Optimization of (-)-cubebin biotransformation to (-)-hinokinin by the marine fungus Absidia coerulea 3A9.

The genus Absidia is widely used in the biotransformation of different classes of natural products. This study evaluates the ability of the Absidia coerulea 3A9 marine derived strain isolated from the ascidian Distaplia stilyfera to perform biotransformations by conducting assays with (-)-cubebin, as substrate. The experiment was optimized using the experimental design proposed by Plackett-Burman for seven factors and eight experiments, to establish the biotransformation conditions that would allow maximum production of biotransformed dibenzylbutyrolactone (-)-hinokinin. An analytical method based on Reverse-Phase-High Performance Liquid Chromatography (RP-HPLC) was developed to quantify the fungal biotransformation product. The factor that influenced the (-)-hinokinin peak area the most positively was the percentage of seawater (%seawater) given that its %relative standard deviation (%RSD) showed a 32.92% deviation from the real value.

Antimicrobial activity from endophytic fungi Arthrinium state of Apiospora montagnei Sacc. and Papulaspora immersa

Papulaspora immersa and Arthrinium state of Apiospora montagnei Sacc. were isolated from the roots of Smallanthus sonchifolius (yacón). The crude extracts from their cultures inhibited the growth of Staphylococcus aureus, Kocuria rhizophila, Pseudomonas aeruginosa and Escherichia coli. The more relevant results were observed in the ethyl acetate extract from P immersa against P aeruginosa (90 µg/mL) and ethyl acetate extract from Arthrinium state of A montagnei Sacc. against P aeruginosa (160 µg/mL). The two endophytic fungi isolated from yacón roots as well as their antimicrobial activity detected in the crude extracts cultures were being reported for the first time.

Mesmo havendo grandes investimentos, a resistência a fármacos continua sendo um grave problema de saúde pública. Produtos naturais têm prevalecido como a maior fonte de novas drogas e muitos deles são isolados de sistemas simbióticos: microorganismos-plantas. Os fungos endofíticos Papulaspora immersa e Arthrinium state of Apiospora montagnei Sacc. foram isolados de raízes de Smallanthus sonchifolius (yacón). Extratos de culturas destes fungos apresentaram atividade antibacteriana frente Staphylococcus aureus, Kocuria rhizophila, Pseudomonas aeruginosa e Escherichia coli, sendo as mais relevantes observadas nas frações acetato de etila provenientes dos fungos P. immersa e Arthrinium state of Apiospora montagnei Sacc. frente a P. aeruginosa, apresentando CIM de 90µg/mL e 160µg/mL, respectivamente.