Synthesis and Properties of Substituted Germylhydrazines

1972 ◽  
Vol 50 (4) ◽  
pp. 553-561 ◽  
Author(s):  
L. K. Peterson ◽  
K. I. Thé
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Degree Of Substitution ◽  
Spectral Measurements ◽  
Mass Spectral ◽  
High Molecular Weight Compound ◽  
Condensed Product ◽  
New Compounds

By using reactions between Me3GeBr or Me2GeCl2 and appropriate lithium hydrazide salts, the following new compounds were prepared: Me2NN(R)GeMe3 (R = H, 1; Me, 2; GeMe3, 3; SiMe3, 4), Me3GeN(Me)NHGeMe3, 5a, MeNHN(GeMe3)2, 5b, (Me3Ge)2NN(Me)GeMe3, 6, Me3GeNHNHGeMe3, 7a, (Me3Ge)2NNH2, 7b, (Me)11Ge4N6H, 11, (Me2GeNNMe2)3, 12, Me2Ge[N(R′)NMe2]2 (R′ = Me, 13; SiMe3, 14). Thus the reaction of Me3GeBr with Li(MeN2H2) and with LiN2H3 gave mixtures of disubstituted isomers, 5a and b, and 7a and b, respectively, rather than mono-substituted derivatives. Reactions of Me2GeCl2 gave (i) an unresolvable, highly condensed product with LiN2H3; (ii) the high molecular weight compound 11, with Li(MeN2H2); and (iii) the cyclic trigermazane 12 with Me2NNHLi; the extent of self-condensation is a function of the degree of substitution of the hydrazine moiety. Reactions with protic reagents (H2O, MeOH, anhydrous HCl) effect cleavage of the Ge—N bond in germylhydrazines. New compounds were characterized on the basis of i.r., n.m.r., and mass spectral measurements.

scholarly journals Cutinase-Like Enzyme from the Yeast Cryptococcus sp. Strain S-2 Hydrolyzes Polylactic Acid and Other Biodegradable Plastics

2005 ◽  
Vol 71 (11) ◽  
pp. 7548-7550 ◽  
Author(s):  
Kazuo Masaki ◽  
Numbi Ramudu Kamini ◽  
Hiroko Ikeda ◽  
Haruyuki Iefuji
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Polylactic Acid ◽  
Biodegradable Plastics ◽  
Remote Homology ◽  
High Molecular Weight Compound ◽  
Polybutylene Succinate

ABSTRACT A purified lipase from the yeast Cryptococcus sp. strain S-2 exhibited remote homology to proteins belonging to the cutinase family rather than to lipases. This enzyme could effectively degrade the high-molecular-weight compound polylactic acid, as well as other biodegradable plastics, including polybutylene succinate, poly (ε-caprolactone), and poly(3-hydroxybutyrate).

SOME FACTORS AFFECTING THE KÖNIGS–KNORR SYNTHESIS OF GLYCOSIDES

1961 ◽  
Vol 39 (10) ◽  
pp. 2025-2034 ◽  
Author(s):  
H. R. Goldschmid ◽  
A. S. Perlin
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Silver Oxide ◽  
Condensation Reaction ◽  
Side Reaction ◽  
Ortho Ester ◽  
Factors Affecting ◽  
High Molecular Weight Compound ◽  
Elemental Iodine

Glycosyl halides decompose readily in the presence of silver oxide under conditions generally used for the Königs–Knorr synthesis of glycosides. This "side reaction" probably accounts for the low yields commonly obtained in the synthesis of oligosaccharides, particularly those involving the formation of a glycosidic union through an unreactive secondary position. The rate of the side reaction, as well as that of the normal condensation reaction, is dependent on the condition of the silver oxide, and is retarded markedly by elemental iodine. This latter effect appears to be related to the improved yield obtained in Königs–Knorr syntheses when iodine is used. Among the products formed in the decomposition of 2,3,4,6-tetra-O-acetyl-α-D-mannopyranosyl bromide are 2,3,4,6-tetra-O-acetyl-D-mannose, a heptaacetyl 1,2,1′-linked dimeric orthoacetate, and a second high-molecular-weight compound that also shows ortho ester properties.

scholarly journals Marine Carbohydrate-Based Compounds with Medicinal Properties

2018 ◽  
Author(s):  
Ariana Vasconcelos ◽  
Vitor Pomin
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Structural Properties ◽  
Therapeutic Potential ◽  
Marine Species ◽  
Antimicrobial Activities ◽  
Chemical Diversity ◽  
Biological Functions ◽  
Medicinal Properties ◽  
New Compounds

The oceans harbor a great diversity of organisms, and have been recognized as an important source of new compounds with nutritional and therapeutic potential. Among these compounds, carbohydrate-based compounds are of particular interest because they exhibit numerous biological functions associated with their chemical diversity. This gives rise to new substances for the development of bioactive products. Many are the known applications of substances with glycosidic domains obtained from marine species. This review covers the structural properties and the current findings on the antioxidant, anti-inflammatory, anticoagulant, antitumor and antimicrobial activities of medium and high molecular-weight carbohydrates or glycosylated compounds extracted from various marine organisms.

Mechanochemical processes accompanying metal grinding in the presence of a high-molecular-weight compound

2012 ◽  
Vol 445 (2) ◽  
pp. 138-140 ◽  
Author(s):  
V. P. Reva ◽  
D. V. Onishchenko ◽  
V. V. Chakov ◽  
B. A. Voronov
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
High Molecular Weight Compound

Microtubule motors and other maps

1990 ◽  
Vol 48 (3) ◽  
pp. 1-1
Author(s):  
Richard B. Vallee
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Cytoplasmic Dynein ◽  
Organelle Transport ◽  
Structural Components ◽  
Microtubule Associated Proteins ◽  
Microtubule Motors ◽  
Associated Proteins ◽  
The Subject ◽  
Intracellular Motility

Microtubules are involved in a number of forms of intracellular motility, including mitosis and bidirectional organelle transport. Purified microtubules from brain and other sources contain tubulin and a diversity of microtubule associated proteins (MAPs). Some of the high molecular weight MAPs - MAP 1A, 1B, 2A, and 2B - are long, fibrous molecules that serve as structural components of the cytamatrix. Three MAPs have recently been identified that show microtubule activated ATPase activity and produce force in association with microtubules. These proteins - kinesin, cytoplasmic dynein, and dynamin - are referred to as cytoplasmic motors. The latter two will be the subject of this talk.Cytoplasmic dynein was first identified as one of the high molecular weight brain MAPs, MAP 1C. It was determined to be structurally equivalent to ciliary and flagellar dynein, and to produce force toward the minus ends of microtubules, opposite to kinesin.

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