标题：A water-soluble high molecular weight substance isolated from Hyuganatsu orange (Citrus tamurana), suspected to be a polysaccharide, inhibits rat osteoclast cell formation
其他摘要：Background: Osteoporosis is detrimental to aged women’s health care. We previously reported that Hyuganatsu orange (Citrus Tamurana) contains active substances that inhibit osteoclast activities. Prior to conducting a human study, we sought to identify the biological active substance in the Hyuganatsu orange which suppresses osteoclast formation. Methods: We isolated five fractions from a Hyuganatsu orange extract according to molecular weight. Each fraction was tested to determine its suppressive effect on the formation of osteoclasts in rats. We also used high-performance liquid chromatography (HPLC), infra-red (IR), and 1H and 13C NMR spectroscopy to evaluate its chemical structure. Data was recorded as mean ± standard error of the mean. The Mann-Whitney test was used, and a p-value of <.05 was considered statistically significant. Results: The highest and lowest molecular weight fractions showed significant suppression activity on rat osteoclast formation (p < .05). The lowest molecular weight fraction was identified as hesperidin using thin layer chromatography. Additionally, IR absorption revealed that the highest molecular weight fraction was not a flavonoid. With regard to chemical structure, 1H and 13C NMR spectroscopy suggested that the highest molecular weight fraction had signals compatible with a polysaccharide such as galacturonic acid. Conclusions: Hyuganatsu orange contains a biological active substance other than hesperidin that may be a polysaccharide and may suppress osteoclast formation.
