A comparison of two strategies to modify the hydroxylation of condensed tannin polymers in Lotus corniculatus L.

Robbins, Mark P.; Bavage, Adrian D.; Allison, Gordon; Davies, Teresa; Hauck, Barbara; Morris, Phillip

doi:10.1016/j.phytochem.2005.03.017

Cited by 10 publications

(8 citation statements)

References 23 publications

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“…As observed in other plant species studied (16)(17)(18) the floral Trifolium flavan-3-ol extension units are dominated by the 2,3cis stereochemistry, epicatechin for procyanidins and epigallocatechin for prodelphinidin fractions (Table 1). However, the terminating flavan-3-ols for the procyanidin fractions are dominated by catechin for T. michelianum (100%) and T. alexandrinum (86%), as found previously for T. pratense (95%), whereas T. incarnatum, T. resupinatum, and T. Vesiculosum have equal proportions of epicatechin and catechin, with cis and trans sterochemistry, respectively, indicating that rigorous control of chain extension was observed for the procyanidin fractions, but the selection of the terminal group may be controlled by alternative mechanisms.…”

Section: Resultssupporting

confidence: 66%

“…As observed in other plant species studied ( − ) the floral Trifolium flavan-3-ol extension units are dominated by the 2,3-cis stereochemistry, epicatechin for procyanidins and epigallocatechin for prodelphinidin fractions ( Table ). However, the terminating flavan-3-ols for the procyanidin fractions are dominated by catechin for T .…”

Section: Resultssupporting

confidence: 63%

“…The presence of both F3′H and F3′5′H leads to the formation of gallocatechin/ epigallocatechin (prodelphinidins). Studies on proanthocyanidin synthesis have involved the reference plant Arabidopsis thaliana (12)(13)(14)(15), the important forage alfalfa (Medicago satiVa) (16), tropical and temperate forage legumes, Desmodium uncinatum (10) and Lotus species (17), respectively, and tobacco petals (18).…”

Section: Introductionmentioning

confidence: 99%

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Floral Trifolium Proanthocyanidins: Polyphenol Formation and Compositional Diversity

Meagher

Widdup²,

Sivakumaran³

et al. 2006

J. Agric. Food Chem.

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Recent studies on the biosynthesis of proanthocyandins have identified key genes and enzymes in the formation of 2,3-cis-flavan-3-ols (epiafzelechin, epicatechin, and epigallocatechin). However, the enzymes that catalyze the polymerization of monomer units remain unknown. Studies of proanthocyanidin synthesis have involved the reference plant, Arabidopsis thaliana, forage legumes, tobacco, and grape. For this paper the floral proanthocyanidins of 10 Trifolium species were studied to identify candidates with contrasting proanthocyanidin chemistry, for the identification of factors involved in polymerization. Proanthocyandins were present in the floral portions (3.1-12.2 g/100 g of dry matter) of Trifolium spp. Thiolyic cleavage of proanthocyanidin fractions liberated flavan-3-ol extension units dominated by cis stereochemistry. The terminal units' stereochemistry of T. michelianum was exclusively trans (catechin), that of T. hirtum mixed trans (catechin and gallocatechin), and that of T. vesiculosum equal proportions of trans and cis (catechin and epicatechin). Compositional dispersion for oligomers was determined by MALDI-TOF MS, which showed a range of ions up to approximately 2200 Da. The three Trifolium spp. highlighted, all annuals, may warrant investigation for insights into proanthocyanidins biosynthesis.

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Section: Resultssupporting

confidence: 66%

Section: Resultssupporting

confidence: 63%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Floral Trifolium Proanthocyanidins: Polyphenol Formation and Compositional Diversity

Meagher

Widdup²,

Sivakumaran³

et al. 2006

J. Agric. Food Chem.

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“…In condensed tannin synthesis, the products of DFR activity, the leucoanthocyanidins, are the precursors of propelargonidin, procyanidin and prodelphinidin units which form the condensed tannin polymers. However, in Lotus corniculatus, the expression of the DHK-accepting DFR of Anthirrhinum majus did not elevate the level of propelargonidin units in leave and stem tissues (Robbins et al, 2005).…”

Section: Discussionmentioning

confidence: 78%

Redirection of anthocyanin synthesis in Osteospermum hybrida by a two-enzyme manipulation strategy

et al. 2007

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“…Li et al 117 mentioned that a minimum concentration of 50 g CT kg −1 in forages is needed to consider forages bloat‐safe. Therefore, plant breeding and genetic engineering technologies have been employed to increase the CT concentrations in some legume forages 118. Besides feeding tannin‐containing forages, tannin extract can be fed to animals to prevent bloat problems.…”

Section: Effects Of Tannins On Bloat Preventionmentioning

confidence: 99%

Exploitation of dietary tannins to improve rumen metabolism and ruminant nutrition

Patra

Saxena

2010

J. Sci. Food Agric.

582

454

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Tannins (hydrolysable and condensed tannin) are polyphenolic polymers of relatively high molecular weight with the capacity to form complexes mainly with proteins due to the presence of a large number of phenolic hydroxyl groups. They are widely distributed in nutritionally important forage trees, shrubs and legumes, cereals and grains, which are considered as anti-nutritional compounds due to their adverse effects on intake and animal performance. However, tannins have been recognised to modulate rumen fermentation favourably such as reducing protein degradation in the rumen, prevention of bloat, inhibition of methanogenesis and increasing conjugated linoleic acid concentrations in ruminant-derived foods. The inclusion of tannins in diets has been shown to improve body weight and wool growth, milk yields and reproductive performance. However, the beneficial effects on rumen modulation and animal performance have not been consistently observed. This review discusses the effects of tannins on nitrogen metabolism in the rumen and intestine, and microbial populations (bacteria, protozoa, fungi and archaea), metabolism of tannins, microbial tolerance mechanisms to tannins, inhibition of methanogenesis, ruminal biohydrogenation processes and performance of animals. The discrepancies of responses of tannins among different studies are attributed to the different chemical structures (degree of polymerisation, procyanidins to propdelphinidins, stereochemistry and C-C bonding) and concentrations of tannins, and type of diets. An establishment of structure-activity relationship would be required to explain differences among studies and obtain consistent beneficial tannin effects.

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A comparison of two strategies to modify the hydroxylation of condensed tannin polymers in Lotus corniculatus L.

Cited by 10 publications

References 23 publications

Floral Trifolium Proanthocyanidins: Polyphenol Formation and Compositional Diversity

Floral Trifolium Proanthocyanidins: Polyphenol Formation and Compositional Diversity

Redirection of anthocyanin synthesis in Osteospermum hybrida by a two-enzyme manipulation strategy

Exploitation of dietary tannins to improve rumen metabolism and ruminant nutrition

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