Two mycosporines were isolated for the first time in two chlorolichen species, Dermatocarpon luridum and Dermatocarpon miniatum. Mycosporine glutaminol (1) and mycosporine glutamicol (2) were isolated along with the ethyl ester of mycosporine glutamicol (3), which was formed during the purification process. Aqueous extracts and pure mycosporines were then investigated for their antioxidant activities and photoprotective properties along with their photostability and photocytotoxicity. Semi-purified mycosporine fractions were much more antioxidant than lichen aqueous crude extracts. Compound 3 (IC50 = 4.00 µg/mL) was found to be as active as quercetin (IC50 = 6.75 µg/mL), while the two genuine mycosporines 1 and 2 exhibited moderate activity. The three mycosporines were found to be stable until 5J/m2 UVA and UVB radiations whereas Trolox, used as a positive control, was degraded up to 10 % and 19 %, respectively. Moreover, these mycosporines and semi-purified extracts did not induce any phototoxicity on HaCaT cells exposed to UVA radiations. Key words: Dermatocarpon luridum - Dermatocarpon miniatum - Verrucariaceae - lichen - mycosporine-like amino acids (MAAs) - photoprotection.