[1] Univ Coll, Dept Bot, Thiruvananthapuram 695034, Kerala, India
[2] Univ Kerala, Dept Bot, Thiruvananthapuram 695034, Kerala, India
[3] Reg Canc Ctr, Lab Immunopharmacol & Expt Therapeut, Thiruvananthapuram 695011, Kerala, India
[4] Govt Coll, Dept Bot, Kasaragod 671123, Kerala, India