Chinese yam (Dioscorea opposita), peeled or whole, is a popular food item that is considered to be healthy. Often, the yam is peeled before cooking. However, it is also consumed with peel. Therefore, in this study, the peel of this yam was extracted sequentially with n-hexane, ethyl acetate and methanol, and studied for its health-benefits, using in vitro bioassays. Bioactivity-guided purifications of extracts of the peel afforded phenanthrenes (1-4), as characterized by spectroscopic methods. Phenanthrene 1 is a novel analogue. The extracts and isolates were tested for anti-inflammatory activity using cyclooxygenase enzyme (COX-1 and -2) inhibitory assays. All phenanthrenes isolated from the yam peel showed higher inhibition of COX enzymes than the over-the-counter nonsteroidal anti-inflammatory drugs (NSAIDs) aspirin, ibuprofen and naproxen.
AliZ, SmillieTJ, KhanaIA. (2013) 7-Oxodioscin, a new spirostan steroid glycoside from the rhizomes of Dioscorea nipponica. Natural Product Communications, 8, 319–321.
2.
XuL, WangJ, ZhaoJ, LiP, ShanT, WangJ, LiX, ZhouL. (2010) Beauvericin from the endophytic fungus, Fusarium redolens, isolated from Dioscorea zingiberensis and its antibacterial activity. Natural Product Communications, 5, 811–814.
JuY, XueY, HuangJ, ZhaiQ, WangX-H. (2014) Antioxidant Chinese yam polysaccharides and its pro-proliferative effect on endometrial epithelial cells. International Journal of Biological Macromolecules, 66, 81–85.
5.
ZhaoG, KanJ, LiZ, ChenZ. (2005) Structural features and immunological activity of a polysaccharide from Dioscorea opposita Thunb roots. Carbohydrate Polymers, 61, 125–131.
6.
KongX-FZhangY-ZYinY-LWuG-YZhouH-JTanZ-LYangFBoM-JHuangR-LLiT-J, GengM-M. (2009). Chinese yam polysaccharide enhances growth performance and cellular immune response in weanling rats. Journal of the Science of Food and Agriculture, 89, 2039–2044.
7.
YangMH, YoonKDChinY-WParkJH, KimJ. (2009) Phenolic compounds with radical scavenging and cyclooxygenase-2 (COX-2) inhibitory activities from Dioscorea opposita. Bioorganic & Medicinal Chemistry, 17, 2689–2694.
8.
YangMHChinY-WYoonKD, KimJ. (2014) Phenolic compounds with pancreatic lipase inhibitory activity from Korean yam (Dioscorea opposita). Journal of Enzyme Inhibition and Medicinal Chemistry, 29, 1–6.
9.
ZhangL, BaiB, LiuX, WangY, LiM, ZhaoD. (2011) α-Glucosidase inhibitors from Chinese yam (Dioscorea opposita Thunb.). Food Chemistry, 126, 203–206.
10.
SautourM, Mitaine-OfferAC, MiyamotoT, WagnerH, Lacaille-DuboisMA. (2004) A new phenanthrene glycoside and other constituents from Dioscorea opposita.Chemical & Pharmaceutical Bulletin, 52, 1235–1237.
11.
BaiB, LiMJ, WangY, LiuXH. (2008) Studies on chemical constituents of Dioscorea opposita. China Journal of Chinese Materia Medica, 11, 1272–1274.
12.
KelmMA, NairMG, StrasburgGM, DeWittDL. (2000) Antioxidant and cyclooxygenase inhibitory phenolic compounds from Ocimum sanctum Linn. Phytomedicine, 7, 7–13.
13.
ZhangC-R, AldosariSA, VidyasagarPSPV, NairKM, NairMG. (2013) Antioxidant and anti-inflammatory assays confirm bioactive compounds in Ajwa date fruit. Journal of Agricultural and Food Chemistry, 61, 5834–5840.
14.
ZhangY, MillsGL, NairMG. (2003) Cyclooxygenase inhibitory and antioxidant compounds from the fruiting body of an edible mushroom, Agrocybe aegerita. Phytomedicine.10, 386–390.
ZhangY, JayaprakasamB, SeeramNP, OlsonLK, DeWittD, NairMG. (2004) Insulin secretion and cyclooxygenase enzyme inhibition by cabernet sauvignon grape skin compounds. Journal of Agricultural and Food Chemistry, 52, 228–233.
17.
SeeramNP, ZhangY, NairMG. (2003) Inhibition of proliferation of human cancer cell lines and cyclooxygenase enzymes by anthocyanidins and catechins. Nutrition and Cancer, 46, 101–106.
18.
AliSIZhangC-RMohamedAA, El-BazFK, HegazyAK, KordMA, NairMG. (2013) Major constituents of Boswellia carteri resin exhibit cyclooxygenase enzymes inhibition and antiproliferative activity. Natural Product Communications, 8, 1365–1366.
19.
LiuY, YadevVR, AggarwalBB, NairMG. (2010) Inhibitory effects of black pepper (Piper nigrum) extracts and compounds on human tumor cell proliferation, cyclooxygenase enzymes, lipid peroxidation and nuclear transcription factor-kappa-B. Natural Product Communications, 5, 1253–1257.
20.
TakasugiM, KawashimaS, MondeK, KatsuiN, MasamuneT, ShirataA. (1987) Antifungal compounds from Dioscorea batatas inoculated with Pseudomonas cichorii. Phytochemistry, 26, 371–375.
