A highly convergent and effective synthesis of the phytoalexin elicitor hexasaccharide.

The peracetylated hexasaccharide 1,2,4-tri-O-acetyl-3-O-(2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl)-6- O- (2,3,4-tri-O-acetyl-6-O-(2,4-di-O-acetyl-3,6-di-O-(2,3,4,6-tetra-O-acety l- beta-D-glucopyranosyl)-beta-D-glucopyranosyl)-beta-D-glucopyranosyl)-alp ha, beta-D-glucopyranose 21 was synthesized in a blockwise manner, employing trisaccharide trichloroacetimidate 2,4-di-O-acetyl-3,6-di-O-(2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl)- alpha-D-glucopyranosyl trichloroacetimidate 17 as the glycosyl donor, and trisaccharide 4-O-acetyl-3-O-(2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl)-6-O-(2,3,4 -tri -O-acetyl-beta-D-glucopyranosyl)-1,2-O-(R,S)ethylidene-alpha-D-glucopyra nose 18 as the acceptor. The donor 17 and acceptor 18 were readily prepared from trisaccharides 3-O-(2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl)-6-O-(2,3,4-tri-O-acet yl- 6-O-chloroacetyl-beta-D-glucopyranosyl)-1,2-O-(R,S)ethylidene-alpha-D- glucopyranose 10 and 3,6-di-O-(2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl)-1,2-O-(R,S) ethylidene-alpha-D-glucopyranose 11, respectively, which were obtained from rearrangement of orthoesters 3,4-di-O-acetyl-6-O-chloroacetyl-alpha-D-glucopyranose 1,2-(3-O-(2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl)-1,2-O-(R,S) ethylidene-alpha-D-glucopyranosid-6-yl orthoacetate) 8 and 3,4,6-tri-O-acetyl-alpha-D-glucopyranose 1,2-(3-O-(2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl)-1,2-O-(R,S) ethylidene-alpha-D-glucopyranosid-6-yl orthoacetate) 9, respectively. The orthoesters were prepared from selective coupling of the disaccharide 3-O-(2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl)-1,2-O-(R,S) ethylidene-alpha-D-glucopyranose 4 with 'acetobromoglucose' (tetra-O-acetyl-alpha-D-glucopyranosyl bromide) and 6-O-chloroacetylated 'acetobromoglucose', respectively. To confirm the selectivity of the orthoester formation and rearrangement, the disaccharide 4-O-acetyl-3-O-(2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl)-1,2-O-(R,S ) ethylidene-alpha-D-glucopyranose 7 was prepared from 4 by selective tritylation, acetylation and detritylation. The title compound, an elicitor-active D-glucohexaose 3-O-(beta-D-glucopyranosyl)-6-O-(6-O-(3,6-di-O-(beta-D-glucopyranosyl)-b eta -D-glucopyranosyl)-beta-D-glucopyranosyl)-alpha,beta-D-glucopyranose 1, was finally obtained by Zemplén deacetylation of 21 in quantitative yield.     

Synthesis of some carbamates of myo-inositol.

The syntheses are described of the 1-O-carbamoyl (11), 1-O-carbamoyl-2-O-stearoyl (10), 1-O-(acetylcarbamoyl)-2-O-stearoyl (12), 1-O-(heptylcarbamoyl) (13), 2-O-(heptylcarbamoyl) (14) 1,2-di-O-(heptylcarbamoyl) (15), and 1-O-(octadecylcarbamoyl) (16) derivatives of myo-inositol. None of these compounds had significant activity against phospholipase C.     

Angiotensin converting enzyme inhibitory activity of amino acid esters of carbohydrates

L-alanyl-D-glucose, L-valyl-D-glucose, L-phenylalanyl-D-glucose and L-phenylalanyl-lactose esters were synthesized enzymatically using two lipases viz., Rhizomucor miehei lipase (RML) and porcine pancreas lipase (PPL) and tested for their potential as inhibitors of angiotensin converting enzyme (ACE) in vitro. The esters exhibited concentration related ACE inhibitory activity. The potency of the various esters measured in terms of IC50 values were as follows: L-phenylalanyl-D-glucose, IC50-0.121 mM (mixture of five diastereomeric esters: 6-O-24.1%; 3-O-23.3%; 2-O-19.2%; 2,6-di-O-16.6% and 3,6-di-O-16.8% from the total yield of 92.4%); L-phenylalanyl-lactose, IC50-0.229 mM (mixture of three diastereomeric esters: 6-O-42.1%; 6'-O-30.9%; and 6,6'-di-O-27.0% from the total yield of 50.58%); alanyl-D-glucose, IC50-0.23 mM (mixture of five diastereomeric esters: 6-O-46.7%; 3-O-11.5%; 2-O-19.9%; 2,6-di-O-6.6% and 3,6-di-O-15.3% from the total yield of 26.5%) and L-valyl-D-glucose, IC50-0.396 mM (mixture of five diastereomeric esters: 6-O-32.4%; 3-O-26.5%; 2-O-26.4%; 2,6-di-O-8.8% and 3,6-di-O-5.9% from the total yield of 68.2%). These in vitro data suggest a potential therapeutic role for the aminoesters of carbohydrates as inhibibitors of ACE.     

Neutral liposomes containing crown ether-lipids as potential DNA vectors

Three crown ether derivatives, 1,2-O-dioleoyl-3-O-{2-[(12-crown-4)methoxy]ethyl}-sn-glycerol (12C4L), 1,2-O-dioleoyl-3-O-{2-[(15-crown-5)methoxy]ethyl}-sn-glycerol (15C5L) and 2,3-naphtho-15-crown-5 (NAP5), have been incorporated into 1-palmitoyl-2-oleoyl-phosphatydilcholine (POPC) liposomes. The size of the crown ether and the lipophilic moiety of 12C4L, 15C5L and NAP5 influence the stability and the properties of the extruded POPC liposomes determined at 25 °C in buffered aqueous solution at pH 7.4. The investigated liposomes are zwitterionic for POPC headgroups but can be turned into cationic aggregates in the presence of divalent cations. The capability of these systems to complex DNA has been demonstrated by SAXS experiments.     

虎尾草化学成分研究

从虎尾草Lysimachia barystachys地上部分中分得8个已知黄酮苷类化合物,通过波谱解析其结构分别鉴定为槲皮素(1),山奈酚(2),金丝桃苷(3)、芦丁(4)、3,5,7,3',4'-五羟基黄酮-3-O-(2,6-二-O-α-L-吡喃鼠李糖)-β-D-吡喃半乳糖苷(5),3,5,7,3',4'-五羟基黄酮-7-O-α-L-吡喃鼠李糖-3-O-α-L-吡喃鼠李糖(1-2)-β-D-吡喃葡萄糖苷(6),3,5,7,4'-四羟基黄酮-3-O-(2,6-二-O-α-L-吡喃鼠李糖)-β-D-吡喃半乳糖苷(7),3,5,7,4'-四羟基黄酮-7-O-α-L-吡喃鼠李糖-3-O-α-L-吡喃鼠李糖(1-2)-β-D-吡喃葡萄糖苷(8).这些化合物除3,4外均为首次从该植物中分离得到.     

Characterization and synthesis of mono- and diphytanyl ethers of glycerol

The methanolyzed lipids of the extreme halophile, Halobacterium cutirubrum, were separated into glycerol diether and glycerol monoether fractions. The diether was shown by synthesis to be 2,3-di-O-(3'R,7'R,11'R,15'-tetramethylhexadecyl)-sn-glycerol. The monoether fraction was separated by thin-layer chromatography on boric acid-impregnated silicic acid into about equal amounts of alpha- and -isomers. The alpha-isomer was found to be identical with the synthetic 3-O-(3'R,7'R,11'R,15'-tetramethylhexadecyl)-sn-glycerol, and the -isomer was identical with the synthetic 2-O-(3'R,7'R,11'R,15'-tetramethylhexadecyl) glycerol.     

Anthocyanins from flowers of Cichorium intybus

From the blue perianth segments of Cichorium intybus we isolated four anthocyanins. The pigments were identified as delphinidin 3,5-di-O-(6-O-malonyl-beta-D-glucoside) and delphinidin 3-O-(6-O-malonyl-beta-D-glucoside)-5-O-beta-D-glucoside and the known compounds were delphinidin 3-O-beta-D-glucoside-5-O-(6-O-malonyl-beta-D-glucoside) and delphinidin 3,5-di-O-beta-D-glucoside. In addition 3-O-p-coumaroyl quinic acid has been identified.     

Synthesis of gallotannins

As a contribution to the synthesis of gallotannins, four O-galloyl-D-glucoses (3-O-, 6-O-, 3,6-di-O-, 3,4,6-tri-O-galloyl-D-glucose) have been prepared by the reaction of tri-O-benzylgalloyl chloride and partially protected glucose derivatives (1,2-O-, and 1,2:5,6-di-O-isopropylidene-alpha-D-glucofuranose), followed successively by catalytic debenzylation (Pd-C) and controlled acid hydrolysis. Their structures were established from their behavior on TLC and from their 1H and 13C NMR spectra.     

Synthesis and mass spectra of 4-O-acetyl-1,5-anhydro-2,3,6-tri-O -(methoxycarbonylmethyl)-D-glucitol and the positional isomers of 4- O-acetyl-1,5-anhydro-di-O-(methoxycarbonylmethyl)-O-methyl-D-glucitol and 4-O-acetyl-1,5-anhydro-O-(methoxycarbonylmethyl)-di-O-methyl-D-glucitol .

Reductive cleavage of fully methylated, partially O-carboxymethylated cellulose had previously been shown to produce 4-O-acetyl-1,5-anhydro-2,3,6-tri-O-methyl-, -2-O-(methoxycarbonylmethyl)-3,6-di-O-methyl-, -3-O-(methoxycarbonylmethyl)-2,6-di-O-methyl-, -6-O-(methoxycarbonylmethyl)-2,3-di-O-methyl-, -2,3-di-O-(methoxycarbonylmethyl)-6-O-methyl-, -2,6-di-O-(methoxycarbonylmethyl)-3-O-methyl-, -3,6-di-O-(methoxycarbonylmethyl)-2-O-methyl-, and -2,3,6-tri-O-(methoxycarbonylmethyl)-D-glucitol. Described herein is the independent synthesis of these derivatives, except for the first, which had been reported. In addition, their 1H-n.m.r. spectra, chemical-ionization (NH3) mass spectra, and electronionization mass spectra are tabulated.     

鬼针草中一个新的查耳酮甙

从鬼针草BidenspilosaL .地上部分的丙酮提取物中 ,分离鉴定了 1 8个化合物 ,其中包括一个新的查耳酮甙类化合物 (α,3,2′,4′ tetrahydroxy 2′ O β D glucopyranosylchalcone,2 )。其它化合物分别鉴定为butein (1 ) ,okanin 4 methylether 3′ O β glucoside (3) ,sulfuretin (4) ,6 ,7,3′,4′ tetrahydroxyaurone (5) ,海生菊苷 (maritimein ,6) ,(Z ) 6 O (6″ acetyl β D glucopyr anosyl) 6 ,7,3′,4′ tetrahydroxy aurone (7) ,(Z ) 6 O (4″,6″ diacetyl β D glucopyranosyl) 6 ,7,3′,4′ tetrahydroxy aurone (8) ,(Z ) 6 O (3″,4″,6″ triacetyl β D glucopyranosyl) 6 ,7,3′,4′ tetrahydroxy aurone (9) ,木犀草素 (luteolin ,1 0 ) ,槲皮素 (quercetin,1 1 ) ,异槲皮苷 (iso quercitrin,1 2 ) ,芦丁 (rutin,1 3) ,黄芪苷 (astragalin,1 4 ) ,quercetin 3,4′ dimethylether 7 O rutinoside (1 5) ,反式丁烯二酸 (1 6) ,2 β D glucopyranosyloxy 1 hydroxy trideca 3 ,5,7,9,1 1 pentayne (1 7)和 3 β D glucopyranosyloxy 1 hydroxy 6 (E ) tetradecene 8,1 0 ,1 2 triyne (1 8)。     

Spectroscopic studies of lipids and biological membranes: carbon-13 and proton magic-angle sample-spinning nuclear magnetic resonance study of glycolipid-water systems.

We have obtained 1H and 13C magic-angle sample-spinning (MAS) nuclear magnetic resonance (NMR) spectra of three glycosyldiacylglycerol-water (1:1, weight ratio) mesophases, at 11.7 T, as a function of temperature, in order to probe lipid headgroup, backbone, and acyl chain dynamics by using natural-abundance NMR probes. The systems investigated were monogalactosyldiacyldiglyceride [MGDG; primarily 1,2-di[(9Z,12Z,15Z)octadec-9,12,15-trienoyl++ +]-3-beta-D-galactopyranosyl- sn-glycerol]; digalactosyldiacyldiglyceride [DGDG; primarily 1,2-di[(9Z,12Z,15Z)octadec-9,12,15-trienoyl++ +]-3- (alpha-D-galactopyranosyl-1-6-beta-D-glactopyranosyl)-sn-glycerol] ; and sulfoquinovosyldiacyldiglyceride [SQDG; primarily 1-[(9Z,12Z,15Z)octadec-9,12,15-trienoyl]-2 -hexadecanoyl-3-(6-deoxyl-6- sulfono-alpha-D-glucopyranosyl)-sn-glycerol]. At approximately 22 degrees C, all three lipid-water systems give well-resoled 13C and 1H MAS NMR spectra, characteristic of fluid, liquid-crystalline mesophases. 13C spin-lattice relaxation times of the headgroup and glycerol backbone carbons of all three materials give, within experimental error, the same NT1 values (approximately 400 ms), implying similar high-frequency motions, independent of headgroup size and charge. Upon cooling, pronounced line broadenings are observed, due to an increase in slow motional behavior. For each lipid, the onset of line broadening is seen with the glycosyl headgroup, glycerol backbone, and the first two or three carbons of the acyl chains. By approximately -20 degrees, all headgroup carbon resonances are broadened beyond detection. Both galactose moieties in DGDG "freeze out" together, implying a rigid-body motion of the disaccharide unit. Upon further cooling, the bulk polymethylene chain resonances in all three systems (in both 13C and 1H MAS) broaden greatly, followed by the olefinic and allylic carbon resonances.(ABSTRACT TRUNCATED AT 250 WORDS)     

Synthesis of 4-substituted phenyl 3,6-anhydro-1,3-dithio-D-glucofuranosides and -pyranosides as well as 2,6-anhydro-1,2-dithio-alpha-D-altrofuranosides possessing antithrombotic activity

1,2,5-Tri-O-acetyl-3,6-anhydro-3-thio-D-glucofuranose was synthesised starting from D-glucose and was used as a donor for the glycosidation of 4-cyano- and 4-nitrobenzenethiol. In the latter reaction, besides an anomeric mixture of the 4-nitrophenyl 2,5-di-O-acetyl-3,6-anhydro-1,3-dithio-D-glucofuranosides, the corresponding 2,6-anhydro-1,2-dithio-D-altrofuranosides were also obtained, formed via a rearrangement of the sugar moiety. A similar rearrangement could be observed during the hydrolysis of the glycosidic bond of methyl 3,6-anhydro-2,4-di-O-(4-nitrobenzoyl)-3-thio-alpha-D-glucopyranoside with aqueous trifluoroacetic acid, affording after acetylation besides 1-O-acetyl-3,6-anhydro-2,4-di-O-(4-nitrobenzoyl)-3-thio-alpha-D-glucopyranose (32alpha), 1,1,5-tri-O-acetyl-3,6-anhydro-2,4-di-O-(4-nitrobenzoyl)-3-thio-D-glucose, methyl 3,6-anhydro-2,4-di-O-(4-nitrobenzoyl)-3-thio-beta-D-glucopyranoside and 1,5-di-O-acetyl-2,6-anhydro-3-O-(4-nitrobenzoyl)-2-thio-alpha-D-altrofuranose (40). Glycosidation of 4-cyanobenzethiol with 32alpha in the presence of trimethylsilyl triflate as promoter afforded 4-cyanophenyl 3,6-anhydro-2,4-di-O-(4-nitrobenzoyl)-1,3-dithio-beta-D-glucopyranoside as a minor component only, besides 4-cyanophenyl 3,6-anhydro-2-S-(4-cyanophenyl)-4-O-(4-nitrobenzoyl)-1,2,3-trithio-beta-D-glucopyranoside. When boron trifluoride etherate was used as promoter in the reaction of 32alpha with 4-cyano- and 4-nitrobenzenethiol, the corresponding beta-thioglycosides were obtained, while 40 gave under identical conditions the alpha anomers exclusively. All thioglycosides obtained after deacylation were submitted to biological evaluation. Among these glycosides, the 4-cyanophenyl 3,6-thioanhydro-1,3-dithio-D-glucofuranoside possessed the strongest oral antithrombotic effect.     

Neuroprotective phenylpropanoid esters of rhamnose isolated from roots of Scrophularia buergeriana

Four phenylpropanoid esters of rhamnose, buergerisides A1, B1, B2 and C1 were isolated from roots of Scrophularia huergeriana MIQ. (Scrophulariaceae), and were characterized as 2-O-acetyl-3,4-di-O-(E)-p-methoxycinnamoyl-alpha-L-rhamnopyranosid e, 2-O-acetyl-3-O-(E)-p-methoxycinnamoyl-alpha-L-rhamnopyranoside, 2-O-acetvl-3-O-(Z)-p-methoxycinnamoyl-alpha-L-rhamnopyranosi de and 4-O-(E)-p-methoxycinnamoyl-alpha-L-rhamnopyranoside, respectively. In addition, six known phenylpropanoids were authenticated as: (E)-cinnamic acid, (E)-p-methoxycinnamic acid, (E)-p-methoxycinnamic acid methyl ester, (E)-p-coumaric acid, (E)-caffeic acid, (E)-ferulic acid and a phenylalcohol, 2-(3-hydroxy-4-methoxyphenyl)ethanol. These ten phenylpropanoids all attenuated glutamate-induced neurotoxicity when added to primary cultures of rat cortical cells in a dose-dependent manner. These results demonstrate that phenylpropanoids isolated from S. buergeriana may exert significant protective effects against glutamate-induced neurodegeneration in primary cultures of cortical neurons.     

Characterization of five isomers of branched cyclomaltoheptaose (beta CD) having degree of polymerization (d.p.) = 9: Reinvestigation of three positional isomers of diglucosyl-beta CD.

It has been confirmed by methylation analyses and chemical syntheses that three isomers of branched cyclomaltoheptaose (beta CD) isolated from the mother liquors of a large-scale preparation of beta CD with Bacillus ohbensis cyclomaltodextrin glucanotransferase are 6(1),6(4)-di-O-(alpha-D-glucopyranosyl)-cyclomaltoheptaose (1), 6(1),6(3)-di-O-(alpha-D-glucopyranosyl)-cyclomaltoheptaose (2), and 6-O-(alpha-isomaltosyl)-cyclomaltoheptaose (4) instead of 6(1),6(2)-di-O-(alpha-D-glucopyranosyl)-cyclomaltoheptaose (3), which was erroneously characterized in an earlier paper. Compound 3 has been newly isolated from a glucosyl-beta CD mixture prepared by hydrolysis with glucoamylase of a maltosyl-beta CD mixture, synthesized from maltose and beta CD through the reverse action of pullulanase. Chromatographic behavior and spectral data (13C-n.m.r. and f.a.b.-m.s.) of these isomers of branched beta CD (1-4), as well as those of another isomer prepared by the reverse action of hydrolytic enzymes, 6-O-(alpha-maltosyl)-cyclomaltoheptaose (5), were compared.     

野桂花化学成分研究

从野桂花（Osmanthus yunnanensis）地上部分95％乙醇提取物中首次分离得到18个化合物,应用波谱方法及与已知品对照的手段鉴定它们为：E-阿魏酸二十烷基酯（1）、β-谷甾醇（2）、羽扇豆醇（3）、齐墩果酸（4）、7-oxo-β—sitosterol（5）、乙酰齐墩果酸（6）、（6＇-O－palmitoyl）－sitosterol-3-O-β—D—glucoside（7）、rotundioic acid（8）、地榆糖甙II（9）、3β-hydroxy－27-p－（E）－eoumaroyloxyolean－12－en-28－oicacid（10）、3β—laydroxy-27-p－（Z）－coumaroyloxy－olean－12－en-28-oicacid（11）、hycandinic acid ester（12）、绿原酸丁酯（13）、4,5-二咖啡酰奎尼酸丁酯（14）、28-O-β-D—glueopyranosyl rottmdioic acid（16）以及三个半萜类化合物：4,5-dihydroxyprenyl caffeate（15）、4-（6-O-caffeoyl -β-D—glucopyranosyloxy）-5-hydroxyprenyl caffeate（17）、4-β-D—glucopyranosyloxy5-hydroxyprenyl caffeate（18）。     

Phenolic derivatives from Ruprechtia polystachya and their inhibitory activities on the glucose-6-phosphatase system

Two new compounds, 5-methyl-2-(2-methylbutanoyl)phloroglucinol 1-O-(6-O-β-D-apiofuranosyl)-β-D-glucopyranoside (1) and trans-2,3-dihydrokaempferol 3-O-(4-O-sulfo)-α-L-arabinopyranoside (2), together with 14 known flavonoids, trans-dihydrokaempferol 3-O-α-L-arabinopyranoside (3), trans-taxifolin 3-O-α-L-arabinofuranoside (4), quercetin 3-O-α-L-rhamnopyranoside (5), quercetin 3'-O-α-L-arabinofuranoside (6), catechin 3-O-α-L-rhamnopyranoside (7), trans-taxifolin 3-O-α-L-arabinopyranoside (8), cis-dihydrokaempferol 3-O-α-L-arabinopyranoside (9), catechin (10), myricetin 3-O-α-L-rhamnopyranoside (11), quercetin 3-O-α-L-arabinopyranoside (12), quercetin 3-O-α-L-arabinofuranoside (13), quercetin 3-O-(3″-galloyl)-α-L-rhamnopyranoside (14), quercetin 3-O-(2″-galloyl)-α-L-rhamnopyranoside (15), and epicatechin 3-O-gallate (16), were isolated from the leaves of Ruprechtia polystachya Griseb. (Polygonaceae). Their structures were established on the basis of extensive 1D- and 2D-NMR experiments as well as MS analyses. All compounds, except 1, showed inhibition of the enzyme glucose-6-phosphatase in intact microsomes.     

A precursor to the beta-pyranosides of 3-amino-3,6-dideoxy-D-mannose (mycosamine).

SN2-type reaction of 3-O-(1-imidazyl)sulfonyl-1,2:5,6-di-O-isopropylidene-alpha-D-gluco furanose with benzoate gave the 3-O-benzoyl-alpha-D-allo derivative 2, which was hydrolysed to give the 5,6-diol 3. Compound 3 was converted into the 6-deoxy-6-iodo derivative 4 which was reduced with tributylstannane, and then position 5 was protected by benzyloxymethylation, to give 3-O-benzoyl-5-O-benzyloxymethyl-6-deoxy-1,2-O-isopropylidene-alpha -D- allofuranose (6). Debenzoylation of 6 gave 7, (1-imidazyl)sulfonylation gave 8, and azide displacement gave 3-azido-5-O-benzyloxymethyl-3,6-dideoxy- 1,2-O-isopropylidene-alpha-D-glucofuranose (9, 85%). Acetolysis of 9 gave 1,2,4-tri-O-acetyl-3-azido-3,6-dideoxy-alpha,beta-D-glucopyranose (10 and 11). Selective hydrolysis of AcO-1 in the mixture of 10 and 11 with hydrazine acetate (----12), followed by conversion into the pyranosyl chloride 13, treatment with N,N-dimethylformamide dimethyl acetal in the presence of tetrabutylammonium bromide, and benzylation gave 3-azido-4-O-benzyl-3,6-dideoxy-1,2-O-(1-methoxyethylidene)-alpha-D -glucopyranose (15). Treatment of 15 with dry acetic acid gave 1,2-di-O-acetyl-3-azido-4-O-benzyl-3,6-dideoxy-beta-D-glucopyranose (16, 86% yield) that was an excellent glycosyl donor in the presence of trimethylsilyl triflate, allowing the synthesis of cyclohexyl 2-O-acetyl-3-azido-4-O-benzyl-3,6-dideoxy-beta-D-glucopyranoside (17, 90%).(ABSTRACT TRUNCATED AT 250 WORDS)     

On the relationship between glycerophosphoglycolipids and lipoteichoic acids of gram-positive bacteria. III. Di(glycerophospho)-acylkojibiosyldiacylglycerol and related compounds from Streptococcus lactis NCDO 712.

1. Streptococcus lactis NCDO 712 contains at lease three unusually polar glycerophosphoglycolipids. One of them was composed of D-glucose, glycerol, fatty acid ester, and phosphorus in the molar ratio of approx. 2 : 3 : 3 : 2. The structure was established as 1,2-di-O-acyl-3-O-[6-(sn-glycero-1-phospho-3-sn-glycero-1-phospho)-alpha-D-glucopyranosyl-(1 leads to 2)-(6-O-acyl-alpha-D-glucopyranosyl)]-glycerol. 2. The second glycerophosphoglycolipid was shown to have the same core structure but is lacking the carbohydrate-linked fatty acid. The third glycero-phosphoglycolipid is a glycosylated derivative of the first one bearing an alpha-galactosyl residue at position 2 of the inner glycolipid-linked glycerophosphate moiety. 3. These novel phosphoglycolipids are considered to be the so far missing link between simple glycerophosphoglycolipids and lipoteichoic acids of Gram-positive bacteria.     

A New Acylated Anthocyanin from the Red Flowers of Camellia hongkongensis and Characterization of Anthocyanins in the Section Camellia Species

Twelve anthocyanins (1-12) were isolated from the red flowers of Camellia hongkongensis Seem. by chromatography using open columns. Their structures were elucidated on the basis of spectroscopic analyses, that is, proton-nuclear magnetic resonance, carbon 13-nuclear magnetic resonance, heteronuclear multiple quantum correlation, heteronuclear multiple bond correlation, high resolution electrospray ionization mass and ultraviolet visible spectroscopies. Out of these anthocyanins, a novel acylated anthocyanin, cyanidin 3-O-(6-O-(Z)-p-coumaroyl)-β-galactopyranoside (6), two known acylated anthocyanins, cyanidin 3-O-(6-O-(E)-p-coumaroyl)-β-galactopyranoside (7) and cyanidin 3-O-(6-O-(E)-caffeoyl)-β-galactopyranoside (8), and three known delphinidin glycosides (10-12) were for the first time isolated from the genus Camellia. Furthermore, pigment components in C. japonica L., C. chekiangoleosa Hu and C. semiserrata Chi were studied.The results indicated that the distribution of anthocyanins was differed among these species. Delphinidin glycoside was only detected in the flowers of C. hongkongensis, which is a special and important species in the section Camellia. Based on the characterization of anthocyanins in the section Camellia species, there is a close relationship among these species,and C. hongkongensis might be an important parent for creating new cultivars with bluish flower color.     

Cholesterol interactions with tetracosenoic acid phospholipids in model cell membranes: role of the double-bond position

The synthesis and thermotropic properties of 1,2-di-(9Z)-9-tetracosenoylphosphatidylcholine [delta 9-PC(24:1,24:1), 1], 1,2-di-(5Z)-5-tetracosenoylphosphatidylcholine [delta 5-PC(24:1,24:1), 2], and 1,2-di-(15Z)-15- tetracosenoylphosphatidylcholine [delta 15-PC(24:1,24:1), 3] are reported. Liposomes prepared from these phospholipids differ from those of the natural sponge phospholipids, 1,2-di-(5Z,9Z)-5,9-hexacosadienoylphosphatidylcholine (4a) and the corresponding ethanolamine (4b), both of which virtually exclude cholesterol from their bilayers. The behavior of 1 and 2 is similar to that of 1,2-di-(6Z,9Z)-6,9-hexacosadienoylphosphatidylcholine (5), which exhibits a partial molecular interaction with cholesterol. In the case of 3, cholesterol appears to interact with the saturated acyl chain regions of this phospholipid in a manner similar to that of its interaction with DPPC acyl chains. This study delineates the effect of the double-bond location in long fatty acyl chains of phospholipids on their interactions with cholesterol.