scholarly journals Oxandrastins: Antibacterial Meroterpenes from an Australian Mud Dauber Wasp Nest-Associated Fungus, Penicillium sp. CMB-MD14

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7144
Author(s):  
Ahmed H. Elbanna ◽  
Zeinab G. Khalil ◽  
Robert J. Capon

The ethyl acetate extract of an ISP-2 agar cultivation of the wasp nest-associated fungus Penicillium sp. CMB-MD14 exhibited promising antibacterial activity against vancomycin-resistant enterococci (VRE), with a bioassay guided chemical investigation yielding the new meroterpene, oxandrastin A (1), the first andrastin-like metabolite with an extra oxygenation at C-2. A culture media optimisation strategy informed a scaled-up rice cultivation that yielded 1, together with three new oxandrastins B–D (2–4), two known andrastins C (5) and F (6), and a new meroterpene of the austalide family, isoaustalide F (7). Structures of 1–7 were assigned based on detailed spectroscopic analysis and chemical interconversion. A GNPS molecular networking analysis of the rice cultivation extract detected the known austalides B (8), H (9), and H acid (10), tentatively identified based on molecular formulae and co-clustering with 7. That the anti-VRE properties of the CMB-MD14 extract were exclusively attributed to 1 (IC50 6.0 µM, MIC99 13.9 µM), highlights the importance of the 2-OAc and 3-OAc moieties to the oxandrastin anti-VRE pharmacophore.

2016 ◽  
Vol 11 (9) ◽  
pp. 1934578X1601100
Author(s):  
Sakon Monggoot ◽  
Jariya Burawat ◽  
Patcharee Pripdeevech

A total of 17 endophytic fungal isolates were obtained from the leaves of Mentha cordifolia Opiz (Lamiaceae). Seven isolates were identified to the level of genus by using taxonomically relevant morphological traits. Colletotrichum and Phomopsis species were dominant among these strains. All strains were separated from M. cordifolia leaf for the first time. The ethyl acetate extracts of all endophytic fungi were tested for antibacterial activity against Salmonella typhimurium TISTR1166 and Pseudomonas aeruginosa TISTR781. Most endophytes exhibited antibacterial activity. Ustilago sp. MFLUCC15-1024 presented the highest inhibition zone diameter with a MIC of 31.25 μg/mL against the tested pathogens. The chemical composition of the ethyl acetate extract of this strain was investigated using gas chromatography-mass spectrometry. Twenty-one components were identified. 2-Phenylethanol (38.7%), E-ligustilide (12.4%), α-eudesmol (10.2%), β-vetivone (4.6%), β-ylangene (3.7%) and verbanol (3.4%) were the major components of the extract. The strong antibacterial activity of Ustilago sp. MFLUCC15-1024 ethyl acetate extract may be attributed to the presence of a high concentration of bioactive compounds including phenyl ethyl alcohol, E-ligustilide and α-eudesmol. The results indicate that there is high diversity of endophytic fungi in M. cordifolia leaf, and that Ustilago sp. MFLUCC15-1024 strain could be an excellent resource of natural antibacterial compounds.


2017 ◽  
Vol 12 (8) ◽  
pp. 1934578X1701200 ◽  
Author(s):  
Dikdik Kurnia ◽  
Dadan Sumiarsa ◽  
Hendra D.A. Dharsono ◽  
Mieke H. Satari

A new phenolic compound (1), a steroid (2), a new steroid glycoside (4), two triterpenoids (3 & 6) and a new phloroglucinol-sesquiterpene (5) have been isolated from the ethyl acetate extract of Sarang Semut ( Myrmecodia pendans) and their structures were determined on the basis of the spectral data. The bioactivity evaluation was conducted with the inhibition zone of compounds (mm) using Kirby-Bauer method at concentrations of 1000 and 5000 ppm for compound 1 against pathogenic oral bacteria Enterococcus faecalis, was 8.55 and 8.05 mm, respectively. Compounds 2–3 against Streptococcus mutans were 9.00 and 8.45 mm (2) and 10.24 and 9.35 mm (3), respectively. Compound 5 against Porphyromonas gingivalis was 11.5 and 10.8 mm, respectively.


Pharmacologia ◽  
2012 ◽  
Vol 3 (11) ◽  
pp. 632-636 ◽  
Author(s):  
P. Bogne Kamga ◽  
G.L. Tiani Mouthe ◽  
B. Ouahouo Wache ◽  
V. Penlap Beng ◽  
F.X. Etoa ◽  
...  

2001 ◽  
Vol 45 (6) ◽  
pp. 1823-1827 ◽  
Author(s):  
Hideki Maki ◽  
Kenji Miura ◽  
Yoshinori Yamano

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.


2021 ◽  
Vol 948 (1) ◽  
pp. 012069
Author(s):  
R Trifani ◽  
Noverita ◽  
T A Hadi ◽  
E Sinaga

Abstract Endosymbiont fungi from marine sponges are a rich source of medicinally active compounds. Indonesia has a huge number of marine sponges. This research was conducted to determine the antibacterial potential of endosymbiont fungi isolated from marine sponges collected from Kotok Kecil Island, Seribu Islands. The screening was conducted with two methods, the modified GIBEX and disc diffusion. Species of marine sponges were isolated, namely Petrosia sp., Stylissa carteri, Cinachyrella australiensis, Callyspongia sp., Petrosia nigrians, and Stylissa massa, and obtained 9 isolates of endosymbiont fungi. The GIBEX test against Escherichia coli and Streptococcus mutans showed that ethyl acetate extract had strongest antibacterial activity. Disc diffusion test of ethyl acetate extract, five isolates had antibacterial activity against S. mutans and four against E. coli. The isolate that showed the strongest antibacterial activity was from Petrosia sp. Which has an inhibition zone of 8.4 mm against E. coli and 7.45 mm against S. mutans. The main active compounds from the isolate of Petrosia sp. are butylhydroxytoluene and phthalic acid di-(2-propylpentyl) esters. Based on this study, we concluded that the endosymbiont fungi of marine sponges are potential to be developed for further development as source of antibacterial agents.


Author(s):  
Priska Nancy Claudia Bali ◽  
Ahmad Raif ◽  
Setia Budi Tarigan

Pandanus amaryllifolius roxb leaves commonly used as food dditives which contain various compound groups namely alkaloid, saponins, flavonoids and tannins that have a role in antibacterial activity. This research is indicated to support the success of antibacterial in fragrant pandanus leaf plants against Salmonella typhi, one of the pathogenic bacteria. The antibacterial effectiveness test of ethanol-ethyl acetate extract (1: 1) of pandanus leaves which evaluated by the Kirby-bauer method and making the extract concentrations of 25%, 50%, 75%, 100%. The results showed that pandanus leaves extract had antibacterial effectiveness against Salmonella typhi with an average inhibition zone diameter of 11.6 mm; 14 mm; 14.3 mm; 15.3 mm; positive controls (Ciprofloxacin) 27 mm; and negative controls (aquadest) didn’t produce the inhibition zone of Salmonella typhi.


Author(s):  
Patel N ◽  
Mohan J S S

The n- Hexane, ethyl acetate, methanol and distilled water Leaf, Stem, Flower and Fruit extracts of Moringa oleifera were evaluated for their antibacterial activity against six Gram-Negative and Gram-Positive bacteria and antifungal activity against seven fungal strains using Ciprofloxacin, Doxycycline, Fluconazole and Ketacozole as positive control. The activity was analyzed by well diffusion and two-fold serial broth dilution method of different extract. The study revealed that all the extracts irrespective of their types, in different concentrations inhibited growth of the test pathogens to varying degrees. Ethyl acetate extract showed maximum activity against all the bacterial strains followed in descending order by methanol, n-.Hexane and distilled water extracts. Ethyl acetate extract showed high antibacterial activity against Serratia marcescens (22mm) Methanol and n-Hexane extract were effective against Enterococcus faecalis and Bacillus subtilis (10mm) respectively. Aqueous extract showed maximum number of inhibition against Staphylococcus aureus (27mm) and Micrococcus luteus (18mm). Ethyl acetate extract showed maximum inhibition against Trichoderma harzianum (16mm) than other extracts were ineffective against selected fungus. MIC values were recorded as 0.125 to 4mg/ml. The phytochemical screening revealed the presence of phenols and flavonoids. Expression to these results it may be concluded that M. oleifera may be a potential source for the curing of various infectious diseases caused by the resistant microbes


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