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.