Effects of ferrous sulfate and methyl jasmonate treatment on the content of 2-(2-phenethyl)chromones in Aquilaria sinensis

The 2-(2-phenylethyl) chromones are the main characteristic constituents for the fragrance and pharmacological activities of agarwood. Iron and methyl jasmonate (MeJA) are two important elicitors that affect the production of secondary metabolites in plants. With the aim to evaluate the response of eight 2-(2-phenylethyl)chromones constituents of Aquilaria sinensis to ferrous sulfate (FeSO₄) and MeJA treatment, the content of eight 2-(2-phenylethyl)chromones in A. sinensis callus tissues treated with 0%, 0.4%, and 0.8% FeSO₄ as well as 0 μmol/L, 50 μmol/L, 100 μmol/L, and 200 μmol/L MeJA for 3, 7, and 15 days were analyzed using liquid chromatograph mass spectrometry. The results showed that the content of eight 2-(2-phenylethyl)chromones were significantly affected under the FeSO₄ and MeJA treatment. The content of 2-(2-phenethyl)chromones, except for 4'-methoxy isoagarotetrol, was highest at 0.8% FeSO₄ treatment for 7 days. For the MeJA treatment, 6-hydroxy-2-(2-phenylethyl)chromone and 6,7-dimethoxy-2-(2-phenylethyl)chromone were highest at 50 μmol/L MeJA for 7 days, while the content of agarotetrol, 4'-methoxy isoagarotetrol, isoagarotetrol, (5S,6S,7S,8R)-8-chloro-5,6,7-trihydroxy-2-phenylethyl-5,6,7,8-tetrahydro-4H-chromen-4-one, 2-(2-phenylethyl)chromone, and 2-[2-(4-methoxyphenyl)ethyl] chromone were significantly increased at 200 μmol/L MeJA for 7 days. Compared with MeJA treatment, FeSO₄ is more likely to induce 2-(2-phenylethyl)chromones in A. sinensis. Our results provide a useful information for large-scale commercial production of 2-(2-phenylethyl)chromones.