Anti-Inflammatory Properties of Oxygenated Isocoumarins and Xanthone from Thai Mangrove-Associated Endophytic Fungus <i>Setosphaeria rostrata</i>
Kedkarn Koopklang,
Siwattra Choodej,
Sujitra Hantanong,
Ratchadaree Intayot,
Siriporn Jungsuttiwong,
Yuwadee Insumran,
Nattaya Ngamrojanavanich,
Khanitha Pudhom
Affiliations
Kedkarn Koopklang
Program in Biotechnology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
Siwattra Choodej
Department of Chemistry, Faculty of Science, King Mongkut’s University of Technology, Thonburi 10140, Thailand
Sujitra Hantanong
Program in Biotechnology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
Ratchadaree Intayot
Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani 34190, Thailand
Siriporn Jungsuttiwong
Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani 34190, Thailand
Yuwadee Insumran
Department of Biology, Faculty of Science and Technology, Rajabath Maha Sarakham University, Maha Sarakham 44000, Thailand
Nattaya Ngamrojanavanich
Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
Khanitha Pudhom
Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
Chronic inflammation plays a crucial role in the development and progression of numerous chronic diseases. To search for anti-inflammatory metabolites from endophytic fungi isolated from plants growing in Thai mangrove areas, a chemical investigation of those fungi was performed. Five new oxygenated isocoumarins, setosphamarins A–E (1–5) were isolated from the EtOAc extract of an endophytic fungus Setosphaeria rostrata, along with four known isocoumarins and one xanthone. Their structures were determined by extensive spectroscopic analysis. The absolute configurations of the undescribed compounds were established by comparative analysis between experimental and calculated circular dichroism (ECD) spectroscopy. All the compounds were evaluated for their anti-inflammatory activity by monitoring nitric oxide inhibition in lipopolysaccharide-induced macrophage J774A.1 cells. Only a xanthone, ravenelin (9), showed potent activity, with an IC50 value of 6.27 μM, and detailed mechanistic study showed that it suppressed iNOS and COX-2 expression.
