Cell-penetrating peptides (CPPs) have emerged as powerful tools in terms of drug delivery. Those short, often cationic peptides are characterized by their usually low toxicity and their ability to transport diverse cargos inside almost any kinds of cells. Still, one major drawback is their nonselective uptake making their application in targeted cancer therapies questionable. In this work, we aimed to combine the power of a CPP (sC18) with an integrin-targeting unit (c[DKP-f 3-RGD]). The latter is composed of the Arg-Gly-Asp peptide sequence cyclized via a diketopiperazine scaffold and is characterized by its high selectivity toward integrin α v β 3 . The two parts were linked via copper-catalyzed alkyne−azide click reaction (CuAAC), while the CPP was additionally functionalized with either a fluorescent dye or the anticancer drug daunorubicin. Both functionalities allowed a careful biological evaluation of these novel peptide-conjugates regarding their cellular uptake mechanism, as well as cytotoxicity in α v β 3 integrin receptor expressing cells versus cells that do not express α v β 3 . Our results show that the uptake follows a "kiss-and-run"-like model, in which the conjugates first target and recognize the receptor, but translocate mainly by CPP mediation. Thereby, we observed significantly more pronounced toxic effects in α v β 3 expressing U87 cells compared to HT-29 and MCF-7 cells, when the cells were exposed to the substances with only very short contact times (15 min). All in all, we present new concepts for the design of cancer selective peptide−drug conjugates.

Amino‐ynones can be seen as precursors of various heterocyclic rings. Although γ‐amino‐ynones have been used to prepare exocyclic vinylogous amides in the presence of Brønsted acids, we describe here the use of zinc chloride as a weak Lewis acid for their conversion into acetylenic cyclic imines. This reaction, which was attempted for a diverse range of γ‐amino‐ynones, proved to be robust and efficient in most cases and was easily extended to δ‐amino‐ynones to yield various acetylenic cyclic imines. Depending on the workup procedure, the latter compounds could be isolated either as free organic compounds or as zinc complexes. The ability of these cyclic imines to form complexes with palladium is also reported.

The role of the microbiota in health and disease has long been recognized and, so far, the cutaneous microbiota in humans has been widely investigated. The research regarded mainly the microbiota variations between body districts and disease skin states (i.e., atopic dermatitis, psoriasis, acne). In fact, relatively little information is available about the composition of the healthy skin microbiota. The cosmetic industry is especially interested in developing products that maintain and/or improve a healthy skin microbiota. Therefore, in the present work, the authors chose to investigate in detail the structure and composition of the basal bacterial community of the face. Ninety-six cheek samples (48 women and 48 men) were collected in the same season and the same location in central northern Italy. Bacterial DNA was extracted, the 16S rDNA gene was amplified by PCR, the obtained amplicons were subjected to next generation sequencing. The principal members of the community were identified at the genus level, and statistical analyses showed significant variations between the two sexes. This study identified abundant members of the facial skin microbiota that were rarely reported before in the literature and demonstrated the differences between male and female microbiota in terms of both community structure and composition.

Reactivity of N-Boc-Protected Amino-Ynones in the Presence of Zinc Chloride: Formation of Acetylenic Cyclic Imines and Their Palladium Complexes. -(VU, H.-D.; RENAULT*, J.; ROISNEL, T.; ROBERT, C.; JEHAN, P.; GOUAULT, N.; URIAC, P.; Eur. J. Org. Chem. 2015, 22, 4868-4875, http://dx.doi.org/10.1002/ejoc.201500569 ; Inst. Sci. Chim., CNRS, Univ. Rennes, F-35042 Rennes, Fr.; Eng.) -H. Haber 47-122