BACKGROUND The plant cell walls play an important role in somatic embryogenesis and plant development. Pectins are major chemical components of primary cell walls while homogalacturonan (HG) is the most abundant pectin polysaccharide. Developmental regulation of HG methyl-esterification degree is important for cell adhesion, division and expansion, and in general for proper organ and plant deve...

An efficient Knoevenegel reaction, addition of Michael, trans-esterification for the synthesis of new polyanionic acyclonucleosids using natural phosphate as catalyst

Esterification of naturally occurring hemins and porphyrins is often a prerequisite for structural studies of these compounds. Porphyrins and hemins are in general more easily purified as their esters than as the free carboxylic acids. In addition, esterification is the most feasible procedure for preparing derivatives of tetrapyrroles for studies by mass spectrometry. The most convenient and f...

Thin adipose tissue slices prepared from middle subcutaneous (MSQ) adipose tissue of pigs weighing 57, 94 or 124 kg were incubated in vitro for 30 rain in the absence of exogenous insulin with one of several substrate combinations: .75 mM [1-14C] palmitate and 10 mM glucose; 10 mM [U-14C] glucose and .75 mM palmitate, or 10 mM [U-laC]glucose in the absence of palmitate. Esterification of palmit...

The effects of short-term food deprivation on lipid metabolism are well documented, but little is known about prolonged fasting. This study monitored the kinetics of glycerol (rate of appearance, R(a) glycerol) and non-esterified fatty acids (R(a) NEFA) in fasting rabbits. Our goals were to determine whether lipolysis is stimulated beyond values seen for short-term fasting, and to characterize ...

This study reports evidence for catalytic deoxygenation of alkanols, alkanals, and alkanediols on dispersed Cu clusters with minimal use of external H(2) and with the concurrent formation of new C-C and C-O bonds. These catalysts selectively remove O-atoms from these oxygenates as CO or CO(2) through decarbonylation or decarboxylation routes, respectively, that use C-atoms present within reacta...

Because vitamin A in milk is largely present as esterified retinol while blood plasma predominantly contains unesterified retinol, experiments were conducted to determine whether membranes from the lactating mammary gland are able to synthesize retinyl esters in vitro. When microsomes from rats lactating for 7 to 14 days were incubated with [(3)H]retinol dispersed in dimethylsulfoxide, some [(3...

Five steers (average 526 kg) fitted with ruminal, duodenal, and ileal cannulas were used in a 5 x 6 Youden square design with 14-d periods. Diets contained chopped alfalfa hay, corn silage, and concentrate (25:35:40, DM basis). Treatments were 1) control (no added fat), 2) tallow (T), 3) partially hydrogenated tallow (PHT), 4) hydrogenated tallow (HT), 5) blend (1:1) of HT and hydrogenated free...

De-esterification is an initial step in the metabolism of certain herbicides, for example, fenoxaprop-ethyl [(+/-)-ethyl 2-[4-[(6-chloro-2-benzoxaolyl)oxy]phenoxy]propanoate] (FE). The ethyl-ester bond cleavage of FE to fenoxaprop acid (FA) by purified enzymes, crude bacterial enzyme preparations, and soils was investigated. In similar experiments fluorescein diacetate (FDA) was used as an alte...

A highly efficient, broad scope, additive-free mild protocol for the oxidative carbene-catalysed esterification of aldehydes (including the related aqueous oxidation to acids) has been developed.