scholarly journals 1-(O-β-Glucosaminyl)-2,3-diglyceride in Bacillus megaterium

1972 ◽  
Vol 126 (3) ◽  
pp. 499-502 ◽  
Author(s):  
P. J. R. Phizackerley ◽  
J. C. MacDougall ◽  
R. A. Moore
Keyword(s):  
Fatty Acids ◽  
Acid Hydrolysis ◽  
Bacillus Megaterium ◽  
Total Lipid ◽  
Alkaline Hydrolysis ◽  
Partial Acid Hydrolysis ◽  
Molar Proportion ◽  
Ester Linkage ◽  
Hydrolysis Of

1. A lipid that contains glucosamine but not phosphorus has been isolated from Bacillus megaterium. It constitutes about 5% of the total lipid glucosaminide in this organism and can be distinguished chromatographically from 2′-(O-β-glucosaminyl)phosphatidylglycerol and 3′-(O-β-glucosaminyl)phosphatidylglycerol, which are also present. 2. The lipid contains glycerol, fatty acids and glucosamine in the molar proportion 1:2:1. The fatty acids are bound by an ester linkage and are similar to those found in other lipids of this organism. Partial acid hydrolysis or alkaline hydrolysis of the lipid yields 1-(O-β-glucosaminyl)glycerol and degradation with nitrite yields 2,5-anhydromannose and diglyceride. 3. The lipid has been identified as 1-(O-β-glucosaminyl)-2,3-diglyceride.

scholarly journals Isomers of glucosaminylphosphatidylglycerol in Bacillus megaterium

1969 ◽  
Vol 114 (2) ◽  
pp. 361-367 ◽  
Author(s):  
J C MacDougall ◽  
P. J. R. Phizackerley
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Clostridium Perfringens ◽  
Phospholipase D ◽  
Bacillus Megaterium ◽  
Sodium Nitrite ◽  
Alkaline Hydrolysis ◽  
The Other ◽  
Partial Acid Hydrolysis ◽  
Ester Linkage

1. The lipids of Bacillus megaterium were extracted and three lipids containing glucosamine were identified. One of these is not a phospholipid, but the other two, which differ in their chromatographic behaviour, contain phosphorus, glycerol, fatty acid and d-glucosamine in the molar proportions 1:2:2:1. 2. In both phosphoglycolipids, the fatty acids are bound in ester linkage, and both yield 2,5-anhydromannose and 3-sn-phosphatidyl-1′-sn-glycerol on treatment with sodium nitrite. 3. Both phosphoglycolipids were N-acetylated and, after removal of fatty acids by mild alkaline hydrolysis, in both cases N-acetylglucosamine was quantitatively released by β-N-acetylhexosaminidase. 4. The glucosaminylglycerols derived from the two phosphoglycolipids by partial acid hydrolysis differ in their behaviour towards periodate. In one case 1 mole of periodate is rapidly consumed/mole of glucosaminylglycerol, but in the other case under identical conditions the consumption of periodate is negligible. 5. The phosphoglycolipids were identified as 1′-(1,2-diacyl-sn-glycero-3-phosphoryl)-3′-O-β-(2-amino-2-deoxy-d-glucopyranosyl)-sn-glycerol and as 1′-(1,2-diacyl-sn-glycero-3-phosphoryl)-2′-O-β-(2-amino-2-deoxy-d-glucopyranosyl)-sn-glycerol. 6. Both phosphoglycolipids are good substrates for phospholipase A: neither is a substrate for phospholipase C from Clostridium perfringens, and only the 3′-glucosaminide is a substrate for phospholipase D.

Kinetic Study of Hydrolysis of Benzoates. Part XXV. Ortho Substituent Effect in Alkaline Hydrolysis of Phenyl Esters of Substituted Benzoic Acids in Water

2006 ◽  
Vol 71 (1) ◽  
pp. 107-128 ◽  
Author(s):  
Vilve Nummert ◽  
Mare Piirsalu ◽  
Vahur Mäemets ◽  
Ilmar Koppel
Keyword(s):  
Acid Hydrolysis ◽  
Alkaline Hydrolysis ◽  
Substituent Effect ◽  
Ethyl Esters ◽  
Benzoic Acids ◽  
Neat Water ◽  
Substituted Benzoic Acids ◽  
Hydrolysis Of Esters ◽  
Hydrolysis Of

The second-order rate constants k2 for alkaline hydrolysis of phenyl esters of meta-, para- and ortho-substituted benzoic acids, X-C6H4CO2C6H5 (X = H, 3-Cl, 3-NO2, 3-CH3, 4-NO2, 4-Cl, 4-F, 4-CH3, 4-OCH3, 4-NH2, 2-NO2, 2-CN, 2-F, 2-Cl, 2-Br, 2-I, 2-CH3, 2-OCH3, 2-CF3, 2-NH2), and of substituted phenyl esters of benzoic acid, C6H5CO2C6H4-X (X = 2-I, 2-CF3, 2-C(CH3)3, 4-Cl, 4-CH3, 4-OCH3, 4-NH2), have been measured spectrophotometrically in water at 25 °C. The substituent effect in alkaline hydrolysis of phenyl esters of para-substituted benzoic acids, similar to that for ethyl esters of para-substituted benzoic acids, was found to be precisely described by the Hammett relationship (ρ = 1.7 in water). The log k value for alkaline hydrolysis of phenyl and ethyl esters of meta-, para- and ortho-substituted benzoic acids, X-C6H4CO2R, was nicely correlated with log km,p,ortho = log ko + (ρ)m,pσ + (ρI)orthoσI + (ρ°R)orthoσ°R + δorthoEsB where σ, σI, σ°R are the Hammett polar, Taft inductive and Taft resonance (σ°R = σ° - σI) substituent constants, respectively. EsB is the steric scale for ortho substituents calculated on the basis of the log k values for the acid hydrolysis of ortho- substituted phenyl benzoates in water owing to the ortho substituent in the phenyl of phenyl benzoates. In water, the main factors responsible for changes in the ortho substituent effect in alkaline hydrolysis of phenyl and ethyl esters of ortho-substituted benzoic acids, X-C6H4CO2R, were found to be the inductive and steric factors while the role of the resonance term was negligible ((ρ°R)ortho ca. 0.3). In alkaline hydrolysis of substituted benzoates in neat water, the ortho inductive effect appeared to be 1.5 times and steric influence 2.7 times higher than the corresponding influences from the ortho position in the phenyl of phenyl benzoates. The contributions of the steric effects in alkaline hydrolysis of esters of ortho-substituted benzoic acids was found to be approximately the same as in acid hydrolysis of esters of ortho-substituted benzoic and acid esterification of ortho-substituted benzoic acids.

Lipids of the fin whale (Balaenoptera physalus) from North Atlantic waters. IV. Fin whale milk

1968 ◽  
Vol 46 (3) ◽  
pp. 197-203 ◽  
Author(s):  
R. G. Ackman ◽  
C. A. Eaton ◽  
S. N. Hooper
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Polyunsaturated Fatty Acids ◽  
Total Lipid ◽  
Iodine Value ◽  
North Atlantic ◽  
Methyl Esters ◽  
Short Chain Fatty Acids ◽  
Fin Whale ◽  
Hydrolysis Of

Fatty acid compositions were determined for total lipid (17.5% of the milk and > 95% triglycerides), 2-monoglyceride obtained by enzymatic hydrolysis of isolated triglyceride, and isolated phospholipid (~1% of total lipids). The total lipid fatty acids of the milk had a composition similar to fin whale depot fat but were enriched in hexadecanoic acid and polyunsaturated fatty acids at the expense of monoethylenic acids; correspondingly the iodine value of 136 (methyl esters) was higher than the normal range (105–120) of North Atlantic fin whale blubber oils. Over 80% of the fatty acids in the 2-position of the triglycerides were accounted for by relatively short chain fatty acids, especially hexadecanoic (54.6%), tetradecanoic (13.7%), and hexadecenoic (11.2%), so that the ester iodine value was only 48. The milk phospholipids had a fatty acid composition basically similar to that of liver phospholipids (methyl ester iodine value 120) with somewhat more polyunsaturated fatty acids and accordingly an iodine value of 144 for methyl esters.

Phosphopeptides Obtained by Partial Acid Hydrolysis of α-Casein2

1957 ◽  
Vol 79 (10) ◽  
pp. 2559-2565 ◽  
Author(s):  
N. J. Hipp ◽  
M. L. Groves ◽  
T. L. McMeekin
Keyword(s):  
Acid Hydrolysis ◽  
Partial Acid Hydrolysis ◽  
Hydrolysis Of

scholarly journals The formation of lipid-linked sugars by cell-free preparations of lactating rabbit mammary gland

1978 ◽  
Vol 170 (3) ◽  
pp. 479-486 ◽  
Author(s):  
D A White
Keyword(s):  
Mammary Gland ◽  
Acid Hydrolysis ◽  
Alkaline Hydrolysis ◽  
Gel Electrophoresis ◽  
Incubation Medium ◽  
Polyacrylamide Gel Electrophoresis ◽  
Protein Fractions ◽  
Exogenous Substrate ◽  
Major Species ◽  
Hydrolysis Of

1. A lactating rabbit mammary-gland microsomal system catalysed the incorporation of mannose from GDP-[U-14C]mannose into three endogenous acceptors, (i) polyprenyl phosphate mannose, (ii) lipid-linked oligosaccharide and (iii) protein. 2. Synthesis of polyprenyl phosphate mannose was stimulated by addition of dolichol phosphate to the incubation medium and was reversed by addition of GDP. The product had properties identical with those of authentic dolichol phosphate mannose. 3. The oligosaccharides derived from acid hydrolysis of the lipid-linked oligosaccharide fraction were of six, eight and nine to ten monosaccharide units, the octasaccharide being the major species formed. The oligosaccharide appeared to be attached to the lipid via a pyrophosphate bridge, since strong alkaline hydrolysis liberated an oligosaccharide phosphate. 4. Polyprenyl phosphate mannose served as a mannose donor to lipid-linked oligosaccharides and protein. When added as exogenous substrate it gave rise to a lipid-linked oligosaccharide of about six units. 5. Incorporation of radioactivity in protein was low, but polyacrylamide-gel electrophoresis of the protein fractions indicated that polypeptides of mol.wts. 115000, 75000 and 33000 were labelled.

SYNTHÈSES DE DÉRIVÉS DE LA LYSINE

1962 ◽  
Vol 40 (8) ◽  
pp. 1626-1631 ◽  
Author(s):  
Louis-Marie Babineau ◽  
Louis Berlinguet
Keyword(s):  
Acid Hydrolysis ◽  
Alkaline Hydrolysis ◽  
Barium Hydroxide ◽  
Primary Amines ◽  
Gaseous Ammonia ◽  
Hydrolysis Of

New N-ε-substituted lysines have been synthetized as follows: by condensing 5-δ-bromobutylhydantoin with different primary amines, 5-δ-alkylaminobutylhydantoins were obtained, the alkaline hydrolysis of which gave the corresponding N-ε-substituted lysines. N-α-Substituted hexahomoserines have also been prepared by acid hydrolysis of the reaction product between α,ε-dihydroxycaproic nitrile and primary amines. 5-Amino-5-carboxypentane sulphonamide has been prepared in the following way: 5-δ-bromobutylhydantoin was reacted with thiourea, and the resulting isothiouronium salt was oxidized with chlorine. Gaseous ammonia was then bubbled through an ethereal suspension of the 5-δ-chlorosulphonyl butylhydantoin and the resulting sulphonamide was hydrolyzed under pressure with barium hydroxide. 5-Amino-5-carboxypentane sulphonamide was then isolated and crystallized.

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