The molecular complex formed by triterpene saponins with sterols is not as stable as steroidal sapon

The molecular complexes formed by triterpene saponins with sterols are not as stable as steroidal saponins, because the ethanol solution of steroidal saponins can be combined with sterols (commonly chosterols.

Precipitates by the formation of insoluble molecular complexes. The molecular complex of steroidal saponins and cholesterol is more stable than triterpene saponins.

Because the ethanol solution of steroidal saponins can form insoluble molecular complexes with sterols (commonly used cholesterol) and precipitate. The molecular complex of steroidal saponins with cholesterol is less stable than that of triterpene saponins. Therefore, it is not as stable as steroidal saponins.

The molecular complex formed by triterpene saponins and sterols is not as stable as steroidal saponins, because it can be extracted by cholesterol precipitation: cholesterol complex-ether reflux extraction to remove cholesterol and obtain saponins. Because steroidal saponins are more complex than triterpene saponins.

Solvents are classified by polarity: three categories, namely lipophilic organic solvents, hydrophilic organic solvents, and water. The solvents are in order of polarity from weak to strong as follows: petroleum ether, carbon tetrachloride, benzene, dichloromethane, chloroform, ether, ethyl acetate, n-butanol, acetone, methanol (ethanol), water.

Methanol (ethanol) is the most commonly used solvent and can be mixed with water in any proportion.

The molecule is large, c is more, the polarity is small, and vice versa, it is large. According to the principle of similar miscibility, the polar solvent extracts the polar compound.

The oxygenated derivatives of terpenoids in volatile oils are the main components of volatile oils with strong biological activity or only aromatic odor. Glycoside shift of ester glycosides in triterpene saponins.

Distinguish steroidal saponins from triterpene saponins by chemical methods:

Acetic anhydride-concentrated sulfuric acid reaction: The sample was dissolved in acetic anhydride, and several drops of concentrated acetic anhydride (1:20) were added, and the color changes such as yellow, red, blue, violet, and green. This reaction can distinguish between triterpene saponins, which end up being red or purple, and steroidal saponins, which end up being blue-green.

Trichloroacetic acid reaction: drop the chloroform solution of the steroidal saponin-containing sample on the filter paper, add 1 drop of trichloroacetic acid test solution, heat to 60, and generate red gradient to purple.

Under the same conditions, triterpene saponins must be heated to 100 to develop color, and also produce a red gradient to purple, which can be used for paper chromatography. This method can also be used to distinguish triterpene saponins from steroidal saponins.

Extraction separation:

Saponins are a class of highly polar macromolecular compounds, which are not easy to crystallize, soluble in water and alcohol, insoluble in organic solvents, and often have many saponins with similar structures in the same plant, which increases the difficulty of separation and purification. Generally, it is extracted with methanol or hydrous ethanol first, and then the alcohol extract is suspended in water and extracted with water-saturated n-butanol, that is, total saponins are obtained.

In addition to conventional normal-phase silica gel column chromatography, reversed-phase silica gel, macroporous adsorption resin and dextran gel column chromatography can also be used for the separation of crude saponins, which can significantly improve the separation effect.

Reversed-phase column chromatography is used more in the separation and purification of saponins, the most commonly used is ODS (C18 reversed-phase packing material), which mainly uses water and alcohol to elution in different proportions, which has a good separation effect for compounds with large polarity, and has less adsorption of the sample, which can reduce sample loss.

1. Steroidal saponins and sterols can be used to form molecular complexes, and the ethanol solution of steroidal saponins can be precipitated by sterols (commonly used cholesterol). When the resulting molecular complex is extracted with ether reflux, the cholesterol is soluble in ether, while the saponin is insoluble, so as to achieve the purification of steroidal saponins and check for the presence of saponins.

2. If a certain amount of hydrolysate is shaken, a large number of continuous foam will be generated, and if the foam height of the two tubes with acid and alkali is the same, it may be triterpene saponins, and if the alkali tube is higher than the acid tube, it may be steroidal saponins.

Summary. Dear, hello, I am glad to answer for you, the difference between cardiac glycosides, steroidal saponins and triterpene saponins is as follows: cardiac glycosides are some glycosides extracted from plants containing steroidal aglycosides, which are composed of two parts, glycosyl groups and glycanyls, and their glycosyl parts are different from other steroidal glycosides, in cardiac glycoside molecules, the cyclic A-B and C-D are cis-fused, and the cyclic B-C is trans-fused, and this fusing mode determines its molecular shape is U-shaped, In the molecule, the two angular methyl groups of C-18 and C-13 in C-18 and C-13 and the hydroxyl group at the 3rd position are of Lu configuration.

The L4 position of the Lu-hydroxyl group is usually free. Digoxin is a white sellenoid crystalline or crystalline powder, odorless and bitter in taste. Soluble in pyridine, slightly soluble in dilute alcohol, insoluble in water or ether.

Short answer question: Compare the differences in cardiac glycosides, steroidal saponins, and triterpenoid saponins in the parent nucleus structure.

Dear, hello, I am happy to answer for you, compare cardiac glycosides, steroidal saponins and triterpene saponins The difference between the nucleus structure is as follows: cardiac glycosides are some glycosides extracted from plants containing steroidal aglycones, which are composed of two parts, glycosides and glycans, and their glycosids have certain differences from other steroidal glycosides, in cardiac glycoside molecules, the cyclic A-B and C-D are cis-fused, and the cyclic B-C is trans-fused, the two angular methyl groups of C-18 and C-19 located in C-10 and C-13 and the hydroxyl group at the 3rd position are of Lu configuration. The L4 position of the Lu-hydroxyl group is usually free.

Digoxin is a white sellenoid crystalline or crystalline powder, odorless and bitter in taste. Soluble in pyridine, slightly soluble in dilute alcohol, insoluble in water or ether.

Both steroidal saponins and triterpene saponins have a steroidal reaction such as the mother nucleus of the bond body, and can distinguish between the two. Acetic anhydride concentrated sulfuric acid reaction: take 2ml of the test solution, evaporate it on a boiling water bath, dissolve the residue with a few drops of acetic anhydride, and add acetic anhydride concentrated sulfuric acid (20:

1) A few drops, the steroidal saponin reaction solution produces huang-red-purple-blue-green-wu green isomorphic se, which gradually fades after zui; Triterpene saponins can only show red-purple SE or blue SE in the end, and then gradually fade SE.

1. Acetic anhydride-concentrated sulfuric acid (liebermann-burchard) reaction can be used to distinguish steroidal saponins from triterpene saponins, steroidal saponins are green at the end, and triterpene saponins are red or purple at the end.

Acetic anhydride-sulfuric acid reaction detection method: the sample is dissolved in acetic anhydride, and a few drops of concentrated sulfuric acid-acetic anhydride (1:20) are added to produce color changes.

In the case of steroidal saponins, in the change of color, they finally appear green, while triterpene saponins can only change to red, purple or blue, and do not appear green.

2. In the second question, it can be seen that there are hydroxyl groups in the 5 positions of the two types of compounds, and the examination is to distinguish whether there is a hydroxyl group on the 3 positions, the flavonoids without the hydroxyl group, and the flavonols with 3-OH are flavonols.

In the zirconium-citrate reaction, the complex formed by the 3-hydroxyl group is more stable than the 5-hydroxyl group and can be used to distinguish between 3-OH or 5-OH flavonoids.

Methods: With the addition of 2% ZroCl2 MeOH, the methanol solution of the sample generated a yellow zirconium complex, and then 2% citric was added, and the 3-OH flavonoids were still bright yellow, and the 5-OH flavonoids were significantly faded from the yellow solution.

(1) Structural characteristics of steroidal saponins: steroidal saponins are composed of 27 carbon atoms, with a total of six rings: A, B, C, D, E, and F, and the E ring and F ring are connected in the form of spirosterone to form spirosterane.

2) Types of steroidal saponins: According to the cyclic state of the F ring in the spirostane structure, it can be divided into: spirostanols, isospirosanols and furosteranol types.

Answer] :d The test point of this question is the chromogenic reaction of triterpene saponins and steroidal saponins. The reactions that can be used to detect saponins are acetic anhydride-concentrated sulfuric acid reaction (liebrmann-burchard reaction), trichloroacetic acid reaction, chloroform-concentrated sulfuric acid reaction, antimony pentachloride reaction, aromatic aldehyde-sulfuric acid (high-sensitivity lichloric acid) reaction, etc., among which acetic anhydride-concentrated sulfuric acid reaction and trichloroacetic acid reaction can be used to identify triterpene saponins and steroidal saponins.

Answer]: Dry oak

The reaction that distinguishes steroidal saponins from acidic triterpene saponins is the lead acetate precipitation reaction. Acidic saponins can be precipitated by neutral lead acetate, and neutral saponins can be precipitated by alkaline lead acetate and separate. Triterpene saponins are acidic saponins, which can be precipitated with neutral lead acetate, while non-conjured steroidal saponins are neutral saponins, which must be precipitated with alkaline lead acetate.