crystal structure characterization of natural allantoin from edible lichen umbilicaria esculenta晶体结构表征天然尿囊素从食用地衣umbilicaria耐糖.pdfVIP

Crystals 2011, 1, 128-135; doi:10.3390/cryst1030128 OPEN ACCESS crystals ISSN 2073-4352 /journal/crystals Article Crystal Structure Characterization of Natural Allantoin from Edible Lichen Umbilicaria esculenta Baojun Xu 1,*, Changkeun Sung 2 and Byunghee Han 3 1 Food Science and Technology Program, Beijing Normal University–Hong Kong Baptist University United International College, Zhuhai, Guangdong 519085, China 2 Department of Food Science and Technology, Chungnam National University, Taejon 305-764, South Korea 3 Department of Chemistry, Chungnam National University, Taejon 305-764, South Korea * Author to whom correspondence should be addressed; E-Mail: baojunxu@.hk; Tel.: +86-756-3620636; Fax: +86-756-3620882. Received: 7 July 2011; in revised form: 3 August 2011 / Accepted: 8 August 2011 / Published: 9 August 2011 Abstract: In China, Korea, and Japan, Umbilicaria esculenta is considered as both food and medicinal resources from lichen. In the current study, a prismatic crystal was first isolated from edible lichen U. esculenta via solvent fractionation. The structure of the crystalline compound was elucidated as allantoin using single-crystal X-ray crystallographic and spectroscopic techniques. In light of the wide use of synthesized allantoin in cosmetic industry as a skin protectant, the biological origin of the allantoin isolated from natural food stuff edible