Glucoconjugated Monoterpene Indole Alkaloids from .

Twenty-six glucoconjugated monoterpene indole alkaloids, including 12 new compounds, rhynchophyllosides A-L (-), and 14 known ones, -, were obtained from the hook-bearing stems of (Miq.) Miq. ex Havil. Their structures were unambiguously elucidated by analyses of UV, MS, NMR, ECD, and single-crystal X-ray diffraction data. The ESI-MS behavior of the new glucoalkaloids was also elucidated. Although comprising the same glucosyl moiety, the aglycone skeletons and glucosidic numbers and linkage varied greatly, implying the diversity in biosynthetic pathways. This is the first report of such structurally diverse glucoconjugated monoterpene indole alkaloids from . Compound represents a new subtype of oxindole alkaloid with a seven-membered D-ring, is a rare monoterpene indole alkaloid with the glucosyl moiety located at C-9, and are the first two oxindole alkaloid diglycosides, and and represent the first two examples of alkaloids with a quinolone nucleus from the genus . Compound exhibited moderate acetylcholinesterase (AChE) inhibitory activity with an IC value of 10.5 μM. Molecular docking was performed to explore the binding mode of inhibitor at the active site of AChE.