Volume 121, 20 March 2016, Pages 225–231
Highlights
- •
- Condensed tannins were analysed in medicinal plant and herbal product extracts.
- •
- Most extracts had procyanidins, but one had highly galloylated tannins.
- •
- A-type linkages were only found in procyanidins.
- •
- Tannins in pine buds, walnut leaves, heather flowers and great water dock roots.
- •
- Determination of thiolysis response factors for different tannin types.
Abstract
Medicinal
plant materials are not usually analysed for condensed tannins (CT).
Thirty commercially available European medicinal plants and herbal
products were screened for CT and fourteen CT samples were analysed in
detail. This is also the first comprehensive CT analysis of pine buds,
walnut leaves, heather flowers and great water dock roots. Acetone/water
extracts contained between 3.2 and 25.9 g CT/100 g of extract, had CT
with mean degrees of polymerisation of 2.9 to 13.3,
procyanidin/prodelphinidin ratios of 1.6/98.4 to 100/0 and cis/trans
flavan-3-ol ratios of 17.7/82.3 to 97.3/2.7. The majority of samples
contained procyanidins, four contained A-type linkages (blackthorn
flowers, heather flowers, bilberry leaves and cowberry leaves) and one
sample also had galloylated procyanidins (great water dock roots).
Graphical abstract
Keywords
- Proanthocyanidins;
- Flavan-3-ols;
- Molar response factors;
- Thiolysis;
- Mean degree of polymerization
Copyright © 2015 Elsevier B.V. All rights reserved.
