Fig. 4.

LC-MS analysis of the new gibberellin, DHGA₁₂ and its position within the GA biosynthetic pathway. a Schematic of the GAS2-catalyzed conversion of GA₁₂ to DHGA₁₂. Cofactor: 24 µL, containing 133 mM 2-oxoglutarate, 133 mM ascorbate, 16.7 mM FeSO₄, and 33.3 mg/mL catalase. b Total ion chromatogram (TIC) of DHGA₁₂ by LC-MS. c MS spectrum of the peak at 4.85 min (retention time) in (b). d Schematic of the chemical synthesis of DHGA_12C (subscript C denotes chemically synthesized DHGA₁₂). The chemical synthesis was conducted in the phosphoric acid solution (0.125 mol/L) at 60 ^oC for 8 h. e TIC of DHGA_12C by LC-MS. f MS spectrum of the peak at 4.85 min (retention time) in (e). g The stereochemical configuration of DHGA₁₂ (green oval) and gibberellin biosynthetic pathway including the GAS2-catalyzed production of DHGA₁₂. 20ox GA 20-oxidase, 3ox GA 3-oxidase, 2ox GA 2-oxidase, LC-MS liquid chromatography/mass spectrometry, GA gibberellins, MS Murashige and Skoog agar