Biotransformation of (-)-cubebin by <i>Aspergillus</i> spp. into (-)-hinokinin and (-)-parabenzlactone, and their evaluation against oral pathogenic bacteria

<p>The biotransformation of the lignan (-)-cubebin by filamentous fungi <i>Aspergillus terreus</i> and <i>Aspergillus niger</i> is an efficient bioprocess for obtaining (-)-hinokinin and (-)-parabenzlactone. The relevance of getting (-)-hinokinin is due to its promising effect against oral pathogens, especially <i>S. sanguinis</i> (both MIC and MBC 12.5 μg/mL), and other previous reported effects against Chagas disease and as anti-inflammatory. The advantage of using fungal transformation is the use of non-toxic and/or non-pollutant reagents and/or solvents in comparison with semi-synthesis. Microbial transformation of (-)-cubebin is also important to evaluate its human metabolism, since <i>Aspergillus</i> species are capable of mimicking P450 reactions, providing possible products of the metabolism, which is important in the assessment of its efficacy and safety. Furthermore, the present study describes a reliable RP-HPLC method to perform quantification of (-)-hinokinin in fungal extracts. It is simple, fast, selective, linear, precise, accurate and robust according to validation guidelines.</p