DescriptionPhenolic compounds from natural sources are receiving increasing attention recent years since they were reported to have a remarkable spectrum of biological activities including antioxidant, anti-inflammatory and anti-carcinogenic activities. They may have many health benefits and can be considered possible chemo-preventive agents against cancer.
In this research, we attempted to isolate and characterize phenolic compounds from two food sources: ginger and Allium ursinum. Solvent extraction and a series of column chromatography methods were used for isolation of compounds, while structures were elucidated by integration of data from MS, 1H-NMR, 13C-NMR, HMBC and HMQC. Antioxidant activities were evaluated by DPPH method and anti-inflammatory activities were assessed by nitric oxide production model.
Ginger is one of most widely used spices. It has a long history of medicinal use dating back 2500 years. Although there have been many reports concerning chemical constituents and some biological activities of ginger, most works used ginger extracts or focused on gingerols to study the biological activities of ginger. We suggest that the bioactivities of shogaols are also very important since shogaols are more stable than gingerols and a considerable amount of gingerols will be converted to shogaols in ginger products. In present work, eight phenolic compounds were isolated and identified from ginger extract. They included 6-gingerol, 8-gingerol, 10-gingerol, 6-shogaol, 8-shogaols, 10-shogaol, 6-paradol and 1-dehydro-6-gingerdione. DPPH study showed that 6-shogaol had a comparable antioxidant activity compared with 6-gingerol, the 50% DPPH scavenge concentrations of both compounds were 21?M. All of the eight isolated compounds had effects on inhibiting LPS-induced NO production, and 6-shogaol showed more inhibitory effect than 6-gingerol with reducing nitrite production by 85 % compared with 35 % by 6-gingerol at 5 ?M.
Flavonoids are a group of phenolic compounds that occur naturally in food of plant origin. Compelling data indicated that flavonoids had important effects on cancer chemoprevention and chemotherapy. Among 10 compounds we isolated from Allium ursinum, a widely used spice, eight of them were flavonoids. Three of them, kaempferol 3-O-?-L-rhamnopyranosyl (1?2)-[3-O-acetyl]-?-D-glucopyranoside, kaempferol 3-O-?-L-rhamnopyronosyl (1?2)-[6-O-acetyl]-?-D-glucopyranoside and 6'-O- acetyl kaempferol-3-O-L-rhamnopyranosyl(1?2)-?-D-glucopyranoside- 7-O-[2-O-(trans-p-coumaroyl)]-?-D-glucopyranoside were new natural products.