Since its introduction a few years ago, the linear ion trap Orbitrap (LTQ Orbitrap) instrument has become a powerful tool in proteomics research. For high resolution mass spectrometry measurements ions are accumulated in the linear ion trap and passed on to the Orbitrap analyzer. Simultaneously with acquisition of this signal, the major peaks are isolated in turn, fragmented and recorded at high sensitivity in the linear ion trap, combining the strengths of both mass analyzer technologies. Here we describe a next generation LTQ Orbitrap system termed Velos, with significantly increased sensitivity and scan speed. This is achieved by a vacuum interface using a stacked ring radio frequency ion guide with 10-fold higher transfer efficiency in MS/MS mode and 3–5-fold in full scan spectra, by a dual pressure ion trap configuration, and by reduction of overhead times between scans. The first ion trap efficiently captures and fragments ions at relatively high pressure whereas the second ion trap realizes extremely fast scan speeds at reduced pressure. Ion injection times for MS/MS are predicted from full scans instead of performing automatic gain control scans. Together these improvements routinely enable acquisition of up to ten fragmentation spectra per second. Furthermore, an improved higher-energy collisional dissociation cell with increased ion extraction capabilities was implemented. Higher-collision energy dissociation with high mass accuracy Orbitrap readout is as sensitive as ion trap MS/MS scans in the previous generation of the instrument.

The aroma link between pepper and wine has recently been elucidated to be due to the important aroma compound rotundone. To date, rotundone is the only known impact odorant with a peppery aroma. Although the concentration found in products of natural origin is small, the odor detection threshold is among the lowest of any natural product yet discovered. We report herein the identification of the first known precursor to rotundone, namely, α-guaiene, and that one mechanism of transformation is simple aerial oxidation.

Artermisinin and its derivatives are now the mainstays of antimalarial treatment; however, their mechanism of action is only poorly understood. We report on the synthesis of a novel series of epoxy-endoperoxides that can be prepared in high yields from simple starting materials. Endoperoxides that are disubstituted with alkyl or benzyl side chains show efficient inhibition of the growth of both chloroquine-sensitive and -resistant strains of Plasmodium falciparum. A trans-epoxide with respect to the peroxide linkage increases the activity compared to that of its cis-epoxy counterpart or the parent endoperoxide. The novel endoperoxides do not show a strong interaction with artemisinin. We have compared the mechanism of action of the novel endoperoxides with that of artemisinin. Electron microscopy reveals that the novel endoperoxides cause the early accumulation of endocytic vesicles, while artemisinin causes the disruption of the digestive vacuole membrane. At longer incubation times artemisinin causes extensive loss of organellar structures, while the novel endoperoxides cause myelin body formation as well as the accumulation of endocytic vesicles. An early event following endoperoxide treatment is the redistribution of the pH-sensitive probe LysoSensor Blue from the digestive vacuole to punctate structures. By contrast, neither artemisinin nor the novel endoperoxides caused alterations in the morphology of the endoplasmic reticulum nor showed antagonistic antimalarial activity when they were used with thapsigargin. Analysis of rhodamine 123 uptake by P. falciparum suggests that disruption of the mitochondrial membrane potential occurs as a downstream effect rather than as an initiator of parasite killing. The data suggest that the digestive vacuole is an important initial site of endoperoxide antimalarial activity.Artemisinin is a sesquiterpene lactone antimalarial with a 1,2,4-trioxane heterocyclic core that incorporates a peroxide linkage that is essential for its activity (44). Artemisinin is of major importance as a frontline treatment for malaria, particularly as it is active against chloroquine (CQ)-resistant strains of Plasmodium falciparum (20,23,24,45,66,74). Several groups have reported on pathways for the synthesis of artemisinin, but all require numerous steps and have low yields (5, 35). As a result, artemisinin-based antimalarials are produced semisynthetically from extracts of Artemisia annua. A period of over 1 year is needed for the horticultural, harvesting, extraction, and manufacturing processes (34,41,45), which limits the ease of scale-up of production and makes artemisinin derivatives much more expensive than traditional antimalarials, such as CQ and sulfadoxine-pyrimethamine. Indeed, artemisinin combinations are too costly for many patients, and the supply of counterfeit or inferior drugs is a major problem (4, 45, 71). Another issue is the fact that artemisinin and its derivatives are not suitable for prophylaxis or for use as a monotherapy due to their very short half-lives in vivo. T...

Among plant-derived odorants, damascenone is one of the most ubiquitous, sometimes occurring as an apparent natural product but more commonly occurring in processed foodstuffs and beverages. It has been widely reported as a component of alcoholic beverages, particularly of wines made from the grape Vitis vinifera . Although damascenone has one of the lowest ortho- and retronasal detection thresholds of any odorant, its contribution to the sensory properties of most products remains poorly understood. Damascenone can be formed by acid-catalyzed hydrolyses of plant-derived apocarotenoids, in both aglycon and glycoconjugated forms. These reactions can account for the formation of damascenone in some, but not all, products. In wine, damascenone can also be subject to degradation processes, particularly by reaction with sulfur dioxide.

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A new method has been developed for the quantitation of 1,8-cineole in red and white wines using headspace solid-phase microextraction (SPME) combined with stable isotope dilution analysis (SIDA) and gas chromatography-mass spectrometry (GC-MS). An extensive survey of Australian wines (44 white and 146 red) highlighted that only red wines contained significant amounts of 1,8-cineole (up to 20 μg/L). Hydrolytic studies with limonene and α-terpineol, putative precursors to 1,8-cineole, showed a very low conversion into 1,8-cineole (< 0.6%) over a 2 year period, which does not account for the difference between white and red wines. 1,8-Cineole was chemically stable in model wine solution over 2 years, and absorption from a Shiraz wine by bottle closures was most evident for a synthetic closure only (14% absorption after 1 year). Two commercial ferments at two different locations were monitored daily to investigate the evolution of 1,8-cineole throughout fermentation. Both ferments showed daily increases in 1,8-cineole concentration while in contact with grape solids, but this accumulation ceased immediately after pressing. This observation is consistent with the extraction of 1,8-cineole into the ferment from the solid portions of the grape berries.

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PurposeThis study aims to explore the nature of Chinese young adults' (CYAs) wine drinking behaviour. It also aims to examine CYAs' wine knowledge and establish whether there are positive relationships between wine knowledge and wine drinking behaviour variables.Design/methodology/approachInformation was obtained from a convenience sample of 414 university students in China using the self‐administration data collection method. The nature of CYAs' basic wine knowledge and wine drinking behaviour including wine drinking frequency, venue, and purpose of wine drinking were examined in the survey.FindingsThe majority of CYAs lack even the most basic wine knowledge. Generally, they drink wine infrequently. A large proportion of CYAs prefer red wine (92 per cent) to white wine (7 per cent). Most (60 per cent) CYAs like to drink wine at home, followed by hotels (21 per cent) and restaurants (15 per cent). About 60 per cent of CYAs drink wine for social communication while 27 per cent drink for body health reasons. A high 96 per cent of CYAs consider themselves likely to drink wine in the future. Significant differences exist between the genders in wine knowledge and likelihood of future wine drinking. Strong correlations were found between consumer wine knowledge and frequency and likelihood of future wine drinking.Research limitations/implicationsThe paper provides an overview of CYAs' wine drinking behaviour by a convenience sample investigation, which could not elude generalization and simplification. Considerable regional diversity in China compels differentiated regional studies in terms of wine purchasing, wine culture and wine marketing.Originality/valueThe paper contributes a baseline study on CYAs' wine knowledge and wine drinking behaviour. It also gives some managerial implications for wineries and wine marketers that will be helpful to wine companies in understanding the emerging Chinese wine market and in enacting wine marketing strategies more effectively.