So far, more than eight analogs of GYMs have been reported from the microalgal species Karenia selliformis and Alexandrium ostenfeldii. The dinoflagellate K. selliformis mainly produced GYM-A, GYM-B, and GYM-C [4,5], and A. ostenfeldii was found to produce 12-methyl GYM-A, 12-methyl...