Please rewrite your question and give more infos about the ester compounds.

- According to March J. (Advanced Organic Chemistry/Third Ed./ 1985 /Wiley Interscience , you c an have esters of organic and inorganic acids.

- Among the organic esters, you have the aliphatic esters and the aromatic esters.

Chemical reaction of esters:

Esters react by nucleophilic substitution at the carboxyl group (sn2 reaction p.e.)

Ester + X (X can be OH- or NH3 . please read the chapter in March ´s book.

Concerning the fluorescence of aromatic esters (with benzene ring) like :

dimethyl 2,5-diaminobenzene-1,4-dicarboxylate give a YELLOW fluorescence in diethylether.

With the introduction of further methylcarboxylate( 2 at the free positions of this molecule) the fluorescence is RED in diethylether.

The esterification of fluorochromes makes them lipophilic prior to an introduction in membranes. Scission to free acid occurs in the cells.

Whether or how the ester group acts can be answered when you rewrite your question and give more infos about the choosed ester compounds.

JRG

Sir the triterpenoid esters precisely .I would like to thank you so much for your explanations

I have a follow-up question. This ester, 7-Hydroxy-6-methoxy-2H-1-benzopyran-2-one is fluorescent at neutral pH and it loses fluorescence at acidic pH and also upon oxidation. Can someone please explain the underlying mechanism

Please refer to following article. Let me know if you need further explanation Chandan kumar Gautam

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