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Three new cage-like monoterpenoid indole alkaloids, scholarisines T–V ( 1 – 3 ), together with three known analogues 4 – 6 were isolated from the leaves of Alstonia scholaris . Among them, 2 represents a unique degraded derivative, whereas 3 shares a rare 5,16- seco lactone scaffold. The structures were mainly established by extensive spectroscopic data analyses, and their plausible biosynthesis pathway from picrinine were proposed. Compared with positive control cefotaxime, alkaloid 2 showed remarkable antibacterial activity against Bacillus subtilis with an MIC value of 3.12 μg/mL, whereas 1 – 3 exhibited significant antibacterial effects on Escherichia coli with an MIC value of 0.78 μg/mL. [ABSTRACT FROM AUTHOR]

Gelselegandines A-C ( 1 – 3 ), three unprecedented gelsedines incorporating additional C 9 aromatic unit as side chain, were isolated from Gelsemium elegans . Their structures were elucidated by means of spectroscopic techniques and electronic circular dichroism (ECD) calculation. Additionally, gelselegandines A–C showed moderate antimicrobial activities against four bacterial strains and two fungi. [ABSTRACT FROM AUTHOR]