Gas Chromatography-Mass Spectrometry Profile of Essential Oils Derived from Zingiber officinale Rosc. Rhizome

White ginger which is also called Jahe Putih (Zingiber officinale) in Indonesia, is widely used in local Indonesian communities. It is a popular ingredient in beverages for stamina and also a bioactive ingredient for many traditional Indonesian food recipes. It is a popular ingredient in beverages for stamina and also a bioactive ingredient for many traditional food recipes. However, with the increase in demand for ginger related products, fake ginger formulated products are widespread in the market. This paper is disclosed the chemical profile of essential oil obtained from steam distillation of the local ginger. The results of this study can be used as a standard to detect original ginger. It was found that the chemical composition of the essential oil obtained from the white ginger contained 0.19% of a dried weight after 3 h of steam distillation. A total of 40 monoterpenoids (C10) and sesquiterpenoids (C15) secondary metabolite compounds were respectively detected in the oil.

Unstructured regions in IRE1α specify BiP-mediated destabilisation of the luminal domain dimer and repression of the UPR

Coupling of endoplasmic reticulum (ER) stress to dimerisation-dependent activation of the UPR transducer IRE1 is incompletely understood. Whilst the luminal co-chaperone ERdj4 promotes a complex between the Hsp70 BiP and IRE1’s stress-sensing luminal domain (IRE1LD) that favours the latter’s monomeric inactive state and loss of ERdj4 de-represses IRE1, evidence linking these cellular and in vitro observations is presently lacking. We report that enforced loading of endogenous BiP onto endogenous IRE1α repressed UPR signalling in CHO cells and deletions in the IRE1α locus that de-repressed the UPR in cells, encode flexible regions of IRE1LD that mediated BiP-induced monomerisation in vitro. Changes in the hydrogen exchange mass spectrometry profile of IRE1LD induced by ERdj4 and BiP confirmed monomerisation and were consistent with active destabilisation of the IRE1LD dimer. Together, these observations support a competition model whereby waning ER stress passively partitions ERdj4 and BiP to IRE1LD to initiate active repression of UPR signalling.