Nicocembranoside A: A new neuroprotective cembrane glycoside from Nicotiana tabacum L.

Cembrane-type diterpenoids are recognized for their medicinal significance.The phytochemical investigation of Nicotiana tabacum L. led to the isolation of Nicocembranoside A (1), a novel cembrane glycoside, represents the ninth naturally occurring cembrane glycoside and the first isolated from N. tabacum leaves. The structure of 1 was elucidated through comprehensive spectroscopic analyses, including 1D (1H, 13C NMR) and 2D NMR (COSY, HSQC, HMBC, ROESY), complemented by HRESIMS and biosynthetic precedence. Additionally, seven known compounds were also isolated and characterized. Preliminary evaluation demonstrated 1 exhibits neuroprotective effect against glutamate-induced cytotoxicityrnin PC12 cells at 10 μM.