# Discovery of structurally diverse polyprenylated acylphloroglucinols with quorum sensing inhibitory activity from Hypericum seniawinii Maxim

## TL;DR

Researchers discovered new compounds from a plant that can inhibit bacterial communication, potentially useful for fighting infections.

## Contribution

Identification of structurally diverse polyprenylated acylphloroglucinols with quorum sensing inhibition from Hypericum seniawinii.

## Key findings

- Hyperisenins A–D are new polyprenylated acylphloroglucinols with unique structural features.
- Compound 4 inhibits quorum sensing in Pseudomonas aeruginosa by reducing rhamnolipid levels.
- Compound 4 may bind to lasR and pqsR to disrupt bacterial communication.

## Abstract

Four previously undescribed polyprenylated acylphloroglucinols, hyperisenins A–D (1–4), along with two known analogues (5 and 6), were obtained from the aerial part of Hypericum seniawinii Maxim. Compounds 1 and 2 were two highly degraded polyprenylated acylphloroglucinols with a cyclohexanone-monocyclic skeleton, while compound 3 was the first example of O-prenylated acylphloroglucinols with a 6/6/6 ring system. Their structures were identified by analyzing NMR, HRESIMS data, and quantum chemical calculations. The biosynthetic pathway of 1 and 2 might originate from bicyclic polyprenylated acylphloroglucinols via a series of complex retro-Claisen, keto − enol tautomerism, and intramolecular cyclization. The bioassay results showed that 4 exhibited quorum sensing inhibitory activity against Pseudomonas aeruginosa, which could decrease the activation of the rhl system, and significantly reduce rhamnolipid levels at a concentration of 100 µM, and the mechanism might be the ability to bind 4 to lasR and pqsR.

The online version contains supplementary material available at 10.1007/s13659-025-00520-z.