ABSTRACT
A new method to synthesize γ-carboline derivatives has been developed starting from 3,5-dibromo-4-pyridinamine by monoarylation using the Suzuki-Miyaura cross-coupling reaction followed by the base-mediated ring closure to pyrrole formation. Synthesis of a series of γ-carboline derivations from the 4-brominated γ-carboline 4a has been achieved by employing various coupling reactions and N-alkylations. This method has been applied for the synthesis of the antimalarial and anticancer natural product isocryptolepine. The photophysical properties of novel γ-carboline derivations are also reported.
Subject(s)
Carbolines , Indole Alkaloids , Molecular Structure , QuinolinesABSTRACT
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.
