Wood polyphenols of Eucalyptus polyanthemos

Sixteen major components have been detected in woody tissues of Eucalyptus polyanthemos. The components identified include 2,3- and 4,6-(hexahydroxydiphenoyl)-glucose, a di-(hexahydroxydiphenoyl)-glucose known as pedunculagin, an ellagitannin which appears to be a cyclic di-(hexahydroxydiphenoyl)-diglucose, 3,4,3′-tri-O-methylellagic acid and its 4′-glucoside, 3,4,3′,4′-tetra-O- and 3,3′-di-O-methylellagic acids. A 3,3′-di-O-methylellagic acid glucoside and 2 gallotannins are possibly present in addition to the unidentified ellagitannin D-13. The distribution of these components in the woody tissues is discussed in relation to heartwood formation. The trimethylellagic acid glucoside was also present in the heartwood of other members of the red-box group of eucalypts.     

Formation and properties of some wood extractives

Chemical and other data concerning the location and site of formation of heartwood extractives are discussed. The biological conditions in the transition zone adjacent to the heartwood boundary are briefly described and some properties of extractives are given. The classes of polyphenolic compounds found in the wood of Eucalyptus species are listed together with the details of ellagic acid derivatives which are the most common class in this genus.     

3,3′-di-O-Methylellagic acid 4-O-rhamnoside from the roots of Prosopis juliflora

From the roots of Prosopis juliflora a new glycoside, 3,3′-di-O-methylellagic acid 4-O-α-l-rhamnopyranoside, and procyanidin have been characterized.     

Spectral differentiation of 3,3′-di-O-methylellagic acid from 4,4′-di-O-methylellagic acid

3,3′-and 4,4′-di-O-methylellagic acid were synthesized, and their spectra (IR, UV, ¹³CFT-NMR) were compared with each other. UV and ¹³C FT-NMR spectra were the most useful for distinguishing them.     

Prinsepiol,a lignan from stems of Prinsepia utilis

Chemical investigation of Prinsepia utilis yielded a new lignan designated prinsepiol, in addition to l-epicatechin and β-sitosteryl-β-glucoside. Prinsepiol was shown to be 1,5 - dihydroxy - 2,6 - di(4′ - hydroxy - 3′ - methoxyphenyl) - 3,7 - dioxabicyclo[3,3,o]octane, on the basis of spectral and other evidence.     

Dimeric phenolic constituents from the roots of Tamarix nilotica

The debarked roots of Tamarix nilotica contain the furanofuran lignan (±)-syringaresinol so far not reported from the Tamaricaceae, and the new natural product ellagic acid 3,3′-dimethyl ether 4-O-β-d-glucopyranoside. Further constituents were isoferulic acid, gallic acid, dehydrodigallic acid and ellagic acid. The structure of the isolated compounds was determined mostly by ¹H and ¹³C NMR spectroscopy.     

Ellagic acids from Callisthene major

3,3′-Di-O-methyl and 3′-O-methyl-3,4-O,O-methylidene ellagic acids have been isolated from Callisthene major.     

Eight flavonol glycosides in Pyrola (pyrolaceae)

As part of a general survey of the flavonoids of Pyrolaceae, the flavonoids of Pyrola virens and P. chlorantha were investigated. Eight flavonol glycosides based upon kaempferol, quercetin and rhamnetin were identified from each of the two species. Two of the glycosides, rhamnetin 3,3′,4′-tri-O-glucoside and rhamnetin 3-O-arabinoside-3′,4′-di-O-glucoside are previously unreported and further, represent an unusual pattern of glycosylation. The similarity of flavonoids and the presence of the unusual substitution pattern supports a conspecific status for the two taxa.     

Individual and combined effects of physicochemical parameters on ellagitannin acyl hydrolase and ellagic acid production from ellagitannin by <Emphasis Type="Italic">Aspergillus oryzae</Emphasis>

The individual and interactive effects of physicochemical parameters on ellagitannin acyl hydrolase activity and ellagic acid production by Aspergillus oryzae using ellagitannins from acorn fringe of oak as substrate were studied. Ellagitannins concentration, incubation time were identified as important physicochemical parameters influencing the enzyme synthesis and the production accumulation, and the substrate concentration with initial pH was determined to has an interactive effect on the enzyme synthesis, while ellagitannins concentration and initial pH with incubation time were found to have interactions on the production accumulation. Furthermore, the parameters were optimized by quadratic programming. Under optimum condition, the fermentation run lasted 84 h with 4 g L⁻¹ ellagitannins concentration, yielding 17.7% ellagic acid. However, the maximum enzyme activity was obtained in 96 h with 5 g L⁻¹ substrate concentration. The research demonstrated a possible way to develop an efficient approach for recovery of higher added-value product (ellagic acid) from forestry byproduct (acorn fringe of oak).     

Optimization of ellagic acid production from ellagitannins by co-culture and correlation between its yield and activities of relevant enzymes

Aspergillus oryzae was co-cultured with Trichoderma reesei using acorn cups extract containing up to 62% ellagitannins as substrate to produce ellagic acid with relatively high levels of ellagitannin acyl hydrolase, cellulase and xylanase. Ellagitannins concentration, initial pH, T. reesei and A. oryzae during the fermentation were identified as important process parameters effecting ellagic acid accumulation and the enzymes syntheses. These parameters were optimized by uniformity design to determine the optimum condition for ellagic acid production. Under optimum operational condition, ellagic acid yield could be arrived at 24%, when the fermentation run lasted 96h with an initial pH of 4.5, an ellagitannins concentration of 4gl(-1), T. reesei of 3ml and A. oryzae of 3ml. Meanwhile, it was found that the three enzymes activities correlated very well with ellagic acid yield, resulting in model with high coefficient of determination (R(2)=0.98). The results indicate that the mixed culture of T. reesei and A. oryzae is an effective approach to produce an enzyme system of degrading ellagitannins for ellagic acid production.     

Natural wood colouring process in Juglans sp. (J. nigra, J. regia and hybrid J. nigra 23 ×J. regia) depends on native phenolic compounds accumulated in the transition zone between sapwood and heartwood

 Radial distribution of soluble phenolics was investigated at different heights in stems of Juglans nigra, J. regia and hybrids J. nigra 23 × J. regia. Four major phenolic compounds were studied: hydrojuglone glucoside (HJG), quercitrin (QUER) and two unknown compounds characterized as two ellagic acid derivatives E1 and E2. HJG and E1 content increased gradually in the sapwood, peaked in the sapwood-heartwood transition zone, and decreased drastically in the heartwood. QUER was accumulated preferentially around the transition zone, and its content was relatively low in the outer part of the sapwood and in the inner part of the heartwood. E2 content was low in the sapwood and increased in the heartwood. The heartwood formation was marked by the accumulation of new soluble compounds. The relationship between wood extractives and wood colour were evaluated and discussed. HJG was considered to be a major precursor of heartwood colour providing chromophores through hydrolysis (deglucosylation), oxidation and polymerization processes. Received: 2 September 1997 / Accepted: 23 November 1997     

Ueber den abbau von polyphenolen durch pilze der gattung Fusarium

The ability of 16 Fusarium species to degrade polyphenols was investigated. Phenols, benzoic acids, cinnamic acids, flavonoids and isoflavones are efficiently catabolized by all strains investigated. o-coumaric acid is transformed into 4-hydroxycoumarin by 7 species. A pronounced capability for methyl ether cleavage is demonstrated by stepwise o-demethylation of veratric acid and 5,7,4′-trimethoxyisoflavone. The latter compound is degraded via the sequence: 5,7,4′-trimethoxyisoflavone → 5,4′-dimethoxy-7-hydroxyisoflavone → biochanin A → genistein → orobol → ring fission products.     

Hydropiperoside,a novel coumaryl glycoside from the root of Polygonum hydropiper

From the methanol extract of the root of Polygonum hydropiper, a novel coumaryl glycoside hydropiperoside was isolated together with anthraquinone, ellagic acid 3,3′-di-O-methyl ether, gallic acid, two quercetin glycosides and an unidentified aromatic δ-lactone possessing antifertility activity. The structure of hydropiperoside was established as β-d-(1,3,6-tri-p-coumaryl)-fructofuranosyl-α-d-glucopyranoside by combination of extensive ¹H NMR and ¹³C NMR spectra, and the FD/MS spectrum.     

Chemical factors affecting the brown-rot decay resistance of Scots pine heartwood

The cell wall chemistry (amount of hemicellulose, f-cellulose, and total lignin) and the concentration of extractives (total acetone-soluble extractives, resin acids, pinosylvins and the total phenolics quantified as tannin acid equivalents) were studied in brown-rot resistant and susceptible juvenile heartwood of Scots pine (Pinus sylvestris L.). The study material consisted of a total of 18 trees from two 34-year-old progeny trials at Korpilahti and Kerimäki. The trees were selected from among 783 trees whose decay rate had previously been screened in a laboratory test using a brown-rot fungus, Coniophora puteana. Samples from neither location showed any significant difference in the concentration (mg/cm³) of hemicellulose, f-cellulose and total lignin between the decay resistant and susceptible trees. At both locations only the concentration of total phenolics was higher in the decay-resistant heartwood than in the decay-susceptible heartwood. At Korpilahti, the amount of acetone-soluble extractives and the concentration of pinosylvin and its derivatives were higher in the resistant than in the susceptible trees.     

Xanthones and triterpenes of Calophyllum tomentosum

The bark, branch timber, sapwood and heartwood extractives of Calophyllum tomentosum contain friedelin, friedelan-3β-ol, betulinic acid, taraxero     

Phytochemical analysis of the labdanum-poor Cistus creticus subsp. eriocephalus (Viv.) Greuter et Burdet growing in central Italy

Phenolic constituents and essential oil from the aerial parts of Cistus creticus subsp. eriocephalus (Viv.) Greuter et Burdet growing in central Italy were analysed by HPLC-MSⁿ and GC–MS, respectively. Furthermore, six constituents were isolated by semipreparative HPLC from the methanol extract and their structures were determined on the basis of 1D and 2D NMR measurements as well as MS spectra. Isolated compounds were one new natural product, i.e. the shikimic acid ester 3,5-diihydroxy-4-(O-β-d-glucopyranosyl)-cyclohex-1-en-1-(O-β-d-glucopyranosyl)-ester (27), and six flavonoid glycosides, namely quercetin-3-O-β-D glucopyranoside (16), quercetin-3-O-rhamnoside (17), tricetin-4′-O-β-D glucopyranoside (24), tricetin-4′-O-β-D rutinoside (21), 3′-methoxy-quercetin-3-O-(3-β-Dglucopyranosyl-2-rhamnopyranosil-4-glucopyranosyl-2-rhamnopyranosil)-glucoside (25) and 3′,4′dimethoxyquercetin-3-O-rhamnopyranoside (26). GC–MS analysis of the essential oil highlighted the occurrence of aliphatic compounds, mainly fatty acids, whereas labdane-type compounds were very scant. Our results showed that C. creticus subsp. eriocephalus has a different chemical profile with respect to the other subspecies due to the lack of labdane derivatives. On the other hand, this subspecies contains several phenolic constituents like ellagitannins, gallotannins and flavonoids, some of which can be of chemotaxonomic value.     

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.     

ent-Eudesmane sesquiterpenoids, galloyl esters of the oak lactone precursor, and a 3-O-methylellagic acid glycoside from the wood of Platycarya strobilacea

ent-Eudesmane sesquiterpenoids, 8,11-dihydroxy-2,4-cycloeudesmane, 11-hydroxy-2,4-cycloeudesman-8-one and 2,4-cyclo-7(11)-eudesmen-8-one, were isolated from the wood of Platycarya strobilacea, which has been used as an aromatic tree since at least the 18th century. On charring the wood, 2,4-cyclo-7(11)-eudesmen-8-one was detected in the smoke. In the charred wood, the concentrations of ellagitannins, such as galloyl pedunculagin, dramatically decreased, whereas concentrations of pentagalloyl glucose, and other gallotannins were relatively stable. In addition, two other compounds, the 6′-O-m- and p-digalloyl oak lactone precursor and the 3-O-methylellagic acid 4′-O-(4″-O-galloyl)-xylopyranoside, were isolated from the charred wood along with m- and p-digallic acid.     

Ellagitannins from Tellima grandiflora

Three ellagitannins present in Tellima grandiflora have been isolated and partly identified. Two are 2,3-digallyl-4,6-hexahydroxydiphenoyl -β-d-glucopyranose and 1,2,3-trigallyl-4,6-hexahydroxydiphenoyl-β-d-glucopyranose. The third is complex, with five gallyl and two hexahydroxydiphenyl residues; hydrolysis yielded glucose, gallic acid and ellagic acid.     

New insights into the bioavailability of red raspberry anthocyanins and ellagitannins

Red raspberries, containing ellagitannins and cyanidin-based anthocyanins, were fed to volunteers and metabolites appearing in plasma and urine were analysed by UHPLC-MS. Anthocyanins were not absorbed to any extent with sub nmol/L concentrations of cyanidin-3-O-glucoside and a cyanidin-O-glucuronide appearing transiently in plasma. Anthocyanins excreted in urine corresponded to 0.007% of intake. More substantial amounts of phase II metabolites of ferulic acid and isoferulic acid, along with 4′-hydroxyhippuric acid, potentially originating from pH-mediated degradation of cyanidin in the proximal gastrointestinal tract, appeared in urine and also plasma where peak concentrations were attained 1–1.5 h after raspberry intake. Excretion of 18 anthocyanin-derived metabolites corresponded to 15.0% of intake, a figure substantially higher than obtained in other anthocyanin feeding studies. Ellagitannins pass from the small to the large intestine where the colonic microbiota mediate their conversion to urolithins A and B which appeared in plasma and were excreted almost exclusively as sulfate and glucuronide metabolites. The urolithin metabolites persisted in the circulatory system and were excreted in urine for much longer periods of time than the anthocyanin metabolites although their overall urinary recovery was lower at 7.0% of intake. It is events originating in the proximal and distal gastrointestinal tract, and subsequent phase II metabolism, that play an important role in the bioavailability of both anthocyanins and ellagitannins and it is their metabolites which appear in the circulatory system, that are key to elucidating the mode of action(s) underlying the protective effects of these compounds on human health.