1) Weigh 180g of 100-200 mesh column chromatography silica gel, spread it on a plate, activate it at 110°C for 2 hours, put it in a 1000ml beaker, mix well with PE, remove the air bubbles, put it into a glass chromatography column by wet method, and then use Wash the column with PE.
2) Weigh 60g of 20% Coleus forskohlii extract, and add it into the chromatography column by wet method when the PE liquid level in the glass chromatography column is about 6cm higher than the surface of the silica gel, slowly add and remove the air bubbles, and then After elution with PE for 30 min, cover the sample with 2 cm thick chromatographic silica gel, and finally wash the column with PE.
3) After washing 600ml of the column with PE, wash the column with PE-ethyl acetate (10:1) directly; collect in conical flasks, 200ml per bottle, and recover the solvent in a water bath until dry. The solution that was washed first was darker and blacker, and there were a lot of impurity spots in it. When the solvent was recovered to a small volume, it was thicker and extremely black in color, but it could be dissolved in ethyl acetate, so it was discarded here. Continue to maintain the original gradient elution in this way, continuously remove the front lipophilic impurities, and recover as much solvent as possible from each bottle, so as to observe the phenomenon.
4) When a large number of crystals appear in the bottle, collect and combine them while opening. The phenomenon at this time is that a large number of crystals are precipitated, and the place washed by the hot solution is bright white, and the rest is brownish yellow. The precipitated crystals were carefully dissolved with ethyl acetate and all solutions from which crystals precipitated were combined. When combined to a certain volume, the water bath recovers the solvent to a small volume, equivalent to 1/3 of the original volume, allowing the crystals to precipitate naturally due to supersaturation when hot, and then separate the crystals from the mother liquor and wash them repeatedly with PE until When the color is lighter, dissolve it with ethyl acetate, collect it in another device, and combine it with the crystallization solution after washing. Use a straw to suck up the upper mother liquor, and the mother liquor and washing liquid continue to merge with the subsequent crystallization liquid. After repeated operations in this way, two parts are finally obtained: one part is the crystallization solution washed repeatedly with PE, the color is light brown and the other part is the mother liquor, the color is extremely dark and private. Identify again, find the spot of Forskolin Forte, but also can’t see that obvious crystal is separated out when solution is recovered to 1000, so this mother liquor abandons or uses when making another preparation.
5) Recover the solvent from the crystallization solution until crystals are about to precipitate when it is hot, take out the water bath, add 6 times the amount of PE, shake it slightly, and a large amount of white crystals will precipitate out in an instant, which is very obvious. When it was naturally cooled to room temperature, a large amount of white crystals could be seen at the bottom. Separate the crystallization and the mother liquor, and continue to concentrate the mother liquor until it is crystallized. Finally, two parts of crystals and a dark mother liquor are obtained. After recovering the solvent from the mother liquor to dryness, it is decolorized with PE, and the decolorized solid is dissolved with ethyl acetate and precipitated. After recrystallizing twice in this way, a large amount of white crystals were finally obtained, and finally 12.4g of the product was collected. After “testing, the content was 85%.