1.Concurrent supercritical fluid chromatographic analysis of terpene lactones and ginkgolic acids in Ginkgo biloba extracts and dietary supplements.
Wang M1, Carrell EJ1, Chittiboyina AG1, Avula B1, Wang YH1, Zhao J1, Parcher JF1, Khan IA2,3,4. Anal Bioanal Chem. 2016 Apr 29. [Epub ahead of print]
Supercritical fluid chromatography was used to resolve and determine ginkgolic acids (GAs) and terpene lactones concurrently in ginkgo plant materials and commercial dietary supplements. Analysis of GAs (C13:0, C15:0, C15:1, and C17:1) was carried out by ESI (-) mass detection. The ESI (-) spectra of GAs simply displayed only the [M-H]- pseudo-molecular ions, and selected ion monitoring (SIM) for those ions was used for the quantification. Analysis of terpene lactones (ginkgolides A, B, C, J and bilobalide) was complicated by in-source collision-induced dissociation (IS-CID) in the ESI source. Thus, MS analysis could be influenced by the fragmentation pattern produced by the IS-CID. However, it was established that the fragmentation pattern, measured by ion survival yield (ISY), was independent of analyte concentration or matrix at a fixed cone voltage in the ESI source. Therefore, MS with SIM mode was applicable for the analysis of these analytes.
2.The Molting Biomarker Metabolite N-acetylglucosamino-1,5-lactone in Female Urine of the Helmet Crab Telmessus cheiragonus.
Yano H1, Kamio M2, Nagai H1. Biol Bull. 2016 Apr;230(2):143-151.
N-acetylglucosamino-1,5-lactone (NAGL) is a molting biomarker in the blue crab Callinectes sapidus The concentration of this compound in urine is highest at the premolt stage. Since sexually mature premolt females release sex pheromone in their urine, NAGL is a candidate sex pheromone molecule in C. sapidus This compound has not been reported in other species. In the present study, we quantified the concentration of NAGL in the urine of the helmet crab Telmessus cheiragonus, using nuclear magnetic resonance spectroscopy, and found that the concentration increases toward the day of molting and decreases after molting. However, the total amount of NAGL collected from individual animals was greatest two to five days after molting, because the amount of urine collected was the lowest at the premolt stage, and it increased after molting. The highest median concentration of NAGL in T. cheiragonas was 29 μmol l-1, which is 75% of the highest concentration reported in C.
3.Sesquiterpene lactone containing extracts from two cultivars of forage chicory (Cichorium intybus) show distinctive chemical profiles and in vitro activity against Ostertagia ostertagi.
Peña-Espinoza M1, Boas U2, Williams AR3, Thamsborg SM3, Simonsen HT4, Enemark HL5. Int J Parasitol Drugs Drug Resist. 2015 Dec;5(3):191-200. doi: 10.1016/j.ijpddr.2015.10.002. Epub 2015 Oct 22.
The study investigated direct anthelmintic effects of sesquiterpene lactones (SL)-containing extracts from forage chicory against free-living and parasitic stages of Ostertagia ostertagi. Freeze-dried leaves from chicory cultivars 'Spadona' and 'Puna II' were extracted using methanol/water. Total SL were further fractionated by solid-phase extraction and resulting extracts were characterised by high-performance liquid chromatography (HPLC). O. ostertagi eggs from faeces of mono-infected calves were hatched and L1 were used in a larval feeding inhibition assay (LFIA), while cultured L3 were used in a larval exsheathment inhibition assay (LEIA). Adult worms were immediately recovered after slaughter and used for motility inhibition assays (AMIA). Electron microscopy (EM) was performed on adult O. ostertagi exposed to 1000 μg extract mL(-1) of both chicory cultivars. In all assays, decreasing concentrations of SL-containing extracts in PBS (1% DMSO) were tested in replicates with 1% DMSO in PBS as negative controls.
4.Characterization of N-acyl homoserine lactones (AHLs) producing bacteria isolated from vacuum-packaged refrigerated turbot (Scophthalmus maximus) and possible influence of exogenous AHLs on bacterial phenotype.
Zhang C1, Zhu S, Jatt AN, Zeng M. J Gen Appl Microbiol. 2016;62(2):60-7. doi: 10.2323/jgam.62.60.
Quorum sensing (QS) is a cell-to-cell communication mechanism through which microbial cells communicate and regulate their wide variety of biological activities. N-acyl homoserine lactones (AHLs) are considered to be the most important QS signaling molecules produced by several Gram-negative bacteria. The present study aimed to screen the AHLs-producing bacteria from spoiled vacuum-packaged refrigerated turbot (Scophthalmus maximus) by biosensor assays, and the profiles of AHLs produced by these bacteria were determined using reversed-phase thin-layer chromatography (RP-TLC) and gas chromatography-mass spectrometry (GC-MS). Effects of exogenous AHLs and QS inhibitor (QSI) on the phenotypes (i.e., extracellular proteolytic activity and biofilm formation) of the AHLs-producing bacteria were also evaluated. Our results demonstrated that eight out of twenty-two isolates were found to produce AHLs. Three of the AHLs-producing isolates were identified as Serratia sp.