Solid-phase microextraction gas chromatography/ion trap mass spectrometry and multistage mass spectrometry experiments in the characterization of germacrene D

Effects of Cabya (Piper retrofractum Vahl.) Fruit Developmental Stage on VOCs

The differences in VOCs can affect the flavor and medicinal value of cabya, and the flavor changes that occur in stages as the fruit develops are currently unknown. In order to investigate the influence of the developmental stage on the aroma composition of cabya essential oil, VOCs at each of the four developmental stages were analyzed by steam distillation (SD) extraction combined with GC-MS detection. The similarities and differences in fruit composition among the developmental stages were evaluated using hierarchical cluster analysis (HCA) and principal component analysis (PCA). A total of 60 VOCs, mainly alcohols, alkenes and alkanes, were identified across all of the developmental stages. The most acidic substances were detected in phase A and have a high medicinal value. There was no significant difference between the B and C phases, and the alcohols in those phases mainly promoted terpenoid synthesis in the D phase. Constituents during the D phase were mainly alkenes, at 57.14%, which contributed significantly to the aroma of the essential oil. PCA and HCA both were able to effectively differentiate the cabya fruit developmental stages based on the SD-GC-MS data. In summary, this study investigated the flavor variation characteristics and the diversity of VOCs in cabya fruits at different developmental stages, and its findings can provide a reference for developing essential oil products for different uses and determining appropriate stages for harvesting cabya resources.

A solvent free method of analysis to rapidly determine trace levels of ten medium and low brominated diphenyl ethers in soil pore water

A solvent free method to rapidly determine trace levels of ten brominated diphenyl ethers in soil pore water.

Expression and Purification of aTuber borchiiFruitbody‐Specific Protein, TBF‐1, fromEscherichia coli: Generation of Polyclonal Antibodies

TBF-1 is a fruitbody-specific protein present in the white truffle species Tuber borchii Vittad. A similar protein has been found only in the closely related species Tuber dryophilum (TDF-1), but not in other truffles. The protein from T. borchii was overexpressed as fusion protein in E. coli and was purified to homogeneity by affinity chromatography. Recombinant protein was used for generating polyclonal antibodies. The antiserum strongly reacted with TBF-1, weakly recognized TDF-1, and did not detect correlate band in the other white truffle species. The high level of expression of this protein in the fruitbody and the specificity of the antibody anti-TBF-1 make it possible to set up a diagnostic tool for detecting these species in natural samples and foodstuffs.

Headspace solid-phase microextraction with gas chromatography and mass spectrometry in the investigation of volatile organic compounds in an ectomycorrhizae synthesis system

Ectomycorrhizae formation represents one of the most significant steps in the truffle life cycle and is determined by a complex molecular signaling between two symbionts. In order to understand the molecular pathway of ectomycorrhiza development, we focused on the signaling interaction between the ectomycorrhizal fungus Tuber borchii Vittad. and the Tilia americana L. plant roots. The medium of a pre-symbiotic (T. americana-T. borchii) in vitro system was analysed by headspace solid-phase microextraction coupled with gas chromatography and mass spectrometry. In total, 73 volatile organic compounds (VOCs) were identified. Twenty-nine of these VOCs were produced only during the interaction phase between the two partners, leading to a hypothesis that these molecules might act as molecular messengers in order to pilot the ectomycorrhizae formation.