Octyl gallate: An antioxidant demonstrating selective and sensitive fluorescent property

- Octyl gallate (OG) is an antioxidant has selective and sensitive fluorescent property.
- Energy transfer played a major role in OG-BSA/HSA interaction.
- STD and displacement studies indicated OG bound to the Sudlow site II of HSA.
- The property of OG can be used to determine OG concentration under certain conditions.

Octyl gallate (OG) is an internationally recognized antioxidant that demonstrates selective and sensitive fluorescent property. The fluorescence of OG can be selectively enhanced in the presence of human serum albumin (HSA) and bovine serum albumin (BSA). The specific structures of HSA and BSA provided the basic conditions for fluorescence enhancement. OG yielded approximately 49- and 11-fold increments in emission intensity in the presence of HSA and BSA at a molar ratio of 1:1, respectively. The lifetimes of HSA and BSA correspondingly decreased. A Förster resonance energy transfer phenomenon occurred during interaction between OG and HSA or BSA. Our in-depth investigation of OG-HSA interaction showed that formation of a stable complex was an important prerequisite to efficiently enhance the fluorescence of OG. The selective and sensitive fluorescent property of OG can possibly be used to determine OG concentration via the standard addition method, which must be performed under certain conditions.