β-Sheet Hydrogen Bonding Patterns in Cystine Peptides
摘要:
Cystine peptides have been shown to adopt conformations in organic solvents that mimic small ss-sheets. Relative hydrogen bond strengths, ss-strand aggregation, and the identity of individual hydrogen bond donors and acceptors have been identified through hydrogen/deuterium exchange.
Repurposing the 3‐Isocyanobutanoic Acid Adenylation Enzyme SfaB for Versatile Amidation and Thioesterification
作者:Mengyi Zhu、Lijuan Wang、Jing He
DOI:10.1002/anie.202010042
日期:2021.1.25
molecules with novel skeletons, but also to identify the enzymes that catalyze diverse chemical reactions. Exploring the substrate promiscuity and catalytic mechanism of those biosynthetic enzymes facilitates the development of potential biocatalysts. SfaB is an acyladenylate‐forming enzyme that adenylates a unique building block, 3‐isocyanobutanoic acid, in the biosynthetic pathway of the diisonitrile
Switching from (R)- to (S)-selective chemoenzymatic DKR of amines involving sulfanyl radical-mediated racemization
作者:Lahssen El Blidi、Nicolas Vanthuyne、Didier Siri、Stéphane Gastaldi、Michèle P. Bertrand、Gérard Gil
DOI:10.1039/c0ob00054j
日期:——
Chemoenzymatic dynamic kinetic resolution (DKR) of amines involving sulfanyl radical-induced racemization happened to be the very first switchable DKR process allowing the synthesis of either (R)- or (S)-amides, in good yield and high enantiomeric excess, depending on the nature of the enzyme; the different steps of the development of (S)-selective DKR are discussed.
Yttrium(III) acylalaninate complexes such as tris(N-hexanoyl-DL-alaninato)yttrium(III) (=Y(hex-DL-ala) 3 ) and tris(N-octanoyl-DL-alaninato)yttrium(III) (=Y(oct-DL-ala) 3 ) form stable glassy states by an evaporation of solvent from the methanol solution. The trend of formation of the stable glassy state is sensitive to a difference in the acylalaninate ligands.
Gel compositions, which contain:
(A) at least one N-acyl amino acid represented by formula (1):
wherein R
1
denotes a straight or branched-chain saturated hydrocarbon group having from 1 to 25 carbon atoms or a straight or branched-chain unsaturated hydrocarbon group optionally containing an aromatic ring, and X denotes an aliphatic or aromatic α-, β-, or γ-amino acid; and
(B) at least one oily base, can be obtained in the form of a translucent to milky white, creamy to solid gel, with an attractive appearance. When employed in aromatic cosmetic compositions such as cosmetics, such gel compositions yield an aromatic cosmetic product that does not produce a clammy or clogging feeling and that affords good spreadability.
Härtbare Polyesterformmassen, enthaltend ein Gemisch aus
A. einem ethylenisch ungesättigten Polyester oder einem endständigen ungesättigten Vinylester,
B. copolymerisierbaren Monomeren,
C. faserförmigen Verstärkungsmitteln
D. pulverförmigen Füllstoffen,
E. organischen Radikalinitiatoren,
F. einem Viskositätserniedriger,
G. üblichen Zusatzstoffen.
Der Viskositätserniedriger ist ein tertiäres oder sekundäres Amin, das eine langkettige Alkyl- oder Acylgruppe sowie eine Carboxylgruppe trägt.
可固化聚酯模塑组合物,含有以下混合物
A. 乙烯基不饱和聚酯或末端不饱和乙烯基酯、
B. 可共聚单体
C. 纤维状增强剂
D. 粉末状填料
有机自由基引发剂
F. 降粘剂
G. 传统添加剂。
降粘剂是一种带有长链烷基或酰基和羧基的叔胺或仲胺。