2,5–FURANDICARBOXYLIC ACID DICINAMIL ETHER AND NEW COPOLYMERS ON ITS BASIS

A method for the synthesis of dicinamyl ester of 2,5-furandicarboxylic acid (DCF) a new unsaturated compound of the furan series and potential monomer for producing copolymers with various vinyl compounds and based on them a new generation of construction and ion-exchange materials has been developed. DCF does not form homopolymers as in bulk as in solution (toluene solvent). However, DCF is actively copolymerized with styrene, methyl methacrylate, methacrylic and acrylic acids to form cross-linked polymers with varying degrees of crosslinking. The copolymerization constants of DCF with all investigated vinyl compounds were determined. The DCF copolymers are enriched with comonomer units for all ratios of the components in the initial reaction mixture. They are statistical, and the comonomer units in the macromolecule are randomly arranged. Copolymers with styrene or methyl methacrylate have higher mechanical strength compared to polystyrene and polymethyl methacrylate. Copolymers containing carboxyl groups and 10-20 % wt. crosslinking agent exhibit good ion-exchange properties with respect to heavy metals. The equilibrium adsorption amount of Cu2+ onto ion-exchange сopolymers (221-234 mg/g) was almost twice as large as that onto Amberlite IRC-748 (120.0 mg/g). Materials with a crosslinking agent content of 2.5-5% wt. form polymer gels with high water absorption. Materials containing 2.5 % wt. crosslinking agent (≥ 1400 % for copolymer DCF /acrylic acid and ≥ 1700 for copolymer DCF/methacrylic acid) are showed maximum swelling. These materials can be recommended as water absorbers.

Direct experimental probing and theoretical analysis of the reaction between the simplest Criegee intermediate CH2OO and isoprene

The reaction of CH2OO with isoprene, the highest-emitted unsaturated compound on Earth, is similar to reactions with small singly-unsaturated alkenes.

The significance of the Cα substituent in the selective inhibition of matrix metalloproteinases 1 and 9

Matrix metalloproteinases (MMPs) cleave and degrade most components of the extracellular matrix, and unregulated MMP activity has been correlated to cancer and metastasis. Hence there is a burgeoning need to develop inhibitors that bind selectively to structurally similar MMPs. The inhibition profiles of peptidomimetics containing Cα substituents at the α,β unsaturated carbon were evaluated against the recombinant forms of ADAM17, MMP1, and MMP9. The dicarboxylic acid D2 and hydroxamate C2 inhibited MMP9 but not MMP1. The unsaturated compound E2 displayed selective inhibition for MMP1, compared with the saturated precursor C2, with an IC50 value of 3.91 μm. The molecular basis for this selectivity was further investigated by the molecular docking of E2 and D2 into the active sites of MMP1 and MMP9. These data demonstrate hydrogen-bonding interactions between the carbonyl group of the Cα substituent of E2 and the side chain of Asn180 present in the active site of MMP1. Conversely, the docked MMP9-D2 structure shows hydrophobic and hydrogen bonding between the ligand’s morpholine substituent and second carboxylic acid group with Leu187 and an amide, respectively. This study suggests that substituents other than P1′ and P2′ may confer selectivity among MMPs and may aid in the search for novel lead compounds.