthesized peptides consisting of terminal basic motifs and internal oligo-leucine sequences and examined their antimicrobial activities. Of these peptides, RLKLLLLLRLK-NH2 and KLKLLLLLKLK-NH2 were found to have potent microbicidal activity against Staphylococcus aureus, Escherichia coli, methicillin-resistant S. aureus and Candida albicans in liquid medium. We also synthesized the D-enantiomer of KLKLLLLLKLK-NH2. This enantiomer was resistant to tryptic digestion and persisted longer in the culture medium, showing greater antimicrobial activity than the original peptide.


Pathogens ◽  
2014 ◽  
Vol 3 (2) ◽  
pp. 473-498 ◽  
Author(s):  
Joana Monte ◽  
Ana Abreu ◽  
Anabela Borges ◽  
Lúcia Simões ◽  
Manuel Simões

2020 ◽  
Vol 1 (2) ◽  
pp. 41-45
Author(s):  
A.Suparlan Isya Syamsu

Preliminary research has been conducted on the antimicrobial activity of n-Butanol extract of forest honey (Apis nigrocincta). This study aims to determine the antimicrobial activity of forest honey from Selayar Regency on the growth of test microbes, using the method of solid dilution with the test microbial Bacillus subtilis, Staphylococcus aureus, Streptococcus mutans, Pseudomonas aeruginosa, Salmonella typhi, Escherichia coli, Vibrio sp, Staphylococcus epidermidis, and Candida albicans against n-butanol extract from forest honey (Apis nigrocincta) at 1 mg/ml. The results obtained showed that n-butanol extract inhibited the growth of bacteria Bacillus subtilis, Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis, and Staphylococcus aureus. To estimate the compounds that provide antimicrobial activity, the TLC-Bioautography test is performed. Obtained the best results from the separation of compounds by TLC using Chlorophorom eluate: Acetone (3: 1). The TLC-Bioautographic test results showed that the spots with an Rf value of 0.29 gave activity to Bacillus subtilis, Escherichia coli, and Staphylococcus epidermidis, and gave positive results on the appearance of flavonoid compounds.


2021 ◽  
Vol 10 (13) ◽  
pp. e329101320579
Author(s):  
Alexandre Horácio Couto Bittencourt ◽  
Jaqueline Souza Machado ◽  
Mariana Garcia da Silva ◽  
Braz Antônio Pereira Cosenza

Devido ao aumento da resistência de patógenos humanos e animais aos medicamentos atuais, pesquisas por novos antimicrobianos têm sido incentivadas, principalmente por meio de plantas medicinais. Eugenia uniflora L., conhecida como pitangueira, é popularmente utilizada com diversas funções terapêuticas, justificando estudos nesta espécie. Assim, os objetivos deste estudo foram avaliar a atividade antibacteriana “in vitro” de extratos de folhas e cascas de Eugenia uniflora L. sobre Escherichia coli e Staphylococcus aureus. Para as etapas de triagem fitoquímica e microbiologia, foram utilizadas as metodologias usuais nessas áreas para obtenção dos extratos e avaliação da atividade antibacteriana com uso de controle positivo e negativo. Os resultados obtidos mostraram que no extrato das folhas foi verificada a presença de saponinas, flavonóides, alcalóides e taninos, enquanto na casca foram obtidos apenas saponinas e alcalóides. Os extratos da folha e da casca foram capazes de inibir o crescimento de Stapylococcus aureus apenas, promovendo halos de inibição de meio de 19,4 mm e 14,4 mm, respectivamente. As análises permitiram concluir que os extratos apresentam metabólitos secundários interessantes e de grande potencial antimicrobiano e que esses extratos foram capazes de inibir apenas as cepas de S. aureus, sendo resistentes às cepas de E. Coli.


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