ALKALOIDS & GLYCOSIDES TEST

basic nitrogenated compounds

__ (alkaloids) comprising the largest class of secondary plant metabolites

water-soluble salts

alkaloids usually occur in plants as their __

Hg
Au
Pt

• alkaloids form double salts with __ and other heavy metals;

• these salts are obtained as precipitates which are micro-crystallographic

Mayer’s test
Dragendorff’s test
Wagner’s test
Valser’s test
Hager’s test

tests for alkaloids

cream precipitate

Mayer’s test positive result

potassium mercuric iodide TS

Mayer’s reagent

orange precipitate

Dragendorff’s test positive result

potassium bismuth iodide TS

Dragendorff’s reagent

reddish brown precipitate

Wagner’s test positive result

iodine potassium iodide TS

Wagner’s reagent

white precipitate

Valser’s test positive result

mercuric iodide TS

Valser’s reagent

yellow precipitate

Hager’s test positive result

saturated solution of picric acid

Hager’s reagent

glycosides

• plant constituents which produces sugars as product of hydrolysis

• sugar ethers

• hydrolyzed by boiling mineral acids

• regulatory, protective, and sanitary compounds

glycone

• sugar component

• common denominator

• inactive

aglycone

• non-sugar component

• basis of classification

• active

cardiac glycosides

steroidal glycosides also known as __

heart muscle

steroidal glycosides have a prominent effect on the __

cyclopentanoperhydrophenanthrene

steroid structure (CPPP nucleus)

cardenolides

more common

bufadienolides

less common (from toad skin of Bufo spp.)

cardenolides

C-23-unsaturated

bufadienolides

C-24, doubly unsaturated

cardenolides

5 membered lactone ring

bufadienolides

6 membered lactone ring