Cytotoxic Monoterpenoid Indole Alkaloids from Tabernaemontana corymbosa as Potent Autophagy Inhibitors by the Attenuation of Lysosomal Acidification

  • J Nat Prod. 2020 May 22;83(5):1432-1439. doi: 10.1021/acs.jnatprod.9b00856.
Yu Zhang  1 ,  Xiao Ding  1 ,  Yu-Xi Yuan  1 ,  Ling-Li Guo  1 ,  Xiao-Jiang Hao  1
Affiliations
  • 1. State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, People's Republic of China.
PMID: 32356659 DOI: 10.1021/acs.jnatprod.9b00856
Abstract

Twenty-six Alkaloids, including the new taberines A-I (1-9), were obtained from Tabernaemontana corymbosa. The structures and absolute configurations were elucidated via MS, NMR, and ECD spectroscopic data analyses. Alkaloids 1-4 are new vobasinyl-ibogan Alkaloids, and 1 is characterized by an unusual 1,3-oxazinane moiety. Alkaloids 4 and 16 exhibited moderate cytotoxic potency against various human Cancer cell lines, while 4, 10, 11, 13, 14, and 16 showed attenuation of lysosomal acidification activity (EC50: 12.9-29.8 μM), thereby inhibiting autophagic flux.