Identification of novel dimers and chemical profiling of acid amide alkaloids in Piper nigrum.

Peppers (Piper nigrum L.) are distinguished by their pungent flavor and aroma. Piperine is a major acid-amide alkaloid with a piperidine ring that gives pepper its flavor and scent. In plant metabolomics research, the accessibility of the chemical standards is critical for scientific credibility. We isolated and identified 10 novel dimers of acid amide alkaloids (9-15 and 20-22), along with 12 known monomers (1-6) and dimers (7, 8, 16-19) from black pepper. Subsequently, we found the distribution of monomers and dimers of acid amide alkaloids in black and white peppers by twenty-two acid amide alkaloids which we obtained using the molecular networking technique and multivariate analysis to reveal the molecular relationships between the acid amide alkaloids in black and white peppers. Our research delved into the chemical diversity of acid amide alkaloids in black and white peppers, which could help inform future culinary and potential medicinal utilization of pepper.