Nauplathizine, a new unusual O-heteroside from Nauplius aquaticus (L)

A novel O-heteroside, (3RS,4RS)-3,4-dihydroxy-4-(2-hydroxy-5-acetylphenyl)-2-[(beta-O-glucopyranosyl)methyl]-but-1-ene (1), named nauplathizine, and a previously known compound, acetophenone-4-O-glucoside (2), were isolated from the antibacterial acetone extract of the aerial parts of Nauplius aquaticus (L) (Asteraceae, Inulae). The structure of 1 was established via its acetylated derivative by means of spectroscopic and chemical data.     

Probing the Methyl Torsional Barriers of the E and Z Isomers of Butadienyl Acetate by Microwave Spectroscopy

The Fourier transform microwave spectra of the E and Z isomers of butadienyl acetate were measured in the frequency range from 2 to 26.5 GHz under molecular‐jet conditions. The most stable conformer of each isomer, in which all heavy atoms are located in a symmetry plane, was identified after analyzing the spectrum by comparison with the results from quantum‐chemical calculations. The barriers to internal rotation of the acetyl methyl group were found to be 149.1822(20) and 150.2128(48) cm^?1 for the E and Z isomers, respectively, which are similar to that of vinyl acetate. A comparison between two theoretical approaches treating internal rotation, the rho axis method and combined axis method, was also performed. The influence of the alkyl R chain on the methyl torsional barriers in CH₃ ‐COOR acetates was explored.     

Modification of Enzyme Activity by Vibrational Strong Coupling of Water

Vibrational strong coupling (VSC) has recently emerged as a completely new tool for influencing chemical reactivity. It harnesses electromagnetic vacuum fluctuations through the creation of hybrid states of light and matter, called polaritonic states, in an optical cavity resonant to a molecular absorption band. Here, we investigate the effect of vibrational strong coupling of water on the enzymatic activity of pepsin, where a water molecule is directly involved in the enzyme's chemical mechanism. We observe an approximately 4.5‐fold decrease of the apparent second‐order rate constant k_cat/K_m when coupling the water stretching vibration, whereas no effect was detected for the strong coupling of the bending vibration. The possibility of modifying enzymatic activity by coupling water demonstrates the potential of VSC as a new tool to study biochemical reactivity.     

Synthesis,Characterization, and Anti-Diabetic Therapeutic Activity of New Vanadyl(II) Complexes with Orotic Acid and Different Amino Acids Mixed Ligands

Russian Journal of General Chemistry - Mixed ligand vanadyl(II) complexes of orotic acid and six different amino acids (isoleucine, threonine, proline, phenylalanine, lysine, and glutamine) have...     

A Comprehensive Overview of the Developments of Cdc25 Phosphatase Inhibitors

Cdc25 phosphatases have been considered promising targets for anticancer development due to the correlation of their overexpression with a wide variety of cancers. In the last two decades, the interest in this subject has considerably increased and many publications have been launched concerning this issue. An overview is constructed based on data analysis of the results of the previous publications covering the years from 1992 to 2021. Thus, the main objective of the current review is to report the chemical structures of Cdc25s inhibitors and answer the question, how to design an inhibitor with better efficacy and lower toxicity?     

Maximal function on the dual of Laguerre hypergroup

In this paper, we are interested in the Laguerre hypergroup $\mathbb{K} = [0,\infty ) \times \mathbb{R}$ which is the fundamental manifold of the radial function space for the Heisenberg group. So, we consider the generalized shift operator generated by the dual of the Laguerre hypergroup which can be topologically identified with the so-called Heisenberg fan, the subset of ?²: $$\bigcup\limits_{j \in \mathbb{N}} {\left\{ {(\lambda ,\mu ) \in \mathbb{R}^2 :\mu = \left| \lambda \right|(2j + \alpha + 1),\lambda \ne 0} \right\} \cup \left\{ {(0,\mu ) \in \mathbb{R}^2 :\mu \geqslant 0} \right\}} ,$$ by means of which the maximal function is investigated. For 1 < p ?? ??, the L _p ( )-boundedness and weak L ₁( )-boundedness result for the maximal function is obtained.     

New Bacteriocin from Bacillus clausii StrainGM17: Purification, Characterization, and Biological Activity

A bacteriocin-producing strain (9,000 AU/ml) was isolated from the rhizosphere of Algerian healthy plants Ononis angustissima Lam. and identified as Bacillus clausii strain GM17. The bacteriocin, called Bac-GM17, was purified from the culture supernatant after heat treatment, ammonium sulfate precipitation, Sephadex G-50 chromatography and Mono Q fast-performance liquid chromatography (FPLC). Based on matrix-assisted laser desorption ionization-time of flight mass spectrometry analysis, the purified Bac-GM17 is a monomer protein with a molecular mass of 5,158.11 Da. The N-terminal sequencing allowed for the straightforward identification of its first 20 residues, which were of pure bacteriocin. It also revealed that this bacteriocin contained a unique sequence, namely DWTCSKWSCLVCDDCSVELT, which suggests the identification of a novel compound. Bac-GM17 was extremely heat stable (20 min at 120 °C) and was stable within the pH range (3–9). It was found to be resistant to the proteolytic action of trypsin, pepsin, papain, pronase E, and proteinase K. It was also noted to display a bactericidal mode of action against Agrobacterium tumefaciens C58 and a fungistatic mode of action against Candida tropicalis R2 CIP203.