Inhibition of 5-lipoxygenase by anthralin (1) and 41 derivatives is determined: the acids 38 and 39, the lactones 40-42 and 9-anthrone (8) are the most potent inhibitors, the lactone 41 reaching the efficacy of nordihydroguaiaretic acid (NDGA). The results were correlated with the hydrophilic/lipophilic balance of the test compounds and their clinical efficacy as far as known. There is no correlation between the "minimum structure" of Krebs and SchalteggeP^ concerning antipsoriatic activity and the inhibitory effects against 5-lipoxygenase.
Dithranol-Derivate: Hemmung der 5-Lipoxygenase und antipsoriatische WirksamkeitDie Hemmung der 5-Lipoxygenase durch Dithranol (1) und 41 Derivate wird bestimmt: die Säuren 38 und 39, die Laktone 40-42 und 9-Anthron (8) sind die stärksten Inhibitoren, das Lakton 41 erreicht die Wirksamkeit der Nordihydroguajaretsäure. Die Ergebnisse werden mit den hydrophilen/lipophilen Eigenschaften der Verbindungen und -soweit bekannt -mit deren klinischer Wirksamkeit in Beziehung gesetzt: es besteht keine Korrelation zwischen der sog. "antipsoriatischen Minimalstruktur" nach Krebs und SchalteggeP^ und der Hemm wirkung auf die 5-Lipoxygenase.Psoriasis is a common chronic inflammatory and proliferative skin disease with unknown aetiology. An important feature is the abnormal metabolism of arachidonic acid, particularly by the lipoxygenase pathways. Lesional skin contains increased concentrations of arachidonic acid, 12-HETE and LTB 4 , whereas the cyclooxygenase-products PGF^ and PGE2 are only modestly elevated 1 *. LTB 4 and 12-HETE are potent chemoattractans for human polymorphonuclear leukocytes (PMNs) 2) , which are part of a characteristic inflammatory infiltrate and were suggested to play an important physiologic role in cutaneous lesion of psoriasis 3 *. In the present study structure-activity relationships concerning the in vitro 5-lipoxygenase inhibitory activity of various anthrone derivatives and related compounds were investigated. The results were compared with the antipsoriatic properties of the compounds according to the "minimum structure" concept by Krebs and SchalteggeP\
Anthralin (dithranol
Materials and Methods