Flipper Probes for the Community.

This article describes four fluorescent membrane tension probes that have been designed, synthesized, evaluated, commercialized and applied to current biology challenges in the context of the NCCR Chemical Biology. Their names are Flipper-TR®, ER Flipper-TR®, Lyso Flipper-TR®, and Mito Flipper-TR®. They are available from Spirochrome.

Evaluation of Quality and Storability of "Italia" Table Grapes Kept on the Vine in Comparison to Cold Storage Techniques.

The aim of the study was to compare the quality of table grapes (cv. Italia) held on the vine compared to grapes stored in cold rooms with or without modified-atmosphere packaging (MAP). The grapes were harvested from 12 plants in 2 vineyards in the same area, differing for the age of the plant. Four- and a fourteen-year-old vines were cultivated with the "Apulia tendone" system. After the first harvest, grapes were divided into small clusters and used for storage treatments in air and in MAP. Samples of 400 g were packaged in polypropylene (PP) trays sealed with a polypropylene/polyamide (PP/PA) film with 20% CO2 in air. MAP and control samples were then stored in the same cold room at 0 °C. Initially and after 8, 21, and 28 days, grapes stored in air and MAP were compared to fresh harvested grapes, stored on the plants. Quality attributes included color, texture, maturity index, phenols, antioxidant activity, sugars, organic acids, sensory parameters, and volatile compounds. The results obtained demonstrated that grapes held on the plant and in MAP showed better quality in terms of appearance scores compared to grapes stored in air. In particular, the application of high CO2 contributed to reduce the deterioration rate of the clusters, minimizing weight loss, and delaying degradation processes, and this particularly for grapes from the 14-year-old vine, where grapes held on the plant degraded faster than grapes in the younger vines. Most volatile compounds did not change their concentration with the storage treatment, except for ethyl acetate and ethanol, which increased in MAP at the end of storage, and to some compound responsible for green odor. In conclusion, keeping the grapes on the plant can be considered a good agronomic practice to preserve the quality, whereas MAP can be applied to better maintain postharvest quality of the product throughout storage and distribution.

Fluorescent Membrane Tension Probes for Early Endosomes.

Fluorescent flipper probes have been introduced recently to image membrane tension in live cells, and strategies to target these probes to specific membranes are emerging. In this context, early endosome (EE) targeting without the use of protein engineering is especially appealing because it translates into a fascinating transport problem. Weakly basic probes, commonly used to track the inside of acidic late endosomes and lysosomes, are poorly retained in EE because they are sufficiently neutralized in weakly acidic EE, thus able to diffuse out. Here, we disclose a rational strategy to target EE using a substituted benzylamine with a higher pKa value as a head group of the flipper probe. The resulting EE flippers are validated for preserved mechanosensitivity, ready for use in biology, particularly to elucidate the mechanics of endocytosis.

Dithienothiophenes at Work: Access to Mechanosensitive Fluorescent Probes, Chalcogen-Bonding Catalysis, and Beyond.

In this review, the multifunctionality of dithieno[3,2-b:2',3'-d]thiophenes (DTTs) is covered comprehensively. This is of interest because all involved research is very recent and emphasizes timely topics such as mechanochemistry for bioimaging or chalcogen bonds for catalysis and solar cells and because the newly emerging privileged scaffold is embedded in an inspiring structural space. At the beginning, DTTs are introduced with regard to nomenclature, constitutional isomers, and optoelectronic properties. The structural space around DTTs is mapped out next with regard to heteroatom substitution in the bridge and core, covering much of the periodic table, eccentric heteroatom doping, and bridge expansions. After a brief summary of synthetic approaches to the DTT scaffold, chalcogen bonds are introduced as, together with redox switching and turn-on fluorescence, one of the three conceptual foundations of the most multifunctionality. Realized functions cover anion binding, transport (ion carriers, ion channels), catalysis, and the first fluorescent probes to image physical forces in living cells. The appearance of DTTs in many other photosystems covers push-pull systems for nonlinear optics and dye-sensitized solar cells, DTT polymers in light-emitting diodes, organic field-effect transistors and organic photovoltaics, DTT self-assembly and templated assembly into thin films and fluorescent fibers, also within cells, and the integration of DTTs into photochromes and biaromatics that violate the Hückel rule..

The table grape 'Victoria' with a long shaped berry: a potential mutation with attractive characteristics for consumers.

BACKGROUND: Puglia is the most important region in Italy for table grape production. Since consumers look for new products, the number of table grape varieties has greatly increased in recent years. RESULTS: In a survey in the Puglia region, we identified several years ago a potential mutation of the cv. Victoria. We described this accession in comparison with the standard Victoria for some amphelographic traits. All the characteristics were very similar to the standard Victoria except for the berry shape, which was significantly more elongated. Moreover, the berry of the mutated Victoria showed higher firmness, lightness and chroma than the standard one, with a more intense yellow colour of the skin (appreciated by consumers). The molecular characterisation with 25 SSR markers showed that normal and mutant Victoria were genetically identical at all the analysed loci, thus suggesting that the two accessions could be considered as clones with the difference in berry shape probably due to a somatic mutation. CONCLUSIONS: This mutation of the cv. Victoria may have interesting perspective for the market since consumers are always attracted by different shape and colour of the fruits (consumers buy with eyes). This accession can be an alternative clone of the already known standard Victoria. © 2017 Society of Chemical Industry.

General, Mild, and Metal-Free Synthesis of Phenyl Selenoesters from Anhydrides and Their Use in Peptide Synthesis.

A mild, practical, and simple procedure for phenyl selenoesters synthesis from several anhydrides and diphenyl diselenide was developed. This transition-metal-free method provides a straightforward entry to storable Fmoc-amino acid selenoesters which are effective chemoselective acylating reagents. An application to oligopeptide synthesis was illustrated.

Effect of harvest time on table grape quality during on-vine storage.

BACKGROUND: Postponing the harvest of grapes is a common practice in southern Italy, in order to delay harvest up to Christmas and make higher income from their sale. The aim of this work was to evaluate the effect of harvest time (over almost 3 months) on the quality of table grapes (cv. Italia). The experiment was repeated for two years (2010 and 2011). In 2010, grapes were harvested starting from 8 October and after 11, 27 and 48 days. In 2011, five harvest times were compared over a period of 56 days. Respiration rate, firmness, colour, sensory attributes, total soluble solids (TSS), pH, titratable acidity (TA), phenols and antioxidant activity were measured. In addition, in the second year, volatile compounds were evaluated. RESULTS: For both years, harvest time influenced most parameters, which indicated that metabolic changes took place in the plants. In 2010, harvest time influenced respiration rate, cluster and berry appearance scores, colour attributes, crunchiness, pH, TA, total phenol content and antioxidant activity. In 2011, harvest time influenced respiration rate, colour attributes, most sensory attributes, TSS and TA. Generally, late harvested grapes showed higher firmness, berry appearance score, sweetness, fruity taste, overall sensory evaluation score and TSS. Regarding volatile compounds, terpene content decreased during ripening, while C6 compounds showed a nonlinear trend. CONCLUSION: The results showed that table grape sensory quality could be increased by delaying harvest up to a certain time of the season, while excessive delay could reduce final grape quality.