Prymnesin-B1

Prymnesin-B1 is a chemical with the molecular formula. It is a member of the prymnesins, a class of ladder-frame polyether phycotoxins made by the alga Prymnesium parvum. It is known to be toxic to fish. It is a so called "B-type" prymnesin, which differ in the number of backbone cycles when compared to A-type prymnesins like prymnesin-2.

Structures
Prymnesins-B1 is formed of a large polyether polycyclic core with several conjugate double and triple bonds, chlorine and nitrogen heteroatoms and a single sugar moiety consisting of α- D -galactopyranose.