scholarly journals Synthesis and photooxidation of styrene copolymer bearing camphorquinone pendant groups

2012 ◽  
Vol 8 ◽  
pp. 337-343 ◽  
Author(s):  
Branislav Husár ◽  
Norbert Moszner ◽  
Ivan Lukáč
Keyword(s):  
Molecular Weight ◽  
Oxygen Atom ◽  
Benzoyl Peroxide ◽  
Carbonyl Groups ◽  
Synthetic Route ◽  
Weight Changes ◽  
Small Molecular Weight ◽  
Polymer Backbone ◽  
Photochemical Behavior ◽  
Styrene Copolymers

(±)-10-Methacryloyloxycamphorquinone (MCQ) was synthesized from (±)-10-camphorsulfonic acid either by a known seven-step synthetic route or by a novel, shorter five-step synthetic route. MCQ was copolymerized with styrene (S) and the photochemical behavior of the copolymer MCQ/S was compared with that of a formerly studied copolymer of styrene with monomers containing the benzil (BZ) moiety (another 1,2-dicarbonyl). Irradiation (λ > 380 nm) of aerated films of styrene copolymers with monomers containing the BZ moiety leads to the insertion of two oxygen atoms between the carbonyl groups of BZ and to the formation of benzoyl peroxide (BP) as pendant groups on the polymer backbone. An equivalent irradiation of MCQ/S led mainly to the insertion of only one oxygen atom between the carbonyl groups of camphorquinone (CQ) and to the formation of camphoric anhydride (11) covalently bound to the polymer backbone. While the decomposition of pendant BP groups formed in irradiated films of styrene copolymers with pendant BZ groups leads to crosslinking, only small molecular-weight changes in irradiated MCQ/S were observed.

Hemostatically potent small molecular weight serine protease from Maclura spinosa (Roxb. ex Willd.) accelerates healing of subcutaneous dermal wounds in Swiss albino mice

Biologia ◽  
2019 ◽  
Vol 75 (1) ◽  
pp. 139-149
Author(s):  
Venkatesh Bommalapura Kulkarni ◽  
Raghu Ram Achar ◽  
Maheshwari Mahadevappa ◽  
Dinesh Sosalagere Manjegowda ◽  
Priya Babu Shubha ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Serine Protease ◽  
Small Molecular Weight ◽  
Swiss Albino Mice ◽  
Albino Mice

Biosynthesis of the Diguanosine Nucleotides. I. Purification and Properties of an Enzyme from Yolk Platelets of Brine Shrimp Embryos

1974 ◽  
Vol 52 (3) ◽  
pp. 231-240 ◽  
Author(s):  
A. H. Warner ◽  
P. C. Beers ◽  
F. L. Huang
Keyword(s):  
Molecular Weight ◽  
Brine Shrimp ◽  
Artemia Salina ◽  
Temperature Optimum ◽  
Small Molecular Weight ◽  
Ph Optimum ◽  
Optimal Activity ◽  
Purification And Properties

An enzyme that catalyzes the synthesis of P1P4-diguanosine 5′-tetraphosphate (Gp4G) has been isolated and purified from yolk platelets of encysted embryos of the brine shrimp, Artemia salina. The enzyme GTP:GTP guanylyltransferase (Gp4G synthetase) utilizes GTP as substrate, has a pH optimum of 5.9–6.0, a temperature optimum of 40–42 °C, and requires Mg2+ and dithiothreitol for optimal activity. The synthesis of Gp4G is inhibited markedly by pyrophosphate, whereas orthophosphate has no effect on the reaction. In the presence of GDP the enzyme also catalyzes the synthesis of P1,P3-diguanosine 5′-triphosphate (Gp3G), but the rate of synthesis is low compared with Gp4G synthesis and dependent upon other small molecular weight components of yolk platelets.

The role of small molecular weight compounds to increase vacuolation induced by VacA toxin in vitro

2010 ◽  
Vol 24 (5) ◽  
pp. 1373-1378 ◽  
Author(s):  
Juan Sun ◽  
Yan Wu ◽  
Zhuang Su ◽  
Zhifang Liu ◽  
Bingzhong Su ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Small Molecular Weight

Toxicity assessment of the extract of compost as a final product from Bio-Toilet

2006 ◽  
Vol 54 (11-12) ◽  
pp. 421-428 ◽  
Author(s):  
T. Kakimolo ◽  
Y. Imai ◽  
N. Funamizu ◽  
T. Takakuwa ◽  
M. Kunimoto
Keyword(s):  
Molecular Weight ◽  
Water Extract ◽  
Weight Fraction ◽  
Sodium Concentration ◽  
Positive Control ◽  
Small Molecular Weight ◽  
Soil System ◽  
Soil Matrix ◽  
Inorganic Matter ◽  
Bio Assay

Bio-Toilet is the name of a dry closet or composting toilet using sawdust as an artificial soil matrix for bioconversion of human excrement into compost. Since feces and urine contain several chemicals such as pharmaceutical residues and endocrine disruptors and they may still remain in compost after biological reaction in the Bio-Toilet, it is required to examine the possibility of soil and/or groundwater pollution by applying compost to a soil system in farmland. In this study, toxicity of Bio-Toilet compost was evaluated by measuring the viability of human neuroblast (NB-1). The bio-assay was applied to the water extract of compost from the Bio-Toilets which are in practical use in Japan. The assay results showed that (1) the extract of feces showed no toxicity, and the extracts of unused sawdust had no or low level toxicity and (2) the extracts of composts had heavier toxicity than unused sawdust. These results implied that some chemicals that have toxicity were generated by biological reactions or accumulated in toilet system. The bio-assay results with fractionated organic matter by its molecular weight showed that the small molecular weight fraction had stronger toxicity than other fractions. The effect of inorganic matter on toxicity was examined by comparing the dose-response relationship of the extracts of compost with positive control with 1M of sodium chloride solution. The comparison showed that sodium concentration in the extract was too low to develop the toxicity and the effect of inorganic matter could be neglected in this study.

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