Bio-guided fractionation of black pepper essential oil by means of preparative gas chromatography.

Objective: Despite advancements in oral anti-diabetic agents, current diabetes treatments remain suboptimal, necessitating the exploration of novel alternatives. Recent research highlights the potential of certain spices and herbs, particularly their volatile fractions, in reducing high blood glucose. This study investigates the anti-diabetic potential of Piper nigrumessential oil. Methods: Piper nigrum essential oil was comprehensively characterized using Gas Chromatography-Mass Spectrometry (GC-MS). Subsequently, target fractions were isolated from the essential oil via preparative gas chromatography (prep-GC) for subsequent biological evaluation. Results: Initial GC-MS analysis provided a detailed chemical profile of the essential oil. A tailored prepGC system, utilizing wide-bore capillary columns, efficiently isolated fractions of interest, significantly reducing analysis time and maximizing sample collection. Initially, the entire monoterpene and sesquiterpene fractions were collected separately and tested for biological activity. Further investigation focused on specific subfractions exhibiting the highest anti-diabetic action. Conclusions: This study demonstrates the efficacy of preparative gas chromatography as a crucial analytical tool preceding biological assays. By isolating specific fractions of Piper nigrum essential oil, we were able to elucidate the individual contributions of investigated terpenes to the observed anti-diabetic activity.