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From the root barks of a Central African tree Millettia dubia De Wild. (Fabaceae), ten previously undescribed oleanane-type glycosides were isolated by various chromatographic protocols. Their structures were elucidated by spectroscopic methods, mainly 2D NMR experiments and mass spectrometry, as mono- and bidesmosidic glycosides of mesembryanthemoidigenic acid, hederagenin and oleanolic acid. The stimulation of the sweet taste receptor TAS1R2/TAS1R3 by these glycosides was evaluated, and structure/activity relationships were proposed. Two of them showed an agonist effect on TAS1R2/TAS1R3. [Display omitted] • Ten different oleanolic acid glycosides were isolated. • Their structures were elucidated by extensive 2D NMR analyses. • The stimulation of the sweet taste receptors TAS1R2/TAS1R3 was evaluated. • Some structure/activity relationships were discussed. [ABSTRACT FROM AUTHOR]

For more than four centuries, the intake of Narthecium ossifragum has been associated with poisoning in domesticated animals. Saponins occurring in flowering tops of the plant are considered to cause kidney damage in calves. At present, there are more than 30 papers on the saponins of N. ossifragum in the literature, although the structures of these compounds have hitherto not been determined. Here, we identify the saponins of N. ossifragum as sarsasapogenin, sarsasapogenin-3- O - β -galactopyranoside, sarsasapogenin-3- O -(2′- O - β -glucopyranosyl- β -galactopyranoside) and sarsasapogenin-3- O -(2′- O - β -glucopyranosyl-3′- O - α -arabinopyranosyl- β -galactopyranoside). Moreover, six aromatic natural products were isolated and characterized from the methanolic extract from flowers of N. ossifragum. Five of these aromatic compounds, chrysoeriol 6- C - β -arabinofuranoside-8- C - β -glucopyranoside, chrysoeriol 6- C - β -arabinopyranosyl-8- C - β -glucopyranoside, chrysoeriol 6- C - β -xylopyranosyl-8- C - β -galactopyranoside, chrysoeriol 6- C - β -galactopyranosyl-8- C - β -glucopyranoside and chrysoeriol 6- C - β -glucopyranosyl-8- C - β -galactopyranoside are undescribed. All compounds were tested for cytotoxicity in mammalian cell lines derived from the heart, kidney, and haematological tissues. The saponins exhibited cytotoxicity in the micromolar range, with proportionally increasing cytotoxicity with increasing number of glycosyl substituents. The most potent compound was the main saponin sarsasapogenin-3- O -(2′- O - β -glucopyranosyl-3′- O - α -arabinopyranosyl- β -galactopyranoside), which produced cell death at concentrations below 3–4 μM in all three cell lines tested. This indicates that the saponins are the toxicants mainly responsible for kidney damage observed in cattle after ingestion of N. ossifragum. Our findings also pave the way for analysis of individual compounds isolated during the biopsies of intoxicated animals. Cytotoxic saponins from flowering tops of Narthecium ossifragum L. Andrea Estefanía Carpinteyro Díaz, Lars Herfindal, Bendik Auran Rathe, Kristine Yttersian Sletta, Svein Haavik and Torgils FossenCytotoxic saponins toxic to kidney cells were characterized from the hepatotoxic plant Narthecium ossifragum. Image 1 • Cytotoxic saponins of Narthecium ossifragum were for the first time identified. • Increasing cytotoxicity with increasing number of glycosyl substituents. • The main saponin was most toxic to all cell lines including kidney cells. • Five undescribed di-C-glycosylflavones were characterized. • Structures were established by 2D NMR and HRMS. [ABSTRACT FROM AUTHOR]

A phytochemical investigation of Blighia unijugata led to the isolation of eleven hederagenin glycosides. Among these compounds, six are previously undescribed, two are described in their native forms for the first time and three are known whereas firstly isolated from Blighia unijugata. The structure of the undescribed compounds was elucidated on the basis of 2D NMR and mass spectrometry analyses as 3 -O- β-D-xylopyranosyl-(1 → 3)-α-L-arabinopyranosyl-(1 → 4)-β-D-glucopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosylhederagenin, 3 -O- β-D-xylopyranosyl-(1 → 3)-α-L-arabinopyranosyl-(1 → 4)-3 -O- acetyl-β-D-glucopyranosyl - (1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosylhederagenin, 3 -O- β-D-glucopyranosyl-(1 → 3)-α-L-arabinopyranosyl-(1 → 4)-β-D-glucopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosylhederagenin, 3 -O- β-D-xylopyranosyl-(1 → 3)-β-D-xylopyranosyl-(1 → 4)-β-D-glucopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosylhederagenin, 3 -O- β-D-xylopyranosyl-(1 → 3)-β-D-xylopyranosyl-(1 → 4)-3 -O- acetyl-β-D-glucopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosylhederagenin, 3 -O- α-L-arabinopyranosyl-(1 → 4)-β-D-glucopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosylhederagenin 28 -O- β-D-glucopyranosyl-(1 → 6)-β-D-glucopyranosyl ester, 3 -O- α-L-arabinopyranosyl-(1 → 4)-β-D-glucopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosylhederagenin 28 -O- β-D-glucopyranosyl ester and 3 -O- β-D-xylopyranosyl-(1 → 4)-β-D-glucopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosylhederagenin 28 -O- β-D-glucopyranosyl ester. These results revealed the existence of several conserved structural features that could be used as chemotaxonomic markers for the Blighia genus such as the glycosidic sequence 3 -O- α-L-arabinopyranosyl-(1 → 4)-β-D-glucopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosyl, the occurrence of 3 -O- acetylated β-D-glucopyranosyl units and the systematic presence of hederagenin as aglycone. Image 1 • Eight undescribed hederagenin glycosides were isolated from Blighia unijugata. • Their structures were determined by spectroscopic methods. • Chemotaxonomic conclusions were discussed. [ABSTRACT FROM AUTHOR]

Eight undescribed triterpenoid saponins together with a known one, and two undescribed sesquiterpene glycosides were isolated from root's barks of Eriocoelum microspermum . Their structures were elucidated by spectroscopic methods including 1D and 2D experiments in combinaison with mass spectrometry as 3- O -α-L-rhamnopyranosyl-(1 → 3)-[α-L-rhamnopyranosyl-(1 → 2)]-α-L-arabinopyranosylhederagenin, 3- O -α-L-rhamnopyranosyl-(1 → 3)-[β-D-glucopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)]-α-L-arabinopyranosylhederagenin, 3- O -α-L-rhamnopyranosyl-(1 → 3)-[β-D-xylopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)]-α-L-arabinopyranosylhederagenin, 3- O -α-L-rhamnopyranosyl-(1 → 4)-[α-L-rhamnopyranosyl-(1 → 2)]-α-L-arabinopyranosylhederagenin 28- O -β-D-glucopyranosyl ester, 3- O -α-L-rhamnopyranosyl-(1 → 3)-β-D-xylopyranosyl-(1 → 4)-β-D-xylopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosylhederagenin, 3- O -α-L-rhamnopyranosyl-(1 → 3)-α-L-arabinopyranosyl-(1 → 4)-β-D-xylopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosylhederagenin, 3- O -β-D-xylopyranosyl-(1 → 4)-α-L-arabinopyranosyl-(1 → 4)-β-D-glucopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosylhederagenin, 3- O -α-L-rhamnopyranosyl-(1 → 4)-α-L-rhamnopyranosyl-(1 → 3)-α-L-arabinopyranosyl-(1 → 4)-β-D-glucopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)]-α-L-arabinopyranosylhederagenin, 1- O -{β-D-xylopyranosyl-(1 → 3)-[α-L-rhamnopyranosyl-(1 → 2)]-β-D-glucopyranosyl-(1 → 4)-α-L-rhamnopyranosyl-(1 → 6)}-[β-D-xylopyranosyl-(1 → 3)]-[α-L-rhamnopyranosyl-(1 → 2)]-β-D-glucopyranosyl-(2E,6E)-farnes-1-ol, 1- O -{β-D-glucopyranosyl-(1 → 3)-[α-L-rhamnopyranosyl-(1 → 2)]-β-D-glucopyranosyl-(1 → 4)-α-L-rhamnopyranosyl-(1 → 6)}-[β-D-xylopyranosyl-(1 → 3)]-[α-L-rhamnopyranosyl-(1 → 2)]-β-D-glucopyranosyl-(2E,6E)-farnes-1-ol. These results represent a contribution to the chemotaxonomy of the genus Eriocoelum highlighting farnesol glycosides as chemotaxonomic markers of the subfamily of Sapindoideae in the family of Sapindaceae. [ABSTRACT FROM AUTHOR]

Phytochemical investigations of the roots of Spergularia marginata had led to the isolation of four previously undescribed triterpenoid saponins, a known one and one spinasterol glycoside. Their structures were established by extensive NMR and mass spectroscopic techniques as 3- O -β-D-glucuronopyranosyl echinocystic acid 28- O -α-L-arabinopyranosyl-(1 → 2)-α-L-rhamnopyranosyl-(1 → 3)-β-D-xylopyranosyl-(1 → 4)-α-L-rhamnopyranosyl-(1 → 2)-α-L- arabinopyranosyl ester, 3- O -β-D-glucopyranosyl-(1 → 3)-β-D-glucuronopyranosyl echinocystic acid 28- O -α-L-arabinopyranosyl-(1 → 2)-α-L-rhamnopyranosyl-(1 → 3)-β-D-xylopyranosyl-(1 → 4)-α-L-rhamnopyranosyl-(1 → 2)- α-L-arabinopyranosyl ester, 3- O -β-D-glucopyranosyl-(1 → 4)-3- O -sulfate-β-D-glucuronopyranosyl echinocystic acid 28- O -α-L-arabinopyranosyl-(1 → 2)-α-L-rhamnopyranosyl-(1 → 3)-β-D-xylopyranosyl-(1 → 4)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosyl ester, and 3- O -β-D-glucopyranosyl-(1 → 4)-β-D-glucuronopyranosyl 21- O -acetyl acacic acid. Their cytotoxicity was evaluated against two human cancer cell lines SW480 and MCF-7. The most active compound showed a cytotoxicity with IC 50 14.2 ± 0.8 μ M (SW480), and 18.7 ± 0.8 μ M (MCF-7), respectively. [ABSTRACT FROM AUTHOR]

Extracellular DNA (exDNA) widely occurs in the environment due to release by either cell lysis or active secretion. The role of exDNA in plant-soil interactions has been investigated and inhibitory effects on the growth of conspecific individuals by their self-DNA have been reported. Transcriptome analysis in the model plant Arabidopsis thaliana showed a clear recognition by the plant roots of self- and nonself-exDNA, with inhibition occurring only after exposure to the former. In this study, an untargeted metabolomics approach was used to assess at molecular level the plant reactions to exDNA exposure. Thus, the effects on the metabolites profile of A. thaliana after exposure to self- and nonself-exDNA from plants and fish, were studied by NMR, LC-MS, chemometrics and molecular networking analyses. Results show that self-DNA significantly induces the accumulation of RNA constituents (nucleobases, ribonucleosides, dinucleotide and trinucleotide oligomers). Interestingly, AMP and GMP are found along with their cyclic analogues cAMP and cGMP, and in form of cyclic dimers (c-di-AMP and c-di-GMP). Also methylated adenosine monophosphate (m6AMP) and the dimeric dinucleotide N-methyladenylyl-(3'→5') cytidine (m6ApC) increased only in the self-DNA treatment. Such striking evidence of self-DNA effects highlights a major role of exDNA in plant sensing of its environment. Metabolomics and molecular networking of Arabidopsis thaliana showed differential and specific accumulation of RNA constituents and analogues only after exposure to the plant self-DNA. [Display omitted] • Arabidopsis thaliana metabolites during self- and nonself-DNA exposure are analysed. • Combined approach of NMR, LC-MS, chemometrics and molecular networking is used. • Self-DNA exposure induced a significant accumulation of specific RNA constituents. • Cyclic AMP and GMP, and N6 methylated adenosine occur only in self-DNA treatment. • This is the first metabolomic study on different effects of self- and nonself-exDNA. [ABSTRACT FROM AUTHOR]

Four new oleanane-type saponins 3- O -α- l -rhamnopyranosyl-(1 → 4)-β- d -glucuronopyranosyl-22- O -β,β-dimethylacryloylA1-barrigenol ( 1 ), 3- O -α- l -rhamnopyranosyl-(1 → 4)-β- d -glucuronopyranosyl-22- O -angeloylA1-barrigenol ( 2 ), 3- O -β- d -glucopyranosyl-(1 → 2)-[β- d -glucopyranosyl-(1 → 6)]-β- d -glucopyranosyl-21,22,28- O -triacetyl-(3β,21β,22α)-olean-12-en-16-one ( 3 ), and 3- O -β- d -glucopyranosyl-(1 → 2)-glucopyranosyl-22- O -β- d -glucopyranosylsteganogenin ( 4 ), along with the known 3- O -β- d -galactopyranosyl-(1 → 2)-[α- l -arabinopyranosyl-(1 → 3)]-β- d -glucuronopyranosyl-22- O -angeloylA1-barrigenol and 3- O -α- l -rhamnopyranosyl-(1 → 4)-β- d -glucuronopyranosyloleanolic acid, were isolated from a methanol extract of the roots of Eryngium kotschyi by multiple chromatographic steps. Saponins 3 and 4 are unusual by the original structure of their aglycon. Compound 3 possessed an oleanane-type skeleton with a 21,22,28-triacetylation and a ketone function at the C-16 position. For compound 4 , the 17,22-seco-oleanolic acid skeleton is rarely found in natural saponins. [ABSTRACT FROM AUTHOR]

Highlights: [•] Four triterpenoid saponins were isolated from Gypsophila arrostii var. nebulosa and G. bicolor roots. [•] Structures were determinated by spectroscopic methods. [•] Compound 1 exhibited a potential cytotoxic activity. [Copyright &y& Elsevier]

Abstract: A phytochemical analysis of the whole plant of Allium schoenoprasum, has led to the isolation of four spirostane-type glycosides (1–4), and four known steroidal saponins. Their structures were elucidated mainly by 2D NMR spectroscopic analysis and mass spectrometry as (20S,25S)-spirost-5-en-3β,12β,21-triol 3-O-α-l-rhamnopyranosyl-(1→2)-β-d-glucopyranoside (1), (20S,25S)-spirost-5-en-3β,11α,21-triol 3-O-α-l-rhamnopyranosyl-(1→2)-β-d-glucopyranoside (2), laxogenin 3-O-α-l-rhamnopyranosyl-(1→2)-[β-d-glucopyranosyl-(1→4)]-β-d-glucopyranoside (3), and (25R)-5α-spirostan-3β,11α-diol 3-O-β-d-glucopyranosyl-(1→3)-[β-d-glucopyranosyl-(1→4)]-β-d-galactopyranoside (4). Four of the isolated compounds were tested for cytotoxic activity against the HCT 116 and HT-29 human colon cancer cell lines. [Copyright &y& Elsevier]

Abstract: 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, (Synadenium grantii 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. [ABSTRACT FROM AUTHOR]

Abstract: Four triterpene saponins, 3-O-β-d-glucopyranosylpresenegenin 28-O-β-d-apiofuranosyl-(1→3)-β-d-xylopyranosyl-(1→4)-[β-d-apiofuranosyl-(1→3)]-α-l-rhamnopyranosyl-(1→2)-{4-O-[(E)-3,4,5-trimethoxycinnamoyl]}-β-d-fucopyranosyl ester, 3-O-β-d-glucopyranosylpresenegenin 28-O-β-d-apiofuranosyl-(1→3)-β-d-xylopyranosyl-(1→4)-[β-d-apiofuranosyl-(1→3)]-α-l-rhamnopyranosyl-(1→2)-[(6-O-acetyl)-β-d-glucopyranosyl-(1→3)]-{4-O-[(E)-3,4,5-trimethoxycinnamoyl]}-β-d-fucopyranosyl ester, 3-O-β-d-glucopyranosylpresenegenin 28-O-β-d-apiofuranosyl-(1→3)-β-d-xylopyranosyl-(1→4)-[β-d-apiofuranosyl-(1→3)]-α-l-rhamnopyranosyl-(1→2)-[β-d-galactopyranosyl-(1→3)]-{4-O-[(E)-3,4,5-trimethoxycinnamoyl]}-β-d-fucopyranosyl ester, and 3-O-β-d-glucopyranosylpresenegenin 28-O-β-d-apiofuranosyl-(1→3)-[α-l-arabinopyranosyl-(1→4)]-β-d-xylopyranosyl-(1→4)-[β-d-apiofuranosyl-(1→3)]-α-l-rhamnopyranosyl-(1→2)-{4-O-[(E)-3,4,5-trimethoxycinnamoyl]}-β-d-fucopyranosyl ester, were isolated from the roots of Securidaca longepedunculata, together with three known compounds. Their structures were established mainly by 2D NMR techniques and mass spectrometry. [Copyright &y& Elsevier]

Abstract: Five anthocyanins, cyanidin 3-(2′′-(6′′′-caffeoyl-β-glucopyranosyl)-6′′-(E-p-coumaroyl)-β-glucopyranoside)-5-β-glucopyranoside, cyanidin 3-(2′′-(6′′′-E-sinapoyl-β-glucopyranosyl)-6′′-(E-p-coumaroyl)-β-glucopyranoside)-5-β-glucopyranoside, cyanidin 3-(2′′-(6′′′-feroyl-β-glucopyranosyl)-6′′-(E-p-coumaroyl)-β-glucopyranoside)-5-β-glucopyranoside, pelargonidin 3-(2′′-(6′′′-E-sinapoyl-β-glucopyranosyl)-6′′-(E-p-coumaroyl)-β-glucopyranoside)-5-β-glucopyranoside, and pelargonidin 3-(2′′-(6′′′-E-p-coumaroyl-β-glucopyranosyl)-6′′-(E-p-coumaroyl)-β-glucopyranoside)-5-β-glucopyranoside, together with five known anthocyanins have been identified in flowers of Cleome hassleriana Queen line. One monoacylated and four diacylated cyanidin 3-sophoroside-5-glucosides were identified as the main anthocyanins in flowers with mauve colouration, while a homologous glycosidic pattern based on pelargonidin was found in the five main anthocyanins from flowers with pink colouration. The anthocyanins identified in C. hassleriana share the same glycosidic pattern as anthocyanins isolated from the genera Raphanus, Brassica and Iberis in the sister family Brassicaceae. [Copyright &y& Elsevier]

Abstract: From the aerial parts of Marrubium thessalum, four labdane diterpenes, 13S-preperegrinine, 3α-hydroxymarrubiin, 9α,13R-15,16-bisepoxy-15β-methoxy-3-oxo-labdan-6β,19-olide and 15-methoxyvelutine C, have been isolated together with four known diterpenes and one methoxylated flavone, ladanein. The structures of the isolated compounds were established by means of NMR (COSY, HSQC, HMBC, NOESY, and ROESY) and MS spectral analyses. Complete NMR assignments are reported for 13R-preperegrinine. Characteristic compounds of the plant were peregrinine and ladanein. [Copyright &y& Elsevier]

Abstract: Nine C-glycosyldeoxyanthocyanidins, 6-C-β-glucopyranosyl-7-O-methylapigeninidin, 6-C-β-glucopyranosyl-7-O-methylluteolinidin, 6-C-β-(2″-O-β-glucopyranosylglucopyranosyl)-7-O-methylapigeninidin, 6-C-β-(2″-O-β-glucopyranosylglucopyranosyl)-7,4′-di-O-methylapigeninidin, 8-C-β-glucopyranosylapigeninidin, 8-C-β-(2″-O-α-rhamnopyranosylglucopyranosyl)apigeninidin, 8-C-β-(2″-O-α-(4″′-O-acetylrhamnopyranosyl)glucopyranosyl)apigeninidin, 6,8-di-C-β-glucopyranosylapigeninidin (8), 6,8-di-C-β-glucopyranosyl-4′-O-methylluteolinidin (9), have been synthesized from their respective C-glycosylflavones (yields between 14% and 32%) by the Clemmensen reduction reaction using zinc-amalgam. The various precursors (C-glycosylflavones) of the C-glycosylanthocyanidins were isolated from either flowers of Iris sibirica L., leaves of Hawthorn ‘Crataegi Folium Cum Flore’, or lemons and oranges. This is the first time C-glycosylanthocyanidins have been synthesized. The structures of all flavonoids including the flavone rotamers were elucidated by 2D NMR techniques and high-resolution electrospray MS. The distribution of the various structural forms of 8 and 9 are different at pH 1.1, 4.5, and 7.0, however, the two pigments undergoes similar structural transformations at the various pH values. Pigments 8 and 9 with C–C linkages between the sugar moieties and the aglycone, were found to be far more stable towards acid hydrolysis than pelargonidin 3-O-glucoside, which has the typical anthocyanidin C–O linkage between the sugar and aglycone. This stability may extend the present use of anthocyanins as nutraceuticals, pharmaceuticals or colorants. [Copyright &y& Elsevier]

Abstract: Lignins from three nonwoody angiosperms were analyzed by 2D NMR revealing important differences in their molecular structures. The Musa textilis milled-wood-lignin (MWL), with a syringyl-to-guaiacyl (S/G) ratio of 9, was strongly acylated (near 85% of side-chains) at the γ-carbon by both acetates and p-coumarates, as estimated from 1H–13C correlations in Cγ-esterified and Cγ–OH units. The p-coumarate H3,5–C3,5 correlation signal was completely displaced by acetylation, and disappeared after alkali treatment, indicating that p-coumaric acid was esterified maintaining its free phenolic group. By contrast, the Cannabis sativa MWL (S/G ∼0.8) was free of acylating groups, and the Agave sisalana MWL (S/G ∼4) showed high acylation degree (near 80%) but exclusively with acetates. Extensive Cγ-acylation results in the absence (in M. textilis lignin) or low abundance (4% in A. sisalana lignin) of β–β′ resinol linkages, which require free Cγ-OH to form the double tetrahydrofuran ring. However, minor signals revealed unusual acylated β–β′ structures confirming that acylation is produced at the monolignol level, in agreement with chromatographic identification of γ-acetylated sinapyl alcohol among the plant extractives. In contrast, resinol substructures involved 22% side-chains in the C. sativa MWL. The ratio between β–β′ and β-O-4′ side-chains in these and other MWL varied from 0.32 in C. sativa MWL to 0.02 in M. textilis MWL, and was inversely correlated with the degree of acylation. The opposite was observed for the S/G ratio that was directly correlated with the acylation degree. Monolignol acylation is discussed as a mechanism potentially involved in the control of lignin structure. [Copyright &y& Elsevier]

Abstract: Two diglucoside stilbene trimers and a benzoisofuranone derivative were isolated from Foeniculum vulgare fruit together with nine known compounds. Their structures were elucidated by spectral methods including 1D, 2D NMR and MS and chemical methods. Antioxidant activity was tested using three methods: DPPH , total antioxidant capacity and assay of lipid peroxidation. [Copyright &y& Elsevier]

Abstract: Bioassay-directed fractionation of the antimalarial active CHCl3 extract of the dried stems of Rourea minor (Gaertn.) Aubl. (Connaraceae) liana led to isolation of two glycosides, rourinoside (1) and rouremin (2), as well as five known compounds, 1-(26-hydroxyhexacosanoyl)-glycerol (3), 1-O-β-d-glucopyranosyl-(2S,3R,4E-8Z)-2-N-(2′-hydroxypalmitoyl)-octadecasphinga-4,8-dienine, 9S,12S,13S-trihydroxy-10E-octadecenoic acid, dihydrovomifoliol-9-β-d-glucopyranoside, and β-sitosterol glucoside. Compounds 1–3 showed weak in vitro activities against Plasmodium falciparum. Their structures and stereochemistry were elucidated by spectroscopic methods and selected enzyme hydrolysis. [Copyright &y& Elsevier]

Abstract: Bioguided-fractionation of the methanol extract of the leaves of Careya arborea led to isolation of a triterpenoid saponin, designated arborenin, and characterized as 3-O-β-d-glucopyranosyl(1→2)-β-d-glucopyranosyl-2α,3β-dihydroxy-taraxast-20-en-28-oic acid (1), together with desacylescin III (2). The structures were determined on the basis of extensive 2D NMR spectroscopic analysis. The saponin showed in vitro antileishmanial activity against Leishmania donovani (strain AG 83). [Copyright &y& Elsevier]

Abstract: Eight cyclolavandulyl esters (β-cyclolavandulyl and β-isocyclolavandulyl acetate, propionate, isobutyrate, isovalerate) were identified in the leaf and root oils of Peucedanum paniculatum L., an endemic species to Corsica, by comparison of their spectroscopic data with those of synthetic material. Their structures were elucidated by spectroscopic methods. The antimicrobial activity of essential oils of leaves and roots was evaluated against eleven microorganisms. [Copyright &y& Elsevier]

Abstract: The novel anthocyanins, malvidin 3-O-(6-O-(4-O-malonyl-α-rhamnopyranosyl)-β-glucopyranoside)-5-O-β-glucopyranoside (2), malvidin 3-O-(6-O-α-rhamnopyranosyl-β-glucopyranoside)-5-O-(6-O-malonyl-β-glucopyranoside) (3), malvidin 3-O-(6-O-(4-O-malonyl-α-rhamnopyranosyl)-β-glucopyranoside)-5-O-(6-O-malonyl-β-glucopyranoside) (4), malvidin 3-O-(6-O-(4-O-malonyl-α-rhamnopyranosyl)-β-glucopyranoside) (5) and malvidin 3-O-(6-O-(Z)-p-coumaroyl-β-glucopyranoside)-5-O-β-glucopyranoside (6), in addition to the 3-O-(6-O-α-rhamnopyranosyl-β-glucopyranoside)-5-O-β-glucopyranoside (1) and the 3-O-(6-O-(E)-p-coumaroyl-β-glucopyranoside)-5-O-β-glucopyranoside (7) of malvidin have been isolated from purple leaves of Oxalis triangularis A. St.-Hil. In pigments 2, 4 and 5 a malonyl unit is linked to the rhamnose 4-position, which has not been reported previously for any anthocyanin before. The identifications were mainly based on 2D NMR spectroscopy and electrospray MS. [Copyright &y& Elsevier]

An anthocyanin, 1, with the novel 4-substituted aglycone, 5-carboxypyranopelargonidin, was isolated in small amounts from the acidified, methanolic extract of strawberries, Fragaria ananassa Duch., by preparative HPLC after purification by partition against ethyl acetate, Amberlite XAD-7 and Sephadex LH-20 column chromatography. It was identified mainly by 2D NMR spectroscopy and electrospray LC-MS as the 3-O-β-glucopyranoside of 5-carboxy-2-(4-hydroxyphenyl)-3,8-dihydroxy-pyrano[4,3,2-de]-1-benzopyrylium, an anthocyanidin which is homologous to 5-carboxypyranomalvidin (vitisidin A) reported in red wines and 5-carboxypyranocyanidin recently isolated from red onions. By comparison of UV–Vis absorption spectra, 1 showed in contrast to 2, pelargonidin 3-O-β-glucopyranoside, a local absorption peak around 360 nm, a hypsochromic shift (8 nm) of the visible absorption maximum, and lack of a distinct UV absorption peak around 280 nm. The similarities between the absorption spectra of 1 in various acidic and neutral buffer solutions implied restricted formation of the instable colourless equilibrium forms, which are typical for most anthocyanins in weakly acidic solutions. The molar absorptivity (∊) of 1 varied little with pH contrary to similar values of for instance the major anthocyanin in strawberry, 2. However, 2 revealed higher ∊-values than 1 at all pH values except 5.1. At pH 5.1, the ∊-value of 1 (6250) was nearly four times the corresponding value of 2 (1720), which showed the potential of 5-carboxypyranopelargonidin derivatives as colorants in solutions with pH around 5. The colours of 1 and 2 in buffered solutions with pH 1.1 and pH 6.9 have been described by the CIELAB coordinates hab (hue angle), C* (chroma), and L* (lightness). [Copyright &y& Elsevier]

The anthocyanins, cyanidin 3-O-(3″-O-β-glucopyranosyl-6″-O-malonyl-β-glucopyranoside)-4′-O-β-glucopyranoside, cyanidin 7-O-(3″-O-β-glucopyranosyl-6″-O-malonyl-β-glucopyranoside)-4′-O-β-glucopyranoside, cyanidin 3,4′-di-O-β-glucopyranoside, cyanidin 4′-O-β-glucoside, peonidin 3-O-(6″-O-malonyl-β-glucopyranoside)-5-O-β-glucopyranoside and peonidin 3-O-(6″-O-malonyl-β-glucopyranoside) have been isolated in minor amounts from pigmented scales of red onion, Allium cepa, in addition to six known anthocyanins. The structures were established mainly by extensive use of 2D NMR spectroscopy and electrospray LC–MS. With exception of cyanidin 4′-glucoside and cyanidin 3,4′-diglucoside reported from Hibiscus esculentus with inadequate documentation, this is the first identification of anthocyanins with 4′-glycosidation. Compared to cyanidin 3-glycosides the cyanidin 4′-glucoside derivatives showed hypsochromic shifts of visible λmax and hyperchromic effects on wavelengths around 440 nm, similar to pelargonidin 3-glycosides. [Copyright &y& Elsevier]

Fourteen sesquiterpenes, three monoterpenes and one diterpene natural product have been isolated from the seeds of Artemisia annua. The possible biogenesis of some of these natural products are discussed by reference to recently reported experimental results for the autoxidation of dihydroartemisinic acid and other terpenoids from Artemisia annua. [Copyright &y& Elsevier]

Four anthocyanins with the same novel 4-substituted aglycone, carboxypyranocyanidin, have been isolated from acidified, methanolic extracts of the edible scales as well as from the dry outer scales of red onion, Allium cepa L. The structures of 1 and 2 were identified as the 3-O-β-glucopyranoside and 3-O-(6″-O-malonyl-β-glucopyranoside) of 5-carboxypyranocyanidin, respectively. This aglycone, 5-carboxy-2-(3,4-dihydroxyphenyl)-3,8-dihydroxy-pyrano[4,3,2-de]-1-benzopyrylium, is with exception of the substitution pattern on the phenyl ring similar to carboxypyranomalvidin (vitisidin A) recently isolated from red wines. In addition to 1 and 2, two analogues of 2 methylated at the terminal carboxyl group of the acyl moiety (3) or at the aglycone carboxyl (4), respectively, were also identified. These latter compounds are most probably formed by esterification of 2 with the solvent (acidified methanol) during the isolation process. The structures were elucidated by 2D NMR spectroscopy and LC–MS. [Copyright &y& Elsevier]

The eudesmane sesquiterpenoid, verticillatol (1), as well as the lignan, (+)-5′-demethoxyepiexcelsin (2), and a known lignan, (+)-epiexcelsin (3), were isolated from Litsea verticillata Hance. Lignan 2 showed moderate anti-HIV activity with an IC50 value of 16.4 μg/ml (42.7 μM), while the known lignan 3 was inactive up to a concentration of 20 μg/ml (48.3 μM). Compound 1 demonstrated weak activity with an IC50 value of 34.5 μg/ml (144.7 μM) while being devoid of cytotoxicity at 20 μg/ml. The structures were elucidated by 1D and 2D NMR spectroscopy, and the absolute configuration of the new sesquiterpenoid was determined by the generation of Mosher esters. [Copyright &y& Elsevier]