A new ceramide from the basidiomycete Russula cyanoxantha

A new phytosphingosine-type ceramide (1) was isolated along with nine other compounds—5α,8α-epidioxy-(22E,24R)-ergosta-6,22-dien-3β-ol, 5α,8α-epidioxy-(24S)-ergosta-6-en-3β-ol, (24S)-ergosta-7-ene-3β,5α,6β-triol,(22E,24R)-ergosta-7, 22-dien-3β,5α,6β-triol, inosine, adenine, l-pyroglutamic acid, fumaric acid, and d-allitol from the ethanol and chloroform/methanol extract of the fruiting bodies of the basidiomycete Russula cyanoxanotha (Schaeff.) Fr. The structure of (1) was established as (2S,3S,4R,2′R)-2-(2′-hydroxytetracosanoylamino) octadecane-1,3,4-triol by means of spectroscopic and chemical methods.     

A new glucoceramide from the watermelon begonia, <Emphasis Type="Italic">Pellionia repens</Emphasis>

A new glucoceramide named pellioniareside (1) was isolated from the aqueous ethanolic extract of whole plants of Pellionia repens, together with lupeol (2), uracil (3), (22E,20S,24R)-5α,8α-epidioxyergosta-6,22-dien-3-β-ol (4), and daucosterol (5). The structure and relative configurations of pellioniareside were identified as (2S,3S,4R,6E,8E)-1-O-β-d-glucopyranosyl-2-[(2R)-2-hydroxytetracosanoylamino]-1,3,4-octadecanetriol-6,8-diene by analysis of spectral data and by chemical evidence.     

Bornane with integrated push–pull butadienes

The {3-[bis(alkylthio)methylene]-1,7,7-trimethyl-bicyclo[2.2.1]hept-2-ylidene}malononitriles ((1R,4S)- 2 , (1S,4R)- 2 and (1R,4S)- 3 ) were prepared starting from 1,7,7-trimethyl-bicyclo[2.2.1]hept-2-ylidenemalononitriles (1R, 4R)- 1 and (1S,4S)- 1 ) arisen from (+)-, (–)-camphor. The reaction of (1R,4S)- 2 with bromine yielded the (1S,8R)-8,11,11-trimethyl-3-methylthio-5-oxo-4-thiatricyclo-[6.2.1.0^2,7]undeca-2,6-diene-6-carbonitrile ( 8 ) after hydrolysis of the initially formed (1S,8R)-6-cyano-8,11,11-trimethyl-3-methylthio-4-thia-tricyclo[6.2.1.0^2,7]undeca-2,6-diene-5-iminium bromide ( 7 ).     

New Nortriterpenoid and Ceramides From Stems and Leaves of Cultivated <Emphasis Type="Italic">Triumfetta cordifolia</Emphasis> A Rich (Tiliaceae)

To highlight the role of plants in traditional healing, the leaves and the stems of cultivated Triumfetta cordifolia were phytochemically studied yielding a new nor-ursane type (1), a new ceramide (2) and a new piperidinic ceramide derivative (3) named, respectively, 2α,19α-dihydroxy-3-oxo-23-nor-urs-12-en-28-oic acid, (2R)-2-hydroxy-N-[(2S,3S,4R,26E)-1,3,4-trihydroxy-26-triaconten-2-yl] tetradecanamide and (2R,8Z)-2-hydroxy-{(2S,3R,5R,6S)-3,5-dihydroxy-6-[(1E,5Z)-hexadeca-1,5-dienyl]-2-(β-d-glucopyranosyloxy)methyl piperidine-1-yl} tetracos-8-enamide (3). These were obtained together with lupeol (4), stigmasterol (5), 3-O-β-d-glucopyranoside of β-sitosterol (6), tormentic acid (7) from stems and heptadecanoic acid (8), β-carotene (9), oleanolic acid (10), and 24-hydroxytormentic acid (11) from leaves. The structures were determined on the basis of NMR data (¹H-, ¹³C-, 2D-NMR analyses), mass spectrometry and confirmed by chemical transformations as well as comparison of spectral data with those reported in the literature. The FRAP method was used to evaluate the antioxidant activity of fractions collected from flash chromatography and isolated compounds. Among the fractions, four reduced Fe^III-TPTZ to Fe^II-TPTZ while isolated pure compounds showed no activity.     

Two Novel Ceramides with a Phytosphingolipid and a Tertiary Amide Structure from <Emphasis Type="Italic">Zephyranthes candida</Emphasis>

Two novel ceramides, Candidamide A (1) with a phytosphingolipid structure, and Candidamide B (2) with a tertiary amide structure, together with 12 known compounds (3–14) have been isolated from the bulbs of Zephyranthes candida, The structures of 1 and 2 have been elucidated to be 1,3,5,6-tetrahydroxy-2-(2′-hydroxytetracosanoyl amino)-8-(E)-octadecadiene (1) and (2S,3S,4R,8E,2′R)-2-[N-(2′-hydroxyoctadecanoyl)-N-(1′′,2′′-dihydroxyethyl)-amino]-8-hexacosene-1,3,4-triol (2) on the basis of spectroscopic evidence including IR, MS, NMR (¹H-NMR, ¹³C-NMR, DEPT, ¹H–¹H COSY, HSQC, HMBC). The known compounds were identified as (2S)-3′,7-dihydroxy-4′-methoxyflavan (3), (2S)-4′-hydroxy-7-methoxyflavan (4), (2S)-4′,7-dihydroxyflavan (5), 7-hydroxy-3′, 4′-methylenedioxyflavan (6), ambrettolide (7), β-sitostero1 (8), β-daucosterin (9), rutin (10), pancratistatin (11), lycorine (12), haemanthidine (13), and haemanthamine (14). In the antimicrobial assay, candidamide A (1) and candidamide B (2) displayed moderate activities against bacteria Staphylococcus aureus and Escherichia coli, and fungi Aspergillus niger, Candida albicans and Trichophyton rubrum.     

New ceramides from <Emphasis Type="Italic">Rantherium suaveolens</Emphasis>

A mixture of five new ceramides was isolated from the aerial parts of Rantherium suaveolens and characterized by spectroscopic and chemical methods. Their structures were elucidated by spectroscopic and chemical methods as (2S, 3S, 4R, 2′R, 14E)-2-(2′-hydroxydocosanoylamino)-14-octadecene-1,3,4-triol (1), (2S,3S,4R,2′R, 14F)-2-(2′-hydroxytricosanoylamino)-14-octadecene-1,3,4-triol (2), (2S,3S,4R,2′R,14F)-2-(2′-hydroxytetracosanoylamino)-14-octadecene-1,3,4-triol (3), (2S,3S,4R,2′R,14E)-2-(2′-hydroxypentacosanoylamino)-14-octadecene-1,3,4-triol (4), and (2S,3S,4R,2′R,14E)-2-(2′-hydroxyhexacosanoylamino)-14-octadecene-1,3,4-triol (5).     

Novel imine from Hemsleya macrocarpa var. clavata

The new substance hemsleyin imine A (1) was isolated along with (2S,3S,4R,2′R)-2-(2′-hydroxytetracosanoylamino)-octadecan-1,3,4-triol (2), (2S,3R,4E,8E)-1-O-β-d-glucopyranosyl-3-hydroxy-2-(2′R-hydroxypalmitoylamino)-4,8-octadecadiene (3) from the rhizomes of Hemsleya macrocarpa var. clavata. Their chemical structures were established mainly by spectral analysis and chemical evidence. Compound 1 possesses the skeleton of an imine moiety, which is novel in natural products.     

New Sphingolipids with a Previously Unreported 9-Methyl-C<Subscript>20</Subscript>-sphingosine Moiety from a Marine Algous Endophytic Fungus <Emphasis Type="Italic">Aspergillus niger</Emphasis> EN-13

Asperamides A (1) and B (2), a sphingolipid and their corresponding glycosphingolipid possessing a hitherto unreported 9-methyl-C₂₀-sphingosine moiety, were characterized from the culture extract of Aspergillus niger EN-13, an endophytic fungus isolated from marine brown alga Colpomenia sinuosa. The structures were elucidated by spectroscopic and chemical methods as (2S,2′R,3R,3′E,4E,8E)-N-(2′-hydroxy-3′-hexadecenoyl)-9-methyl-4,8-icosadien-1,3-diol (1) and 1-O-β-d-glucopyranosyl-(2S,2′R,3R,3′E,4E,8E)-N-(2′-hydroxy-3′-hexadecenoyl)-9-methyl-4,8-icosadien-1,3-diol (2). In the antifungal assay, asperamide A (1) displayed moderate activity against Candida albicans.     

New glyceroglycolipid and ceramide from <Emphasis Type="Italic">Premna microphylla</Emphasis>

Iwo new compounds (1,2) were isolated from the ethanolic extract of the leaves of Premna microphylla, together with five known compounds. The structures of compounds 1 and 2 were elucidated as (2S,3S,4R,11E)-2-[(2R)-2-hydroxytetracosanoylamino]-11-octadecene-1,3,4-triol (1) and 1-O(9Z,12Z, 15Z-octadecatrienoyl)-3-O-[β-d-galactopyranosyl-(1→6)-O-β-d-galactopyranosyl-(1→6)-α-d-galactopyranosyl] glycerol (2) by means of spectroscopic and chemical methods.     

Zirconium phosphonate immobilized chiral amino alcohol for heterogeneous enantioselective addition of diethylzinc to benzaldehyde

The chiral (1R,2S)-(−)-2-amino-1,2-diphenylethanol and (1S,2R)-(+)-2-amino-1,2-diphenylethanol had been immobilized on the layered frame of zirconium phosphate to obtain zirconium phosphonates (1R,2S)-(−)-4a and (1S,2R)-(+)-4b. The enantioselective addition of Et₂Zn to benzaldehyde using zirconium phosphonates (1R,2S)-(−)-4a and (1S,2R)-(+)-4b as heterogeneous catalysts yielded secondary alcohol in 80.1% yield and e.e. values of up to 54.3%, which was only 7.6% e.e. lower than that using the corresponding ligands (1R,2S)-(−)-2a and (1S,2R)-(+)-2b as homogeneous catalysts. The zirconium phosphonates (1R,2S)-(−)-4a and (1S,2R)-(+)-4b were characterized by IR, SEM, XRD and TG analysis. SEM and XRD data showed that the catalysts (1S,2R)-(+)-4b and (1R,2S)-(−)-4a were in aggregate and mesopore structure with the same interlayer spacing 2.48 nm and pore diameter 5.6 nm.     

Two novel glucosylceramides from gonads and body walls of the Patagonian starfish Allostichaster inaequalis

From the water-insoluble lipid fraction of the chloroform/methanol/water extract of the gonads and body walls of the Patagonian starfish Allostichaster inaequalis, two new glucosylceramides (4 and 7) were isolated together with the known phalluside-1 (1) and two glucosylceramides (2 and 3) previously isolated from the starfish Cosmasterias lurida. The new compounds were characterized as (2S,3R,4E,8E,10E)-1-(β-d-glucopyranosyloxy)-3-hydroxy-2-[(R)-2-hydroxy-15-tetracosenoyl] amino-4,8,10-octadecatriene (4) and (2S,3R,4E,15Z)-1-(β-d-glucopyranosyloxy)-3-hydroxy-2-[(R)-2-hydroxyhexadecanoyl] amino-4,15-docosadiene (7) by means of spectroscopic and chemical methods.     

Microbial synthesis of chiral intermediates for β-3-receptor agonists

Chiral intermediates were prepared by biocatalytic processes for the chemical synthesis of β-3-receptor agonists. These include: (i) the microbial reduction of 4-benzyloxy-3-methanesulfonylamino-2′-bromoacetophenone 1 to the corresponding (R)-alcohol 2 by Spingomonas paucimobilis SC 16113. In the biotransformation process, a reaction yield of >85% and an optical purity of 99.5% were obtained for the desired (R)-alcohol 2; (ii) the enzymatic resolution of racemic α-methyl phenylalanine amide, 3, and α-methyl-4-hydroxy-phenylalanine amide, 5, by amidase from Mycobacterium neoaurum ATCC 25795 to prepare the corresponding (S)-amino acids 4 and 6. Reaction yields of 49.9 and 49 M% (theoretical maximum yield 50 M%) and optical purities of 99 and 94% were obtained for the desired (S)-amino acids 4 and 6, respectively; (iii) the asymmetric hydrolysis of methyl-(4-methoxyphenyl)-propanedioic acid, ethyl diester, 7, to the corresponding (S)-monoester 8 by pig liver esterase. A reaction yield of 96 M% and an optical purity of 96% were obtained for (S)-monoester 8 when reactions were carried out in a biphasic system containing 10% ethanol at 10°C.     

Synthesis of 2,2′-bithiophene-5,5′-tetrahydroisoquinoline as michellamine analogs

Atropisomers of 2,2′-bithiophene-5-tetrahydroisoquinoline, S -8, R -8, and 2,2′-bithiophene-5,5′-tetrahydroisoquinoline, (S,S)-11, (R,S)-11, (R,R)-11, analogs of michellamines have been synthesized in low yield under Stille coupling conditions (Pd⁰-mediated cross coupling reactions) of stannanes 1 or 2 with non-racemic bromotetrahydroisoquinoline 6. The use of non-racemic iodotetrahydroisoquinoline 7 instead of 6 significantly improves the efficiency of the coupling, affording the atropisomers in moderate yields.     

Isolation and structure of glucosylceramides from the starfish Cosmasterias lurida

From the water-insoluble lipid fraction of the methylene chloride/methanol extract of the starfish Cosmasterias lurida, two new glucosylceramides together with a known glucosylceramide, ophidiacerebroside E, were isolated by chromatographic procedures and characterized by spectroscopic (¹H and ¹³C nuclear magnetic resonance, mass spectrometry) methods. The new compounds were identified as (2S, 3R, 4E, 8E, 10E)-1-(β-d-glucopyranosyloxy)-3-hydroxy-2-[(R)-2-hydroxyheptadecanoyl)amino]-9-methyl-4,8,10-octadecatriene (3) and (2S,3R,4E,8E,10E)-1-(β-d-glucopyranosyloxy)-3-hydroxy-2-[(R)-2-hydroxyoctadecanoyl)amino]-9-methyl-4,8,10-octadecatriene (4).     

Enantiospecific synthesis of (3S,6R)-3-hydroxy-1,7-dioxaspiro[5.5]undecane and its (4R)-4-hydroxy isomer [minor components of olive fruit fly (Dacus oleae) sex pheromone]

The synthesis of (3S,6R)-3-hydroxy-1,7-dioxaspiro[5.5]undecane (8) and its (4R)-4-hydroxy isomer (11) from (3R,4S,6R)-3,4-dihydroxy-1,7-dioxaspiro[5.5]undecane (1), obtained from D-fructose, has been accomplished by regioselective deoxygenation at C-4 and C-3, respectively, of the appropriately protected derivatives.Enantiospecific synthesis of spiroacetals. Part III. For Part II, see Izquierdo et al. (1991).     

Absolute configuration of mosquito oviposition attractant pheromone, 6-acetoxy-5-hexadecanolide

6-Acetoxy-5-hexadecanolide (Ia) in the oviposition attractant pheromone released from egg apical droplets of the mosquitoCulex pipiens fatigans Wied. is shown to be the (–)-(5R,6S)- enantiomer. Identification was by chromatography of the 6-trifluoroacetoxy derivatives of the natural pheromone and of the synthetic (–)-(5R,6S)- (Ib) and (+)-(5S,6R)- (IIb) enantiomers on a capillary column having a chiral stationary phase comprising a derivative of (1S,3S)-chrysanthemic acid. The synthetic (–)-(5R,6S)- enantiomer (Ia) attracted oviposition of four fold more mosquito egg rafts than the control (P < 0.01) whereas for the (5S,6R)- enantiomer (IIa) there was no statistically significant oviposition attraction.     

Reaction products of α-tocopherol with a free radical initiator, 2,2′-azobis(2,4-dimethylvaleronitrile)

α-Tocopherol wss reacted with an alkylperoxyl radical at 37°C in ethanol. 2,2′-Azobis(2,4-dimethylvaleronitrile) was used to generate the alkylperoxyl radicals. The reaction products of α-tocopherol were isolated by reverse-phase and normal-phase high performance liquid chromatography, and their structures were characterized by infrared, ultraviolet,¹H and¹³C nuclear magnetic resonances and mass spectrometry. They were 8aS-hydroperoxy-α-tocopherone, 8aR-hydroperoxy-α-tocopherone, a mixure of 7,8-epoxy-8aS-ethoxy-α-tocopherone, and 7,8-epoxy-8aR-ethoxy-α-tocopherone, 8aS-(1R-cyano-1,3-dimethyl)butylperoxy-α-tocopherone, 8aS-(1S-cyano-1,3-dimethyl)butylperoxy-α-tocopherone, a mixture of 8aR-(1S-cyano-1,3-dimethyl)butylperoxy-α-tocopherone and 8aR-(1S-cyano-1,3-dimethyl)butylperoxy-α-tocopherone, 4aR,5S-epoxy-8aS-ethoxy-α-tocopherone, 4aS,5R-epoxy-8aS-ethoxy-α-tocopherone and 4aR,5S-epoxy-8aR-ethoxy-α-tocopherone.     

Contact Sex Pheromone Components of the Seed Beetle, <Emphasis Type="BoldItalic">Callosobruchus analis</Emphasis> (F.)

Callosobruchus analis (Coleoptera: Chrysomelidae: Bruchinae), found throughout tropical Asia and Africa, is a pest of stored legumes. Previous work has shown that females of this species produce a contact sex pheromone that elicits copulatory behavior in males. Comparisons of copulatory activity between any two of four congeneric species suggest that the contact sex pheromones are species specific. In laboratory bioassays, male C. analis exhibited copulatory behavior to a female dummy to which a crude extract of virgin females was applied. The extract had been collected by a filter paper method and was purified by acid–base partition and chromatographic techniques. Gas chromatography-mass spectrometry (GC-MS) analyses of active fractions revealed that the active compounds were 2,6-dimethyloctane-1,8-dioic acid (1) and callosobruchusic acid, (E)-3,7-dimethyl-2-octene-1,8-dioic acid (2), previously identified as contact sex pheromones of Callosobruchus maculatus (F.) and C. chinensis (L.), respectively. The stereoisomeric and chemical compositions were determined by the 2D-HPLC-Ohrui-Akasaka method as (2S,6R)-1:(S)-2 = 1.8:1, which meant that both compounds in C. analis were stereochemically pure, unlike the case of C. maculatus and C. chinensis. An examination of the influence of synthetic pheromone compounds on male copulatory activity revealed that (2S,6R)-1 is the main component, and that (S)-2 has an additive effect. In the examination of the stereochemistry-activity relationship, no copulatory behavior was elicited by (2R,6S)-1, and, furthermore, the enantiomer significantly masked the pheromonal activity of (2S,6R)-1. Glass rod dummy assays also suggested the presence of synergists. These results could elucidate the specificity of mate recognition in C. analis.     

Identification and synthesis of insect pheromone

(Z,Z)-3,13-Octadecadien-1-ol1a is identified as the sex pheromone from the poplar pole clearwing moth,Sphecia siningensis Hsu, by GCMS analysis, synthesis, EAG, and field bioassay. Species isolation among Sesiidae by pheromone is also discussed.Studies on the identification and synthesis of insect pheromone XXVII. Stereoselective synthesis of (5R, 6S)-(–)- and (5S, 6R)-(+)-mosquito oviposition attractant pheromone and stereochemistry of asymmetric addition of a chiral sulfoxide to a chiral aldehyde. Zhou, W.S., Cheng, J.F. and Lin, G.Q.,Acta Chemica Sinica 46:274, 1985.     

Isorhizochalin: a Minor Unprecedented Bipolar Sphingolipid of Stereodivergent Biogenesis from the <Emphasis Type="Italic">Rhizochalina incrustata</Emphasis>

Isorhizochalin (1) was isolated as its peracetate from the EtOH extract of the sponge Rhizochalina incrustata. Its structure and absolute stereochemistry were elucidated as (2S,3R,26R,27R)-2,27-diamino-3-O-β-d-galactopyranosyl-oxy-26-hydroxyoctacosan-18-one by extensive NMR, MS studies, chemical transformations, including micromolar-scale Baeyer–Villiger oxidation, and by analysis of CD spectra of isorhizochalinin perbenzoate (2b). Isorhizochalin is an unprecedented C-2 epimer of rhizochalin having an erythro configuration at the glycosylated 2-amino-3-alkanol α-terminus in contrast with a canonical threo configuration for other representatives of this structural group. Probable biogenesis of 1 is discussed in the context of known sphingolipid biosynthesis beginning with condensation of alanine with a fatty acyl CoA thioester. The aglycone, isorhizochalinin (2a), shows cytotoxicity against human leukemia HL-60 and THP-1 cells with IC₅₀ values of 2.90 and 2.20 μM, respectively.