Peroxide scavenging potential of ultraviolet-B-absorbing mycosporine-like amino acids isolated from a marine red alga Bryocladia sp.

*Correspondence: Rajeshwar P. Sinha, Laboratory of Photobiology and Molecular Microbiology, Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi-221005, India e-mail: [email protected] Ultraviolet-B (UV-B; 280–315 nm)-absorbing mycosporine-like amino acids (MAAs) were extracted and purified from a marine red alga Bryocladia sp. by using high performance liquid chromatography. We have detected four MAAs having retention times 3.23, 2.94, 3.56, and 2.67min with absorbance maxima (λmax) at 323, 328, 335, and 340 nm, respectively. The effect of UV-B on the induction of these MAAs was studied. In comparison to control, there was 3–22% induction of MAAs after 12 and 24 h of UV-B exposure. Apart from MAAs, other pigments such as chl a, carotenoids and total proteins were inversely affected by UV-B irradiation. In addition, peroxide scavenging potential of these MAAs were also investigated. With 2mM hydrogen peroxide (H2O2) concentration, only <5% of MAAs were found to be affected. However, with the increased H2O2, 40–60% decline in the MAAs concentration with a corresponding peak shifting toward the blue wavelength was recorded. In addition, most of the MAAs were found to be reacting slowly with increasing H2O2 (upto 10mM) concentration after an incubation period of 5 and 30min, which indicates the remarkable scavenging potential and stability of MAAs against oxidative stress. Thus, the isolated MAAs from marine red alga Bryocladia sp. may act as an efficient peroxide scavenger.