Liquid chromatography-electrospray ionization-mass spectrometry/mass spectrometry characterization of depsides and depsidones from the Chilean lichen Parmotrema perlatum.

Lichens are recognized by their unique compounds and diverse applications in food, medicines, and cosmetics. Using ultra-high pressure liquid chromatography, coupled with a high-resolution mass spectrometer, metabolomic profiling of the lichen Parmotrema perlatum, from a methanolic extract, was performed. Based on characteristic fragmentation patterns, twenty-five lichenic substances were tentatively identified including 5 depsides, 12 depsidones, 2 diphenyl ethers, 1 aromatic considered as possible artifact, 1 dibenzofuran, 1 carbohydrate, 1 organic acid, and 2 undefined compounds. To the best of our knowledge, this is a more complete report of their phytochemistry from P perlatum. Our findings of the P perlatum profile may contribute and complement the current data of the Parmotrema genus.

Secondary Metabolites Diversity of Aspergillus unguis and Their Bioactivities: A Potential Target to Be Explored.

Aspergillus unguis belongs to the Aspergillus section Nidulantes. This species is found in soils and organisms from marine environments, such as jellyfishes and sponges. The first chemical study reported in the literature dates from 1970, with depsidones nidulin (1), nornidulin (2), and unguinol (3) being the first isolated compounds. Fifty-two years since this first study, the isolation and characterization of ninety-seven (97) compounds have been reported. These compounds are from different classes, such as depsides, depsidones, phthalides, cyclopeptides, indanones, diarylethers, pyrones, benzoic acid derivatives, orcinol/orsenillate derivatives, and sesterpenoids. In terms of biological activities, the first studies on isolated compounds from A. unguis came only in the 1990s. Considering the tendency for antiparasitic and antibiotics to become ineffective against resistant microorganisms and larvae, A. unguis compounds have also been extensively investigated and some compounds are considered very promising. In addition to these larvicidal and antimicrobial activities, these compounds also show activity against cancer cell lines, animal growth promotion, antimalarial and antioxidant activities. Despite the diversity of these compounds and reported biological activities, A. unguis remains an interesting target for studies on metabolic induction to produce new compounds, the determination of new biological activities, medicinal chemistry, structural modification, biotechnological approaches, and molecular modeling, which have yet to be extensively explored.

Antitumor effect of depsidones from lichens on tumor cell lines and experimental murine melanoma

Abstract Lichens have exhibited numerous biological activities, including growth inhibition of tumor cells. This study evaluated the antiproliferative activity of hypostictic and salazinic acids against tumor cell lines (B16-F10, PC-03, MCF7, HT-29, HEP-G2, K562 and 786-0) by the SRB assay in vitro and antitumor activity in experimental murine melanoma in vivo. Activation of caspase-3 was quantified by flow cytometry. The murine experimental melanoma model B16-F10 was used in BALB/c mice for evaluation of antitumor activity. Hypostictic acid showed significant antiproliferative activity in K562 cells (GI50 2.20 µM), B16-F10 (GI50 13.78 µM) and 786-0 (GI50 14.24 µM), whereas salazinic acid was more active against K562 cells (GI50 64.36 µM), HT-29 (GI50 67.91 µM) and B16-F10 (GI5078.64 µM). Quantification of capase-3 revealed that the test compounds did not increase the expression of that enzyme. In the in vivo antitumor evaluation in B16-F10 melanoma, the isolated compounds inhibited tumor growth in relation to weight and volume. Hypostictic acid (16.7 mg/kg) inhibited 72% and salazinic acid 88% of tumor volume (p < 0.05). The results indicated that, both in the in vitro and in vivo models, the compounds evaluated showed antiproliferative and antitumor activities.

Depsidones and an α-pyrone derivative from Simplicillium sp. PSU-H41, an endophytic fungus from Hevea brasiliensis leaf [corrected].

Nine previously undescribed depsidones (simplicildones A-I) and one previously undescribed α-pyrone (simplicilopyrone) were isolated from the endophytic fungus Simplicillium sp. PSU-H41 along with 11 known compounds. Their structures were established by extensive spectroscopic analysis. Simplicildone A and known botryorhodine C displayed weak antibacterial against Staphylococcus aureus with equal MIC values of 32 µg/mL. Additionally, botryorhodine C was active against methicillin-resistant S. aureus with the same MIC value. Simplicildone C exhibited weak antifungal activity against Cryptococcus neoformans with an MIC value of 32 µg/mL. In addition, simplicildones A and C and botryorhodine C were noncytotoxic against noncancerous Vero cells.