Experiments on the isolation and identification of monocotyledonine

Summary

Euphorbiaceae plant a leaf autumn, also known as the bottom of the leaf beads, also known as dog apricot strip, its roots, leaves and shoots contain a variety of alkaloids, the structure has been clear more than a dozen kinds. Among them, Ichibaqiu alkaloid has the highest content, and has been used in clinical practice. Ichibanchu alkaloids and its derivatives can excite the central X nerve, enhance myocardial contraction, elevate blood pressure, clinical use of Ichibanchu nitrate to treat facial nerve paralysis, poliomyelitis sacral neuritis and polyneuritis caused by infection of the lateral femoral neuritis, and has become a common neurological disorders of the drug.

Operation method

ion exchange resin method

Principle

Ion exchange resins are solid polymer compounds with a reticulated three-dimensional structure and insoluble in acids, alkalis and organic solvents. The unit structure of ion exchange resin consists of two parts. One part is immovable and has a three-dimensional structure of the network skeleton, the other part is movable active ions. The active ions can migrate freely between the network skeleton and the solution, and when the resin is in solution, the active ions on it can produce an exchange process with the same ions in the solution. This exchange takes place in equal equivalents. If the resin releases active cations, it can exchange with the cations in the solution, called cation exchange resin; if the release of active anions, it can exchange the anions in the solution, called anion exchange resin.

Materials and Instruments

Ichiba alkali
Silicon tungstic acid Potassium iodide Bismuth potassium iodide Ether Ethanol Nitric acid Iodomethane Acetone Sulfuric acid Ammonium hydroxide
Sarcophagus extractor Enamel cylinder Percolation vat Cation exchange column Petri dish Beaker Cuvette

Move

I. Extraction and isolation of alkaloids



II. Qualitative experiments on alkaloids
1. Take 1 ml of the percolating solution and add a few drops of silicotungstic acid reagent to produce a pale yellow precipitate.
2. Take 1 ml of the percolating solution and add a few drops of potassium iodide reagent to produce a light tan precipitate.
3. Take 1 ml of the percolating solution and add a few drops of bismuth potassium iodide reagent to produce a brown-red precipitate.
III. Preparation of monocotyledonine derivatives
1. Preparation of monohydrine nitrateWeigh 200 mg of monilaurine, add 6 ml of ether and 9 ml of anhydrous ethanol, so that all the alkaloids are dissolved, add 10% nitric acid anhydrous ethanol solution of 14 ml dropwise, dropwise add ether to turbidity, placed, white crystals precipitated, filtered, the crystals were washed with anhydrous ethanol - ether (1: 1) for several times, drying, that is, to obtain nitric acid monilaurine.Nitric acid a leaf autumn base, no smell, taste bitter, soluble in water, insoluble in alcohol. mp. 222 ℃.
2. Preparation of methylated substances of Ipomoea alkaloidsThe sample was weighed 100 mg, methyl iodide (MeI) 0.4 ml and acetone 10 ml refluxed in water bath for 1 hr, after cooling the crystals were precipitated, filtered, the crystals were washed with ether and recrystallized with NeOH-EtOH to obtain yellow needle crystals, mp. 232°C.
Figure 1. Reaction formula
IV. Identification
1. TLC
(1) Adsorbents

_Al2O3 (basicity Ⅱ~Ⅲ, particle size >200 mesh)
(2) Expanding agent
a. _CHCl3: Ben. : EtOH (25:25:2)b. _CHCl3 c. _Et2O
2. IR _νmax1 790 ^cm-1 (proton on unsaturated lactone ring)1,730 ^cm-1 (carbonyl group of lactone)1 620 ^cm-1 (double bond)
3. UV _λmax 256.6, 311.6 nm
4. Determination of Specific Spectrophotometry
[α]=-1,042

Common Problems

I. Introduction to Ichiba alkaloids

Euphorbiaceae (Securinega suffruticosa (Pall) Rehd), also known as leaf bottom beads, alias dog apricot strip, China's resources are very rich. Its roots, leaves and shoots contain a variety of alkaloids, the structure has been clear there are more than a dozen. Among them, Ichibanchu alkaloid has the highest content and has been used in clinic. Ipecac and its derivatives can excite the central X nerve, enhance myocardial contraction, elevate blood pressure, clinical use of Ipecac nitrate for the treatment of facial nerve paralysis, polio sacral neuritis and polyneuritis caused by infection of lateral femoral neuritis, becoming a common drug for neurological disorders.

Ichibanchu alkaloids taste light yellow prismatic crystals, insoluble in water, soluble in alcohol, chloroform, more difficult to dissolve in petroleum ether, its structure is as follows:

Figure 2. Structural formula of one-night autumn base

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