Progress in the isolation, purification, structural characteristics and biological functions of polysaccharides from okra (Abelmoschus esculentus (L.) Moench): A review.

Abelmoschus esculentus (L.) Moench (A. esculentus L.), commonly known as okra, is a famous tonic traditional Chinese medicine which have drawn significant interest because of its excellent edible and medicinal properties. A. esculentus L. polysaccharides (APs) are the main bioactive substances of A. esculentus L. In the past decades, various methods (e.g. triple-phase partitioning and -assisted extraction etc.) have shown promise in extraction, and diverse techniques (e.g. ethanol precipitation and chromatography etc) have already been in use in purification. Although techniques for the isolation and purification of APs are constantly evolving to better cope with their complex structural features, these techniques still need to be innovated. APs are heteropolysaccharides with complex structures, exhibiting various biological activities, such as antioxidant, anti-inflammatory and antidepressant effects. However, the structure-activity relationships (SARs) and mechanisms between their higher structures and pharmacological effects need to be further investigated. In view of this, this review provides a comprehensive overview of recent advances in APs extraction, purification, structural characterization and bioactivity, discusses structure-activity relationships, and outlines the current applications, challenges and prospect of APs. The aim of this review is to provide valuable insights and information to facilitate the use of APs in food and pharmaceutical applications.