Phukettosides A–E, mono- and bis-iridoid glycosides, from the leaves of Morinda umbellata L

• Published in: Phytochemistry (Oxford) 2023-12, Vol.216, p.113890-113890, Article 113890
• Main Authors: Kaweetripob, Wirongrong, Thongnest, Sanit, Boonsombat, Jutatip, Batsomboon, Paratchata, Salae, Abdul-Wahab, Prawat, Hunsa, Mahidol, Chulabhorn, Ruchirawat, Somsak
• Format: Article
• Language: English
• Subjects: Antioxidant; Bis-iridoid glycoside; Cytotoxic activity; Diels-Alder cycloaddition; Flavonoid; Iridoid glycoside; Morinda umbellata; Rubiaceae
• ISSN: 0031-9422; 1873-3700
• DOI: 10.1016/j.phytochem.2023.113890

Four undescribed bis-iridoid glycosides, named phukettosides A–D, and one iridoid glycoside, referred to as phukettoside E, were isolated and fully characterized from the leaves of Morinda umbellata L. Phytochemical analysis also revealed the presence of eight known compounds. The structures were determined through extensive analysis of 1D and 2D-NMR spectroscopic and HRMS spectral data, and the absolute configurations of the isolates were deduced through ECD calculations. Biogenetic pathways for the bis-iridoid glycosides, phukettosides A–C, through intermolecular Diels-Alder type reactions, were proposed. The isolated compounds, with the exception of phukettosides B and D, were evaluated against a panel of cancer cell lines (MOLT-3, HuCCA-1, A549, HeLa, HepG2, and MDA-MB-231) and a non-cancerous cell line (MRC-5) for their cytotoxicity. None of the isolates had significant cytotoxic effects on the tested cell lines. [Display omitted] •Bis- and mono-iridoid glycosides were isolated from Morinda umbellata leaves.•The bis-iridoid glycosides probably arise from intermolecular Diels-Alder reactions.•The absolute configurations were confirmed by ECD calculation.•Cancer chemoprevention and the cytotoxicity of the isolates were evaluated.