Cytotoxic activity of orsellinates.
The series of 2,4-dihydroxy-6-methylbenzoates 2-10 (methyl to hexyl orsellinates) prepared by alcoholysis of lecanoric acid (1)--a natural product from the lichen Parmotrema tinctorum (Nyl.) Hale - was submitted to the brine shrimp lethality test (BST), which was also performed for 2,4-dihydroxy-6-methylbenzoic acid (11) (orsellinic acid) and the derivative ethyl-2-hydroxy-4-methoxy-6-methylbenzoate (12) (4-methoxy-ethyl orsellinate), in order to detect new substances with probable antineoplasic activity. Results showed that chain elongation--increase in lipophilicity (log P)--causes a rise in the cytotoxic activity of orsellinates. Hexyl orsellinate (7) showed the highest cytotoxic activity (LC50 = 31 microM). A correlation between lipophilicity (log P) and cytotoxic activity (log 1/LC50) is presented. Compounds with ramified chains--iso-propyl, sec-butyl and tert-butyl orsellinates (8-10)--were less active than those with the correspondent linear chain. The activities presented by 4-methoxy-ethyl orsellinate (12) and ethyl orsellinate (3) suggest that the hydroxy group at the C-4 position causes effect in the cytotoxic activity of orsellinates against Artemia salina.
Gomes
Alcir T
AT
Universidade Federal de Mato Grosso do Sul, Departamento de Química, C. Postal 549, 79070-900, Campo Grande, Mato Grosso do Sul, Brazil.
Honda
Neli K
NK
Roese
Fernanda M
FM
Muzzi
Rozanna M
RM
Sauer
Leandro
L
D000818:Animals; D001156:Artemia; D002470:Cell Survival / Q000187:drug effects*; D008011:Lichens / Q000737:chemistry*; D015394:Molecular Structure; D012118:Resorcinols / Q000737:chemistry / Q000633:toxicity*; D013329:Structure-Activity Relationship
D012118:Resorcinols; C501612:orsellinic acid