Esculentoside B

Biosci Biotechnol Biochem. 1999;63(9):1657-9.

Inhibition of Plant Transformation by Phytolaccoside B from Phytolacca americana Callus.[Pubmed: 27389651]

The newly established GUS expression bioassay on the callus extracts of 22 species of plants revealed that the methanol extract of Phytolacca americana callus had the most potent inhibitory activity against agrobacterial plant transformation.
METHODS AND RESULTS:
A triterpene glycoside phytolaccoside B was isolated from the extract as a genuine plant transformation inhibitor having neither antiagrobacterial nor phytotoxic activity. This compound is promising for use as a biochemical probe for studies on the plant transformation mechanism.

J. Nat. Prod., 2008, 71(10):1720-5.

Evidence for the mechanism of action of the antifungal phytolaccoside B isolated from Phytolacca tetramera Hauman.[Pubmed: 18816139 ]

Phytolaccoside B (Esculentoside B,1), an antifungal monodesmoside triterpenoid glycoside isolated from berries of Phytolacca tetramera Hauman (Phytolaccaceae), alters the morphology of yeasts and molds.
METHODS AND RESULTS:
The malformations were similar to those produced by enfumafungin, a known inhibitor of (1-->3)-beta-D-glucan synthase, an enzyme that catalyzes the synthesis of (1-->3)-beta-D-glucan, one of the major polymers of the fungal cell wall. However, enzymatic assays revealed that 1 did not inhibit (1-->3)-beta-D-glucan synthase, but it did produce a notable enhancement of the chitin synthase 1 activity and, concomitantly, a rise in chitin, another important polymer of the fungal cell walls.
CONCLUSIONS:
This finding was corroborated by fluorescence microscopy and also by quantification of the chitin. In addition, a 2-fold increase in the thickness of the fungal cell wall was observed with transmission electronic microscopy. On the other hand, 1 neither bound to ergosterol nor caused hemolysis of red blood cells, although some fungal membrane damage was observed at the MIC of 1.