Siladenoserinols M–P, sulfonated serinol derivatives from a tunicate
Graphical abstract
Introduction
A number of biological active secondary metabolites have been discovered from tunicates and have been applied for drug development [[1], [2], [3]]. Tunicates contain species-specific chemicals, which are thought to be produced by the symbionts [4,5]. The family Didemnidae is known to be an especially rich source of biologically active compounds, including cyclic peptides [6], pyridoacridine-type alkaloids [7], and pyrrole-derived alkaloids [8]. Serinolipids have been isolated from several Didemnum species so far [[9], [10], [11], [12], [13]] and intriguing pharmacological properties such as cytotoxicity [9,10], antibacterial activity [11], and HIV-1 integrase inhibitory activity [12] were reported. In our previous study, twelve sulfonated serinol derivatives, siladenoserinols A–L, which were isolated from the tunicate of the family Didemnidae collected in Indonesia, were discovered to be inhibitors of p53–Hdm2 interaction [13]. In our continuing research on the constituents of the Didemnidae tunicate, four new sulfonated serinolipid derivatives, siladenoserinols M–P (1–4) (Fig. 1), were isolated. We here describe the isolation, structure elucidation, and biological activities of 1–4.
Section snippets
Isolation of sulfonated serinol derivatives
A tunicate of the family Didemnidae was collected in Indonesia in 2011 and the specimen was extracted with EtOH and then MeOH. The extract was partitioned between water and EtOAc, and the aqueous residue was successively extracted with n-BuOH. The n-BuOH fraction was concentrated and subjected to SiO2 and ODS column chromatography followed by HPLC purification to afford siladenoserinols M–P (1–4).
Structure elucidation of 1
Siladenoserinol M (1) has the molecular formula of C33H58N2O11S, as determined by HRESIMS. The 1H
General experimental procedures
Optical rotations were measured on a JASCO DIP-1000 polarimeter in MeOH. UV spectra were measured on a JASCO V-550 spectrophotometer in MeOH. The IR spectrum was recorded on a PerkinElmer Frontier FT-IR spectrophotometer. 1H and 13C NMR spectra were recorded on a JEOL JNM-ECX-400 or Bruker Avance III 600 NMR spectrometer in CD3OD. Chemical shifts were referenced to the residual solvent peaks (δH 3.30 and δC 49.0 for CD3OD). ESIMS spectra were measured on a Bruker amaZon speed mass spectrometer,
Acknowledgements
This work was partially supported by JSPS KAKENHI Grants 22406001 (S.T.), 17H03994 (S.T.), 18K06719 (H. K.), and 18K14933 (Y. H.).
References (17)
Med. Res. Rev.
(2000)- et al.
Chem. Rev.
(1997) - et al.
J. Nat. Prod.
(1988) - et al.
J. Nat. Prod.
(2012) - et al.
J. Nat. Prod.
(2011) - et al.
J. Chromatogr. B
(2004) Chem. Rev.
(1993)- et al.
Chem. Rev.
(2008)
Cited by (8)
Chemical diversity and biological activities of marine-derived sulphur containing alkaloids: A comprehensive update
2023, Arabian Journal of ChemistryThe phosphate ester group in secondary metabolites
2022, Natural Product ReportsMarine natural products
2020, Natural Product ReportsAnti-Mycobacterial Activity of Polycarpine and Polycarpaurine A from an Indonesia Marine Ascidian Polycarpa sp.
2023, Tropical Journal of Natural Product ResearchAnti-Mycobacterial Activity of Polycarpine and Polycarpaurine A from an Indonesia Marine Ascidian Polycarpa sp.
2023, Tropical Journal of Natural Product ResearchStructural analysis of previously unknown natural products using computational methods
2022, Journal of Natural Medicines