Comparison of geranylgeranyl and phytyl substituted methylquinols in the tocopherol synthesis of spinach chloroplasts

Geranylgeranyl substituted methylquinols are shown to be precursors of tocopherol biosynthesis in spinach chloroplasts as well as phytyl substituted ones. The geranylgeranyl substituted quinols are methylated even to a greater extent than the phytyl substituted ones. The connection to the so far known biosynthetic origin of -tocopherol is probably -tocotrienol which is hydrogenated to γ-tocopherol and then further methylated to -tocopherol

Ethynyl and substituted ethynyl-terminated polysulfones

Ethynyl and substituted ethynyl-terminated polysulfones and a process for preparing the same are disclosed. These polysulfones are thermally cured to induce cross-linking and chain extension, producing a polymer system with improved solvent resistance and use temperature. Also disclosed are substituted 4-ethynylbenzoyl chlorides as precursors to the substituted ethynyl-terminated polysulfones and a process for preparing the same

Substituted phenylarsonic acids; structures and spectroscopy

Full NMR and ESI-MS spectra, and differential scanning calorimeter data are presented for 15 substituted phenylarsonic acids, including two new fluoro-substituted examples. X-ray crystal structure determinations of five examples (phenylarsonic acid and the 4-fluoro-, 4-fluoro-3-nitro-, 3-amino-4-hydroxy- and 3-amino-4-methoxy-substituted derivatives) were determined and the H-bonding crystal-packing patterns analysed

Ethynyl and substituted ethynyl-terminated polysulfones

Ethynyl and substituted ethynyl-terminated polysulfones and their synthesis are disclosed. These polysulfones are thermally cured to induce cross-linking and chain extension, producing a polymer system with improved solvent resistance and use temperatures. Also disclosed are substituted 4-ethynylbenzoyl chlorides as precursors to the substituted ethynyl-terminated polysulfones and a process for preparing the same

Biocatalytic Route to Chiral Precursors of β-Substituted-γ-Amino Acids

In this work, we utilized commercial lipases (from Thermomyces lanuginosa, Rhizopus delemar, and Mucor miehei) as biocatalysts for the efficient synthesis of precursors of β-substituted-γ-amino acids. This biocatalytic route provides a practical and efficient synthesis of a wide range of optically active compounds by accepting a number of aliphatic and aromatic 3-substituted-3-cyano-2-(ethoxycarbonyl)propanoic acid ethyl esters (2) without compromising enantioselectivity or yields. The resolution step allows for the nearly quantitative recovery of the unreacted enantiomer of R-(2) as well as the newly formed 3-substituted-3-cyano-2-(ethoxycarbonyl)propanoic acid (3) in high enantio and diastereoselectivity. The use of a facile thermal decarboxylation of (3) in aqueous solution to produce 3-substituted-3-cyanopropanoic acid ethyl esters (4) enable us to prepare a wide range of optically active precursors of β-Substituted-γ-Amino Acids

In Defense of the Dealers: Why the SEC Should Allow Substituted Compliance with the European Union for Security-Based Swap Dealers

Following the 2008–2009 financial crisis, legislators around the world enacted laws that regulated the over-the-counter (OTC) derivatives markets for the first time. These laws, though necessary, have duplicative requirements that dampen market efficiency. In the United States, the Securities and Exchange Commission is contemplating a “substituted compliance” regime with other jurisdictions. This regime would allow market participants to comply with one jurisdiction’s requirements for certain transactions, rather than the requirements of multiple jurisdictions. This Note argues that the SEC should allow substituted compliance for OTC derivatives, but only for dealers located in the United States and European Union. Some advocate for a broader substituted compliance regime. These arguments, however, overlook nuances of the SEC’s announced approach. Others argue that the SEC should avoid substituted compliance altogether. Ultimately, if the SEC allows substituted compliance narrowly and thoughtfully, it could preserve the economic benefits of a domestic financial market, while preventing some causes of the recent financial crisis

Electrochemical Properties of LaNi5–xGex Alloys in Ni-MH Batteries

Electrochemical studies were performed on LaNi5–xGex metal hydride alloys with 0 <= x <= 0.5. We carried out single-electrode studies to understand the effects of the Ge substituent on the hydrogen absorption characteristics, the electrochemical capacity, and the electrochemical kinetics of hydrogen absorption and desorption. The electrochemical characteristics of the Ge-substituted alloys are compared to those of the Sn-substituted alloys reported earlier. LaNi5–xGex alloys show compositional trends similar to LaNi5–xSnx alloys, but unlike the Sn-substituted alloys, Ge-substituted alloys continue to exhibit facile kinetics for hydrogen absorption/desorption at high solute concentrations. Cycle lives of LaNi5–xGex electrodes were measured in 300 mAh laboratory test cells and were found to be superior to the Sn-substituted LaNi5 and comparable to a Mm(Ni,Co,Mn,Al)5 alloy. The optimum Ge content for LaNi5–xGex metal hydride alloys in alkaline rechargeable cells is in the range 0.4 <= x <= 0.5

In Defense of the Dealers: Why the SEC Should Allow Substituted Compliance with the European Union for Security-Based Swap Dealers

Following the 2008–2009 financial crisis, legislators around the world enacted laws that regulated the over-the-counter (OTC) derivatives markets for the first time. These laws, though necessary, have duplicative requirements that dampen market efficiency. In the United States, the Securities and Exchange Commission is contemplating a “substituted compliance” regime with other jurisdictions. This regime would allow market participants to comply with one jurisdiction’s requirements for certain transactions, rather than the requirements of multiple jurisdictions. This Note argues that the SEC should allow substituted compliance for OTC derivatives, but only for dealers located in the United States and European Union. Some advocate for a broader substituted compliance regime. These arguments, however, overlook nuances of the SEC’s announced approach. Others argue that the SEC should avoid substituted compliance altogether. Ultimately, if the SEC allows substituted compliance narrowly and thoughtfully, it could preserve the economic benefits of a domestic financial market, while preventing some causes of the recent financial crisis

Micelle formation, gelation and phase separation of amphiphilic multiblock copolymers

The phase behaviour of amphiphilic multiblock copolymers with a large number of blocks in semidilute solutions is studied by lattice Monte Carlo simulations. The influence on the resulting structures of the concentration, the solvent quality and the ratio of hydrophobic to hydrophilic monomers in the chains has been assessed explicitely. Several distinct regimes are put in evidence. For poorly substituted (mainly hydrophilic) copolymers formation of micelles is observed, either isolated or connected by the hydrophilic moieties, depending on concentration and chain length. For more highly substituted chains larger tubular hydrophobic structures appear which, at higher concentration, join to form extended hydrophobic cores. For both substitution ratios gelation is observed, but with a very different gel network structure. For the poorly substituted chains the gel consists of micelles cross-linked by hydrophilic blocks whereas for the highly substituted copolymers the extended hydrophobic cores form the gelling network. The interplay between gelation and phase separation clearly appears in the phase diagram. In particular, for poorly substituted copolymers and in a narrow concentration range, we observe a sol-gel transition followed by an inverse gel-sol transition when increasing the interaction energy. The simulation results are discussed in the context of the experimentally observed phase properties of methylcellulose, a hydrophobically substituted polysaccharide.Comment: 14 pages, 14 figures; Soft Matter (2011