- COMPOSITIONS COMPRISING ENZYME CLEAVABLE LINKER PLATFORMS AND CONJUGATES THEREOF
-
The present invention relates to a cleavable linker platform. In particular, the invention relates to construction of an enzyme cleavable linker platform conjugated to a drug or a diagnostically relevant compound, a biomolecule, and an enzyme cleavable group, for which cleavage of the enzyme cleavable group leads to release of the drug or diagnostically relevant compound.
- -
-
Page/Page column 49; 50
(2021/01/23)
-
- Combinatorial synthesis of PEG oligomer libraries
-
A simple chain-extending approach was established for the scale-up of the monoprotected monodisperse PEG diol materials. Reactions of THP-(OCH2CH2)n—OMs (n=4, 8, 12) with a large excess of commercially available H—(OCH2CH2)n—OH (n=1-4) under basic conditions led to THP-(OCH2CH2)n—OH (n=5-15). Similarly, Me-(OCH2CH2)n—OH (n=4-11, 13) were prepared from Me-(OCH2CH2)n—OMs (n=3, 7, 11). For the chain elongation steps, 40-80% yields were achieved through extraction purification. PEG oligomer libraries I and II were generated in 50-95% overall yields by alkylation or acylation of THP-(OCH2CH2)n—OH (n=1-15) followed by deprotection. Alkylation of Me-(OCH2CH2)n—OH (n=1-11, 13) with X—(CH2)m—CO2R (X=Br or OMs) and subsequent hydrolysis led to PEG oligomer library III in 30-60% overall yields. Combinatorial purification techniques were adapted to the larger-scale library synthesis. A total of 498 compounds, each with a weight of 2-5 g and a minimum purity of 90%, were synthesized.
- -
-
Page/Page column 11
(2010/02/15)
-
- Kinetics and quantitative structure-activity relationships for pseudomonas sp. Lipase-catalyzed hydrolysis of both monoesters and diesters of ethylene glycol
-
The goal of this work is to study kinetics and quantitative structure-activity relationships for steady states of Pseudomonas sp. lipase-catalyzed hydrolysis of both diesters and monoesters of ethylene glycol. Based on the steady-state kinetics of the enzyme-catalyzed hydrolysis of the diesters of ethylene glycol, the diesters and the monoesters react simultaneously as soon as monoester has started to build up in the reaction medium. In other words, the apparent Km values of the diesters are the Km values of the diesters (KmA) plus the Km values of the monoesters (KmB), and all Vmax values are about the same. Moreover, the pH-stat titration curve of the enzyme-catalyzed hydrolysis of the diesters of ethylene glycol is initially hyperbolic, then there is a sharp falloff in the hydrolysis rate. The abrupt stoppage of the reaction (relaxation stage) may be due to the existence of two phases in the reaction medium, that is, the product (ethylene glycol) and the substrates (the diesters of ethylene glycol) are not miscible. Furthermore, quantitative structure-activity relationships for varied acyl groups of mono- and diesters of ethylene glycol are studied. The fact that both pKmA and pK mB values are linearly correlated with the hydrophobicity constant (π) but not with the electronic substituent constants (σ*) indicates that the affinity of these substrates for the enzyme depends only on the hydrophobicitv of substrates. Copyright
- Chiou, Shyh-Ying,Cheng, Yu-Ru,Lu, Chun-Ping,Lin, Yan-Fu,Lin, Long-Yau,Lin, Gialih
-
p. 201 - 207
(2007/10/03)
-
- Design, synthesis, and evaluation of water-soluble phospholipid analogues as inhibitors of phospholipase C from Bacillus cereus
-
The rate of hydrolysis of natural phospholipids by the phosphatidyleholine-preferring phospholipase C from Bacillus cereus (PLC Bc) follows the order phosphatidylcholine > phosphatidylethanolamine ? phosphatidyl-L-serine. To probe the structural basis for this substrate specificity, a series of water-soluble, nonhydrolyzable substrate analogues were needed so their complexes with the enzyme could be studied via X-ray crystallography and isothermal titration calorimetry (ITC). Accordingly the water-soluble dithiophospholipids 2-10 having choline, ethanolamine, and L-serine headgroups were synthesized, and the inhibitory activity of each was determined in an assay using 1,2-dihexanoyl-sn-glycero-3-phosphocholine (C6PC) as the monomeric substrate. The 1,2-dibutanoyl dithiophosphocholine 2 was a weak inhibitor, whereas the related 1,2-dipentanoyl dithiophospho-choline 3 and the ethylene glycol dithiophosphocholines 4 and 5 were moderate inhibitors. The 1,2-ω -hydroxydiacyl dithiophosphocholines 6 and 7 were potent inhibitors, while the related compound 8, which had shorter acyl side chains, was a weak inhibitor. The dithiophosphoethanolamine 9 was a modest inhibitor, whereas the dithiophospho-L-serine 10 was a somewhat weaker inhibitor. Overall, the phospholipid analogues had increasing Ki values according to the order 2 ? 10 3 4 ≈ 5 ≈ 8 9 ? 6 ? 7 and increasing solubility according to the sequence 5 ≈ 7 4 ≈ 6 ≈ 9 3 10 8 2.
- Franklin, Christopher L.,Li, Hui,Martin, Stephen F.
-
p. 7298 - 7307
(2007/10/03)
-
- Cobalt(II) catalyzed oxidation of 2-substituted 1,3-dioxolanes with molecular oxygen
-
Cobalt(II) chloride catalyzed oxidation of 2-substituted 1,3-dioxolanes in 1,2-dimethoxyethane afforded formate esters and acids in high yields.Is was found that the presence of catalytic amounts of ZnCl2 increased the rate of oxidation.A free-radical mechanism is proposed, involving participation of superoxocobalt, and the esterification of the alcohol and acid.
- Li, Pei,Alper, Howard
-
-
- Acetals oxidation into esters with electrophilic halogens
-
A preparative oxidation of dioxolanes groups into esters is described. Among the different electophilic halogens and solvents which have been tested, ICl/H2O in methylene chloride and Br2/H2O in acetonitrile gave the best results.
- Mingotaud,Florentin,Marquet
-
p. 2401 - 2404
(2007/10/02)
-
- Capryloyloxyalkyl acrylates, polymers and copolymers thereof and their preparation
-
This invention relates to capryloyloxyalkyl acrylates of the general formula, CH2=CH-CO-O-R-O-CO-(CH2)6-CH3,wherein R is an alkylene group of 2 to 6 carbon atoms, and their polymers and copolymers containing structure units of the general formula where R are identical or different alkylene groups as defined above, and the polymer contains either 100 % of the capryloyloxyalkyl acrylate structure units or additional vinyl monomer and particularly vinyl chloride structure units in the main chain or side chains. The invention also pertains to methods for the preparation of capryloyloxyalkyl acrylates corresponding intermediates and to methods for producing the polymers and copolymers containing capryloyloxyalkyl acrylate structure units either by polymerization or copolymerization of capryloyloxyalkyl acrylates with the respective vinyl comonom ers or by polymerization of the vinyl comonomers, particularly vinyl chloride, in the presence of a poly(capryloyloxyalkyl acrylate). The invention is particularly applicable to the production of new types of plasticized PVC where migration and extraction of the plasticizing component is excluded.
- -
-
-
- A SIMPLE ELECTROCHEMICAL OXIDATION OF ALDEHYDE ACETALS TO ESTERS IN NEUTRAL SOLUTION
-
Anodic oxidation of aldehyde acetals to esters under very mild conditions is achieved in a neutral solution by utilizing N-hydroxy-phthalimide as a mediator.The oxygen source of the oxidation is thought to be not dioxygen but water.Keywords: acetal; anodic oxidation; mediator; N-hydroxy-phthalimide; ester; glyceride.
- Masui, Masaichiro,Kawaguchi, Tetsuo,Yoshida, Sumiko,Ozaki, Shigeko
-
p. 1837 - 1839
(2007/10/02)
-
- Palladium(II)-catalysed Oxidative Ring Cleavage of Cyclic Acetals with t-Butyl Hydroperoxide: Preparation of Monoesters of Diols
-
Reaction of five- and six-membered cyclic acetals with tBuOOH in the presence of palladium(II) catalyst gives monoesters of diols in good yields.
- Hosokawa, Takahiro,Imada, Yasushi,Murahashi, Shun-Ichi
-
p. 1245 - 1246
(2007/10/02)
-