Procyanidins and polyphenols of Larix gmelini bark

Shen, Zhaobang; Haslam, Edwin; Falshaw, C. P.; Begley, Michael J.

doi:10.1016/s0031-9422(00)84524-0

Cited by 84 publications

(40 citation statements)

References 9 publications

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“…A further 30% of the extractable phenolics was removed using aqueous acetone. In addition to soluble leaf phenolics, butanol/ HC1 extraction of the marc produced a dense cyanidin solution, the result of acidolysis and oxidation of carbohydrate-bound procyanidins (Shen et al, 1986). The extraction removed approximately 32 and 52%, respectively, of the starting mass of the marcs of I. goldmanii and I. umbellifera (Table 5).…”

Section: Resultsmentioning

confidence: 99%

Divergence in Structure and Activity of Phenolic Defenses in Young Leaves of Two Co-Occurring Inga Species

Lokvam

Kursar

2005

J Chem Ecol

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Abstract-The leaves of tropical forest trees are most likely to suffer herbivore damage during the period of expansion. Herbivore selection on young leaves has given rise to a variety of leaf developmental strategies and age-specific chemical defense modes. We are studying correlations between leaf developmental types and chemical defenses in the Neotropical genus Inga. We have characterized defense metabolites in Inga goldmanii and Inga umbellifera, two species that co-occur in the lowland moist forest of Panama. These congeners have markedly different young-leaf developmental phenotypes but suffer approximately equal rates of herbivory. Bioassays of whole and fractionated leaf extracts using larvae of Heliothis virescens show that /. goldmanii chemical defenses are nearly three times more inhibitory than those of/, umbellifera. In both species, most of the inhibitory activity resides in complex mixtures of monomeric and polymeric flavan-3-ols. This group comprises >30% of young leaf dry weight in both /. goldmanii and /. umbellifera. The species' phenolic chemistry differs markedly, however, both in the structure of the monomeric units and in the distribution of polymer sizes. The differences in chemical structure have pronounced effects on their bioactivities, with /. goldmanii fiavans being twice as inhibitory to H. virescens larvae as /. umbellifera fiavans, and more than three times more efficient at protein binding. Given the extraordinarily high polyphenol concentrations that are found in the young leaves of these species, protein precipitation could be an important mechanism of growth inhibition. Nevertheless, our data show that another mode of phenolic action, possibly oxidative stress, occurs simultaneously.

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Section: Resultsmentioning

confidence: 99%

Divergence in Structure and Activity of Phenolic Defenses in Young Leaves of Two Co-Occurring Inga Species

Lokvam

Kursar

2005

J Chem Ecol

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“…The synthesis of gallotannins does not proceed via the amino acid phenylalanine but via an intermediate compound of the shikimate pathway, dehydroshikimic acid (Gross 1992;Ossipov et al 1997). In contrast, the synthesis of proanthocyanidins competes directly with synthesis of proteins with aromatic amino acids, due to phenylalanine as the common precursor (Shen et al 1986;Nurmi et al 1996). This produces a typical Y-shaped resource based trade-o (de Jong and van Noordwijk 1992) between the synthesis of such proteins and proanthocyanidins but not between gallotannins and proteins containing aromatic amino acids Koricheva et al 1998).…”

Section: Biochemical Traits Underlying Leaf Qualitymentioning

confidence: 99%

Multiplicity of biochemical factors determining quality of growing birch leaves

Kause¹,

Ossipov

Haukioja³

et al. 1999

Oecologia

114

136

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Due to rapidly changing physical and biochemical characteristics of growing leaves, correlations between traits of foliage biochemistry and the performance indices of flush feeding herbivores may vary considerably following relatively minor changes in experimental conditions. We examined the effects of the seasonal and inter-tree variation of a comprehensive array of biochemical compounds on the success of an early season geometrid, Epirrita autumnata, feeding on maturing foliage of mountain birch, Betula pubescens ssp. czerepanovii. We monitored the concentrations of individual phenolics, sugars, total nitrogen, nitrogen of proteins, and nitrogen of soluble compounds, water and acetone-insoluble residue. Simultaneously we recorded larval consumption, physiological performance, growth, and pupal mass of E. autumnata. We found significant phenological changes in almost all leaf traits measured. In bioassays with half-grown leaves, leaf gallotannin concentrations showed a nonlinear effect: in trees with high foliar gallotannin concentrations (over 10 mg g), physiological performance was strongly reduced by high gallotannin concentrations. In trees with lower gallotannin concentrations, on the other hand, larval growth was reduced by soluble proanthocyanidins, not gallotannins. Differences between high and low gallotannin trees largely depended on phenology, i.e., on the age of leaves. However, not all the differences in leaf traits between late (with high gallotannin concentrations at the time of the bioassay) and early flushing trees disappeared with leaf maturation, indicating that there is also phenology-independent variance in the tree population. In the full-grown leaves of all the study trees, low concentrations of water and of nitrogen of proteins (but not nitrogen of soluble compounds) were the main factors reducing pupal masses of E. autumnata, while neither gallotannin nor proanthocyanidins now played a significant role. The observed change in the factors underlying leaf quality (from gallotannins and proanthocyanidins to nitrogen and water) relate to the activity of the shikimate pathway and the formation of cell walls: gallotannins and proanthocyanidins are both produced in the pathway, and these tannins are assumed to contribute - via binding into cell walls - to tough and durable cell walls. Interestingly, low quality of leaves did not automatically translate into low foliar consumption (i.e., benefits to the tree). On the trees with young, high gallotannin leaves, larvae actually increased consumption on low quality foliage. In the group of trees with slightly more developed, low gallotannin leaves, the quality of leaves did not clearly modify amounts consumed. In full-grown leaves, low leaf quality strongly reduced leaf consumption. These results emphasize the strong influence of tree phenology on the relationships between biochemical compounds and the herbivore.

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“…And the extraction is usually achieved by using traditional methods such as heating reflux extraction and homogenated extraction [2,4,5]. However, use of these organic solvents is problematic in the extraction of proanthocyanidins due to their toxicity, volatility and flammability.…”

Section: Introductionmentioning

confidence: 99%

Application of Ionic Liquids in the Microwave-Assisted Extraction of Proanthocyanidins from Larix gmelini Bark

Yang

Sun

Yang

et al. 2012

IJMS

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Ionic liquid based, microwave-assisted extraction (ILMAE) was successfully applied to the extraction of proanthocyanidins from Larix gmelini bark. In this work, in order to evaluate the performance of ionic liquids in the microwave-assisted extraction process, a series of 1-alkyl-3-methylimidazolium ionic liquids with different cations and anions were evaluated for extraction yield, and 1-butyl-3-methylimidazolium bromide was selected as the optimal solvent. In addition, the ILMAE procedure for the proanthocyanidins was optimized and compared with other conventional extraction techniques. Under the optimized conditions, satisfactory extraction yield of the proanthocyanidins was obtained. Relative to other methods, the proposed approach provided higher extraction yield and lower energy consumption. The Larix gmelini bark samples before and after extraction were analyzed by Thermal gravimetric analysis, Fourier-transform infrared spectroscopy and characterized by scanning electron microscopy. The results showed that the ILMAE method is a simple and efficient technique for sample preparation.

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Procyanidins and polyphenols of Larix gmelini bark

Cited by 84 publications

References 9 publications

Divergence in Structure and Activity of Phenolic Defenses in Young Leaves of Two Co-Occurring Inga Species

Divergence in Structure and Activity of Phenolic Defenses in Young Leaves of Two Co-Occurring Inga Species

Multiplicity of biochemical factors determining quality of growing birch leaves

Application of Ionic Liquids in the Microwave-Assisted Extraction of Proanthocyanidins from Larix gmelini Bark

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