Glabralides A–C (1–3), three novel meroterpenoids including two unprecedented skeletons were isolated from the whole plants of Sarcandra glabra. Glabralide A (1) represented a unique skeleton of the chalcone-coupled monoterpenoid, bearing a bicyclo [2.2.2] octene core unit with five chiral centers. The structures were established by spectroscopic methods, including 2D NMR experiments, and the absolute configurations were determined using circular dichroic (CD) spectra. The plausible biogenetic pathway for 1 suggested that α-phellandrene was conjugated with chalcone by Diels-Alder cyclization, and for 3 implied that α-phellandrene and o-hydroxy phenylacetate cyclized by an uncommon radical addition and cationic cyclization.

从Sarcandra glabr a的整个植物中分离出了Glabralides A–C（1-3），这三个新颖的类金属萜包括两个空前的骨架。Glabralide A（1）代表查尔酮偶联的单萜的独特骨架，带有一个带有五个手性中心的双环[2.2.2]辛烯核单元。通过包括2D NMR实验在内的光谱方法建立结构，并使用圆二色（CD）光谱确定绝对构型。可能的生物发生途径为1，表明Diels-Alder环化使α-芹菜烯烯与查尔酮结合，而3则暗示α-芹菜烯烯和o-羟基苯乙酸酯通过不常见的自由基加成和阳离子环化而环化。