Study On Chemical Constituents, Quality Control And Technology For Extraction Of Polyphenol Of Portulaca Oleracea L

Portulaca oleracea L. (Portulacacea), widespread in temperate and tropical regions of the world, is a well-known edible and medicinal plant. Modern pharmacological research revealed that it has various activities, such as antibacterial, anti-oxidation, anti-aging, anti-anoxia, analgesic, anti-inflammatory, and neuroprotection activities. Many types of chemical compounds were present in this plant, including alkaloids, terpenoids, organic acids, coumarins, flavonoids, volatile oil and polysaccharides. To date, bioactive constituents in this herb are not so clear, and quality control of this herb in Chinese Pharmacopeia covers only morphological identification, microscopic identification, TLC identification and moisture test. In view of these facts, chemical constituents, quality control of P. oleracea were intensively studied in this paper, and the technology for extraction of polyphenol from this herb was investigated as well.1. The chemical constituents of P. oleracea were studied,10 compounds were isolated from 70% ethanol extract through silica gel, Sephadex LH-20 and polyamide column chromatography. Based on NMR, MS data and physico-chemical properties, these compounds were elucidated as oleracein F (1), oleracein G (2), oleracein E (3), cyclo(Ala- Tyr) (4), cyclo(Phe-Ile) (5), adenosine (6), friedelin (7), salicylic acid (8), acacetin-7-O-β-D-rhamnosidoglucoside (9), n-tetracosanoic acid (10). Among them, compound 1 and 2 were novel natural products, showing DPPH scavenging activity, with EC50 of 21.00 and 37.69μM, respectively. Compound 4,5,8,9 were isolated from this plant for the first time.2. Methods for quality control of Herba Portulacea were studied. Physico-chemical identification methods and the HPLC fingerprints of the herba were established, and limits of moisture, total ash, acid-insoluble ash, water extract, ethanol extract and total phenol contents were determined.3. Technology for extraction and purification of total polyphenol from P. oleracea were studied. The optimal technologies are as the following:the crude drug was refluxed with six volumes of 60% ethanol for 3 times,1 h each time. The extracts were combined and condensed under reduced pressure to the concentration of 0.5g crude drug/ml. The supernant solution was applied to two volumes of HPD700 resin, and first eluted with 4.5BV of water, then eluted with 4.5BV of 50% ethanol, the 50% ethanol eluates were combined and condensed to driness.