Green chemical and biological synthesis of cadaverine: recent development and challenges.

Cadaverine has great potential to be used as an important monomer for the development of a series of high value-added products with market prospects. The most promising strategies for cadaverine synthesis involve using green chemical and bioconversion technologies. Herein, the review focuses on the progress and strategies towards the green chemical synthesis and biosynthesis of cadaverine. Specifically, we address the specific biosynthetic pathways of cadaverine from different substrates as well as extensively discussing the origination, structure and catalytic mechanism of the key lysine decarboxylases. The advanced strategies for process intensification, the separation and purification of cadaverine have been summarized. Furthermore, the challenging issues of the environmental, economic, and applicable impact for cadaverine production are also highlighted. This review concludes with the promising outlooks of state-of-the-art applications of cadaverine along with some insights toward their challenges and potential improvements.

A green route to methyl acrylate and acrylic acid by an aldol condensation reaction over H-ZSM-35 zeolite catalysts.

A one-step aldol condensation reaction to produce MA and AA is a green and promising strategy. Here, the aldol condensation reaction was first conducted with DMM and MAc over different types of zeolite catalysts. The H-ZSM-35 zeolite demonstrates excellent catalytic performance with a DMM conversion of 100% and a MA + AA selectivity of up to 86.2% and superior regeneration ability, with great potential for industrial operation.

Neofunctionalization of zona pellucida proteins enhances freeze-prevention in the eggs of Antarctic notothenioids.

The mechanisms by which the eggs of the Antarctic notothenioid fishes avoid freezing are not fully understood. Zona pellucida proteins (ZPs) are constituents of the chorion which forms a protective matrix surrounding the egg. Here we report occurrence of freezing temperature-related gene expansion and acquisition of unusual ice melting-promoting (IMP) activity in a family of Antarctic notothenioid ZPs (AnnotoZPs). Members of AnnotoZPs are shown to bind with ice and non-colligatively depress the melting point of a solution in a range of 0.26 to 0.65 °C at a moderate concentration. Eggs of zebrafishes expressing an AnnotoZP transgene show improved melting point depression and enhanced survival in freezing conditions. Mutational analyses in a representative AnnotoZP indicate the ZP domain and patches of acidic residues are essential structures for the IMP activity. AnnotoZPs, therefore, represent a group of macromolecules that prevent freezing by a unique ZP-ice interaction mechanism distinct from the known antifreeze proteins.

catena-Poly[(diaqua-cadmium)-µ-4,4'-[sulfonyl-bis-(1,4-phenyl-ene-oxy)]-di-acet-ato-κO,O':O'',O'''].

In the title coordination polymer, [Cd(C(16)H(12)O(8)S)(H(2)O)(2)](n), the Cd(II) ion is situated on a crystallographic twofold rotation axis, being coordinated by four O atoms from two bidentate 4,4'-[sulfonyl-bis-(1,4-phenyl-ene-oxy)]diacetate (L) ligands and two water mol-ecules in a highly distorted CdO(6) octa-hedral geometry. Each complete ligand L, which is also generated by twofold symmetry with the S atom lying on the rotation axis, bridges two Cd(II) atoms to form a polymeric zigzag chain propagating in the [10-1] direction. O-H⋯O hydrogen bonds between the coordinated water mol-ecules and carboxyl-ate O atoms are involved in the packing.

(E)-N'-(3,4-Dimethoxy-benzyl-idene)-2-(8-quinol-yloxy)acetohydrazide-methanol-water (1/1/1).

In the title compound, C(20)H(19)N(3)O(4)·CH(4)O·H(2)O, the Schiff base mol-ecule is almost planar, with a dihedral angle of 1.2 (1)° between the benzene ring and the quinoline ring system. An intra-molecular N-H⋯O hydrogen bond generates an S(6) ring. In the crystal, the methanol and water solvent mol-ecules are linked to the Schiff base mol-ecule via N-H⋯O, O-H⋯O, O-H⋯N and O-H⋯(O,N) hydrogen bonds.