Polyphenols of Eucalyptus sideroxylon wood

Twenty-three major components were detected in the methanol extractives of the heartwood of Eucalyptus sideroxylon. The components identified include resveratrol, resveratrol-β-glucoside, 3,3′-di- and 3,3′,4-tri-o-methylellagic acids and their glucosides. The 3,3′-di-o-methylellagic acid 4′-glucoside isolated had properties significantly different from those previously reported for this compound. Also present were gailic acid, catechin, ellagic acid, an unidentified stilbene, the ellagitannins D-6 and D-13, polymerized leucocyanidin and an oily material. The sapwood contained gailic acid, small amounts of ellagitannins and ellagic acids and traces of other components. The heartwood extractives of related eucalypt species were also examined.     

In vitro antifungal activity and mode of action of selected polyphenolic antioxidants on Botrytis cinerea

Six selected antioxidants (catechin, quercetin-3-galactoside, cyanidin-3-glucoside, pelargonidin-3-glucoside, ellagic and gallic acids) were evaluated in vitro for their antifungal activities and mode of action on Botrytis cinerea Pers., one of the most important pathogens of strawberries. Inhibitory effects were found for all the tested antioxidants, but varied at different fungal developmental stages. Catechin and quercetin-3-galactoside showed linear inhibitory effects on germ tube elongation, with the highest suppression ratios of 54.8% and 58.8% respectively. No significant effect was found on spore germination between treatments and control. Gallic acid showed very strong and linear inhibition on spore germination (r = ?0.95), but the effect diminished after spore germination. Cyanidin-3-glucoside and pelargonidin-3-glucoside provided effective control on the fungi as concentrations increased. The arresting effect of ellagic acid on development of B. cinerea was quadratic. Ellagic acid inhibited germ tube elongation and mycelial growth at its highest and lowest concentrations, while no effects were observed at its medium concentration used in this study.     

Controlling selectivity and enhancing yield of flavonoid glycosides in recombinant yeast

Flavonoid glycosides are known for their medicinal properties and potential use as natural sweeteners. In this study, Saccharomyces cerevisiae expressing a flavonoid glucosyltransferase from Dianthus caryophyllus was used as a whole-cell biocatalyst. The yeast system’s performance was characterized using the flavanone naringenin as a model substrate for the production of naringenin glycosides. It was found that final naringenin glycoside yields increased in a dose-dependent manner with increasing initial naringenin substrate concentrations. However, naringenin concentrations >0.5 mM did not give further enhancements in glycoside yield. In addition, a method for controlling overall selectivity was discovered where the glucose content in the culture medium could be altered to control the selectivity, making either naringenin-7-O-glucoside (N7O) or naringenin-4′-O-glucoside (N4O) the major products. The highest yields achieved were 87 mg/L of N7O and 82 mg/L of N4O using 40MSGI and 2xMSGI media, respectively. The effects of two intermediates involved in UDP-glucose biosynthesis, uridine 5′-monophosphate (UMP) and orotic acid, on glycoside yields were also determined. Addition of UMP to the culture medium significantly decreased glycoside yield. In contrast, addition of orotic acid to the culture medium significantly enhanced the glycoside yield and shifted the selectivity toward N7O. The highest naringenin glycoside yield achieved using 10 mM orotic acid in the 40MSGI media was 155 mg/L, a 71% conversion of substrate to product.     

Acylated anthocyanins and flavonols from purple flowers of Dendrobium cv. ‘Pompadour’

Two rare anthocyanins, cyanidin 3-(6-malonylglucoside)-7,3′-di(6-sinapylglucoside) and the demalonyl derivative, were characterised as the purple floral pigments of Dendrobium cv. ‘Pompadour’. Nine known flavonol glycosides were also identified, including the 3-rutinoside-7-glucosides of kaempferol and quercetin. One new glycoside was detected: the ferulyl ester of quercetin 7-rutinoside-7-glucoside. These flavonoid patterns are typical for plants in the family Orchidaceae.     

Chalcones and other flavonoids from Asarum sensu lato (Aristolochiaceae)

Seventy-five taxa belonging to the genus Asarum sensu lato were studied for their composition of flavonoids. Three chalcones and an aurone were found as major components. The chalcones were identified as chalcononaringenin 2′,4′-di-O-glucoside, 4,2′,4′-tri-O-glucoside, 4-O-glucoside, and the aurone as aureisidin 4,6-di-O-glucoside. The glycoside, 2′,4′-di-O-glucoside was detected in all taxa examined, and is a chemotaxonomical feature of Asarum sensu lato. 4,2′,4′-Tri-O-glucoside was found from the taxa classified into the genera Asiasarum, Geotaenium and Heterotropa by Maekawa's system. On the other hand, the glycoside was not detected from three Asarum sensu stricto species, A. caudigerum, A. caulescens and A. leptophyllum. In contrast, aurone, aureusidin 4,6-di-O-glucoside occurred in two Asarum s.s., A. caulescens and A. leptophyllum. Thus, the Asarum s.s. and other Maekawa's genera, Asiasarum, Geotaenium and Heterotropa could distinguish by the presence or absence of some anthochlor pigments. Other flavonoids were isolated from the selected 18 Asarum species. They were characterized as some flavonol 3- or 3,7-O-glycosides based on kaempferol, quercetin and isorhamnetin, flavone, apigenin 6,8-di-C-glycoside, flavanone, naringenin 5,7-di-O-glucoside, and xanthone, mangiferin.     

Flavonoids from Haplophyllum pedicellatum, H. robustum AND H. glabrinum

Haplophyllum pedicellatum, H. robustum and H. glabrinum all yielded the known compound gossypetin 8,3′-dimethyl ether 3-rutinoside. In addition the first two species afforded isorhamnetin and its 3-rutinoside. A new glycoside, gossypetin 8,3′-dimethyl ether 3-glucoside was obtained from H. pedicellatum together with the 3-malonylrutinoside, 3-malonylglucoside and 3-galactoside of isorhamnetin plus kaempferol 3-malonylglucoside. H. robustum yielded isorhamnetin 7-glucoside and 3-glucoside and quercetin 3-galactoside, while H. glabrinum was found to contain gossypetin 8-methyl ether 3-malonylrutinoside in addition to kaempferol and isorhamnetin 3-glucoside.     

Effects of cultivar, fruit number and reflected photosynthetically active radiation on Fragaria x ananassa productivity and fruit ellagic acid and ascorbic acid concentrations

BACKGROUND AND AIMS: A number of strawberry varieties were surveyed for their total ellagic acid concentration, and attempts were made to determine if ellagic acid and ascorbic acid concentrations of two strawberry cultivars could be increased by polythene reflective mulches. METHODS: After adjusting crop yields and cultivation using polythene mulches with two different PAR reflective capacities, field- and polytunnel-grown strawberries were analysed for ellagic acid and ascorbic acid concentrations by HPLC. Comparative measurements of yield and fruit quality were determined along with plant developmental changes. KEY RESULTS: Ellagic acid concentration varied widely with strawberry cultivar (60-341 microg g(-1) frozen weight), as did the ratio of conjugated ellagic acid : free ellagic acid. Also, there was significant year-to-year variation in total ellagic acid concentration with some cultivars. Mulches with different reflective capacities impacted on strawberry production; highly reflective mulches significantly increased growth and yield, the latter due to increases in fruit size and number. CONCLUSIONS: Highly reflective mulches significantly increased total concentrations of ellagic acid and ascorbic acid relative to control in fruit of different cultivars. The potential of agronomic practices to enhance the concentration and amounts of these important dietary bioactive compounds is discussed.     

A chemotaxonomic study of flavonoids from european teucrium species

A survey of aerial tissues of 42 European taxa of the genus Teucrium has revealed the widespread presence of five surface flavonoids: cirsiliol, cirsimaritin, cirsilineol, salvigenin and 5-hydroxy-6,7,3′,4′-tetramethoxyflavone. The latter two compounds are useful taxonomic markers in that salvigenin is characteristic of species of section Polium, while 5-hydroxy-6,7,3′,4′-tetramethoxyflavone is completely confined to species of the other five sections surveyed. Eleven flavone glycosides, four flavonol glycosides and the glycoflavone vicenin-2 were found to occur as vacuolar constituents. One of the flavone glycosides, cirsimaritin 4′-glucoside, only occurs in the species T. arduini, while two others, hypolaetin and isoscutellarein 7-acetyl-allosylglucosides, are characteristic of the closely related T. chamaedrys and T. webbianum. 6-Hydroxyluteolin is widely present as the 7-glucoside and 7-rhamnoside, the latter compound being a new glycoside. In general, the chemical results are correlated with sectional classification and usefully indicate that at least one taxon, T. compactum, is misplaced within the genus. Phyletically, the restriction of flavonol glycosides mainly to section Teucrium suggests that this may be the basic group within the genus.     

9-hydroxy substituted iridoids from Gelsemium sempervirens

Two chemotypes of Gelsemium sempervirens were investigated. One, cultivated in Copenhagen, contained six iridoids in appreciable amounts, namely gelsemide, gelsemide 7-glucoside, gelsemiol, gelsemiol 1- and 3-glucoside, and 9-hydroxysemperoside. The other sample, collected in the wild in North Carolina, U.S.A., contained semperoside and the known brasoside as well as the coumarin glycoside fabiatrin. The two iridoids were found only in trace amounts in the cultivated specimen. The structures of the seven new iridoids were established mainly by spectroscopic methods and that of gelsemide was confirmed by X-ray analysis. Two new structural features were noted: three of the compounds carried a hydroxyl group at the 9-position, while two contained the glucosyl moiety at C-3. All iridoids were lactones of the asperuloside type with or without a 3,4-double bond.     

Phenolic compounds from parasitic Sapria himalayana f. albovinosa and Sapria myanmarensis (Rafflesiaceae) in Myanmar

Three anthocyanins, four flavonols, three aromatic acids and five gallotannins were isolated from Sapria himalayana f. albovinosa in Myanmar. They were identified as cyanidin 3-O-glucoside (1), cyanidin 3-O-xyloside (2) and peonidin 3-O-glucoside (3) (anthocyanins), quercetin 3-O-glucoside (4), quercetin 7-O-glucoside (5), quercetin 3-O-glucuronide (6) and isorhamnetin 3-O-glucoside (7) (flavonols), ellagic acid (8), gallic acid (9) and ethyl gallate (10) (aromatic acids), and 1,2,4,6-tetragalloylglucose (11), 1,4,6-trigalloylglucose (12), 1,2,6-trigalloylglucose (13), 1,2,4-trigalloylglucose (14) and 1,6-digalloylglucose (15) (gallotannins) by UV, LC-MS, acid hydrolysis, NMR and/or HPLC comparisons with authentic samples. The chemical composition of S. myanmarensis was qualitatively the same with that of S. himalayana f. albovinosa. Phenolic compounds of the Rafflesiaceae species including Sapria, Rafflesia and Rhizanthes were isolated and identified in this survey for the first time.     

The flavonol glycosides in the fruit of Pyrus communis L. cultivar Bon Chrétien

1. Two new flavonol glycosides were isolated from the fruit of Pyrus communis L. cultivar Bon Chrétien. These were identified as isorhamnetin 3-rhamnogalactoside and a derivative of isorhamnetin 3-glucoside which was associated (possibly acylated) with an unknown aliphatic organic acid. 2. The melting point of isorhamnetin 3-glucoside isolated from Bon Chrétien pears is different from that of isorhamnetin 3-glucoside previously isolated from Argemone mexicana and Calendula officinalis. 3. Isorhamnetin 3-rhamnoglucoside was isolated from the fruit of Pyrus communis L. cultivar Bon Chrétien. This glycoside appears to be identical with narcissin, previously isolated from Narcissus tazetta and Lilium auratum. 4. Isoquercitrin, previously reported to be present in pear leaves, was isolated from the fruit of Bon Chrétien pears. 5. The isolated glycosides were present in the peels and flesh of the fruit, but were absent from the cores.     

Biologically-active flavonoids from Gossypium arboreum

A new flavonol glycoside, gossypetin 8-O-rhamnoside, was isolated from flower petals of Gossypium arboreum along with quercetin 7-O-glucoside, quercetin 3-O-glucoside and quercetin 3′-O-glucoside. These compounds showed antibacterial activity against Pseudomonas maltophilia and Enterobacter cloacae.     

Capsugenin,a dammarane triterpene from Corchorus capsularis

From the leaves of Corchorus capsularis a new dammarane triterpene glycoside, capsin, has been isolated. Capsin was identified as the 3-glucoside of 20,24-epoxy-3β,12β,25,30-tetrahydroxydammarane from spectral data. Capsin was tentatively assigned the (20S, 24S)-configuration by comparison with data available for similar compounds. One of the oxidation products of the aglycone appears to be a friedo-type derivative, formed by concerted methyl migration on decarboxylation of a C-30 carboxylic acid intermediate.     

The Metabolic Fate of (4-Chloro-2-Methylphenoxy)Acetic Acid in Higher Plants: II. METABOLISM IN LIQUID CULTURED CALLUS CELLS OF WHEAT (Triticum aestivum L. )

Callus cells of two wheat cultivars in liquid medium rapidlyabsorbed (4-chloro-2-methylphenoxy)acetic acid (MCPA) and convertedit to ethanol-soluble products. The herbicide was transformedby methyl-hydroxylation, the major terminal residue being analcoholic glycoside of (4-chloro-2-hydroxymethylphenoxy)aceticacid. Minor metabolites were an ether-soluble conjugate of MCPA,an MCPA-glycoside and five additional aglycones. No metaboliteswere released into the medium. The rate of metabolism was lowerthan that of uptake such that a substantial amount of the radioactivityinitially accumulating in the cells was unmodified MCPA. Metabolismwas qualitatively and quantitatively similar to that in shootsexcised from seedlings. Cells also absorbed an ether-solubleconjugate of MCPA which had been isolated from carrot (Daucuscarota L. ), though less readily than MCPA itself. MCPA andthe above metabolites were produced, with the alcoholic glycosideagain as the major residue. Some MCPA was present in the medium,due probably to the action of extracellular hydrolases. Key words: MCPA, Triticum aestivum, Cell culture, Hydroxylation     

Ellagic acid 4-O-rutinoside from pods of Prosopis juliflora

From the pods of Prosopis juliflora a new glycoside, ellagic acid 4-O- rutinoside, has been characterized.     

Cyanidin glycosides in flowers of genus Corydalis (Fumariaceae)

Nine taxa of Corydalis were surveyed for their floral anthocyanins. Five cyanidin glycosides: cyanidin 3-glucoside, cyanidin 3-sambubioside, cyanidin 3-rutinoside, cyanidin 3-(2^G-xylosylrutinoside) and cyanidin 3-(2^G-xylosylrutinoside)-7-glucoside were isolated from these taxa and identified by chemical and spectroscopic techniques. A novel anthocyanin was found in the flowers of Corydalis elata and Corydalis flexuosa cultivars, and identified to be cyanidin 3-(2^G-xylosylrutinoside)-7-glucoside. Two anthocyanins, cyanidin 3-sambubioside and cyanidin 3-(2^G-xylosylrutinoside), were also found for the first time in Corydalis flowers. Furthermore, the major anthocyanin constituent of the flowers was cyanidin 3-sambubioside in the outer petals of Corydalis ambigua and Corydalis lineariloba, and cyanidin 3-rutinoside in those of Corydalis decumbens, Corydalis curvicalcarata and Corydalis speciosa. Similarly, Corydalis incisa contained cyanidin 3-(2^G-xylosylrutinoside), and C. flexuosa ‘China Blue’ and ‘Blue Panda’, and C. elata contained the most complex structural pigment, cyanidin 3-(2^G-xylosylrutinoside)-7-glucoside, as their dominant anthocyanin in their outer petals. According to the results of anthocyanin analyses, these nine plants were classified into four groups: groups A (three taxa), B (two taxa), C (one taxa) and D (three taxa). On the other hand, the anthocyanin constituent of their inner petals was composed of cyanidin 3-rutinoside as only one dominant anthocyanin.     

In vitro Shoot Regeneration from Seedling Root Segments of Brassica oleracea and Brassica napus Cultivars

Root segments taken from aseptically-grown seedlings of Brassicaoleracea var. italica cv. Green Comet were used in an investigationof factors affecting in vitro regeneration. Shoot regenerationwas found to increase with seedling age and to be highest inroot segments adjacent to the hypocotyl and lowest in segmentsadjacent to the root tip. In a comparison of a range of mediaand agar concentrations shoot formation was favoured by complexmedia containing reduced nitrogen and was higher on gelled mediathan in liquid medium. The effects of various cytokinins andauxins were investigated; KN was the best cytokinin and IAAand Picloram the best auxins for shoot induction. Root segmentsfrom six other Brassica cultivars were grown on the medium devisedfor Green Comet; shoots were regenerated from two B. oleraceacultivars and two B. napus cultivars, but not from the B. campestriscultivars tested. Brassica oleracea var. italica, Brassica napus, Brassica campestris, seedling root culture, shoot regeneration     

An ellagic acid glycoside from the pods of Prosopis juliflora

From the fresh pods of Prosopis juliflora, a new glycoside has been isolated and characterized as ellagic acid 4-O-α-L-rhamnosylgentiobioside.     

Four acylated flavonol glycosides from leaves of Strychnos variabilis

Four new acylated flavonol glycosides have been isolated and identified from the leaves of Strychnos variabilis: quercetin 3-(4″-trans-p-coumaroyl)robinobioside-7-glucoside (variabiloside A) and its cis derivative (variabiloside B), kaempferol 3-(4″-trans-p-coumaroyl)robinobioside-7-glucoside (variabiloside C) and its cis derivative (variabiloside D).