Antidepressant Effect of Crocin in Mice with Chronic Mild Stress

This study aimed to investigate the antidepressant property of crocin (Crocetin digentiobiose ester) using a chronic mild stress (CMS)-induced depression model in experimental mice. The tail suspension test (TST) and the sucrose preference test were used to evaluate the antidepressant effect on albino mice of either sex after three weeks of CMS. The period of immobility in the TST and percentage preference for sucrose solution were recorded. By monitoring brain malondialdehyde (MDA) level, catalase (CAT) activity, and reduced glutathione (GSH) level, the antioxidant potential was assessed. Three dosages of crocin (4.84, 9.69, and 19.38 mg/kg) were evaluated. When compared to controls, animals that received crocin administration during three periods of CMS had considerably shorter immobility times during the TST. Crocin treatment also raised the percentage preference for sucrose solution in a dose-dependent manner, bringing it to parity with the conventional antidepressant, imipramine. Animals that received a high dose of crocin had a much greater spontaneous locomotor activity. Furthermore, a high dose of crocin remarkably lowered plasma corticosterone and nitrite levels brought on by CMS. Additionally, high doses of crocin given during CMS greatly enhanced reduced glutathione levels while considerably reducing the brain’s MDA and catalase activities. In conclusion, high doses of crocin may have an antidepressant effect in an animal model through several mechanisms. However, further studies should be carried out to explore the role of neurotransmitters for their antidepressant property.     

Azatruxene-Based,Dumbbell-Shaped,Donor–π-Bridge–Donor Hole-Transporting Materials for Perovskite Solar Cells

Three novel donor–π-bridge–donor (D -π-D) hole-transporting materials (HTMs) featuring triazatruxene electron-donating units bridged by different 3,4-ethylenedioxythiophene (EDOT) π-conjugated linkers have been synthesized, characterized, and implemented in mesoporous perovskite solar cells (PSCs). The optoelectronic properties of the new dumbbell-shaped derivatives (DTTXs) are highly influenced by the chemical structure of the EDOT-based linker. Red-shifted absorption and emission and a stronger donor ability were observed in passing from DTTX-1 to DTTX-2 due to the extended π-conjugation. DTTX-3 featured an intramolecular charge transfer between the external triazatruxene units and the azomethine–EDOT central scaffold, resulting in a more pronounced redshift. The three new derivatives have been tested in combination with the state-of-the-art triple-cation perovskite [(FAPbI₃)_0.87(MAPbBr₃)_0.13]_0.92[CsPbI₃]_0.08 in standard mesoporous PSCs. Remarkable power conversion efficiencies of 17.48 % and 18.30 % were measured for DTTX-1 and DTTX-2 , respectively, close to that measured for the benchmarking HTM spiro-OMeTAD (18.92 %), under 100 mA cm⁻² AM 1.5G solar illumination. PSCs with DTTX-3 reached a PCE value of 12.68 %, which is attributed to the poorer film formation in comparison to DTTX-1 and DTTX-2 . These PCE values are in perfect agreement with the conductivity and hole mobility values determined for the new compounds and spiro-OMeTAD. Steady-state photoluminescence further confirmed the potential of DTTX-1 and DTTX-2 for hole-transport applications as an alternative to spiro-OMeTAD.     

Design, synthesis and X-ray structure of protein-ligand complexes: important insight into selectivity of memapsin 2 (beta-secretase) inhibitors

Structure-based design, synthesis, and X-ray structure of protein-ligand complexes of memapsin 2 are described. The inhibitors are designed specifically to interact with S2- and S3-active site residues to provide selectivity over memapsin 1 and cathepsin D. Inhibitor 6 has exhibited exceedingly potent inhibitory activity against memapsin 2 and selectivity over memapsin 1 (>3800-fold) and cathepsin D (>2500-fold). A protein-ligand crystal structure revealed cooperative interactions in the S2- and S3-active sites of memapsin 2. These interactions may serve as an important guide to design selectivity over memapsin 1 and cathepsin D.     

Non‐Planar and Flexible Hole‐Transporting Materials from Bis‐Xanthene and Bis‐Thioxanthene Units for Perovskite Solar Cells

Two new hole‐transporting materials (HTMs), BX‐OMeTAD and BTX‐OMeTAD , based on xanthene and thioxanthene units, respectively, and bearing p‐methoxydiphenylamine peripheral groups, are presented for their use in perovskite solar cells (PSCs). The novelty of the newly designed molecules relies on the use of a single carbon‐carbon bond ‘C?C’ as a linker between the two functionalized heterocycles, which increases the flexibility of the molecule compared with the more rigid structure of the widely used HTM spiro‐OMeTAD. The new HTMs display a limited absorbance in the visible region, due to the lack of conjugation between the two molecular halves, and the chemical design used has a remarkably impact on the thermal properties when compared to spiro‐OMeTAD. BX‐OMeTAD and BTX‐OMeTAD have been tested in ([(FAPbI₃)_0.87(MAPbBr₃)_0.13]_0.92[CsPbI₃]_0.08)‐based PSC devices exhibiting power conversion efficiencies of 14.19 and 16.55 %, respectively. The efficiencies reached, although lower than those measured for spiro‐OMeTAD (19.63 %), are good enough to consider the chemical strategy used as an interesting via to design HTMs for PSCs.     

Near-UV to red-emitting charged bis-cyclometallated iridium(III) complexes for light-emitting electrochemical cells

Herein we report a series of charged iridium complexes emitting from near-UV to red using carbene-based N^C: ancillary ligands. Synthesis, photophysical and electrochemical properties of this series are described in detail together with X-ray crystal structures. Density Functional Theory calculations show that the emission originates from the cyclometallated main ligand, in contrast to commonly designed charged complexes using bidentate N^N ancillary ligands, where the emission originates from the ancillary N^N ligand. The radiative process of this series of compounds is characterized by relatively low photoluminescence quantum yields in solution that is ascribed to non-radiative deactivation of the excited state by thermally accessible metal-centered states. Despite the poor photophysical properties of this series of complexes in solution, electroluminescent emission from the bluish-green to orange region of the visible spectrum is obtained when they are used as active compounds in light-emitting electrochemical cells.     

Synthesis of Amphiphilic RuII Heteroleptic Complexes Based on Benzo[1,2‐b:4,5‐b′]dithiophene: Relevance of the Half‐Sandwich Complex Intermediate and Solvent Compatibility

The detailed synthesis and characterization of four ruthenium(II) complexes [RuLL′(NCS)₂] is reported, in which L represents a 2,2′‐bipyridine ligand functionalized at the 4,4′ positions with benzo[1,2‐b:4,5‐b′]dithiophene derivatives (BDT) and L′ is 2,2′‐bipyridine‐4,4′‐dicarboxylic acid unit (dcbpy) (NCS=isothiocyanate). The reaction conditions were adapted and optimized for the preparation of these amphiphilic complexes with a strong lipophilic character. The photovoltaic performances of these complexes were tested in TiO₂ dye‐sensitized solar cell (DSSC) achieving efficiencies in the range of 3–4.5 % under simulated one sun illumination (AM1.5G).     

A Computational and Experimental Study of Thieno[3,4‐b]thiophene as a Proaromatic π‐Bridge in Dye‐Sensitized Solar Cells

Four D ‐π‐A dyes (D=donor, A=accpetor) based on a 3,4‐thienothiophene π‐bridge were synthesized for use in dye‐sensitized solar cells (DSCs). The proaromatic building block 3,4‐thienothiophene is incorporated to stabilize dye excited‐state oxidation potentials. This lowering of the excited‐state energy levels allows for deeper absorption into the NIR region with relatively low molecular weight dyes. The influence of proaromatic functionality is probed through a computational analysis of optimized bond lengths and nucleus independent chemical shifts (NICS) for both the ground‐ and excited‐ states. To avoid a necessary lowering of the TiO₂ semiconductor conduction band (CB) to promote efficient dye–TiO₂ electron injection, strong donor functionalities based on triaryl‐ and diarylamines are employed in the dye designs to raise both the ground‐ and excited‐state oxidation potentials of the dyes. Solubility, aggregation, and TiO₂ surface protection are addressed by examining an ethylhexyl alkyl chain in comparison to a simple ethyl chain on the 3,4‐thienothiophene bridge. Power conversion efficiencies of up to 7.8 % are observed.     

Fully Aromatic Self-Assembled Hole-Selective Layer toward Efficient Inverted Wide-Bandgap Perovskite Solar Cells with Ultraviolet Resistance

Ultraviolet-induced degradation has emerged as a critical stability concern impeding the widespread adoption of perovskite solar cells (PSCs), particularly in the context of phase-unstable wide-band gap perovskite films. This study introduces a novel approach by employing a fully aromatic carbazole-based self-assembled monolayer, denoted as (4-(3,6-dimethoxy-9H-carbazol-9-yl)phenyl)phosphonic acid (MeO-PhPACz), as a hole-selective layer (HSL) in inverted wide-band gap PSCs. Incorporating a conjugated linker plays a pivotal role in promoting the formation of a dense and highly ordered HSL on substrates, facilitating subsequent perovskite interfacial interactions, and fostering the growth of uniform perovskite films. The high-quality film could effectively suppress interfacial non-radiative recombination, improving hole extraction/transport efficiency. Through these advancements, the optimized wide-band gap PSCs, featuring a band gap of 1.68 eV, attain an impressive power conversion efficiency (PCE) of 21.10 %. Remarkably, MeO-PhPACz demonstrates inherent UV resistance and heightened UV absorption capabilities, substantially improving UV resistance for the targeted PSCs. This characteristic holds significance for the feasibility of large-scale outdoor applications.     

Morus alba Prevented the Cyclophosphamide Induced Somatic and Germinal Cell Damage in Male Rats by Ameliorating the Antioxidant Enzyme Levels

Cytogenetic analysis is essential to determine the effect of mutagens and antimutagens on genetic material. This study was done to evaluate the protective effect of root bark extract of Morus alba (M. alba) against cyclophosphamide induced somatic and germinal cell damage in male rats. The ethanolic extract of M. alba (0.25, 0.5 and 1 g/kg, 2 weeks) was evaluated against cyclophosphamide (75 mg/kg, single dose) induced nuclear damage. The sampling was done after 48 h of the clastogen treatment. The somatic and germinal nuclear damage was studied by bone marrow micronucleus and sperm analysis, respectively. Serum superoxide and catalase levels were estimated to determine the antioxidant status in each group. The results were analyzed statistically to find the significant variation. The administration of M. alba for 2 weeks suppressed dose-dependently the changes induced by cyclophosphamide. M. alba (0.5 g/kg) decreased the frequency of micronucleated erythrocyte, sperm shape abnormality and enhanced the sperm count, sperm motility and polychromatic-normochromatic erythrocytes ratio significantly (p < 0.05) in comparison with the cyclophosphamide treated group. The highest tested dose of M. alba (1 g/kg) produced more prominent suppression (p < 0.01) in the cyclophosphamide-induced somatic and germinal cell defects. The results also showed significant (p < 0.05) improvement in the serum antioxidant enzymes levels with M. alba when compared with the challenge group. The lower dose of M. alba extract (0.25 g/kg) prevented the CP-induced changes but was found to be statistically insignificant. Therefore, antimutagenic potential of the high dose of the extract of M. alba is possibly due to its antioxidant nature. The ability of the M. alba extract to prevent the nuclear damage could play an important role in overcoming several mutational defects that are associated with anticancer chemotherapy.     

Ca(II)-catalyzed diastereoselective formal [4+2] annulation of a 3-component solvent-free povarov reaction

Diastereoselective, three-component annulation reaction involving glyoxals, anilines and dienophiles is developed under calcium catalysis. When indene is the dienophile, the reaction gave excellent diastereoselectivity to yield tetrahydro-indenoquinolines, these were further aromatized to get indenoquinolines in one-pot. Aryl acetylenes are used as dienophiles to get 2-acyl quinolines in good yields.