Water-soluble Phenolic Compounds Research Articles

Phytotoxicity and Detoxification of Fresh Coir Dust and Coconut Shell

Phytotoxicity and detoxification of fresh coir dust and milled coconut shell were studied using lettuce bioassay, phytotoxin analysis and incubation with liming and other amendments at different temperatures. Fresh coir dust and fresh fine coconut shell severely inhibited root elongation of lettuce. The phytotoxicity was attributed to the phenolic compounds in the substrates and the higher concentration of water-soluble phenolic compounds in the finer substrates aggravated the phytotoxicity. The critical concentration of phenolic compounds toxic to lettuce root growth was found to be about 2 mg L−1. Fresh coir dust and coconut shell could be detoxified by incubation. Liming and elevated incubation temperature significantly increased the processes of detoxification.

Antioxidant activity of plant extracts on the inhibition of citral off‐odor formation

Grape seed, pomegranate seed, green tea, and black tea extracts were used to inhibit the off-odor from citral degradation. A 0.1 M citrate buffer (pH 3), containing 100 ppm citral and 200 ppm gallic acid equivalent plant extract, was incubated at 40 degrees C. The reaction mixtures were analyzed by high-performance liquid chromatography (HPLC) at days 0, 6, 10, 13, and 16 to monitor degradation of citral and formation of alpha, p-dimethylstyrene, p-cymene-8-ol, and p-methylacetophenone. The addition of plant phenolic extracts could not inhibit citral degradation, however, all four plant extracts significantly inhibited p-methylacetophenone formation. The samples, with the addition of plant extracts, exhibited higher concentrations of alpha, p-dimethylstyrene and p-cymene-8-ol than the control. This is presumed to be due to the oxygen-scavenging effect of plant extracts blocking the pathway from p-cymene-8-ol to p-methylacetophenone. Our results suggest that these plant extracts act as general antioxidants inhibiting the generation ofp-methylacetophenone regardless of the types of water-soluble phenolic compounds existing in the plant extracts.

Separation and characterization of phenolic compounds in fennel (Foeniculum vulgare) using liquid chromatography-negative electrospray ionization tandem mass spectrometry.

Liquid chromatography (LC) diode array detection (DAD) coupled to negative electrospray ionization (ESI) tandem mass spectrometry (MS/MS) was used for the rapid and sensitive identification of water-soluble phenolic compounds in fennel waste. The plant material was first extracted and then chromatographed on Sephadex LH-20 to afford seven fractions, each of them being subjected to LC-MS analysis. Identification of the compounds was carried out by interpretation of UV, MS, and MS/MS spectra. Forty-two phenolic substances were identified, 27 of which had not previously been reported in fennel, including hydroxycinnamic acid derivatives, flavonoid glycosides, and flavonoid aglycons.

Novel octulosonic acid derivatives in the composite Smallanthus sonchifolius

Two novel octulosonic acid derivatives with a 6,8-dioxabicyclo[3.2.1]octane skeleton that are major water-soluble phenolic compounds were found in the roots of Smallanthus sonchifolius. The structures of these compounds were determined to be (1 R,2 S,3 S,4 R,5 S,7 R)-4-hydroxy-7-hydroxymethyl-3-[3-(3,4-dihydroxyphenyl)-1-oxo-2-propenyloxy]-6,8-dioxabicyclo[3.2.1]octan-5-carboxylic acid (4- O-caffeoyl-2,7-anhydro- d- glycero-β- d- galacto-oct-2-ulopyranosonic acid) and (1 R,2 S,3 R,4 R,5 S,7 R)-2,4-dihydroxy-7-hydroxymethyl-2,3-bis[3-(3,4-dihydroxyphenyl)-1-oxo-2-propenyloxy]-6,8-dioxabicyclo[3.2.1]octan-5-carboxylic acid (4,5-di- O-caffeoyl-2,7-anhydro- d- glycero-β- d- galacto-oct-2-ulopyranosonic acid) by MS, NMR and CD spectral analyses.

Caffeic acid derivatives in the roots of yacon (Smallanthus sonchifolius).

Five caffeic acid derivatives were found in the roots of yacon, Smallanthus sonchifolius (Poepp. and Endl.) H. Robinson, Asteraceae, as the major water-soluble phenolic compounds. The structures of these compounds were determined by analysis of spectroscopic data. Two of these were chlorogenic acid (3-caffeoylquinic acid) and 3,5-dicaffeoylquinic acid, common phenolic compounds in plants of the family Asteraceae. Three were esters of caffeic acid with the hydroxy groups of aldaric acid, derived from hexose. The structure of the aldaric moiety was determined by hydrolysis and comparison of NMR spectra with those of standard aldaric acids. The compounds were novel caffeic acid esters of altraric acid: 2,4- or 3,5-dicaffeoylaltraric acid, 2,5-dicaffeoylaltraric acid, and 2,3,5- or 2,4,5-tricaffeoylaltraric acid.

Kalmia angustifolia: Ecology and Management1

Kalmia angustifolia is a problematic understory shrub in boreal forests of eastern Canada. In this article, we discuss the nature of its interference with conifer regeneration, and control measures using herbicides. Although laboratory studies suggest the leaching of water-soluble phenolic compounds from Kalmia, allelopathic interference cannot be invoked as a cause of conifer regeneration failure because of lack of field evidences. Because of severe inhibitory effects of Kalmia on conifer growth and its role in long-term habitat degradation, the development of strategies for Kalmia management is a priority research area. Neither prescribed burning, plowing, scarification, nor 2,4-D application was proven effective in Kalmia control. Two studies were carried out using transplanted Kalmia to determine the efficacy of several herbicides and a herbicide plus burning treatment to control Kalmia. In one experiment, eight treatments were applied. They were control, glyphosate (3.36 kg/ha), glyphosate (2.88 kg/h...

Some Aspects of the Relationship between Redox Metabolism and the Structure of Calciphytes

Calciphyte species form a systematically and structurally heterogeneous group of plants capable of tolerating highly stressful conditions. Various structural adaptations occur in calciphytes to protect them against excess light (leaf pubescence) and moisture loss (waxy coating). Their shoot structure determines the volume of primary plant production. The present work studied the relationship between the antioxidant status and structural features of some calciphyte species. Redox metabolism in plant leaves was assessed using parameters such as water content, photosynthetic pigments, soluble carbohydrates, water-soluble phenolic compounds, water-soluble and membrane-bound proteins, and lipid peroxidation (LPO) level. The data obtained showed that the contents of the components regulating redox metabolism correlate both with each other and with the structural parameters of plants. In particular, the content of photosynthetic pigments in multi-species communities is lower in taller plants than in low-growing ones. The content of phenolic compounds and the level of LPO in calciphyte leaves are associated with the level of development of wax covering. The plants forming clumps and vigorous shoots exhibit increased LPO activity

Water soluble phenolic compounds of the marine phanerogam Posidonia oceanica in a Mediterranean area colonised by the introduced chlorophyte Caulerpa taxifolia

Unbound phenolic compounds of leaves of the marine phanerogam Posidonia oceanica (L.) Delile from an area colonised by the introduced chlorophyte Caulerpa taxifolia (Vahl) C. Ag. have been investigated and their concentration assessed using high performance liquid chromatography (HPLC). Leaves of the colonised area exhibited high maximum values of phenolic contents in comparison with a reference area. Nonetheless, because of the high variability of the values, further studies will be needed to confirm that P. oceanica plants are producing unbound phenolic compounds in reaction to growth of C. taxifolia. Ferulic acid, phloridzin, phloroglucinol, p-anisic acid, acetosyringone, sinapic acid, phenol, p-hydroxybenzoic acid, p-coumaric acid and cinnamic acid represent more than 95% of the mean relative concentration of phenolic compounds measured. Several of these compounds had not hitherto been reported in P. oceanica.

SHORT COMMUNICATION: Influence of soil temperature and moisture on water-soluble phenolic compounds in manured soil

Water-soluble phenolic compounds were measured in fresh and decomposed animal manures. Following manure addition to soil, less than 50% of the water-soluble phenolic compounds were recovered within 1 h. The concentration of phenolic compounds decreased more slowly with decreasing temperatures to 4 °C and increasing soil moisture content during a 14-d incubation. The results suggest that water-soluble phenolic compounds were both adsorbed onto soil particles and decomposed by microorganisms. Key words: Animal manure, phenolic compounds, compost

Effect of mango ( Mangifera indica L.) seed kernels pre-extract on the oxidative stability of ghee

A pre-extract (PE) prepared by heating mango ( Mangifera indica L.) seed kernel powder (MSKP) and ghee (1:1 w/w) to 120°C contained 430 mg% phospholipids and 224 mg% water-extractable phenolic compounds. The presence of at least eleven phospholipids in a chloroform-methanol extract of MSKP and eight water-soluble phenolic compounds in PE was confirmed. Addition of the PE to ghee at 4, 6, 8 and 10% (v/v) levels increased the phospholipid content of ghee samples over the control to 11·2, 20·9, 26·4 and 34·4 mg% of ghee and those of water-extractable phenolic compounds to 7·4, 11·1, 15·5 and 20·7 mg% of ghee, respectively. The samples of ghee with added BHA contained levels of these compounds similar to those of control samples. The antioxidant potentialities calculated from the induction periods of ghee samples stored at 80°C in comparison to control were in the order: 1·3 (0·02% BHA) < 2·6 (4% PE) < 2·9 (6% PE) < 3·1 (8% PE) < 3·2 (10% PE) suggesting that the phospholipids and the phenolic compounds of MSKP, transferred to ghee, help enhance the shelf-life by protecting against autoxidation.

Spectrophotometric Measurement of Leached Phenolic Compounds as an Indicator of Freeze Damage

Abstract Rhododendron leaf disks (Rhododendron L., cv. Jean Marie de Montague) release water-soluble phenolic compounds when subjected to lethal freezing stress. Following low-temperature exposure, the levels of phenolic compounds leached from the disks are assessed by spectrophotometric measurement (260 nm). The increase in phenolics is highly correlated with other viability tests—electrolyte leakage, visual browning, ethane production, and TTC reduction have r values of 0.99, 0.99, 0.95, and −0.88, respectively. Chemical names used: Trichloroacetic acid (TCA), polyvinylpolypyrrolidone (PVPP), 2,3,5-triphenyl tetrazolium chloride (TTC).

Leaching of phenolic compounds from leaf and needle litter of several deciduous and coniferous trees

Leaf and needle litter of the deciduous trees beech, birch, oak, ash, common maple, hornbeam, hazelnut, willow, poplar, hawthorn and the coniferous trees pine, spruce-fir, douglas-fir and larch were collected immediately after “leaf-fall” in October and analysed for their water-soluble phenolic compounds. By collecting leaf and needle litters three times in the period from October to January leaching rates of these organic compounds could be determined. There were considerable differences in the amount and leaching rate of water-soluble phenolics between litter-types. The concentration found in freshly deposited litter of the leaf-forming species was high and most of the water-soluble phenolics in these litter types were released in the period from October to January. In needle litters concentrations of water-soluble phenolics were low and they leached at a slow rate. By using gas chromatography, 14–18 phenolic compounds could be identified in the leachates. Benzoic acids dominated the phenolic spectra in October. In the course of time cinnamic acids became more important in the water-leachates. The results are discussed in view of their importance for the relationship between woodland-types and understory vegetation.

Phenolic components and degradability of cell walls of grass and legume species

Cell walls separated from the aerial parts of Lolium multiflorum, Lolium perenne and Phleum pratense contained bound cis and trans ferulic and p-coumaric acids and diferulic acid which were released from the walls by treatment with sodium hydroxide. The total content of these acids in L. multiflorum ranged from 5 to 16.8 mg/g of wall, the trans-ferulic acid content varying between 2.8 and 8.9 mg/g of wall. In addition, small amounts of p-hydroxybenzoic acid were released from senescent leaf blade plus sheath parts. Cell walls from legume species gave much smaller amounts of the acids, the total content of aerial parts of Trifolium pratense being <0.8 mg/g of wall. The degra dability of the cell walls with a commercial cellulase preparation was determined and the water-soluble phenolic compounds released were estimated by UV absorption spectroscopy.

Extracellular products from Chlorococcum ellipsoideum and Chlamydomonas globosa.

Extracellular products of Chlorococcum and Chlamydomonas were isolated from culture filtrates. Five groups of substances were found in both species: (i) steam-volatile acids, (ii) yellow water-soluble phenolic compounds, (iii) lipophilic substances, (iv) proteins and (v) polysaccharides. Chlorococcum had higher concentrations of all groups than Chlamydomonas; moreover, the two species differed slightly in the composition of groups (ii) and (iii). Probably, these is a great similarity between green algae in the production of extracellular compounds.