glyceollins

Glyceollins are a group of phytoalexins produced by soybean plants (Glycine max) and related species in response to pathogen attack or environmental stress. They belong to the pterocarpan class of isoflavonoids, and the best known members are glyceollin I, glyceollin II, and glyceollin III. Minor forms have been reported in some studies.

The production of glyceollins is part of the plant’s inducible defense system. Elicitors such as fungal pathogens (notably Phytophthora sojae), wounding, or abiotic stress can trigger their synthesis and accumulation in infected or stressed tissues. The biosynthetic pathway involves the isoflavonoid/phenylpropanoid network, with regulation influenced by plant hormones including jasmonic acid, ethylene, and salicylic acid. Biosynthesis converts common phenylpropanoid intermediates into the pterocarpan structure that characterizes glyceollins, which then accumulate at sites of attack to help limit pathogen spread.

Biological activities attributed to glyceollins include antimicrobial and antifungal effects observed in vitro, contributing to soybean defense against a range of pathogens. In mammalian systems, glyceollins have attracted interest for estrogen receptor–modulating activity (often described as antiestrogenic) and for potential antiproliferative effects in cancer cell models. These activities appear to be context-dependent and remain the subject of ongoing research. Additional studies have explored anti-inflammatory and antioxidant properties, but data are still limited.

Glyceollins are primarily found in soybeans and related species, with levels influenced by cultivar, tissue type, and stress exposure. They are studied for understanding plant immunity, for potential use in breeding disease resistance, and as lead compounds in natural-product research.