Proanthocyanidin Block Arrays (PACBAR) for Comprehensive Capture and Delineation of Proanthocyanidin Structures

Authors: JING, SHUXI - University Of Illinois; Zeller, Wayne; FERREIRA, DANEEL - University Of Mississippi; ZHOU, BIN - Chinese Academy Of Sciences; NAM, JOO-WON - Yeungnam University; RUSSO-BEDRAN, ANA - Marquette University; CHEN, SHAO-NONG - University Of Illinois; PAULI, GUIDO - University Of Illinois

Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/13/2020
Publication Date: 11/11/2020
Citation: Jing, S., Zeller, W.E., Ferreira, D., Zhou, B., Nam, J., Russo-Bedran, A., Chen, S., Pauli, G.F. 2020. Proanthocyanidin Block Arrays (PACBAR) for Comprehensive Capture and Delineation of Proanthocyanidin Structures. Journal of Agricultural and Food Chemistry. 68(47):13541-13549. https://doi.org/10.1021/acs.jafc.0c05392.
DOI: https://doi.org/10.1021/acs.jafc.0c05392

Interpretive Summary: Proanthocyanidins (PACs), also referred to as condensed tannins, are a subset of polyphenols naturally occurring in many plant species. Proanthocyanidin research spans multiple disciplines including human and ruminant health, productivity and sustainability, material sciences, and chemical ecology. The thrust of new and expanded analytical methods providing detailed structural analysis of purified PACs makes it necessary to establish consensus development of a universal PAC nomenclature scheme and is the subject of this paper. The proposed nomenclature consists of three parts: a color coded graphical system and two single line, plain text descriptors (macro- and micro-PAC Block ARays) delineating exact PAC structures. The color coded graphical PACBAR is for visual purposes, intended to replace the chemical formula, and can function as precise but “graphical abstract” for PAC structures. The plain text macro- and micro-PACBARs are not only compatible with current nomenclature, but also readable and communicable. The macro- PACBAR contains all elements of a PAC name, is fully descriptive and amenable to computational and database tools. Meanwhile, micro-PACBAR utilizes default structural features to reduce code length for enhanced communication purposes and intended to replace trivial or systematic names. The proposed PACBAR system accurately captures PAC structures, allows for rapid visualization, and can readily be reduced to an electronic searchable entry in order to foster interdisciplinary research.

Technical Abstract: Proanthocyanidins (PACs) are near-ubiquitous and chemically complex metabolites, prototypical of higher plants. Their roles in food/feed/nutrition and ethnomedicine are widely recognized but poorly understood. With the analysis of evidence that underlies this challenge, this perspective identifies shortcomings in capturing and delineating PAC structures as key factors. While several groups have forwarded new representations, a consensus method that captures PAC structures concisely and offers high integrity for electronic storage is required to reduce confusion in this expansive field. The PAC block arrays (PACBAR) system fills this gap by providing precise and human- and machine-readable structural descriptors that capture PAC metabolomic structural diversity. PACBAR enables communication of PAC structures for the development of precise structure-activity relationships and will assist in advancing PAC research to the next level.