HPLC and NMR Studies of Phenoxazone Alkaloids from Pycnoporus Cinnabarinus

Abstract

Crude extracts of the red-orange, bracket fungus Pycnoporus cinnabarinus, collected from five distinct Australian localities were subjected to a chemical and biological profiling study. Subsequent detailed investigation of two of these specimens resulted in the isolation of the new phenoxazone alkaloid, pycnoporin (8), together with cinnabarin (1), tramesanguin (2), and cinnabarinic acid (3). Ergosterol peroxide (11) was also identified from one of the specimens studied. Compounds 1-3 and 8 were elucidated by detailed spectroscopic analyzes, which included the application of elevated temperature-controlled NMR experiments. In addition to the isolation and characterization of 8, this study describes the first successful HPLC purification strategy and complete 2D NMR spectroscopic characterization of compounds 1-3. Also reported are the antioxidant and antiinflammatory activities of the crude extracts of one of the P. cinnabarinus specimens. Compounds 1-3, 8 and 11 displayed varying degrees of antitumor activity while ergosterol peroxide (11) also showed slight antimicrobial and antiviral activities. This is the first report documenting the significant antitumor activity of cinnabarin (1).

Peroxides with Anthelmintic, Antiprotozoal, Fungicidal and Antiviral Bioactivity: Properties, Synthesis and Reactions

“…Ergosterol peroxide ( 187 ) isolated from different natural sources including the fungi Pycnoporus cinnabarinus demonstrated moderate antiviral activity against Herpes simplex и Polio virus [ 123 ], and also antifungal activity against pathogenic fungi Microsporum canis , Trichophyton rubrum and Epidermophyton floccosum ( Scheme 30 ) [ 124 ]. Ergosterol peroxide acetate 189 was synthesized with quantitative yield by photo-oxidation of ergosterol acetate 188 in the presence of trityl tetrafluoroborate ( Scheme 30 ) [ 125 ].…”

Does the chemistry of fungal pigments demand the existence of photoactivated defense strategies in basidiomycetes?

“…7, 9) [70,73]. In its oxidized form-as the phenoxazones cinnabarin (41), tramesanguin (42), and cinnabarinic acid (43)-this structural class was shown to be the coloring principle of the red-orange wood-decaying polypores Pycnoporus sanguineus, P. cinnabarinus, and P. coccineus [74][75][76][77]. Furthermore, the phenoxazon 2-aminophenoxazin-3-one (44) occurs wound-induced in the agaricoid Lepiota americana (synonymous Leucoagaricus americanus) [78].…”

The Structural Diversity of Marine Microbial Secondary Metabolites Based on Co-Culture Strategy: 2009–2019

“…To the best of our knowledge, the only one steroid, ergosterol (136), was found from the co-culture broth of two marine mangrove epiphytic fungi, Aspergillus sp. FSY-01 and FSW-02 ( Figure 25) [21,85]. It was an essential component of fungal cell membrane with strong specificity and stable structure.…”