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Updated: Dec 15, 2025

Quantitative 31P NMR Analysis of Lignins and Tannins
Published on: August 2, 2021
Rare A-Type, Spiro-Type, and Highly Oligomeric Proanthocyanidins from Pinus massoniana
Bin Zhou1, Yvette Alania2,3, Mariana C Reis2,3
1Department of Pharmaceutical Sciences (PSCI), College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois 60612, United States.
Abstract:
An investigation of the dental bioactive proanthocyanidin (PAC) oligomer fractions led to three structurally distinct new PACs (1-3) from pine bark. Pinutwindoublin (1) is the first reported trimer with double A-type interflavanyl linkages (2α→O→5,4α→6 and 2α→O→7,4α→8). Pinuspirotetrin (2) represents the first reported PAC tetramer with a heterodimeric framework consisting of one spiro-type and one A-type dimer. Pinumassohexin (3) was elucidated as a mixed A + B-type hexamer that consists of a peanut-derived tetramer, peanut procyanidin E, and an A-type dimer (5). Compound 3 increased the modulus of elasticity of dentin by an impressive 4.3 times at a concentration of 0.65%.
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