Table 2.

Relative toxicity of the paralytic shellfish toxins. Toxicity of the PSTs due to change in moiety is listed in descending order. Data obtained from [95].

StructureΩ	Toxin	Relative toxicityΦ
	Zetekitoxin AB	63, 160, 580ω
	Non-Sulfated
	STX NeoSTX	1 05–1.1
	Mono-sulfated
	GTX1/4¥ GTX2/3¥	0.39/1.09–0.48/0.76 0.8/0.33–0.9/0.9
	Decarbamoylated
	dcSTX dcNeoSTX dcGTX1-4	0.43 0.43 0.18–0.45
	Di-sulfated
	C1-4	<0.01–0.14

^ΩRefer to Table 1 for assigned R groups. Moieties highlighted in red differentiate from the structure of STX;

^¥α/β epimeric mixture;

^ΦRelative toxicity based on the mouse bioassay results obtained from [95–98];

^ωBased on binding affinity to human brain, heart and muscle Na⁺ channels assessed in Xenopus oocytes, respectively [89].