Abstract
A new 2-arylbenzofuran derivative, mornigrol D (1), along with two new flavones, mornigrol G (2) and mornigrol H (3), and six known compounds, norartocarpetin (4), dihydrokaempferol (5), albanin A (6), albanin E (7), moracin M (8), and albafuran C (9), were isolated from the barks of Morus nigra. Their structures were elucidated by spectroscopic analysis. Compounds 1 and 9 showed antioxidative activities in vitro with inhibition ratios of 98 and 99% at the concentration of 10− 4 mol/l, and of 74 and 75% at the concentration of 10− 5 mol/l. In addition, compounds 1 and 4 showed potent anti-inflammatory activities (inhibition of release of β-glucuronidase from rat polymorphonuclear leucocytes induced by platelet activating factor) with inhibitory ratios of 65.9% (P < 0.01) and 67.7% (P < 0.01) at a concentration of 10− 5 mol/l.
Acknowledgements
This research program was financially supported by the Special Foundation for Basic Research of the Ministry of Science and Technology, China (No. 2007FY130100). The authors acknowledge the Department of Instrumental Analysis, Institute of Materia Medica, Chinese Academy of Medical Sciences, and Peking Union Medical College for all spectral analysis. We especially thank Prof. Yi-Kang Si for his help in the determination of absolute configuration and Prof. Lin Ma for the plant identification.