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Collagenase, hyaluronidase, elastase, and tyrosinase enzymes are overexpressed and overactive in the skin aging process and hydrolyze the components of the dermal extracellular matrix (ECM) of the skin; these enzymes produce the clinical framework of aging, which includes skin dryness, hyperpigmentation, wrinkles, and inelasticity.The aim of this study was to explore the potential use of waste from two Argentine native fruits, namely Ziziphus mistol, and red and orange varieties of Solanum betaceum, as sources of bioactive compounds.Phenolic enriched extracts (PEE) from waste of Z. mistol and S. betaceum were obtained, and their total contents of phenolics and flavonoids were evaluated. The bioactive properties of the extracts were analyzed by measuring their antioxidant capacity and the inhibitory activity on collagenase, hyaluronidase, elastase, and tyrosinase enzymes.The increased ability to inhibit the collagenase was demonstrated by the PEE of Z. mistol seeds and peel, while the enzyme elastase was mostly inhibited by extracts of S. betaceum skin. Z. mistol seed extract was the most active to inhibit hyaluronidase, reaching 96% inhibition at a concentration of 100 μg GAE/mL. The most active extracts to inhibit the tyrosinase enzyme were obtained from the peel of two varieties of chilto fruits, orange and red, and the mistol seed.The results obtained suggest that Z. mistol and S. betaceum waste may be considered as a source of bioactive phenolics. Here, Argentine native fruits waste is presented as a most promising alternative in cosmetic products, with future uses such as hydrogels, creams, or lotions.

Background: The overexposure to sun ultraviolet (UV) radiation produce photoaging by effect of free radicals on lipid, protein, and nucleic acid or by direct activation of responsible enzymes of cleavage of extracellular matrix components (EMC). Aims: To develop new anti-photoaging agents, the anti-aging activity of four “jarillas” standardized extracts from Argentina (Zuccagnia punctata Cav., Larrea divaricata Cav., Larrea cuneifolia Cav., and Larrea nitida Cav.) were examined. Methods: The effect on the activity and expression of enzymes related to photoaging (collagenase, hyaluronidase, elastase, tyrosinase) and the antioxidant capacity of four “jarillas” extracts were examined. Results: The results suggest that “jarillas” extracts could protect EMC by inhibition of skin aging-related enzymes and suppression of the expression of metalloproteinases (MMP-1) in human skin fibroblasts from photoinduced damage. Modulation of MMP-1 expression induced by UV radiation in human skin cells could be associated, at least in part, with the ROS scavenging capacity of “jarilla” extracts. The extract of Z punctata was more active than Larrea species extracts in all the trials. The activity of Z punctata and Larrea extracts could be ascribed to chalcones and lignans, major constituents of “jarillas,” respectively. Conclusions: The results obtained would indicate the potential of these adapted species to live in arid zones of Argentina, exposed to high ultraviolet radiation in production of cosmetic products and justify the promotion of their sustainable use and the development of crops. Fil: Orqueda, Maria Eugenia. Universidad Nacional de Tucumán. Instituto de Bioprospección y Fisiología Vegetal. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Noa Sur. Instituto de Bioprospección y Fisiología Vegetal; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; Argentina Fil: Moreno, María Alejandra. Universidad Nacional de Tucumán. Instituto de Bioprospección y Fisiología Vegetal. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Noa Sur. Instituto de Bioprospección y Fisiología Vegetal; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; Argentina Fil: Zampini, Iris Catiana. Universidad Nacional de Tucumán. Instituto de Bioprospección y Fisiología Vegetal. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Noa Sur. Instituto de Bioprospección y Fisiología Vegetal; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; Argentina Fil: Bravo, Karent. Universidad de Antioquia; Colombia Fil: Osorio, Edison. Universidad de Antioquia; Colombia Fil: Isla, Maria Ines. Universidad Nacional de Tucumán. Instituto de Bioprospección y Fisiología Vegetal. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Noa Sur. Instituto de Bioprospección y Fisiología Vegetal; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; Argentina

The viability of noble gas axled boron nanowheels Ngn M©B10- (Ng=Ar-Rn; M=Nb, Ta; n=1, 2) is explored by ab initio computations. In the resulting Ng2 -M complexes, the Ng-M-Ng nanorod passes through the center of the B10- ring, providing them with an inverse sandwich-like structure. While in the singly Ng bound analogue, the Ng binding enthalpy Hb at 298 K ranges from 2.5 to 10.6 kcal mol-1 , in doubly Ng bound cases it becomes very low for the Ng2 M©B10- →Ng+NgM©B10- dissociation channel, except for the case of Rn, for which the corresponding Hb values are 3.4 (Nb) and 4.0 kcal mol-1 (Ta). For a given Ng, Ta has slightly higher Ng-binding ability than Nb. The corresponding free-energy changes indicate that these systems, particularly the Xe and Rn complexes, are good candidates for experimental realization in a low-temperature matrix. The Ng-M bonds were found to be covalent in nature, as reflected in their large Wiberg bond indices, formation of a 2c-2e σ orbital between Ng and M centers in natural bond orbital and adaptive natural density partitioning (AdNDP) analyses, and the short Ng-M distances. Energy decomposition analysis and a study on the natural orbitals for chemical valence show that the Ng-M contact is supported mainly by the orbital and electrostatic interactions, with almost equal contributions. Although both the Ng→M σ donation and Ng←M π backdonation play roles in the origin of orbital interaction, the former is significantly dominant over the latter. Further, AdNDP analysis indicates that the doubly aromatic character (both σ and π) in MB10- clusters is not perturbed by the interaction with Ng atoms.

Introduction Enzymatic inhibition of acetylcholinesterase (AChE) is an essential therapeutic target for the treatment of Alzheimer's disease (AD) and AChE inhibitors are the first-line drugs for it treatment. However, butyrylcholinesterase (BChE), contributes critically to cholinergic dysfunction associated with AD. Thus, the development of novel therapeutics may involve the inhibition of both cholinesterase enzymes. Objective To evaluate, in an integrated bioguided study, cholinesterases alkaloidal inhibitors of Amaryllidaceae species. Methodology The proposed method combines high-performance thin-layer chromatography (HPTLC) with data analysis by densitometry, enzymatic bioautography with different AChEs and BChEs, the detection of bioactive molecules through gas chromatography mass spectrometry (GC–MS) analysis of spots of interest, and theoretical in silico studies. Results To evaluate the bioguided method, the AChE and BChE inhibitory activities of seven Amaryllidaceae plant extracts were evaluated. The alkaloid extracts of Eucharis bonplandii exhibited a high level of inhibitory activity (IC50 = 0.72 ± 0.05 μg/mL) against human recombinant AChE (hAChE). Regarding human serum BChE (hBChE), the bulb and leaf extracts of Crinum jagus had the highest activity (IC50 = 8.51 ± 0.56 μg/mL and 11.04 ± 1.21 μg/mL, respectively). In the HPTLC spots with high inhibitory activity, several alkaloids were detected using GC–MS, and some of these alkaloids were identified. Galanthamine, galanthamine N-oxide and powelline should be the most prominent inhibitors of substrate accommodation in the active site of the Torpedo californica AChE (TcAChE), hAChE and hBChE enzymes. Conclusions These results are evidence of the chemical relevance of the Colombian's Amaryllidaceae species for the inhibition of cholinesterases and as potent sources for the palliative treatment of AD. Copyright © 2017 John Wiley & Sons, Ltd.

The interaction among E3 (E=Si, Ge, Sn) clusters and different ligands (L) encompassing five carbon-based donors (cyclic (alkyl)(amino)carbene (cAAC), N-heterocyclic carbene (NHC), saturated NHC (SNHC), mesoionic carbenes (MIC1, and MIC2)), two nitrogen-based donors (trimethylamine and pyridine), and two phosphorous-based donors (phosphinine and trimethylphosphine) in E3(L)3 complexes is explored through DFT computations. Although all carbenes form very strong bonds with E3 clusters, cAAC makes the strongest bond with Si3 and Ge3 clusters, and MIC1 with the Sn3 cluster. Nevertheless, other ligand-bound complexes are also viable at room temperature. This finding indicates that experimentalists may make use of them to synthesize the desired clusters based on precursor availability. The nature of the interaction in E−L bonds is analyzed through natural bond orbital analysis; energy decomposition analysis, in combination with the natural orbital for chemical valence; and adaptive natural density partitioning analysis. The L→E σ-donation and L←E π-back-donation play important roles in making contacts between L and E3 clusters favorable; where the former is significantly more dominant over the latter.

The most stable form of a B36 cluster has a central hexagonal hole. Such an interesting finding has led to the possible synthesis of a 2D boron sheet by employing the B36 cluster as the building unit. Herein, a DFT study to investigate the reason for the central location of the hexagonal hole in the B36 cluster is presented. The results show that the B36 cluster with a central hexagonal hole is highly thermodynamically and kinetically stable. More importantly, such high stability is further understood through chemical bonding analysis.

DFT-based calculations reveal that the global minimum of IrB12- is a C3v symmetric bowl-like structure in which the Ir atom is located on the concave side of the bowl similar to its lighter congeners, CoB12- and RhB12-.

The potential energy surfaces of the singlet and triplet states of the title clusters are computed by DFT methods.

Inverse carbon-free sandwich structures with formula E2P 4 (E=Al, Ga, In, Tl) have been proposed as a promising new target in main-group chemistry. Our computational exploration of their corresponding potential-energy surfaces at the S12h/TZ2P level shows that indeed stable carbon-free inverse-sandwiches can be obtained if one chooses an appropriate Group 13 element for E. The boron analogue B2P4 does not form the D4h-symmetric inverse-sandwich structure, but instead prefers a D2d structure of two perpendicular BP2 units with the formation of a double B-B bond. For the other elements of Group 13, Al-Tl, the most favorable isomer is the D4h inverse-sandwich structure. The preference for the D2d isomer for B2P 4 and D4h for their heavier analogues has been rationalized in terms of an isomerization-energy decomposition analysis, and further corroborated by determination of aromaticity of these species. Topsy turvy sandwiches: The possibility of the formation of inverse carbon-free sandwiches for clusters of type E2P4 with Group 13 elements B-Tl has been explored. This proposition is based on consideration of the aromaticity of the square-planar P4 2- unit, which should favor the formation of the cluster with a proper choice of the E + ions Moshinsky Foundation, SIP-IPN (Grants 20113309 and 20120968), and Conacyt (Grant INFRA-2012-01-188147) supported the work in Mexico. The CGSTIC (Xiuhcoalt) at Cinvestav is gratefully acknowledged for generous allocation of computational resources. Financial support from the Spanish MICINN (projects CTQ2011-23156/BQU and CTQ2011-25086/BQU), the FEDER fund (European Fund for Regional Development; grant UNGI08-4E-003), and the Generalitat de Catalunya (2009SGR637 and Xarxa de Referencia en Quimica Teorica i Computacional) is greatly acknowledged. E. M. acknowledges financial support of the EU under Marie Curie Career Integration grant (PCI09-GA-2011-294240) and the Beatriu de Pinos program from AGAUR for the postdoctoral grant (BP_B_00236). The authors are grateful to the Research Executive Agency of the European Research Council for financial support through the PIRSES-GA-2009-247671 project of the FP7-PEOPLE-2009-IRSES program. The authors thank Eloy Ramos for his helpful assistance with APOST-3D program