# Diverse and Bioactive Lactones from the Sri Lankan Mangrove-Derived Fungus Talaromyces sp. SCSIO41445

## TL;DR

This study isolated new bioactive lactones from a Sri Lankan mangrove fungus and tested their ability to inhibit neuraminidase enzymes.

## Contribution

The discovery of three new lactones and their neuraminidase inhibitory activity from a Talaromyces fungus.

## Key findings

- Three new lactones (penicianstinoid L, talaromyketide J, and peniciisocoumarin K) were isolated and characterized.
- Three lactones (11, 15, and 16) showed neuraminidase inhibitory activity with IC50 values between 20.78 and 46.66 µM.
- Molecular docking confirmed the potential of these compounds to interact with neuraminidase enzymes.

## Abstract

Three previously uncharacterized lactones, namely penicianstinoid L (1), talaromyketide J (2) and peniciisocoumarin K (3), along with twenty-eight known compounds (4–31), were yielded from the mangrove-derived fungus Talaromyces sp. SCSIO41445, collected from Mangrove Park (NARA), Sri Lanka. Their structures were established by HRESIMS and NMR spectroscopic analysis (including 1H and 13C NMR, HSQC, and HMBC), with the stereostructures of 2 and 3 being confirmed by single-crystal X-ray crystallographic analysis. Furthermore, compounds 1–31 were evaluated in terms of their neuraminidase (NA) inhibitory activities. These bioassay results revealed that three lactones (11, 15, and 16) of them exerted NA inhibitory effects, with IC50 values of 46.66 ± 2.31, 20.78 ± 1.89, and 34.14 ± 2.56 µM, respectively. Moreover, molecular docking analysis demonstrated the potential of these compounds to inhibit NA enzymes, revealing specific interactions between the compounds and target proteins.