Extraction and Preparation Aloin and Aloe-emodin From Aloe Powder
|Keywords||Aloin Aloe-emodin Extract Preparation Stability|
Aloe vera is a higher economic value of medicinal plants, aloe planting bases in China has a large area, but the processing technology is relatively backward. Aloin and aloe emodin is one of the major functional components of aloe, widely used in medicine, health care, cosmetics and other fields. Aloin and aloe emodin prepared to provide a scientific basis and technical support for the development of aloe products, aloe industry in China is of great significance. This article first determine the aloin and aloe emodin HPLC analysis conditions. The Aloin HPLC chromatography conditions: Column: Eclipse XDB-C18 column (4.6 mm × 250 mm, 5μm); detection wavelength: 354 nm; mobile phase: methanol - water (55:45); flow rate: 0.8 mL / min , column temperature: room temperature; aloe emodin HPLC chromatographic conditions: Column: Eclipse XDB-C18 column (4.6 mm × 250 mm, 5μm); detection wavelength: 254 nm; mobile phase: methanol-0.1% phosphoric acid solution (80 flow rate: 0.8 mL / min; Column temperature: room temperature: 20); And determination of aloin and aloe emodin raw aloe powder content, to provide a reference for subsequent experiments carried out. Ethyl acetate as extractant, on the basis of single factor orthogonal experimental method to examine the extraction temperature, extraction time, extraction dosage, extract the number of four factors on the the Aloin extraction rate, the optimum process : aloe vera powder 14 g, extraction temperature of 57 ° C, extraction time of 30 min, the solvent amount of 300 mL, extracted 4 times. Under this condition the Aloin the extraction rate of up to 77.15%. The crude extract was re-dissolved in iso-butanol, -5 ° C freezer 24 h, aloin crystals were obtained by filtration, and a purity of 80.73%, yield 51.35%. Aloin crystals are added to the water, and the mixture was stirred at room temperature for 30 min, filtered, and dried, to obtain a 93.5% pure aloin. High performance liquid chromatography, time, temperature, pH, metal ions, and other factors that impact on the the aloin stability in aqueous solution. The results show that the aloin is unstable in water. After leaving for 6 days at room temperature and its content is decreased by 90.5%. Temperature and pH on the stability of aloin significant impact. 80 ℃, 8 hours Aloin degradation of up to 98%; 5 ℃, 4 days a degradation of less than 5%. When the pH of ≥ 7 Aloin degradation of more than 95% within 12 hours; pH 2.0 hours, 4 days a degradation of only 21.1%. Mn2, Cu2, Fe3 metal ions on the the Aloin degradation has a role in promoting, while Mg2 Aloin degradation inhibition. In this paper, we design prepared a Aloin ferric chloride oxidation aloe powder, aloe emodin. Aloe vera powder was added to a solution of hydrochloric acid, under the conditions of 106 ° C under reflux for 30 min, removed by filtration residue, retain the filtrate was heated to boiling, adding ferric chloride solution, the reaction was kept 8 h aloin to aloe-emodin conversion conversion rate of 89.15%. Aloe-emodin crude toluene Soxhlet extraction, extract -5 ℃ low temperature crystallization, drying, can be obtained 95.59% of aloe emodin boutique.