Germination and Growth Inhibition of Surface Lipids from Nicotiana Species and Identification of Sucrose Esters

Abstract

Germination and growth inhibiting activities of surface lipids from 54 Nicotiana species were investigated. Almost half of the extracts were found to have such activities. Among them the surface lipids of N. glutinosa, N. bigelovii, N. sylvestris, N. repanda, N. stocktonii, and N. nesophila were rather strong. Guided by a bioassay using the inhibitory effects on tobacco seed germination and growth, two types of sucrose esters were isolated and identified from the surface lipids of N. glutinosa. The ester positions of each compounds were identified by ¹³C-NMR using deuterium exchange of HO ⇌ OD. The structures were (2,3,4-tri-O-acyl)-α-d-glucopyranosyl)-(3-O-acetyl)-β-d-fructofuranqside (M1) and (2,3,4-tri-O-acyl)-α-d-glucopyranosyl-β-d-fructofuranoside (M2). The main fatty acids of M1 and M2 were acetic (only in M1), propionic, 2-methylbutyric, 4-methylpentanoic, 4-methylhexanoic, 5-methylhexanoic, and octanoic acids. These sucrose esters obtained from N. glutinosa inhibited not only tobacco seed germination and growth but also other plants’ growth.