Halides and oxide halides of molybdenum and tungsten. III. Oxo-bridged species of tungsten(IV) and molybdenum(V)

1968 ◽  
Vol 21 (4) ◽  
pp. 883 ◽  
Author(s):  
R Colton ◽  
GG Rose
Keyword(s):  
Partial Hydrolysis ◽  
First Time ◽  
Hydrolysis Of ◽  
And Tungsten

The compound formulated in the literature as K2W(OH)Cl5 has been shown to be the oxo-bridged dimer K4[WT2Ocl10], and the diamagnetic dimer formed by the partial hydrolysis of the MOOCl2- ion has been isolated for the first time and shown to be the oxo-bridged [Mo2O3Cl8]4- ion.

Organic material dissolved during oxygen-alkali pulping of hot water extracted birch sawdust

TAPPI Journal ◽  
2015 ◽  
Vol 14 (4) ◽  
pp. 237-244 ◽  
Author(s):  
JONI LEHTO ◽  
RAIMO ALÉN
Keyword(s):  
Acetic Acid ◽  
Betula Pendula ◽  
Cooking Time ◽  
Hot Water ◽  
Partial Hydrolysis ◽  
Chemical Pulping ◽  
Black Liquors ◽  
Aliphatic Carboxylic Acids ◽  
Hydrolysis Of ◽  
Cooking Conditions

Untreated and hot water-treated birch (Betula pendula) sawdust were cooked by the oxygen-alkali method under the same cooking conditions (temperature = 170°C, liquor-to-wood ratio = 5 L/kg, and 19% sodium hydroxide charge on the ovendry sawdust). The pretreatment of feedstock clearly facilitated delignification. After a cooking time of 90 min, the kappa numbers were 47.6 for the untreated birch and 10.3 for the hot water-treated birch. Additionally, the amounts of hydroxy acids in black liquors based on the pretreated sawdust were higher (19.5-22.5g/L) than those in the untreated sawdust black liquors (14.8-15.5 g/L). In contrast, in the former case, the amounts of acetic acid were lower in the pretreated sawdust (13.3-14.8 g/L vs. 16.9-19.1 g/L) because the partial hydrolysis of the acetyl groups in xylan already took place during the hot water extraction of feedstock. The sulfur-free fractions in the pretreatment hydrolysates (mainly carbohydrates and acetic acid) and in black liquors (mainly lignin and aliphatic carboxylic acids) were considered as attractive novel byproducts of chemical pulping.

scholarly journals Optimisation of Recombinant Myrosinase Production in Pichia pastoris

2021 ◽  
Vol 22 (7) ◽  
pp. 3677
Author(s):  
Zuzana Rosenbergová ◽  
Kristína Kántorová ◽  
Martin Šimkovič ◽  
Albert Breier ◽  
Martin Rebroš
Keyword(s):  
Pichia Pastoris ◽  
Plant Defence ◽  
Plant Secondary Metabolites ◽  
Specific Productivity ◽  
Fermentation Conditions ◽  
Threefold Increase ◽  
Dry Cell Weight ◽  
First Time ◽  
Hydrolysis Of ◽  
Dry Cell

Myrosinase is a plant defence enzyme catalysing the hydrolysis of glucosinolates, a group of plant secondary metabolites, to a range of volatile compounds. One of the products, isothiocyanates, proved to have neuroprotective and chemo-preventive properties, making myrosinase a pharmaceutically interesting enzyme. In this work, extracellular expression of TGG1 myrosinase from Arabidopsis thaliana in the Pichia pastoris KM71H (MutS) strain was upscaled to a 3 L laboratory fermenter for the first time. Fermentation conditions (temperature and pH) were optimised, which resulted in a threefold increase in myrosinase productivity compared to unoptimised fermentation conditions. Dry cell weight increased 1.5-fold, reaching 100.5 g/L without additional glycerol feeding. Overall, a specific productivity of 4.1 U/Lmedium/h was achieved, which was 102.5-fold higher compared to flask cultivations.

THE ALDOBIOURONIC ACIDS OF HEMICELLULOSE B OF OAT HULLS

1956 ◽  
Vol 34 (3) ◽  
pp. 338-344 ◽  
Author(s):  
E. L. Falconer ◽  
G. A. Adams
Keyword(s):  
Glucuronic Acid ◽  
The Other ◽  
Partial Hydrolysis ◽  
Oat Hulls ◽  
Hydrolysis Of

Partial hydrolysis of hemicellulose B from oat hulls yielded two aldobiouronic acids, which were identified as 2-O-(4-O-methyl-α-D-glucopyruronosyl)-D-xylose and 2-O-(α-D-glucopyruronosyl)-D-xylose respectively. In addition, two aldotriouronic acids were isolated, one yielding on hydrolysis xylose and 4-O-methyl-glucuronic acid, and the other, xylose, galactose, and glucurone.

scholarly journals Biosynthesis of anandamide and N-palmitoylethanolamine by sequential actions of phospholipase A2 and lysophospholipase D

2004 ◽  
Vol 380 (3) ◽  
pp. 749-756 ◽  
Author(s):  
Yong-Xin SUN ◽  
Kazuhito TSUBOI ◽  
Yasuo OKAMOTO ◽  
Takeharu TONAI ◽  
Makoto MURAKAMI ◽  
...  
Keyword(s):  
Biosynthetic Pathway ◽  
Brain Homogenate ◽  
Wide Distribution ◽  
Rat Tissues ◽  
Lysophospholipase D ◽  
Pla2 Enzyme ◽  
First Time ◽  
Hydrolysis Of ◽  
The Brain

Anandamide (an endocannabinoid) and other bioactive long-chain NAEs (N-acylethanolamines) are formed by direct release from N-acyl-PE (N-acyl-phosphatidylethanolamine) by a PLD (phospholipase D). However, the possible presence of a two-step pathway from N-acyl-PE has also been suggested previously, which comprises (1) the hydrolysis of N-acyl-PE to N-acyl-lysoPE by PLA1/PLA2 enzyme(s) and (2) the release of NAEs from N-acyllysoPE by lysoPLD (lysophospholipase D) enzyme(s). In the present study we report for the first time the characterization of enzymes responsible for this pathway. The PLA1/PLA2 activity for N-palmitoyl-PE was found in various rat tissues, with the highest activity in the stomach. This stomach enzyme was identified as group IB sPLA2 (secretory PLA2), and its product was determined as N-acyl-1-acyl-lysoPE. Recombinant group IB, IIA and V of sPLA2s were also active with N-palmitoyl-PE, whereas group X sPLA2 and cytosolic PLA2α were inactive. In addition, we found wide distribution of lysoPLD activity generating N-palmitoylethanolamine from N-palmitoyl-lysoPE in rat tissues, with higher activities in the brain and testis. Based on several lines of enzymological evidence, the lysoPLD enzyme could be distinct from the known N-acyl-PE-hydrolysing PLD. sPLA2-IB dose dependently enhanced the production of N-palmitoylethanolamine from N-palmitoyl-PE in the brain homogenate showing the lysoPLD activity. N-Arachidonoyl-PE and N-arachidonoyl-lysoPE as anandamide precursors were also good substrates of sPLA2-IB and the lysoPLD respectively. These results suggest that the sequential actions of PLA2 and lysoPLD may constitute another biosynthetic pathway for NAEs, including anandamide.

Enzyme system of Clostridium stercorarium for hydrolysis of arabinoxylan: reconstitution of the in vivo system from recombinant enzymes

Microbiology ◽  
2004 ◽  
Vol 150 (7) ◽  
pp. 2257-2266 ◽  
Author(s):  
Helmuth Adelsberger ◽  
Christian Hertel ◽  
Erich Glawischnig ◽  
Vladimir V. Zverlov ◽  
Wolfgang H. Schwarz
Keyword(s):  
Extracellular Enzymes ◽  
Enzyme System ◽  
Thermophilic Bacterium ◽  
Recombinant Enzymes ◽  
Type Mode ◽  
Complete Set ◽  
First Time ◽  
Hydrolysis Of

Four extracellular enzymes of the thermophilic bacterium Clostridium stercorarium are involved in the depolymerization of de-esterified arabinoxylan: Xyn11A, Xyn10C, Bxl3B, and Arf51B. They were identified in a collection of eight clones producing enzymes hydrolysing xylan (xynA, xynB, xynC), β-xyloside (bxlA, bxlB, bglZ) and α-arabinofuranoside (arfA, arfB). The modular enzymes Xyn11A and Xyn10C represent the major xylanases in the culture supernatant of C. stercorarium. Both hydrolyse arabinoxylan in an endo-type mode, but differ in the pattern of the oligosaccharides produced. Of the glycosidases, Bxl3B degrades xylobiose and xylooligosaccharides to xylose, and Arf51B is able to release arabinose residues from de-esterified arabinoxylan and from the oligosaccharides generated. The other glycosidases either did not attack or only marginally attacked these oligosaccharides. Significantly more xylanase and xylosidase activity was produced during growth on xylose and xylan. This is believed to be the first time that, in a single thermophilic micro-organism, the complete set of enzymes (as well as the respective genes) to completely hydrolyse de-esterified arabinoxylan to its monomeric sugar constituents, xylose and arabinose, has been identified and the enzymes produced in vivo. The active enzyme system was reconstituted in vitro from recombinant enzymes.

scholarly journals NH<sub>3</sub>-promoted hydrolysis of NO<sub>2</sub> induces explosive growth in HONO

2018 ◽  
Author(s):  
Wanyun Xu ◽  
Ye Kuang ◽  
Chunsheng Zhao ◽  
Jiangchuan Tao ◽  
Gang Zhao ◽  
...  
Keyword(s):  
North China Plain ◽  
North China ◽  
Ph Value ◽  
Primary Source ◽  
Field Measurements ◽  
Oh Radicals ◽  
The North ◽  
The North China Plain ◽  
First Time ◽  
Hydrolysis Of

Abstract. The study of atmospheric nitrous acid (HONO), which is the primary source of OH radicals, is crucial to atmospheric photochemistry and heterogeneous chemical processes. The heterogeneous NO2 chemistry under haze conditions was pointed out to be one of the missing sources of HONO on the North China Plain, producing sulfate and nitrate in the process. However, controversy exists between various proposed mechanisms, mainly debating on whether SO2 directly takes part in the HONO production process and what roles NH3 and the pH value play in it. In this paper, never before seen explosive HONO production (maximum rate: 16 ppb/hour) was reported and evidence was found for the first time in field measurements during fog episodes (usually with pH > 5) and haze episodes under high relative humidity (usually with pH 

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