Amdigenol D, a long carbon-chain polyol, isolated from the marine dinoflagellate Amphidinium sp

[Display omitted] •A novel long carbon-chain polyol compound, amdigenol D, has been isolated.•Structure elucidation was performed by NMR spectroscopy and MS/MS analyses.•Amdigenol D includes two common core structures of amphidinol analogs.•Amdigenol D has a C101-linear carbon-chain and is a longest amdigenol analog to date. A novel polyol compound, amdigenol D, produced by the dinoflagellate Amphidinium sp. has been isolated. Its structure was elucidated by NMR spectroscopy and MS/MS analyses. Amdigenol D consists of a C101-linear carbon backbone including two core structures of amphidinol analogs. Amdigenol D is the longest amdigenol analog identified to date.