Dear Abdullah Abdullah sorry to see that your very interesting technical question has not yet received any expert answers. Please note that we are synthetic inorganic chemists (organolanthanide chemistry), so that I am not a proven expert in natural products and plant extraction. My rather simple approach to answering this question is the following: Methanol has a rather low boiling point of 65 °C which is only 30-40 degrees higher than normal summer temperatures. Thus I think you should not really worry about decomposition of plant materials during Soxhlet extraction. After all, what are highly thermolabile plant ingredients good for? I assume that compounds which already decompose above ca. 60 °C will not have many practical applications. If you want to use a solvent which has an even lower boiling point, you might want to try methyl acetate which boils at 57 °C. Of course you can aways try cold extraction using any other solvents.

It often helps reading the answers given to closely related question which have been asked earlier on RG. In this context, please have a look at the following RG thread:

Phytochemicals extraction methods, which is the best?

https://www.researchgate.net/post/Phytochemicals-extraction-methods-which-is-the-best

(12 answers)

Also please share your question with Yasser Fakri Mustafa who is a leading expert in plant extraction and natural products chemistry.

I hope this helps. Good luck with your research and best wishes, Frank Edelmann

Dear Abdullah Abdullah

First of all, I would thank Professor Frank T. Edelmann for sharing this concern. Second, as you know, phytochemicals are classified into primary and secondary metabolites. I proposed that you design the study to investigate the second type. Accordingly, if the natural ingredient intended to be extracted has a known phytochemical composition, you can detect which chemicals may be decomposed. Otherwise, I think that you would not be able to detect the decomposition of unknown phytochemicals. Also, methanol, as a weak nucleophile, can facilitate the decomposition of several ester-containing molecules. I recommend doing the extraction using other extraction methods, such as those facilitated by microwave or ultrasound, and then comparing the results with those acquired by Soxhlet.

All the best to you.

You can make an original study, and compare the pytochemical profile using different types of extraction.

The following cases must be Carefully considered in the experiment by soxhlet apparatus.

1- How type of secondary metabolite do you want and its possible fractionations

2- Polarity and non-polarity of the solvent

3- Pay special attention to some physical and chemical features of the solvent such as boiling point, type of bonds, etc.

Good luck.

The solvents you are planning to use like Methanol and ethylacetate do not go beyond the temperature of 75 C, since both are good solvents are likely to extract organic matter like terpenes, simple alkaloids etc , there is no possibility of loosing / decomposing any compounds during soxleht extraction using methamol and ethylacetate

The solvents you are planning to use like Methanol and ethylacetate do not go beyond the temperature of 75 C, since both are good solvents are likely to extract organic matter like terpenes, simple alkaloids etc , there is no possibility of loosing / decomposing any compounds during soxleht extraction using methamol and ethylacetate