“…According to literature survey, compounds G1, G2, G3, G5, G6, G13, G17, G19 and G25 are reported derivatives and G4, G7, G8, G10, G11, G16, G22, G26 and G28 are listed in the literature with chemical abstracts service registry number 95204-52-7, 932130-00-2, 1002499-52-6, 705955-02-8, 705954-02-5, 119755-00-2, 1197607-87-6, 1223618-35-6 and 1211129-24-6, respectively, but corresponding scientific reference data are not available (Schwyzer et al, 1955;Thomsen et al, 1983;Haworth et al, 1952;Farese et al, 1996;Blanco et al, 2005).…”