Two New Scaralane-type Sesterterpenoids Isolated from the Marine Sponge Hyrtios erectus

Four sesterterpenoids were isolated from a South China marine sponge of the genus Hyrtios, and their chemical structures were elucidated by extensive investigation of HRMS and 2D-NMR spectrum. Two of the compounds were new natural products and characterized to be scalarinether (1) and 21-hydroxy-16-deacetyl-12-epi-scalarafuran acetate (2). Two known sesterterpenes were identified as scalarin (3) and isoscalara furan-A (4).