Glaucarubin

Originator

Glarubin,Massengill,US,1959

Definition

ChEBI: Glaucarubin is a triterpenoid.

Manufacturing Process

The preparation of pure glaucarubin from Aceituno meal is conveniently carried out by extracting the Aceituno meal with water, using about 100 gallons of the water per hundred pounds of meal. If the meal is in the form of a relatively solid cake, it should be soaked in the water for a time to cause disintegration. The temperature of the water is then raised to about 70°C for the actual extraction, and the mixture is moderately agitated, while maintaining a temperature of about 70°C for a period of about three hours, until extraction is substantially complete. If desired, the extraction may be conducted at lower temperatures down to about room temperature although at such lower temperatures, the extraction is much slower and less efficient at temperatures substantially higher than 70°C, there may be partial destruction or decomposition of the product being recovered.
The slurry or extraction mixture is filtered while hot, and the resulting filter cake is washed with about five to ten gallons of hot water; the primary filtrate and wash water are combined and held for further processing. In order to insure complete extraction of the desired material, the filter cake is again extracted with about 100 gallons of water at 70°C. Although not essential, it is desirable to add to the second extraction a small quantity of acetic acid. The acetic acid appears to aid in obtaining a complete and thorough extraction. After extraction for about three hours with agitation at a temperature of about 70°C, the slurry is again filtered and the cake washed as before with about five to ten gallons of hot water. The resulting filtrate and wash are then combined with the primary filtrate and wash.
The combined filtrates or total aqueous extracts are cooled to about room temperature and filtered to remove any residual solids from solution. The clarified aqueous extract is then concentrated to about 70 gallons at a temperature below about 50°C, thus reducing the volume to about one-third the original volume. The resulting concentrate is cooled to room temperature or below and filtered to remove any tar or gum that may have separated. The presence of tar or gum at this stage of the process will vary depending upon the starting material and the manner in which the primary extraction has been carried out. It has been found, however, that unless any tar or gum present in the initial extract is removed by the procedure described, it will seriously interfere with the further concentration and crystallization steps hereinafter described.
After removal of such tar or gum, the concentrate is further evaporated at a temperature below about 50°C to about one-fourth the volume, i.e., 70 gallons is concentrated to about 15 to 20 gallons. This concentrate is cooled to a temperature of about 0°C to 5°C and allowed to stand for an extended period, such as overnight, whereupon there is a separation of crude crystalline glaucarubin therefrom. The crude crystals thus formed are removed by filtration and the mother liquors again concentrated to about one-half volume and cooled to permit separation of a second batch of crude glaucarubin crystals. The two batches of crude glaucarubin crystals are combined and dried preparatory to further purification.
The crude glaucarubin crystals obtained as above described from 100 pounds of Aceituno meal are slurried with about sevenandanehalf gallons of anhydrous methanol and refluxed until the crystals dissolve. The hot solution is then filtered and the resulting filter cake washed with methanol. The filter cake is then again extracted with an additional seven-and-one-half gallon quantity of anhydrous methanol in the manner described, and filtered. The methanol filtrates and washes are combined and concentrated at atmospheric pressure until crystals begin to appear, i.e., generally after concentration to about one-fifteenth volume. The solution is then cooled to about 0°C to 50°C and allowed to stand for crystallization to go substantially to completion. The resulting crystals are filtered off and the mother liquors are further concentrated and cooled to collect a second crop of crystals. The two crops of crystals are then combined and may be further purified by redissolving in methanol, filtering through activated charcoal, and recrystallizing after concentration of the methanol filtrate.
The purified crystalline glaucarubin thus obtained is colorless and odorless and is estimated to have a purity of about 96% to 97%. It has the formula C25H36O10 and melts at 262°C to 263°C with decomposition (capillary tube).

Therapeutic Function

Amebicidal