38841-15-5Relevant academic research and scientific papers
Polar Metabolites of the Tropical Green Seaweed Caulerpa taxifolia Which Is Spreading in the Mediterranean Sea: Glycoglycerolipids and Stable Enols (α-Keto Esters)
Mancini, Ines,Guella, Graziano,Defant, Andrea,Luz Candenas,Armesto, Cristina P.,Depentori, Daniela,Pietra, Francesco
, p. 1681 - 1691 (2007/10/03)
Examination of the polar components of the green seaweed Caulerpa taxifolia (VAHL) C. AGARDH, which is heavily spreading in the northeastern Mediterranean, led to two families of compounds. The new (2R)-3-O-β-D-galactopyranosyl-1-O-[(7Z,10Z,13Z)-hexadeca-7,10,13-trienoyl]- 2-O-[(9Z,12Z,15Z)-octadeca-1,12,15-trienoyl]-sn-glycerol (2) was isolated in low abundance, like the analogues 1 and 3 already known from freshwater cyanobacteria. The acyl positions in 1-3 were determined by enzymatic methods and the absolute configuration from the O-galactosylglycerol obtained upon alcaline methanolysis. More abundant were the (4-hydroxyphenyl)- and (3,4-dihydroxyphenyl)pyruvic acid methyl esters, occurring in the enol (Z) forms 13a and 14a accompanied by very minor (E) forms 13b and 14b. The latter became predominant on UV irradiation of 13a or 14a, allowing the determination of the C=C configuration of these isolatable, stable enols from 1H,13C NMR couplings (larger H-C(3)/C(1) coupling constant in the (E) than in the (Z) isomer). Contrary to literature implications, the O-galactosylglycerolipids 1-3 lack any cholinergic or histaminergic activity; similarly, enols (= α-keto esters) 13 and 14 or terpenoids of this seaweed were also devoid of such biological activities (see Table).
New enzyme catalyzed synthesis of monoacyl galactoglycerides
Bjoerkling, Fredrik,Godtfredsen, Sven Erik
, p. 2957 - 2962 (2007/12/18)
1-Acyl-3-O-β-d-galactopyranosylglycerides have been prepared by β-galactosidase catalysedtrans-galactosidation of lactose (1) or o-nitrophenyl galactopyranoside (4) with 2,3-epoxypropanol (2) and subsequent opening of the so formed 1-O-β-d-galactopyranosyl-2,3-epoxypropanol (3) with a fatty acid.
STRUCTURAL INVESTIGATIONS OF THE GALACTAN OF THE SNAIL LYMNAEA STAGNALIS
Bretting, Hagen,Jacobs, Guenter,Thiem, Joachim,Koenig, Wilfried A.,Knaap, Wil van der
, p. 201 - 218 (2007/10/02)
A galactan, isolated from the spawn of the snail Lymnaea stagnalis, contained D-galactose and 0.9percent of nitrogen, but neither L-galactose nor phosphate groups.The D20 values of the galactan and its first Smith-degradation product were +19.5 deg and +20 deg, respectively.During each of two consecutive Smith-degradations of the galactan, 1 mol of periodate was consumed and 0.45 mol of formic acid was liberated per mol of "anhydrogalactose" unit.Methylation analyses of the galactan and its first Smith-degradation product yielded equal proportions of 2,3,4,6-tetra-O-methyl- and 2,4-di-O-methyl-galactose.Only small quantities of 2,4,6- 4.9 molpercent) and 2,3,4-tri-O-methylgalactose (0.7 molpercent) were formed from the galactan, whereas the first Smith-degraded product gave 15.6 and 20.4 molpercent, respectively.The product of the second Smith-degradation disintegrated and the following oligosaccharides were identified: β-D-Gal-(1-1)-L-Gro, β-D-Gal-(1-3)-β-D-Gal-(1-1)-L-Gro, β-D-Gal-(1-6)-β-D-Gal-(1-1)-L-Gro, β-D-Gal-(1-6)-D-Gal-β-D-Gal-(1-3)-β-D-Gal-(1-1)-L-Gro, β-D-Gal-(1-3)--β-D-Gal-(1-1)-L-Gro, β-D-Gal-(1-3)-β-D-Gal-(1-3)-β-D-Gal-(1-6)-β-D-Gal-(1-1)-L-Gro, and β-D-Gal-(1-3)-β-D-Gal-(1-3)-β-D-Gal-(1-1)-L-Gro.Thus, the galactan is highly branched with the backbone containing sequences of either exclusively (1-6)-linked or of more or less regularly alterneting (1-3)- and (1-6)-linked units.The side chains vary in length and in the degree of branching.In immunoprecipitin studies, a high degree of species-specificity was seen when various snail galactans were tested with the antiserum to the Lymnaea stagnalis galactan.
