Authors:Khabat Noori Hussein, Tímea Molnár, Richard Pinter, Adrienn Toth, Emna Ayari, Laszlo Friedrich, Istvan Dalmadi, and Gabriella Kiskó
planktonic cells, which inhibits proton permeability, leading to cellular leakage, which later results in cell death ( Ilham et al., 2014; Luz et al., 2012 ). This study was conducted using different methods to illustrate the in vitro antimicrobialactivity
The present study was designed to investigate the antioxidant and antimicrobial activities of pressurized liquid extracts from Haberlea rhodopensis Friv. The total phenolic content was performed using the Folin-Ciocalteu phenol reagent. To determine the antioxidant activities of the extracts, several complementary tests were used: ABTS and DPPH radical scavenging activities, oxygen radical absorbance capacity, and ferric-reducing antioxidant power assay. The phenolic concentration was 15.98±0.09 and 9.42±0.06 mg GAE g−1 DW for 70 and 85% ethanol extracts, respectively. Of all the performed methods, the highest antioxidant activity values were measured by the ORAC assay — 224.6±6.6 and 154.0±9.9 μM TE g−1 DW for 70 and 85% ethanol extracts, respectively. Results also showed that both extracts exhibited very weak antimicrobial activity against the examined microorganisms. However, the 70% ethanol extract possessed higher inhibition ability, which correlated with higher total phenolic content and antioxidant activity.
Authors:Rodica Olar, Mihaela Badea, Veronica Lazar, Carmen Balotescu, Elena Cristurean, and Dana Marinescu
N,N-Dimethylbiguanide derivatives (HDMBG)X, where X=CH3COO
(1), Cl (2)
and NO3 (3) respectively,
exhibit in vitro antimicrobial activity
on representative bacterial and fungal strains. The presence of N,N-dimethylbiguanidium
ion for all derivatives was evidenced by IR and 1H
NMR spectra. Thermal analysis gave information on their decomposition steps
and also on the accompanying thermodynamic effects. According to TG and DTG
curves processes as melting, oxidative degradation as well as oxidative condensation
of –C=N– units occur. The different nature of the anions results
different melting points. Paracyanide formation at various condensation degrees
Endophytic fungi of three tissues (petiole, bark and leaf) of Alstonia scholaris were assessed. A total number of 1,152 endophytic fungi were isolated from 1,002 different plant segments of seven different localities of Paschim Medinipur, West Bengal, India. The isolated fungi belong to nineteen genera, including four unidentified fungi and yeast. Colletotrichum sp. (20.39%) and Sordaria sp. (29.68%) were most commonly isolated from this plant. Hyalopus sp., Fusarium sp. and Curvularia sp. were also isolated. The colonization frequency of endophytic fungi is much higher in leaves (44.66%) in comparison to petioles (32.16%) and barks (23.17%). The study provided evidence for tissue specificity of endophytic fungi. The endophytic fungal species diversity was higher in plant segments collected from Gopegarh and Khoirullahchak, while diversity was the lowest in Rice mill area. Screenings of antimicrobial activity of these isolated endophytic fungi were done. Eight endophytic fungi showed antimicrobial activity. Among them Curvularia sp., Aspergillus sp. and one unidentified fungus showed maximum activity against test pathogens.
Jassen, A. M, Chin, N. L. J. & Scheffer, J. J. C. (1986): Screening for antimicrobialactivity of some essential oils by the agar overlay technique. Pharmaceutisch Weekblad Scientific Edition , (8), 289-292.