to my knowledge α-13’OH was the main product of α-TOH metabolism. it's formed by hepatic α-tocopherol (α-TOH) catabolism and acts as a regulatory metabolite. It is a reagent used in the laboratory, intended only for research.
more information in the article: Antioxidants 2021, 10, 173. https://doi.org/10.3390/antiox10020173