Glycolipids of monogalactosyldiacylglycerol in Phalaenopsis leaves during growth and spike induction periods form mixed liposomes that enhance the inhibition of Escherichia coli growth

Abstract

Chemical components in the hexane‐extract mixture from Phalaenopsis leaves were isolated and identified during the spike induction process. Several lipophilic components in the hexane‐extract mixture were isolated and identified as oleic acid, 1,2‐O‐dilinolenoyl‐MGDG, 1‐O‐linolenoyl‐2‐O‐linoleoyl‐MGDG, and α‐tocopherol by HPLC and NMR techniques. It is noteworthy that only one isomer of α‐tocopherol was isolated from Phalaenopsis leaves based on NMR spectra analysis. MGDG have a great potential to be a control factor in the regulation of spike process of Phalaenopsis. It is the first time to identify the chemical MGDG related to temperature‐controlled process of Phalaenopsis. These components have hydrophilic and hydrophobic moieties in the same molecule to act as potential amphiphiles. The use of the entire mixed hexane extract to form liposomes containing the dmbpyPtCl2 complex greatly enhanced the reactivity of the complex for inhibiting E. coli growth compared with the use of a single amphiphile.