TY - JOUR
T1 - Unlocking the structure-activity relationship of mangrove condensed and hydrolysable tannins
T2 - Unveiling their potential ecological significance in antioxidant and antibacterial functions
AU - Lang, Tao
AU - Hussain, Muzammil
AU - Li, Mingdang
AU - Tam, Nora Fung yee
AU - Pan, Min
AU - Lee, Fred Wang Fat
AU - Xu, Steven Jing Liang
AU - Jiang, Mingguo
AU - Wang, Yibing
AU - Mu, Lin
AU - Zhou, Haichao
N1 - Publisher Copyright:
© 2025 Elsevier B.V.
PY - 2025/5
Y1 - 2025/5
N2 - Tannins play key roles in regulating ecological processes within mangrove ecosystems, but the structures of mangrove condensed tannins (CT) and hydrolysable tannins (HT), as well as their antioxidant and antibacterial activities, are not well understood. In this study, MALDI-TOF MS was used to analyze the structural components of oligomers and polymers in phenolic extracts from Kandelia obovata, Aegiceras corniculatum, and Sonneratia apetala. Results identified two primary structural units: procyanidins (PC) and prodelphinidins (PD), with mass-to-charge ratios of 288 Da and 304 Da, respectively, and a 16 Da interval indicating differences in hydroxylation. Thiolysis degradation and acidic hydrolysis, combined with HPLC-ESI-MS, revealed significant variations in the mean degree of polymerization (mDP): oligomers had mDP values of 1.1–1.2, while polymers ranged from 7.8 to 9.1. Antioxidant assays (Folin-Ciocalteu, FRAP, TEAC, and DPPH) showed that PC < PD < HT in antioxidant capacity, with polymers exhibiting stronger activity than oligomers. Antibacterial tests revealed that A. corniculatum exhibited the weakest activity, while K. obovata and S. apetala showed similar efficacy against bacteria from Actinobacteria, Bacteroidetes, and Proteobacteria. This study enhances our understanding of mangrove phenolics' structural characteristics and their ecological roles in maintaining mangrove ecosystem functions.
AB - Tannins play key roles in regulating ecological processes within mangrove ecosystems, but the structures of mangrove condensed tannins (CT) and hydrolysable tannins (HT), as well as their antioxidant and antibacterial activities, are not well understood. In this study, MALDI-TOF MS was used to analyze the structural components of oligomers and polymers in phenolic extracts from Kandelia obovata, Aegiceras corniculatum, and Sonneratia apetala. Results identified two primary structural units: procyanidins (PC) and prodelphinidins (PD), with mass-to-charge ratios of 288 Da and 304 Da, respectively, and a 16 Da interval indicating differences in hydroxylation. Thiolysis degradation and acidic hydrolysis, combined with HPLC-ESI-MS, revealed significant variations in the mean degree of polymerization (mDP): oligomers had mDP values of 1.1–1.2, while polymers ranged from 7.8 to 9.1. Antioxidant assays (Folin-Ciocalteu, FRAP, TEAC, and DPPH) showed that PC < PD < HT in antioxidant capacity, with polymers exhibiting stronger activity than oligomers. Antibacterial tests revealed that A. corniculatum exhibited the weakest activity, while K. obovata and S. apetala showed similar efficacy against bacteria from Actinobacteria, Bacteroidetes, and Proteobacteria. This study enhances our understanding of mangrove phenolics' structural characteristics and their ecological roles in maintaining mangrove ecosystem functions.
KW - Antibacterial activity
KW - Antioxidant activity
KW - Condensed and hydrolysable tannins
KW - Degree of polymerization
KW - Mangrove
UR - http://www.scopus.com/inward/record.url?scp=86000728653&partnerID=8YFLogxK
U2 - 10.1016/j.ijbiomac.2025.141918
DO - 10.1016/j.ijbiomac.2025.141918
M3 - Article
C2 - 40074115
AN - SCOPUS:86000728653
SN - 0141-8130
VL - 307
JO - International Journal of Biological Macromolecules
JF - International Journal of Biological Macromolecules
M1 - 141918
ER -