Carotenoids from the soft coral Sarcophyton elegans - Chau Van Minh.; Dinh Thi Thu Thuy.; Do Cong Thung; Nguyen Hai Dang.; Nguyen Hoai Nam.; Nguyen Phuong Thao.; Nguyen Tien Dat.; Nguyen Xuan Cuong; Phan Van Kiem.; Tran Hong Quang