Seisuke Ito

Comparative Composition of Brown Rice Lipids (Lipid Fractions) of Indica and Japonica Rices

The brown rice lipids were analyzed from three japonica and two indica rices. They had substantially no difference in the ratio of NL, GL, and PL, the C16/C18 (16:0/the sum of 18:0, 18:1, 18:2, and 18:3) ratio in PL classes, and in the order of unsaturated index in each glycerolipid class among the five varieties. However, the chemical compositions of glyceroglycolipids and cerebroside were different in indica and japonica rices. The contents of 18:3 of MGDG and DGDG were higher in japonica than indica rices, but those of 16:0 were reversed. The ratio of C14-20/C21-26 of the hydroxy fatty acids in cerebroside was 1.18 in japonica and 0.62 in indica rices. Furthermore, the ratio of the trihydroxy sphingoid bases to dihydroxy ones showed a great difference between the subspecies. Unsaturated fatty acid contents in the TG and PL classes were largely different from each other among japonica rices harvested in separate districts.

Characterization of acylmono-, mono-, di-, tri- and tetraglycosylsterol and saponin in Adzuki bean (Vigna angularis) seeds

Five sterylglycosides (acylmono-, mono-, di tri- and tetraglycosylsterol) and a saponin were isolated from Adzuki beans and characterized. In the glycosylsterols, the principal component sterols were sitosterol and stigmasterol; the major sugar component was glucose. The glucose units were shown to be linked by β1,6-bonds. The three oligoglycosylsterols were shown to be gentiobiosylsterol, gentiotriosylsterol and gentiotetraosylsterol; the latter two are novel sterylglycosides. The saponin was identified as glucopyranosyl-(β1→2)-glucopyranurosyl-(β1→3′)-soyasapogenol B (Azukisaponin I) which had previously been found in Adzuki beans.

Further studies on sphingolipids in wheat grain

The principal molecular species of sphingolipids in wheat grain were confirmed to beN-2′-hydroxylignoceroyl-4-hydroxysphinganine for ceramide, and 1-O-β-glucosyl-, 1-O-[β-mannosyl(1→4)-O-β-glucosyl]-, 1-O-[β-mannosyl(1→4)-O-β-mannosyl(1→4)-O-β-glucosyl]-and 1-O[β-mannosyl(1→4)-O-β-mannosyl(1→4)-O-β-mannosyl(1→4)-O-β-glucosyl]-N-2′-hydroxypalmitoyl (or hydroxyarachidoyl)-cis-8-sphingenine for mono-, di-, tri- and tetraglycosylceramide, respectively. A novel glycolipid, cellobiosylceramide, was found as the minor diglycosylceramide; the major species was characterized to be 1-O-[β-glucosyl(1→4)-O-β-glucosyl]-N-2′-hydroxypalmitoyl (or hydroxyarachidoyl)-cis-8-sphingenine. It was observed in these sphingolipids that the dihydroxy bases were combined mainly with C16 and C20 acids, whereas the trihydroxy bases combined mostly with acids of chain length of 20 or more.

Effects of growth temperature on lipids of Adzuki bean cells

Abstract Suspension cultures of cells of Adzuki bean (Vigna angularis) , a chilling-sensitive species, that had been maintained at 3° for 2 days exhibited the same sensitivity to freezing-damage as similar cultures maintained at 24°. In general, in chilling-resistant plants, acclimation increases the relative amounts of phospholipids and decreases those of sterols in membranes. Moreover, the phospholipids of acclimated cells have a higher percentage of unsaturated fatty acyl chains than those of control cells. In Adzuki bean cells grown at low temperature the concentrations of highly unsaturated glyceroglycolipids were slightly elevated but the relative amounts of stigmasterol was conspicuously elevated in all classes of sterols. No significant changes in cerebroside species were detected.

Two diglycosyldiacylglycerol isomers in plant leaves, ferns, mosses and seaweeds

Abstract Diglycosyldiacylglycerols (DGDGs) were isolated from leaves of 35 vascular plants, seven ferns, three mosses and five marine algae, and their glycosidic structures determined. A novel DGDG isomer [Gal(β1 → 6)-Gal(β1 → 3′)-diacylglycerol (DG)], which had been previously found in Adzuki beans ( Vigna angularis ), was found to be present in six angiosperms, six gymnosperms, two ferns, all mosses examined and two marine algae, along with large amounts of the well-known DGDG isomer [Gal(α1→6)-Gal(β1→3′)-DG]. Because significant amounts (5–8%)of the novel isomer were found in leaves of the conifers Pinus nigra, P. mugo, Abies sachalinensis and Thuja occidentalis , as in ferns, the component 1,2-DG residues in two DGDG isomers and the monoglycosyldiacyl-glycerols (MGDGs), were determined. The molecular species compositions, based on the fatty acid combination, of the novel DGDG isomers and MGDG were roughly similar in all of the plants examined, but were somewhat different from that of the well-known DGDG isomers, although the most abundant species was commonly 18:3-18: 3. The DG species of the novel DGDG isomers were highly unsaturated, 16:3–18:3 or 18:3–18:4 being the principal types. There DG species are minor components in the DGDGs.

Changes in molecular species of glycerolipids from developing Vigna angularis seeds

Abstract The molecular species of six glycerolipids, triacylglycerol (TG), monoglycosyldiacylglycerol (MGDG), diglycosyldiacylglycerol (DGDG), phosphatidylethanolamine (PE), phosphatidylcholine (PC) and phosphatidylinositol (PI) of developing Adzuki bean seeds were studied. The amounts of the six glycerolipids increased gradually until 40 days after flowering, and thereafter decreased. During seed development, the major molecular species of TG were palmitoyllinoleoyllinolenin, palmitoyldilinolenin, dilinoleoyllinolenin, palmitoyldilinolenin and linoleoyldilinolenin. The major molecular species of the diacylglycerol residue in PC, PE and PI were palmitoyllinolein, dilinolein, palmitoyllinolenin and their relative proportions differed slightly. The percentages of the molecular species in TG, PE, PC and PI during seed development varied slightly, while those of MGDG and DGDG varied sharply from 40 to 50 days after flowering.

Cerebrosides in Seed-Plant Leaves: Composition of Fatty Acids and Sphingoid Bases

Cerebroside (monoglycosylceramide) is a major lipid class in plasma membranes and tonoplasts of several plant species [1,2]. It has been reported that cerebrosides would set the phase transition temperature of lipids in plasma membranes and tonoplasts, which has proposed a possible mechanism of chilling injury of plants [3]. In addition, changes of cerebroside content in plasma membranes after acclimation to cold stress [2] and water-deficit stress [4] were reported. These findings have suggested that cerebroside may play physiological roles in plasma membranes and tonoplasts. In this communication, we report the composition of fatty acids and sphingoid bases in cerebrosides from leaves of various seed-plants for primarily discussing whether the apparent correlation of cerebroside composition with chilling sensitivity.

Steryl Glycoside in Alfalfa Leaves

Steryl glycoside was isolated and purified from alfalfa leaves to be analyzed for constituent sterol and sugar. The major component sterols were β-sitosterol as well as stigmasterol and the component sugar was only glucose, suggesting that the typical molecular species of steryl glycoside in alfalfa leaves are β-sitosteryl glucoside and stigmasteryl glucoside.

Glycolipids of bovine milk

1. 牛乳の代表的な糖脂質として,セラミドモノヘキソシドとセラミドジヘキソシドを単離し,それぞれの構成分を調べた.2. 脂肪酸については両者の間に差がなく,どちらもC23:0, C24:0, C22:0およびC16:0の脂肪酸が主成分であった.3. 構成糖としては,セラミドモノヘキソシドにグルコース1分子,セラミドジヘキソシドにグルコースとガラクドース各1分子が含まれていた.4. スフィンゴシン塩基としては,CMHもCDHもともにC16-スフィンゴシン,C16-ジヒドロスフィンゴシン,C17-スフィンゴシン,16-メチル-C17-スフィンゴシン,C18-スフィンゴシンおよびC18-ジヒドロスフィンゴシンを含み,そのなかでC18-スフィンゴシンの量第がもっとも多かった.

Sphingomyelin in Cow's Milk

(1) 牛乳から純粋なスフィンゴミエリンを単離し,その脂肪酸と長鎖塩基の組成を調べた. (2) 牛乳スフィンゴミエリンの構成脂肪酸として,C12からC24までの19種が検出された.その大部分は長鎖の飽和脂肪酸で,そのうちで主なものは多い方から順に,C23:0,C22:0,C24:0,C16:0であった. (3) 牛乳スフィンゴミエリンを構成する長鎖塩基として,多い方から順に,C18-スフィンゴシン,C16-スフィンゴシン,16-メチル-C17-スフィンゴシン,C16-ジヒドロスフィンゴシン,C17-スフィンゴシン,C18-ジヒドロスフィンゴシン,および多分17-メチル-C18-スフィンゴシンの7種が検出された.そのうち,C18-スフィンゴシンとC16-スフィンゴシンが全塩基の過半を占めていた.