Diversity of bacterial and fungal endophytic communities presents in the leaf blades of Sinningia magnifica, Sinningia schiffneri and Sinningia speciosa from different cladus of Gesneriaceae family: A comparative analysis in three consecutive years.

Sinningia is a genus of plants of Gesneriaceae family with species native to Brazil and is a source of several classes of bioactive secondary metabolites, such as quinones, terpenoids, flavonoids, and phenylethanoid glycosides. However, the diversity of endophytic microorganisms associated with them and the impact of endophytes on the biosynthesis of bioactive substances is unknown. Therefore, we sought to evaluate the microbial diversity, behavior, and frequency of endophytes in leaves blades of S. magnifica, S. schiffneri, and S. speciosa. These plants were collected in different regions and environments of Brazil and were studied comparatively for three consecutive years. The total DNA obtained from the blades of the plant leaves were sequenced by the Illumina MiSeq platform, followed by bioinformatics analysis to assess the microbial diversity of endophytes associated with each plant species and study year. The results of the taxonomic diversity showed a dynamic microbial community, which contained several bacterial phyla among them, Actinomycetota, Bacteroidota, Bacillota, and Pseudomonadota, and for the fungal phyla Ascomycota and Basidiomycota. Comparing the three years of study, the richness of the genera, over time, was decreasing, with signs of recovery towards the third year. The alpha and beta diversity indices confirm a great phylogenetic richness in the endophytic communities of bacteria and fungi associated with the leaf blades of Sinningia. However, these communities are comparatively little conserved, showing population and taxonomic changes of the microorganisms over time, possibly as a measure of adjustment to environmental conditions, evidencing both its fragility and versatility against the effects of environmental change on its endophytic microbial communities.

Evaluation of antimicrobial and antiproliferative activities of Actinobacteria isolated from the saline lagoons of northwestern Peru.

Extreme environments Morrope and Bayovar Salt lagoons, several ecosystems and microhabitats remain unexplored, and little is known about the diversity of Actinobacteria. We suggest that the endemic bacteria present in this extreme environment is a source of active molecules with anticancer, antimicrobial, and antiparasitic properties. Using phenotypic and genotypic characterization techniques, including 16S rRNA sequencing, we identified these bacteria as members of the genera Streptomyces, Pseudonocardia, Staphylococcus, Bacillus, and Pseudomonas. Actinobacteria strains were found predominantly. Phylogenetic analysis revealed 13 Actinobacteria clusters of Streptomyces, the main genus. Three Streptomycetes, strains MW562814, MW562805, and MW562807 showed antiproliferative activities against three tumor cell lines: U251 glioma, MCF7 breast, and NCI-H460 lung (non-small cell type); and antibacterial activity against Staphylococcus aureus ATCC 6538, Escherichia coli ATCC 10536, and the multidrug resistant Acinetobacter baumannii AC-972. The antiproliferative activities (measured as total growth inhibition [TGI]) of Streptomyces sp. MW562807 were 0.57 µg/mL, for 0.61 µg/mL, and 0.80 µg/mL for glioma, lung non-small cell type, and breast cancer cell lines, respectively; the methanolic fraction of the crude extract showed a better antiproliferative activity and could inhibit the growth of (U251 (TGI = 38.3 µg/mL), OVCAR-03 (TGI = 62.1 µg/mL), and K562 (TGI = 81.5 µg/mL)) of nine tumor cells types and one nontumor cell type. Extreme enviroments, such as the Morrope and Bayovar Salt saloons are promising sources of new bacteria, whose compounds may be useful for treating various infectious diseases or even some types of cancer.

Antibacterial and antifungal properties of crude extracts and isolated compounds from Lychnophora markgravii.

Antimicrobial activity of dichloromethane and ethanol extracts and five compounds: pinostrobin (I), pinocembrin (II), tectochrysin (III), galangin 3-methyl ether (IV) and tiliroside (V) isolated from Lychnophora markgravii aerial parts against fifteen microorganisms was determined. The structures of these compounds were elucidated based on ESI-MS and NMR spectroscopic data. Both extracts showed antimicrobial activity against several tested microorganisms. Pinostrobin, tectochrysin and galangin 3-methyl ether showed the strongest antibacterial and antifungal effects.

Antimicrobial photodynamic effect of extracts and oxoaporphine alkaloid isomoschatoline from Guatteria blepharophylla.

Photodynamic Therapy, a tumor therapy idealized at the beginning of the last century, emerges nowadays as a promising treatment alternative against infectious diseases. In this study we report a bioguided study of Guatteria blepharophylla phytoderivatives for antimicrobial PDT. Crude extracts and fraction from the species bark were obtained and further fractionated for substances isolation. All samples were evaluated in relation to their photophysical (absorbance and fluorescence) and photochemical properties (1,3-DPBF bleaching method). Then, bioassays were conducted using as biological models bacteria and yeast strains and a diode laser as a light source. Phytochemical analyses lead to the isolation of 5 isoquinoline alkaloids from oxoaporphine subclass, denominated GB1 to GB5. Photophysical and photochemical analysis showed that extracts, fraction and GB1 (isomoschatoline) presented absorption profile with bands at 600-700nm and were positive for singlet oxygen production. Photobiological assays indicate that these samples presented photodynamic antimicrobial activity against both gram-positive and gram-negative bacterial and some Candida ssp. yeast strains at sub-inhibitory concentrations. The susceptibility of gram-negative bacteria was significantly enhanced when CaCl2 or MgCl2 were employed. Greater energy doses and double sample's dosage also decreased microbial survival. It is suggested that GB1 photodynamic activity happens through both types I and II photochemical mechanisms, but with a predominance of the latter. Phytoderivatives of G. blepharophylla promoted antimicrobial effect, however more detailed study concerning chemical composition of the crude extracts and fractions as also photophysical and photochemical characteristics of GB1 are necessary to ensure their potential as photosensitizers at antimicrobial photodynamic inactivation.

Chemical composition of the essential oil from the leaves of Anaxagorea brevipes (Annonaceae) and evaluation of its bioactivity.

The essential oil obtained by hydrodistillation from leaves of Anaxagorea brevipes was analysed by gas chromatography fitted with a flame ionisation detector (GC-FID) and coupled to mass spectrometry (GC-MS). Thirty one components were identified, representing around 75.7% of total oil. The major components were ß-eudesmol (13.16%), α-eudesmol (13.05%), γ-eudesmol (7.54%), guaiol (5.12%), caryophyllene oxide (4.18%) and ß-bisabolene (4.10%). The essential oil showed antimicrobial activity against Gram-positive bacteria and yeast with the MIC values between 25.0 and 100 µg/mL. The highest antiproliferative activity was observed for the oil against MCF-7 (breast, TGI = 12.8 µg/mL), NCI-H460 (lung, TGI = 13.0 µg/mL) and PC-3 (prostate, TGI = 9.6 µg/mL) cell lines, while against no cancer cell line HaCat (keratinocyte) the TGI was 38.8 µg/mL. The oil exhibited a small antioxidant activity assessed through ORAC-FL assay (517 µmol TE/g). This is the first report regarding the chemical composition and bioactivity of A. brevipes essential oil.