PTPN1 and type 2 diabetes mellitus: In addition, brown algae present anti-diabetic, antioxidant, and antimicrobial effects [7,8,9], and so compound 6 was tested for its inhibitory activity against protein tyrosine phosphatase 1B (PTP1B), used as a potential therapeutic drug target in the treatment of type 2 diabetes, antioxidant activity with 1,1-diphyl-2-picrylhydrazyl (DPPH) free radicals, and antimicrobial activities against resistant clinical isolates of Candida albicans, methicillin-resistant Staphylococcus aureus (MRSA), and Escherichia coli.