A, R1 = R2 = R3 = Me, known as α-tocopherol, is designated α-tocopherol or 5,7,8-trimethyltocol; R1 = R3 = Me; R2 = H, known as, β-tocopherol, is designated, β-tocopherol or 5,8-dimethyltocol; R1 = H; R2 = R3 = Me, known as γ-tocopherol, is designated γ-tocopherol or 7,8-dimethyltocol; R1 = R2 = H; R3 = Me, known as δ-tocopherol, is designated δ-tocopherol or 8-methyltocol. B, R1 = R2 = R3 = H, 2-methyl-2-(4,8,12-trimethyltrideca-3,7,11-trienyl)chroman-6-ol, is designated tocotrienol; R1 = R2 = R3 = Me, formerly known as ζ1 or ζ2-tocopherol, is designated 5,7,8-trimethyltocotrienol or α-tocotrienol. The name tocochromanol-3 has also been used; R1 = R3 = Me; R2 = H, formerly known as ε-tocopherol, is designated 5,8-dimethyltocotrienol or β-tocotrienol; R1 = H; R2 = R3 = Me, formerly known as η-tocopherol, is designated 7,8-dimethyltocotrienol or γ-tocotrienol. The name plastochromanol-3 has also been used; R1 = R2 = H; R3 = Me is designated 8-methyltocotrienol or δ-tocotrienol.