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Supplemental Material, sj-pdf-1-jrp-10.1177_07316844221075706 for Probing mechanical properties of graphene oxide/epoxy composites based on nano indentation technique by Cun Zhao, Yufen Zhao, Xiaoyuan Pei, Shengkai Liu, Yuanhua Xia, Chunying Min, Ruiqi Shao, Chunhong Wang, Wei Wang and Zhiwei Xu in Journal of Vibration and Control

Supplemental Material, sj-pdf-1-jrp-10.1177_07316844221075706 for Probing mechanical properties of graphene oxide/epoxy composites based on nano indentation technique by Cun Zhao, Yufen Zhao, Xiaoyuan Pei, Shengkai Liu, Yuanhua Xia, Chunying Min, Ruiqi Shao, Chunhong Wang, Wei Wang and Zhiwei Xu in Journal of Vibration and Control

Pentacoordinated spirophosphorane as a simple, effective and novel organocatalyst for the Michael addition reaction has been investigated. The bisaminoacyl spirophosphorane that possessed a thiourea-like moiety and an amine group was applied to the Michael addition reaction of 1, 3-dicarbonyl compound with β-nitrostyrene, affording the desired adduct in good yield. Furthermore, the mechanism of the Michael addition reaction catalyzed by spirophosphorane was proposed with the help of the analysis of single crystal structure, NMR experiments. It was identified that 1, 3-dicarbonyl compound and β-nitrostyrene formed hydrogen bonds with amine group and N-H groups of spirophosphorane catalyst, respectively. Then the two reactants approached each other, and the methylene of 1, 3-dicarbonyl compound attacked the olefin carbon of β-nitrostyrene to form nucleophilic addition product. This report is the first example of spirophosphorane as a novel organocatalyst to successfully catalyze the Michael addition reaction.

A one-pot synthetic strategy was developed for the synthesis of heterocyclic 1,4,2-oxazaphosphinanes via a three component Kabachnik-Fields reaction of 2-aminophenol, diphenyl H-phosphonate and carbonyl compounds. Through this newly developed method, 12 organophosphorus heterocycles and 2 related chrysin derivatives were synthesized with high yields. The target compounds were characterized by 1H, 31P and 13C NMR and MS.

Brefeldin A (BFA; C16H24O4, MW 280), a naturally occurring macrolide, exhibits diverse biological activities, such as antibiotic, antiviral, cytostatic, antimitotic, and antitumor effects. Owing to the wide activities of BFA, there is a need to develop a method for rapid identification of BFA in crude microbial extracts. In this paper, a method has been established and validated for screening and identification of individual as well as total BFA by high-performance liquid chromatography and liquid chromatography/electrospray mass spectrometry in fungal raw materials.

Using electrospray ionization mass spectrometry, the nano-structures of wheat starch granules, which were gelatinized and then filtered through a Millipore membrane, were analyzed for their possible composition and degrees of polymerization. Results showed that ESI–MS may be a reliable and fast technique for the analysis of nano-structures of wheat starch granules.

The direct observation of a transition state analogue (TSA) complex for tyrosine phosphorylation by a signaling kinase has been achieved using (19)F NMR analysis of MEK6 in complex with tetrafluoroaluminate (AlF(4)(-)), ADP, and p38α MAP kinase (acceptor residue: Tyr182). Solvent-induced isotope shifts and chemical shifts for the AlF(4)(-) moiety indicate that two fluorine atoms are coordinated by the two catalytic magnesium ions of the kinase active site, while the two remaining fluorides are liganded by protein residues only. An equivalent, yet distinct, AlF(4)(-) complex involving the alternative acceptor residue in p38α (Thr180) is only observed when the Tyr182 is mutated to phenylalanine. The formation of octahedral AlF(4)(-) species for both acceptor residues, rather than the trigonal bipyramidal AlF(3)(0) previously identified in the only other metal fluoride complex with a protein kinase, shows the requirement of MEK6 for a TSA that is isoelectronic with the migrating phosphoryl group. This requirement has hitherto only been demonstrated for proteins having a single catalytic magnesium ion.

In this paper, based on the known crystal structures of Square Pyramid (SP) and Trigonal Bipyramid (TBP) penta-coordinated phosphorus compounds containing amino acid side chains, such as amino, carboxyl, hydroxyl or thiol, a software designed to survey the P(5)-Structure of phosphorylated proteins. By this software, it was found that 382 of 398 phosphorus-related kinases (96%) from current PDB could go through the penta-coordinated phosphorus transition state or intermediate. For example, in protein 1HE8, amino group in Lysine16 was within 3.58 A from the phosphorus atom, and a potential TBP structure consisting GNP2 and N Z could be overlapped with an authentic TBP with an RMSD value of 0.71 A.