[jamesm]

Hi,

I am hoping someone will verify if what I think is correct, and if not correct me:

• Methyl jasmonate (CAS 39924-52-2) = C₁₃H₂₀O₃
• Methyl dihydrojasmonate (CAS 24851-98-7; mixture of cis and trans)= C₁₃H₂₂O₃

Is the difference between the two chemicals that one (methyl dihydrojasmonate) is hydrated (conjugated by water)? Would it be correct for a researcher to expect the biological effects of both to be very similar (e.g. due to hydration of MeJA inside plant tissue), e.g. when sprayed on plants?

Also, would one or the other be expected to have greater (longer) stability in weakly basic aqueous solution?

Thank you

[discodermolide]

In the dihydro-compound the alkene in the chain has been removed.
Here for sructure: http://en.wikipedia.org/wiki/Methyl_dihydrojasmonate
and here for methyl jasmonate http://en.wikipedia.org/wiki/Methyl_jasmonate

I would not expect them to have similar biological properties as I guess that the double bond is partially responsible for the biological activity. Note that hydration is not the same as hydrogenation.

They are both esters so their stability in aqueous base will be very similar.

[jamesm]

Hello there,

Thank you very much for your response. Your explanation comports very well with (and gives an explanation for the) published literature [e.g. 1] that the biological activity of MeJA (methyl jasmonate) is higher than MDJ (methyl dihydrojasmonate); as well as other jasmonates such as JA (jasmonic acid) and dihydrojasmoic acid.

The only company (of which I'm aware) that has carried out considerable research into efficacy of MDJ vs. MeJA and JA as biotic and abiotic stress reducer found MDJ to have lower biological activity than the other two forms, with MeJA being the highest out of all jasmonate forms.

Thanks again

[1] Rohwer, C.L. & Erwin, J.E. (2008). Horticultural applications of jasmonates: A review. Journal of Horticultural Science & Biotechnology, 83(3), pp. 283–304