Visualization of Asparaptine in Asparagus (Asparagus officinalis) Using MALDI-IMS.

Asparaptine, an inhibitor of angiotensin-converting enzyme (ACE), is a newly discovered compound in asparagus. Asparaptine is a conjugate of arginine and asparagusic acid; this compound is suggested to be effective for preventing high blood pressure. For this reason, asparaptine has attracted remarkable attention in recent years, and it was therefore necessary to carry out further research. No studies to date have investigated the localization of asparaptine in asparagus. In this study, the localization of asparaptine in asparagus was clarified using matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI-IMS), a powerful method to visualize molecules.