Analogs of poison ivy urushiol. Synthesis and biological activity of disubstituted n-alkylbenzenes

Abstract

The total synthesis of different isomers and analogues of poison ivy urushiol is described. These include the positional isomers 1-5 and the nitrogen-containing analogues 6 and 8 and their mesylamino derivatives 7 and 9. 3,4-Dimethoxybenzaldehyde, m-dimethoxybenzene, resorcinol, and p-dimethoxybenzene were used as starting materials for compounds 1, 2, 3, and 4, respectively. Compound 5 is prepared by catalytic hydrogenation of bilobol isolated from Ginkgo biloba. Compounds 6 and 7 were prepared from anacardic acid as the starting material while compounds 8 and 9 were prepared from phenol as the starting material. Compounds 1-9 were tested for their ability to cross-react with poison ivy urushiol in sensitized guinea pigs. Compounds 6 and 8 were reactive at the 10-microgram dose level when applied topically, while compound 1 was a skin irritant at that dose. On the other hand, compounds 2-5, 7, and 9 showed no cross-reactivity up to the 30-micrograms dose level. Structural requirements for cross allergenicity are discussed.

A new and efficient synthesis of ortho- and para-benzoquinones of cardanol derivatives by the catalytic system MeReO3–H2O2

“…These latter transformations are noteworthy because of the stringent restriction being imposed by various governing bodies concerning the presence of halogenated phenolic derivatives in the waste water produced by bleaching processes and the consequent necessity to find new and efficient catalytic procedures for the oxidative treatment of these compounds. 39, 40 The cytotoxic effects of compounds 2-5, 8, 9, 12, 13, 15, 17, and 19 were evaluated using murine fibroblast cell line (3T3 cells), plasmocytoma murine cell line (NSO cells), normal human lymphocytes PHA-stimulated and human lymphoblastoid cell line (Daudi cells). Results reported in Table 1 are referred to fibroblast cell line and are representative of all other cell lines studied.…”

Accession-Level Differentiation of Urushiol Levels, and Identification of Cardanols in Nascent Emerged Poison Ivy Seedlings

“…The alk(en)yl chain can be either a pentadec(en)yl or a heptadec(en)yl chain with zero to three vinyl bonds at conserved positions [7,8,9,10,11]. The ortho-1,2-dihydroxyl groups on urushiol are essential for allergenicity [6,12], and the severity of allergenicity increases with either a longer alkyl chain [13] and/or increasing number of double bonds [14]. Given these structural features both Dewick [15] and Giessman [16] proposed that urushiol is derived from fatty acid metabolism.…”

Heat-induced alterations in cashew allergen solubility and IgE binding

“…Cashew nut processing involves several steps to shell the edible nut and clear the nut of undesirable solids and oils. Cashew nuts contain anacardic acid and other irritants that must be removed before they can be consumed [12] , [17] . Under a general protocol of cashew nut processing, the raw nut undergoes several rounds of heating and cooling to facilitate extraction of the nut from the shell and skin.…”