1.Key Laboratory of Water Pollution Treatment & Resource Reuse of Hainan Province, College of Chemistry and Chemical Engineering, Hainan Normal University , Haikou 571158, China； 2.Key Laboratory of Natural Polymer Functional Material of Haikou City , College of Chemistry and Chemical Engineering, Hainan Normal University , Haikou 571158, China； 3.Key Laboratory of Tropical Medicinal Resource Chemistry of Ministry of Education, College of Chemistry and Chemical Engineering, Hainan Normal University , Haikou 571158, China.