Furostanol glycosides from Trigonella foenum-graecum seeds

Two new furostanol glycosides trigofoenosides A and D have been isolated from the Trigonella foenum-graecum seeds as their methyl ethers, A-1 and D-1. Their structures have been determined as (25S)-22-O-methyl-furost-5-ene-3β,26-diol, 3-O-α-L-rhamnopyranosyl (1 → 2)-β-D-glucopyranoside; 26-O-β-D-glucopyranoside (A-1) and (25S)-22-O-methyl-furost-5-ene-3β,26-diol, 3-O-α-L-rhamnopyranosyl (1 → 2)-[β-D-glucopyranosyl (1 → 3)]-β-D-glucopyranoside; 26-O-β-D-glucopyranoside (D-1).     

Isolation and characterization of a furostanol glycoside from fenugreek

From the seed of fenugreek, a new glycoside has been isolated and shown to have the structure, (25S)-22-O- methyl-5α-furostan-3β,22,26-triol 3-O-α-rhamnopyranosyl(1→2)[-β-d-glucopyranosyl (1→3)]-β-d- glucopyranoside-26-O-β-d-glucopyranoside.     

Aloeresin c,a bitter c,o-diglucoside from cape aloe

A new bitter C,O-diglucoside, aloeresin C, was isolated from commercial Cape aloe. Its structure, 2-acetonyl-7-O-β-D-glucopyranosyl-8-C-β-D-[2′-O-(E)-p-coumaroyl]glucopyranosyl-5-methylchromone, was established by spectral and chemical methods.     

7-O-methyl-(2R:3R)-dihydroquercetin 5-O-β-D-glucoside and other flavonoids from Podocarpus nivalis

In the course of a chemotaxonomic survey of New Zealand Podocarpus species, a number of new flavonoid glycosides have been isolated from P. nivalis. These are: luteolin 3′-O-β-D-xyloside, luteolin 7-O-β-D-glucoside-3′-O-β-D-xyloside, dihydroquercetin 7-O-β-D-glucoside, 7-O-methyl-(2R:3R)-dihydrokaempferol 5-O-β-D-glucopyranoside, 7-O-methyl-(2R:3R)-dihydroquercetin 5-O-β-D-glucopyranoside, 7-O-methylkaempferol 5-O-β-D-glucopyranoside and 7-O-methylquercetin 5-O-β-D-glucopyranoside. Diagnostically useful physical techniques for distinguishing substitution patterns in dihydroflavonols are discussed and summarized. Glucosylation of the 5-hydroxyl group in (+)-dihydroflavonols is shown to reverse the sign of rotation at 589 nm.     

Acylated cyanidin 3-sambubioside-5-glucosides from the purple-violet flowers of Matthiola longipetala subsp. bicornis (Sm) P. W. Ball. (Brassicaceae)

A novel acylated cyanidin 3-sambubioside-5-glucoside was isolated from the purple-violet flowers of Matthiola longipetala subsp. bicornis (Sm) P. W. Ball. (family: Brassicaceae), and determined to be cyanidin 3-O-[2-O-(2-O-(trans-feruloyl)-β-xylopyranosyl)-6-O-(trans-feruloyl)-β-glucopyranoside]-5-O-[6-O-(malonyl)-β-glucopyranoside] by chemical and spectroscopic methods. In addition, two known acylated cyanidin 3-sambubioside-5-glucosides, cyanidin 3-O-[2-O-(2-O-(trans-sinapoyl)-β-xylopyranosyl)-6-O-(trans-feruloyl)-β-glucopyranoside]-5-O-[6-O-(malonyl)-β-glucopyranoside] and cyanidin 3-O-[2-O-(β-xylopyranosyl)-6-O-(trans-feruloyl)-β-glucopyranoside]-5-O-[6-O-(malonyl)-β-glucopyranoside] were identified in the flowers.     

Silica gel-catalyzed migration of acetyl groups from a sulfur to an oxygen atom

During the chromatographic separation of 3-S-acetyl-1,2-O-isopropylidene-3-thio-α-d-allofuranose on silica gel, a migration of the acetyl group from S to O was observed to give 6-O-acetyl-1,2-O-isopropylidene-3-thio-α-d-allofuranose, whereas 3-S-acetyl-6-O-benzoyl-1,2-O-isopropylidene-3-thio-α-d-allofuranose gave 5-O-acetyl-6-O-benzoyl-1,2-O-isopropylidene-3-thio-α-d-allofuranose. No acetyl migration was observed, however, in the case of 3-O-acetyl-1,2-O-isopropylidene-α-d-allofuranose.     

Some metabolites of Botrytis cinerea related to botcinolide

Four new botcinolide derivatives 4-O-methylbotcinolide, 3-O-acetyl-5-O-methylbotcinolide, 3-O-acetyl-2-epibotcinolide and 2-epibotcinolide have been isolated from the plant pathogen, Botrytis cinerea. Their structures have been established by extensive spectroscopic methods.     

Unique flavonoid glycosides from the new zealand white pine, Dacrycarpus dacrydioides

A number of new flavonoid glycosides have been isolated from foliage of the New Zealand white pine, Dacrycarpus dacrydioides. These include tricetin 3′,5′-di-O-β-glucopyranoside; the 3′-O-β-xylopyranoside, 7-O-α-rhamnopyranoside and 7-O-α-rhamnopyranoside-3′-O-β-xylopyranoside of 3-O-methylmyricetin; the 3′-O-β-xylopyranoside, 7-O-α-rhamnopyranoside and 7-O-α-rhamnopyranoside-3′-O-β-xylopyranoside of 3-O-methyl-quercetin, and the 3′-O-β-xylopyranoside and 7-O-α-rhamnopyranoside-3′-O-β-xylopyranoside of 3,4′-di-O-methylmyricetin. The accumulation of 3-methoxyflavones and B-ring trioxygenated flavonoids appears to distinguish D. dacrydioides from all other New Zealand members of the classical genus Podocarpus. Support for De Laubenfels' proposed separation of Dacrycarpus from this genus is seen in the present work.     

Naphthoquinones produced by Fusarium oxysporum isolated from citrus

Six naphthoquinone pigments are described which were produced by Fusarium oxysporum isolates obtained from roots of diseased citrus trees. These were 8-O-methylbostrycoidin, 9-O-methylfusarubin, 9-O-methylanhydro-fusarubin, 5-O-methyljavanicin, 5-O-methylsolaniol and 1,4-naphthalenedione-3,8-dihydroxy-5,7-dimethoxy-2-(2-oxopropyl). These naphthoquinones had not been previously identified from F. oxysporum isolates.     

Asplenetin,a flavone and its glycoside from Launaea asplenifolia

A new flavone, asplenetin, has been isolated from Launea asplenifolia and characterized as 5,7,3′,4′,5′-pentahydroxy-3-(3-methylbutyl)flavone. Its glycoside, asplenetin 5-O-neohesperidoside, is also reported.     

A tetra-acylated cyanidin 3-sophoroside-5-glucoside from the purple-violet flowers of Moricandia arvensis (L.) DC. (Brassicaceae)

A novel tetra-acylated cyanidin 3-sophoroside-5-glucoside was isolated from the purple-violet flowers of Moricandia arvensis (L.) DC. (Family: Brassicaceae), and determined to be cyanidin 3-O-[2-O-(2-O-(4-O-(6-O-(4-O-(β-glucopyranosyl)-trans-caffeoyl)-β-glucopyranosyl)-trans-caffeoyl)-β-glucopyranosyl)-6-O-(trans-caffeoyl)-β-glucopyranoside]-5-O-[6-O-(malonyl)-β-glucopyranoside] by chemical and spectroscopic methods.     

Cyanosalvianin, a supramolecular blue metalloanthocyanin, from petals of Salvia uliginosa

A metalloanthocyanin, cyanosalvianin, was found in blue petals of Salvia uliginosa. Cyanosalvianin consisted of 3-O-(6-O-p-coumaroylglucopyranosyl)-5-O-(4-O-acetyl-6-O-malonylglucopyranosyl) delphinidin, 7,4′-di-O-glucopyranosylapigenin and magnesium ion. We reproduced the same blue color as the petals by mixing the three components together. An ESI-MS measurement gave a molecular weight of 9014 indicating the composition of cyanosalvianin to be six molecules of the anthocyanin component, six molecules of the flavone component and two magnesium ions. The special arrangement of the organic components in cyanosalvianin was analyzed by CD and 2D-NMR spectroscopy. It was clarified that cyanosalvianin has a similar structure to that of commelinin, a metalloanthocyanin isolated from blue dayflower, Commelina communis.     

Production of a hybrid 16-membered macrolide antibiotic by genetic engineering of Micromonospora sp. TPMA0041

Some polyketide-derived bioactive compounds contain sugars attached to the aglycone core, and these sugars often enhance or impart specific biological activity to the molecule. Mycinamicin II, a 16-member macrolide antibiotic produced by Micromonospora griseorubida A11725, contains a branched lactone and two different deoxyhexose sugars, d-desosamine and d-mycinose, at the C-5 and C-21 positions, respectively. We previously engineered an expression plasmid pSETmycinose containing the d-mycinose biosynthesis genes from M. griseorubida A11725. This plasmid was introduced into Micromonospora sp. FERM BP-1076 cells, which produce the 16-membered macrolide antibiotic izenamicin. The resulting engineered strain TPMA0041 produced 23-O-mycinosyl-20-deoxy-izenamicin B₁ and 22-O-mycinosyl-izenamicin B₂. 23-O-mycinosyl-20-deoxy-izenamicin B₁ has been produced by the engineered strain M. rosaria TPMA0001 containing pSETmycinose as 23-O-mycinosyl-20-deoxo-20-dihydro-12,13-deepoxyrosamicin (=IZI) in our recent study, and 22-O-mycinosyl-izenamicin B₂ has previously been synthesized as a macrolide antibiotic TMC-016 with strong antibacterial activity. The production of 22-O-mycinosyl-izenamicin B₂ (=TMC-016) was increased when propionate, a precursor of methylmalonyl-CoA, was added to the culture broth.     

Synthesis and X-ray structure of a C5-C4-linked glucofuranose-oxazolidin-2-one

The formation of (4R)-4-carbamoyl-4-[(4R)-3-O-benzyl-1,2-O-isopropylidene-β-l-threofuranos-4-C-yl]-oxazolidin-2-one instead of expected imidazolidin-2,4-dione (hydantoin) derivative from 5-amino-5-cyano-5-deoxy-3-O-benzyl-1,2-O-isopropylidene-α-d-glucofuranose or 3-O-benzyl-1,2-O-isopropylidene-α-d-xylo-hexofuranos-5-ulose under Bucherer-Bergs reaction conditions is reported. Single crystal X-ray diffraction data revealed that ³T₄ is the prefered conformation for the furanose ring, while E₂ and ²T₁ conformations are adopted by the 1,3-dioxolane and 2-oxazolidinone five-membered rings, respectively.     

Anthocyanins with unusual furanose sugar (apiose) from leaves of Synadeniumgrantii (Euphorbiaceae)

Four anthocyanins, cyanidin 3-O-(2″-(5?-(E-p-coumaroyl)-β-apiofuranosyl)-β-xylopyranoside)-5-O-β-glucopyranoside, cyanidin 3-O-(2″-(5?-(E-p-coumaroyl)-β-apiofuranosyl)-β-xylopyranoside), cyanidin 3-O-(2″-(5?-(E-caffeoyl)-β-apiofuranosyl)-β-xylopyranoside) and cyanidin 3-O-(2″-(5?-(E-feroyl)-β-apiofuranosyl)-β-xylopyranoside) were isolated from leaves of African milk bush, (Synadeniumgrantii Hook, Euphorbiaceae) together with the known cyanidin 3-O-β-xylopyranoside-5-O-β-glucopyranoside and cyanidin 3-O-β-xyloside. The four former pigments are the first reported anthocyanins containing the monosaccharide apiose, and the three 5?-cinnamoyl derivative-2″-(β-apiosyl)-β-xyloside subunits have previously not been reported for any compound.     

New syntheses of 2′-C-methylnucleosides starting from d-glucose and d-ribose

Effective general methods have been developed for the synthesis of 2′-C-methylnucleosides starting from d-glucose and d-ribose. 3-O-benzyl-1,2-O-isopropylidene-3-C-methyl-α-d-allofuranose was prepared in 5 steps from d-glucose and converted into 1,2,3-tri-O-acetyl-2-C-methyl-5-O-p-methylbenzoyl-d-ribofuranose (5), the starting compound for nucleoside synthesis. Compound 5 was also synthesised from 2-C-hydroxymethyl-2,3-O-isopropylidene-5-O-trityl-d-ribofuranose, prepared in 3 steps from d-ribose. Condensation of 5 with the bis-trimethylsilyl derivatives of uracil, N⁴-benzoylcytosine, and N⁶-benzoyladenine in the presence of F₃CSO₃OSiMe₃ followed by removal of the protecting acyl groups yielded the corresponding 2′-C-methylnucleosides.     

Comprehensive Analysis of Herpes Simplex Virus 1 (HSV-1) Entry Mediated by Zebrafish 3-O-Sulfotransferase Isoforms: Implications for the Development of a Zebrafish Model of HSV-1 Infection

Binding of herpes simplex virus 1 (HSV-1) envelope glycoprotein D (gD) to the receptor 3-O-sulfated heparan sulfate (3-OS HS) mediates viral entry. 3-O-Sulfation of HS is catalyzed by the 3-O-sulfotransferase (3-OST) enzyme. Multiple isoforms of 3-OST are differentially expressed in tissues of zebrafish (ZF) embryos. Here, we performed a comprehensive analysis of the role of ZF 3-OST isoforms (3-OST-1, 3-OST-5, 3-OST-6, and 3-OST-7) in HSV-1 entry. We found that a group of 3-OST gene family isoforms (3-OST-2, -3, -4, and -6) with conserved catalytic and substrate-binding residues of the enzyme mediates HSV-1 entry and spread, while the other group (3-OST-1, -5, and -7) lacks these properties. These results demonstrate that HSV-1 entry can be recapitulated by certain ZF 3-OST enzymes, a significant step toward the establishment of a ZF model of HSV-1 infection and tissue-specific tropism.     

A spirostanol glycoside from Agave cantala

A new steroidal saponin has been isolated from the ethanolic extract of the roots of Agave cantata and shown to be 3-O-[β-d-glucopyranosyl]-6O-[β-d-glucopyranosyl]-(25R)-5α-22α-O- spirostan-3β, 6α-diol.     

Anthocyanins in Caprifoliaceae

The qualitative and relative quantitative anthocyanin content of 19 species belonging to the genera Sambucus, Lonicera and Viburnum in the family Caprifoliaceae has been determined. Altogether 12 anthocyanins were identified; the 3-O-glucoside (2), 3-O-galactoside (5), 3-O-(6″-O-arabinosylglucoside) (7), 3-O-(6″-O-rhamnosylglucoside) (9), 3-O-(2″-O-xylosyl-6″-O-rhamnosylglucoside) (10), 3-O-(2″-O-xylosylgalactoside) (11), 3-O-(2″-O-xylosylglucoside) (12), 3-O-(2″-O-xylosylglucoside)-5-O-glucoside (14), 3-O-(2″-O-xylosyl-6″-O-Z-p-coumaroylglucoside)-5-O-glucoside (15) and 3-O-(2″-O-xylosyl-6″-O-E-p-coumaroylglucoside)-5-O-glucoside (16) of cyanidin, in addition to the 3-O-glucosides of pelargonidin and delphinidin (1 and 3). Pigment 7 is the first complete identification of the disaccharide vicianose, 6″-O-α-arabinopyranosyl-β-glucopyranose, linked to an anthocyanidin.     

Studies on the structure of a polysaccharide from Epidermophyton floccosum and approach to a synthesis of the basic trisaccharide repeating units

An alkali-soluble polysaccharide, designated as S-Iawe, has been isolated from the maycelia of Epidermophyton floccosum. Methylation, periodate oxidation, and acetolysis studies suggested that S-lawe is composed of (1→6)-Oα-d-mannopyranosyl-(1→6)-O-[α-d-mannopyranosyl-(1→2)]-O-α-d-mannopyranosyl repeating units. Condensation of 2,3,4,6-tetra-O-acetyl-α-d-mannopyranosyl bromide with methyl 3-O-benzyl-4,6-O-benzylidene-α-d-mannopyranoside in the presence of mercuric cyanide gave in 70% yield methyl 3-O-benzyl-4,6-O-benzylidene-2-O-(2,3,4,6-tetra-O-acetyl-α-d-mannopyranosyl)-α-d-mannopyranoside. Condensation of the debenzylidenated disaccharide with 2,3,4,6-tetra-O-acctyl-α-d-mannopyranosyl bromide afforded the corresponding trisaccharide repeating unit.