ESIMS analysis of fucoidan preparations from Costaria costata, extracted from alga at different life-stages

► Four fucoidan fractions were extracted from brown alga Costaria costata. ► Alga was collected at different life stages - vegetative (May) and generative (July). ► Content and structure of fucoidans changed along with life stage. ► Vegetative alga produced partially sulfated high-MW mannoglucuronofucan. ► Generative alga synthesized highly sulfated galactofucan with lower MW.