The passing of Professor Boris Žemva, known simply as Boris among his colleagues, on November 2, 2023 marks the loss of one of the most influential figures in modern inorganic fluorine chemistry. Over nearly five decades of research, he shaped several fundamental directions in the chemistry of noble gases, high-oxidation-state fluorides, and coordination chemistry involving weak ligands. Through his scientific insight, experimental mastery, and dedication to mentoring younger generations, he left a legacy that extends far beyond his publications and discoveries.
New pyrrolo[1,2-a]quinoxaline-2-carboxylic acid hydrazone derivatives were synthesized from nitroaniline using a multi-step pathway. Structure characterization of these novel substituted pyrrolo[1,2-a]quinoxaline-carboxylic acid hydrazones was achieved by using FT-IR, 1H NMR, 13C NMR, X-Ray and HRMS spectral analysis. These pyrroloquinoxaline hydrazone compounds were then evaluated in vitro for their potential on the human acute myeloid leukemia cell line MV4-11, in which (N'-pyridin-2-ylmethylene)pyrrolo[1,2-a]quinoxaline-2-carboxylic acid hydrazone 1a showed an IC50 value of 15.51 µM. Given the structural similarities between our hydrazone derivatives 1 and some recently published quinoline-type hydrazone compounds for antimalarial use, our compounds were also evaluated for their antimalarial activity. Among them, compound 1c demonstrated promising antiplasmodial activity, with an IC50 of 0.02 μM against the 3D7 strain of Plasmodium falciparum, exhibiting a selectivity index (SI) exceeding 5000 against this strain. Against the chloroquine-resistant Plasmodium falciparum W2 strain, hydrazone 1e emerged as the most potent and promising antimalarial candidate (IC50 = 0.03 mM), demonstrating a cytotoxicity to-antiprotozoal activity ratio exceeding 3333.
Natural gas sweetening, involving removal of CO2 and H2S from CH4, is conventionally carried out by amine scrubbing, which is highly energy intensive. In the present study, we report the synthesis of poly(vinyl alcohol-co-acrylic acid) (PVA-co-AAc) based nanocomposite membranes incorporated with surface-stabilized magnesium nanoparticles (MgNPs) through a simple aqueous route. The MgNPs act as Lewis basic sites providing reversible chemisorption for CO2/H2S, while the polymer matrix ensures hydrophilic pathways for solution–diffusion along with mechanical robustness. The prepared membranes were characterized by FTIR, XRD, SEM, TEM, AFM, TGA/DSC, DMA and tensile strength. Gas permeation studies at 25–60 °C and 1–10 bar revealed improved CO2/CH4 and H2S/CH4 selectivity, with CO2/CH4 selectivity reaching 20.8, without loss in permeance. The synergistic effect of polymer–nanoparticle interaction enhanced both stability and separation performance. Process analysis indicates potential energy savings compared to conventional amine processes, showing promise for industrial scale natural gas sweetening.
A series of novel 2-(1-(4-(4-chlorophenyl)thiazol-2-yl)-1H-pyrazol-4-yl)benzo[d]oxazoles 5 were synthesized from 2-[(E)-{1-[4-(4-chlorophenyl)-1,3-thiazol-2-yl]-1H-pyrazol-4-yl}(hydroxyimino)methyl]phenol 4 through Beckmann rearrangement. All the synthesized compounds were characterized with the help of IR, 1H and 13C NMR and LCMS techniques. All the synthesized compounds were screened for their in vitro anti-inflammatory and antioxidant activities. Among the newly synthesized compounds, compound 5c and 5e showed good anti-inflammatory activity and compounds 5c and 5d showed good antioxidant activity. Molecular docking study could provide valuable insights into the mechanism of anti-inflammatory activity. Furthermore, molecular docking studies into the active site of COX-2 enzyme indicated that compound 5c binds with good affinity, which is consistent with its considerable efficacy in the in vitro tests.
The present study investigated chemical composition and in vitro bioactivities of the essential oil (EO) of Macaranga trichocarpa leaves. The EO was analyzed using gas chromatography–mass spectrometry. The results showed the identification of 61 volatile constituents representing 97.54% of the total oil content. Sesquiterpene hydrocarbons were the predominant class (52.58%), with (E)-β-caryophyllene (17.66%), α-curcumene (16.04%), β-pinene (13.83%), linalool (9.52%), and β-caryophyllene epoxide (5.19%), identified as the major constituents. The EO showed weak antioxidant activity in both DPPH and ABTS radical scavenging assays. The EO demonstrated potent α-amylase inhibitory activity (IC50 = 120.70 ± 0.47 µg/mL), comparable to acarbose. Cytotoxicity evaluation using the MTT assay revealed that the EO exerted a dose-dependent inhibitory effect against the human hepatocellular carcinoma (HepG2) cell line. These findings provide the first report on the chemical composition of M. trichocarpa leaf EO, along with preliminary in vitro screening of its enzymatic and cytotoxic properties.
