A geranylated chalcone with antiplatelet activity from the leaves of breadfruit (Artocarpus altilis)

Platelet plays a crucial role in cardiovascular diseases (CVDs) development. Abnormalities in platelet aggregation provokes thromboembolism, eventually leading to death. In Indonesia, breadfruit (Artocarpus altilis) leaf is traditionally used to treat CVDs. This study aimed to evaluate the antiplatelet activity of A. altilis leaf extract (AAE) and to identify its active compound. A. altilis leaves were extracted with ethanol, and the antiplatelet activity was assessed using ADP-induced platelet aggregation. The major compound was isolated with column chromatography followed by preparative TLC, and the structure was determined on the basis of UV, MS, IR, and NMR spectra. The binding mode of the active compound to platelet receptors was characterized in in silico study. AAE exhibited an antiplatelet activity (IC50 of 252.23 µg/mL). A geranylated chalcone, 2-geranyl-2ʹ,3,3,4ʹ-tetrahydroxydihydrochalcone (GTDC) was identified as the antiplatelet compound (IC50 of 9.09 µM). GTDC actions with P2Y12 platelet receptor involving three amino acid residues.

Effects of Halogen, Chalcogen, Pnicogen, and Tetrel Bonds on IR and NMR Spectra

Complexes were formed pairing FX, FHY, FH2Z, and FH3T (X = Cl, Br, I; Y = S, Se, Te; Z = P, As, Sb; T = Si, Ge, Sn) with NH3 in order to form an A⋯N noncovalent bond, where A refers to the central atom. Geometries, energetics, atomic charges, and spectroscopic characteristics of these complexes were evaluated via DFT calculations. In all cases, the A–F bond, which is located opposite the base and is responsible for the σ-hole on the A atom, elongates and its stretching frequency undergoes a shift to the red. This shift varies from 42 to 175 cm−1 and is largest for the halogen bonds, followed by chalcogen, tetrel, and then pnicogen. The shift also decreases as the central A atom is enlarged. The NMR chemical shielding of the A atom is increased while that of the F and electron donor N atom are lowered. Unlike the IR frequency shifts, it is the third-row A atoms that undergo the largest change in NMR shielding. The change in shielding of A is highly variable, ranging from negligible for FSnH3 all the way up to 1675 ppm for FBr, while those of the F atom lie in the 55–422 ppm range. Although smaller in magnitude, the changes in the N shielding are still easily detectable, between 7 and 27 ppm.

Enhancing hydrophobicity, strength and UV shielding capacity of starch film via novel co-cross-linking in neutral conditions

Starch films are developed as the biodegradable packaging materials to replace the petroleum-based materials in recent years. Thus, it is extremely beneficial to improve the hydrophobicity and mechanical strength of starch films, through a novel approach of co-cross-linking in neutral conditions, with glyoxal and AZC. In this work, systematic studies have been conducted to assess the performance of the co-cross-linked starch along with the control starch and starch cross-linked by glyoxal or AZC alone. Results showed that the co-cross-linked starch films exhibited significantly improved hydrophobicity and strength and the wet stress reached 1.53 MPa, compared to the control, glyoxal or AZC cross-linked starch films. More interestingly, the co-cross-linked film also demonstrated excellent UV shielding capacity and transmittance at visible wavelength range. The reaction mechanism was revealed based on the findings from UV, FT-IR and NMR spectra. This work established an innovative approach to improving the performance of starch film in neutral conditions for packaging applications.

Experimental and theoretical studies on compositions, structures, and IR and NMR spectra of functionalized protic ionic liquids

DMCEAP and DMEOAP are composed of neutral and ionized species in the liquid phase as investigated through experimental spectroscopy and DFT calculations.

Hollow circular compound-based inclusion complexes of an ionic liquid

Inclusion complex formation between hollow circular compounds, e.g. crown ethers, and an ionic liquid, 1-methyl-3-octylimidazolium tetrafluoroborate, in acetonitrile solvent is studied by means of conductivity measurements, IR and NMR spectra.

Synthesis, Characterization and Evaluation of Biological Activity of some Substituted(E)-2-Benzylidenehydrazinecarbothio Amides

A series of substituted (E)-2-benzylidenehydrazinecarbothioamide compounds were synthesized by condensation of thiosemicarbazide with substituted benzaldehydes. The synthesized substituted (E)-2-benzylidenehydrazinecarbothioamide compounds were characterized by their physical constants, UV, IR and NMR spectra. The antimicrobial activities of these synthesized substituted (E)-2-benzylidenehydrazinecarbothioamide compounds have been screened by Bauer-Kirby method using human pathogenic bacteria and fungal species. The antimicrobial activities of all synthesized (E)-2-benzylidenehydrazinecarbothioamide compounds have shown significant activity.

Synthesis of a Polysiloxane with High Reaction Activity

A novel building block in organic synthesis, poly (4-iodobutoxylmethylsiloxane)(PIBMS) with high reaction activity was prepared by poly (hydromethylsiloxane)(PHMS), methyl iodide and tetrahydrofuran (THF) in the presence of a catalytic amount of PdCl2. The structure of PIBMS was characterized by the FT-IR and NMR spectra. The reaction conditions were optimized.