2-Methoxybenzaldehyde effectively repels ants.

Ants can particularly make for harmful pests, infesting human homes and reducing crop yields. The damage caused by ants and the efforts to mitigate the damage are hugely costly. Broad-spectrum insecticides are used most commonly; however, due to their negative side effects, there is increasing interest in nontoxic alternatives. One promising commercially available alternative is 2-hydroxybenzaldehyde, which is naturally produced by various arthropods as a means of chemical defense and effectively repels ants. Here we conduct a structure-activity relationship investigation, testing how different chemical modifications alter the repellence of 2-hydroxybenzaldehyde. We find that 2-methoxybenzaldehyde is considerably more effective than 2-hydroxybenzaldehyde at repelling the common black garden ant, Lasius niger. We next compare the most effective repellent chemicals against 4 particularly harmful ant species to confirm that the results obtained with L. niger are general to ants and that our results are relevant to mitigate the costs of ant damage.

Isolation and characterization of human repetin, a member of the fused gene family of the epidermal differentiation complex.

The human repetin gene is a member of the "fused" gene family and localized in the epidermal differentiation complex on chromosome 1q21. The "fused" gene family comprises profilaggrin, trichohyalin, repetin, hornerin, the profilaggrin-related protein and a protein encoded by c1orf10. Functionally, these proteins are associated with keratin intermediate filaments and partially crosslinked to the cell envelope (CE). Here, we report the isolation and characterization of the human repetin gene and of its protein product. The repetin protein of 784 amino acids contains EF (a structure resembling the E helix-calcium-binding loop-F helix domain of parvalbumin) hands of the S100 type and internal tandem repeats typical for CE precursor proteins, a combination which is characteristic for "fused" proteins. Repetin expression is scattered in the normal epidermis but strong in the acrosyringium, the inner hair root sheat and in the filiform papilli of the tongue. Ultrastructurally, repetin is a component of cytoplasmic non-membrane "keratohyalin" F-granules in the stratum granulosum of normal epidermis, similar to profilaggrin. Finally, we show that EF hands are functional and reversibly bind Ca(2+). Our results indicate that repetin is indeed a member of the fused gene family similar to the prototypical members profilaggrin and trichohyalin.

A new model using liposomes that allow to distinguish between absorption and oxidative properties of sunscreens.

We have developed a new model using liposome-encapsulated fluorescent probes, aiming at assessing both the physical and the biological protection provided by filter molecules such as those incorporated in sunscreens. The fluorescent indicator Indo-1 or 2',7'-dichlorofluorescin (DCFH) was inside the liposomes, in the aqueous inner compartment, whereas the filter molecules octyl methoxycinnamate (OMC), benzophenone-3 (BP3) or avobenzone, widely used in sunscreens, were incorporated into liposome membranes. When liposome suspensions were placed in a fluorometer cuvette exposed to an incident UV beam, the decrease of Indo-1 fluorescence as a function of filter concentration was related to the extinction coefficient of the filters. On the other hand, when liposome suspensions were exposed to moderate UVB doses allowing Indo-1 photobleaching, the remaining intact Indo-1 was linked to the protection provided by filter-containing liposome membranes. Finally, when liposome-encapsulated DCFH was exposed to UVB, the degree of photo-oxidation of the fluorescent probe into 2',7'-dichlorofluorescein accounted for the photoprotection provided by the filter contained in liposome membranes. BP3 was more potent and slightly less efficient than the other two filters in preventing Indo-1 fluorescence; all three filters provided a similar concentration-dependent protection of Indo-1 photobleaching, whereas only OMC was able to prevent the photooxidation of DCFH. The liposome model presented here has the advantage of combining both physical and biological parameters to assess the photoprotection provided by filter molecules, and the lack of photoprotection by two sunscreen molecules having a good filter capacity highlights the need for such a biological parameter when talking about the safety of sunscreens.