Is it different for any natural compound class to the other? for example is it different method for hydrolysis a glycoside from a flavonoids or a terpenoids or another classes?
Complete acid hydrolysis
Complete acid hydrolysis was carried out for 40-60 min. using 5ml 2N-hydrochloric acid. The hydrolysate was then extracted with ethyl acetate, and the received extract was subjected to paper chromatographic investigation to detect the aglycones. The mother liquor was carefully neutralized, and then subject to paper chromatographic investigation to detect the sugars.
10 mg of each sample was hydrolyzed with 2 M HCl in 1, 4-dioxane (1: 1, 1.5 ml) and refluxed for 2 h, cooled followed by addition of 5 ml of water.
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tnx, and What do I do If I want to hydrolysed all the glycoside compound of an extract or a plant. like comparison of free phenolic acids and their glycoside in a plant?
Complete acid hydrolysis
Complete acid hydrolysis was carried out for 40-60 min. using 5ml 2N-hydrochloric acid. The hydrolysate was then extracted with ethyl acetate, and the received extract was subjected to paper chromatographic investigation to detect the aglycones. The mother liquor was carefully neutralized, and then subject to paper chromatographic investigation to detect the sugars.
Very nicely, the answer has been given by Fatma Aly. Thanks to Fatma Aly.
HCl often causes isomerisation in the aglycone (steroid / triterpenoid). Pl use dilute sulfuric acid.
Paper chrom is almost oudated and has lot of disadvantages. Pl use TLC
There are enzymatic methods to separate sugars from glycosides. Acid hydrolysis may damage the compound you require. Please determine the sugars present in the glycoside and use a particular enzyme accordingly. It may be a costly process but you will get your aglycones and sugar intact.
Thank you vivek. I almost forgot to touch the topic. From chemistry angle we go as a first step for acid hydrolysis. One you know your sugars and aglycone, then one should check possible changes that might have occurred- it is possible to surmise from the structures. Enzymatic hydrolysis helps us in determining the sequence and types of attachment of sugar moieties. Now MS techniques have come up and used along with NMR will give clues to the structure of the glycoside. It is a good but tedious area.
Not at all Dr. Bapuji :) . Yes Sir, as you mentioned its quite tedious, but we are using LC-MS techniques for our Acyl-sugar work and its become easier and faster too.
You should optimize the hydrolysis for your specific compounds. They can be labile to the acid treatment/heat etc.
You can adopt acid hydrolysis with MeOH/ 2N HCl/ or H2SO4 for 30-40min at 100 C. You can also go for enzymatic hydrolysis if the compounds are liable to be degraded with strong acid and high temperature. Please note that selection of correct hydrolysis method is compound of class of compound specific that need to be optimized. After hydrolysis , you may check the sugar partr through PC and examine aglycone part by chromatographic methods like LC/LCMS.
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