Volatiles from Cinnamomum cassia buds.

While the chemical composition of leaf and stem bark essential oils of the Chinese cinnamon, Cinnamomum cassia (L.) J. Presl, has been well investigated, little is known about the volatilom of its buds, which appeared recently on German markets. Soxhlet extracts of the commercial samples were prepared, fractionated using silica gel and characterised by gas chromatography-flame ionisation detector (GC-FID) for semi-quantification, by gas chromatography-mass spectrometry (GC-MS) for identification and by GC-FID/olfactometry for sensory evaluation. Cinnamaldehyde was the most abundant compound with concentrations up to 40 mg/g sample. In total, 36 compounds were identified and 30 were semi-quantified. The extracts contained mostly phenylpropanoids, mono- and sesquiterpene hydrocarbons and oxygenated derivatives. Because of the high abundance of cinnamaldehyde, the aldehyde fraction was removed from the extracts by adding hydrogen sulphite to improve both the detection of trace compounds and column chromatography. The aldehyde fraction was analysed by GC-MS separately. The highest flavour dilution factor of 316 was calculated for cinnamaldehyde. Other main sensory contributors were 2-phenylethanol and cinnamyl alcohol. This report provides the first GC-olfactometry data of a plant part of a Cinnamomum species. The strongly lignified C. cassia buds combine a high abundance of cinnamaldehyde with comparably low coumarin concentrations (<0.48 mg/g), and provide a large cinnamaldehyde depot for slow release applications.

Bimolecular Generation of Excitonic Luminescence from Dark Photoexcitations in Ruddlesden-Popper Hybrid Metal-Halide Perovskites.

The nature of photoexcitations in Ruddlesden-Popper (RP) hybrid metal halide perovskites is still under debate. While the high exciton binding energy in the hundreds of millielectronvolts indicates excitons as the primary photoexcitations, recent reports found evidence for dark, Coulombically screened populations, which form via strong coupling of excitons and the atomic lattice. Here, we use time-resolved mid-infrared spectroscopy to gain insights into the nature and recombination of such dark excited states in (BA)2(MA)n-1PbnI3n+1 (n = 1,2,3) via their intraband electronic absorption. In stark contrast to results in the bulk perovskites, all samples exhibit a broad, unstructured mid-IR photoinduced absorbance with no infrared activated modes, independent of excitonic confinement. Further, the recombination dynamics are dominated by a bimolecular process. In combination with steady-state photoluminescence experiments, we conclude that screened, dark photoexcitations act as a population reservoir in the RP hybrid perovskites, from which nongeminate formation of bright excitons precedes generation of photoluminescence.

Vom Paintball gezeichnet.

We report the case of a 29-year-old patient who presented in the emergency room with severe abdominal pain. After initially inconspicuous medical history and laboratory evaluation, repeated focused history taking led to the correct diagnosis: a paintball projectile had left its mark. The patient had suffered a third-degree rupture of the spleen with delayed manifestation two weeks after the trauma. He could be successfully managed with an organ-preserving non-operative approach.

Unique Pattern of Protein-Bound Maillard Reaction Products in Manuka (Leptospermum scoparium) Honey.

As a unique feature, honey from the New Zealand manuka tree (Leptospermum scoparium) contains substantial amounts of dihydroxyacetone (DHA) and methylglyoxal (MGO). Although MGO is a reactive intermediate in the Maillard reaction, very little is known about reactions of MGO with honey proteins. We hypothesized that the abundance of MGO should result in a particular pattern of protein-bound Maillard reaction products (MRPs) in manuka honey. A protein-rich high-molecular-weight fraction was isolated from 12 manuka and 8 non-manuka honeys and hydrolyzed enzymatically. By HPLC-MS/MS, 8 MRPs, namely, N-ε-fructosyllysine, N-ε-maltulosyllysine, carboxymethyllysine, carboxyethyllysine (CEL), pyrraline, formyline, maltosine, and methylglyoxal-derived hydroimidazolone 1 (MG-H1), were quantitated. Compared to non-manuka honeys, the manuka honeys were characterized by high concentrations of CEL and MG-H1, whereas the formation of N-ε-fructosyllysine was suppressed, indicating concurrence reactions of glucose and MGO at the ε-amino group of protein-bound lysine. Up to 31% of the lysine and 8% of the arginine residues, respectively, in the manuka honey protein can be modified to CEL and MG-H1, respectively. CEL and MG-H1 concentrations correlated strongly with the MGO concentration of the honeys. Manuka honey possesses a special pattern of protein-bound MRPs, which might be used to prove the reliability of labeled MGO levels in honeys and possibly enable the detection of fraudulent MGO or DHA addition to honey.