A metal-free natural dye has been developed to selectively convert methane to methyl trifluoroacetate (CH3TFA) using visible light, probably due to the formation of a chloride-bridged dimer undergoing fast intra-complex charge transfer.
Development of a sequential preparation of multivalent bioconjugates using a single non-canonical amino acid. Through the genetic incorporation of a halogenated alkynyl amino acid a 1,3-dipolar cycloadditon followed by a Sonogashira cross-coupling can facilitate the introduction of two unique moieties to a protein in a site-specific fashion.
Proteins represent powerful biomacromolecules due to their unique functionality and broad utility both in the cell and in non-biological applications. The genetic encoding of non-canonical amino acids (ncAAs) facilitates functional diversification of these already powerful proteins. Specifically, ncAAs have been demonstrated to provide unique functional handles to bioorthogonally introduce novel functionality via conjugation reactions. Herein we examine the ability of a single ncAA to serve as a handle to generate multivalent bioconjugates to introduce two or more additional components to a protein, yielding a multivalent conjugate. To accomplish this aim, p-bromopropargyloxyphenyalanine (pBrPrF) was genetically encoded into both superfolder green fluorescent protein (sfGFP) and ubiquitin model proteins to serve as a conjugation handle. A sequential bioconjugation sequence involving a copper-assisted cycloaddition reaction coupled with a subsequent Sonogashira cross-coupling was then optimized. The linkage of two additional molecules to the model protein via these reactions yielded the desired multivalent bioconjugate. This domino approach using a single ncAA has a plethora of applications in both therapeutics and diagnostics as multiple unique moieties can be introduced into proteins in a highly controlled fashion.
This work described a comprehensive study to estimate chemical constituents of essential oils (EOs) extracted from different parts of the Callistemon citrinus viz: fruits, leaves and aerial part. The EOs were characterized using physicochemical parameters, and GC-FID/MS. It was observed that among different parts, aerial part has the highest oil yield (0.90 %) followed by leaves and fruits. Further, seventeen compounds were characterized, and represented total amount (97.2–99.5 %) with domination of monoterpenes (12.5–34.6 %) and oxygenated monoterpenes hydrocarbon (61.8–86.8 %). α-pinene (11.8–24.7 %), α-phellandrene (1.2–3.0 %), p-cymene (3.3–3.9 %) and 1,8-cineole (58.3–85.1 %) were found as major compounds in C. citrinus samples. These major compounds are the quality chemical markers of C. citrinus oil. The findings revealed significant quantitative variations in EO composition of samples and were also clearly supported by multivariate statistical analysis. Moreover, EOs were evaluated for glucosidase and colon cancer cell lines inhibitory activities, which were found promising.
One-dimensional titanium dioxide photocatalysts with a Pt co-catalyst exhibit a remarkable selectivity of nearly 100 % in converting ethanol into valuable 1,1-diethoxyethane, which is different from typical acetaldehyde production on titanium dioxide nanoparticles. The introduced oxygen vacancies in the catalyst help double the ethanol transformation rate with respect to that of its pristine counterpart.
Developing an environmentally benign and highly effective strategy for the value-added conversion of biomass platform molecules such as ethanol has emerged as a significant challenge and opportunity. This challenge stems from the need to harness renewable solar energy and conduct thermodynamically unfavorable reactions at room temperature. To tackle this challenge, one-dimensional titanium dioxide photocatalysts have been designed and fabricated to achieve a remarkable photocatalytic selectivity of almost 100 % for transforming ethanol into value-added 1,1-diethoxyethane, contrasting the primary production of acetaldehyde in titanium dioxide nanoparticles. By incorporating a Pt co-catalyst and infusing oxygen vacancies into the one-dimensional catalyst, the ethanol transformation rate was doubled to 128.8 mmol g−1 h−1 with respect to that of its unmodified counterpart (about 66.7 mmol g−1 h−1). The underlying mechanism for this high conversion and selectivity resides in the narrowed bandgap of the catalyst and the prolonged lifetime of the photo-generated carriers. This is a promising strategy for the photocatalytic transformation of essential biomass platform molecules that intertwines morphological control and defect engineering.
Alepterolic acid is a diterpene occurring in the fern Aleuritopteris argentea with potential biological activity that warrants further structural modification. In the present work, sixteen alepterolic acid derivatives were synthesized and evaluated for their anticancer activities. Among them, N-[m-(trifluoromethoxy)phenyl] alepterolamide displayed comparable activity (IC50=4.20±0.21 μM) in MCF-7 cells. Moreover, mechanistic investigations indicated this compound was significantly capable of diminishing cell proliferation and viability of MCF-7 cells. After treatment with N-[m-(trifluoromethoxy)phenyl] alepterolamide, a significant increase in cleaved caspase-9, cleaved caspase-3, cleaved poly (ADP-ribose) polymerase (PARP) and Bax/Bcl2 ratio were observed in MCF-7 cells, leading to caspase-dependent apoptotic pathways. Further studies showed this compound promoted cellular apoptosis and inhibited migration in MCF-7 cells via modulation of the Akt/p70S6K signaling pathway. All these results revealed the potential of N-[m-(trifluoromethoxy)phenyl] alepterolamide as an appealing therapeutic drug candidate for breast cancer.
![Exploring the Synthetic and Antioxidant Potential of 1,2-Disubstituted Benzimidazoles using [Et3NH][HSO4] Ionic Liquid Catalyst](https://onlinelibrary.wiley.com/cms/asset/cd1b67c7-efc5-4bc5-8fe5-d7241e933820/cbdv202301159-toc-0001-m.png)
An [Et3NH][HSO4] ionic-liquid catalyzed, intermolecular C−N bond formation for 1,2-disubstituted benzimidazole synthesis was achieved by the reaction of OPD and substituted aldehydes at ambient reaction conditions. Operational simplicity, use of easily available substrate and reagents, good yields (74–95 %) in short reaction time (4–18 min), simple work-up, and column chromatographic free synthesis are the remarkable features of this new protocol. The applicability of [Et3NH][HSO4] ionic-liquid as a green and inexpensive catalyst with good recyclability and compatibility with a broad range of functional group having heteroatom, electron-withdrawing, and electron-releasing groups manifested the sustainability, eco-friendliness, and efficiency of the present methodology. Moreover, the antioxidant studies of the synthesized compounds using DPPH and ABTS assays were appealing and several synthesized compounds showed significant antioxidant activity.
The Cover Feature shows a mechanical grinding process with the help of metal balls that enable transformation of a planar polyarene into a curved aromatic structure. The illustration was made by Cheryn Liaw Yu Ting. More information can be found in the Research Article by G. Báti, S. Laxmi et al.
Naturalness is gaining ground among perfumers and the use of natural raw materials is spreading in perfumery. Forgotten perfumery plants are of concern to develop innovative and natural ingredients for modern perfume industries. The main purpose of this study was to evaluate the potential interest of Crataegus monogyna Jacq. extracts as fragrance ingredient. To this end, various extractions, phytochemical characterizations and organoleptic evaluations of hawthorn were conducted on fresh, frozen, and dried flowering aerial parts, to identify those most likely to be of interest. More than a hundred compounds, anisaldehyde being the predominant one, were characterized for the first time in the volatile fraction, using HS-SPME-GC-MS technology. Impact of plant treatment and harvest year on the extracts were also discussed. From this work, a new and natural hawthorn-based ingredient was developed to complete the perfumers’ palette.
Many synthetic pesticides were used to control a severe storage pest, booklouse (Liposcelis bostrychophila). However, considering the environmental impact, plant secondary metabolites were acceptable alternatives. An endemic plant, Magnolia laevifolia, has a significant and unique odour, so its essential oil (EO) could be an option for bio-pesticide development. This study extracted EOs from leaves, flowers, carpels and seeds of M. laevifolia. The common and major compound of EOs was isocapnell-9-en-8-one, which was present at 17.7 to 91.6 % in these four parts. We found no regular pattern in the composition of EO in terms of parts and collection time according to principal component analysis. The contact and repellent activities of EOs against the booklouse were then conducted. Leaves and flowers’ EOs collected in the flowering stage had the best contact toxicity. The percent repellency values of the EOs from different parts of M. laevifolia reached above 80 % after 2 and 4 h exposure at 63.17 nL/cm2, with the same levels as DEET (p<0.05). It was shown that parts of plants and collecting time could influence the insecticidal activities of M. laevifolia EOs against booklouse, but collecting time played a significant decisive role in the contact test.
![Crown-Ether-Ring Size Dependent Crystal Structures, Phase Transition and Dielectric Properties of [M(crown)]BF4⋅xH2O (M+=Na+, K+; crown=15-crown-5, 18-crown-6; x=0 or 1)](https://chemistry-europe.onlinelibrary.wiley.com/cms/asset/f6314307-cac2-42e4-956c-1e9022637094/ejic202300523-toc-0001-m.png)
The supramolecular crystals show crown-ether ring size dependent crystal structure, phase transition and dielectric properties.
Crown ethers demonstrate significant conformational flexibility and rotational symmetry, rendering them invaluable in the realms of supramolecular chemistry and crystal engineering. These unique natures facilitate the construction of supramolecular crystals of crown ethers, characterized by disorder-order phase transitions, imparts unique properties that hold promise for diverse applications across multiple fields. In this study, four supramolecular compounds, namely [Na(15-crown-5)]BF4 (1), [Na(18-crown-6)]BF4⋅H2O (2), [K(15-crown-5)]BF4 (3) and [K(18-crown-6)]BF4⋅H2O (4) were synthesized and characterized by microanalysis, thermogravimetric analysis, differential scanning calorimetry and powder X-ray diffraction techniques. Herein, 15-crown-5 and 18-crown-6 correspond to 1,4,7,10,13-pentaoxacyclopentadecane and 1,4,7,10,13,16-hexaoxacyclooctadecane, respectively. It was observed that the crystal structure, phase transition, and dielectric properties of these supramolecular compounds are significantly influenced by the size of the crown-ether rings. The research extensively discussed the correlation between the coordination mode of metal ions of K+ or Na+ with crown ethers, the compatibility between metal ions and crown-ether rings in terms of size, and the effects of crown-ether disorder on dielectric permittivity during phase transitions. Our discoveries hold significant implications for the design and development of crown-ether supramolecular functional materials.