Four Yellow Monoterpenoid Quinoline Alkaloids from the Stem of Tabernaemontana bovina.
Jing WuYang YuYi WangMei-Fen BaoBao-Bao ShiJohann SchinnerlXiang-Hai CaiPublished in: Organic letters (2019)
Four unprecedented yellow alkaloids named as taberbovines A-D (1-4) were isolated from stems of Tabernaemontana bovina Lour. Their structures were elucidated by the comprehensive spectroscopic data, computational chemistry, and X-ray crystal diffraction. Alkaloids 1-4 possessed a unique 6/6/5/6/5 ring system and were assigned to monoterpenoid quinolines. Biosynthetically, the isolated alkaloids may be derived from Aspidosperma-type alkaloid by oxidation and rearrangements. Taberbovines A-D exhibited the good inhibitory activities of formation NO in LPS induced RAW264.7 macrophages.