phenanthrenes and Dermatitis--Allergic-Contact

Topics: Abietanes; Dermatitis, Allergic Contact; Female; Humans; Middle Aged; Phenanthrenes; Plant Extracts; Plant Leaves; Rosmarinus

Nonterpenoid and diterpenoid phenanthrenequinones (PACs) have been found in the plant kingdom. Some of them occur in plants used in traditional Chinese medicine like Tan-Shen whereas others are constituents of orchids that are popular as ornamental plants.. Case reports and our own observations in orchid nurseries suggest that some or even all of these PACs possess a distinct sensitizing potency. Occasional exposure (particularly of botanists) to field-grown orchids, as well as occupational contact with sawdust of PAC-containing tropical timbers, caused allergic contact dermatitis. However, experimental studies in guinea pigs to determine the sensitizing capacity of PACs have not been performed so far.. Guinea pigs were sensitizied by a modified Freund's complete adjuvant method with four naturally occurring and 22 synthetic PACs in order to find out which and how many substituents at the carbons of the three rings of the PAC will influence the sensitizing power of the molecule. Subsequently, the lowest unoccupied molecular orbital (LUMO) coefficients were calculated to show whether a correlation exists between chemical reactivity and sensitizing capacity.. Sensitizing capacity was found to be strong in two PACs, moderate in eight PACs, and weak in ten PACs. Five PACs were extremely weak in sensitizing capacity, and one PAC was completely negative. Two substituents on the left-hand carbons C-7 and C-8 of ring C were shown to be responsible for a strong sensitizing capacity. One methoxy group alone or three of them, especially when localized at C-5, decreased the sensitizing capacity to moderate. Substitution with a methoxy group at C-3 and/or at C-2 of the quinonoid ring itself (ring A) led to a weak sensitizing capacity. The ortho-quinones 1,2-PAC and 9,10-PAC were also weakly sensitizing. In fact, LUMO coefficient calculations corroborated a good correlation between chemical reactivity and sensitizing capacity.. Substitution with methoxy groups at C-7 and/or at C-8 of ring C of 1,4-phenanthrenequinone increases the LUMO coefficients at the 2,3 double bond of ring A and thus facilitates nucleophilic substitution of protein nitrogen or sulfur nucleophiles at this electron-deficient double bond. The four naturally occurring PACs that were investigated--cypripedin, denbinobin, annoquinone-A, and latinone--do not fulfill these criteria and are thus only weak sensitizers. However, as-yet-unstudied phenanthrenequinones occurring in plants or trees and having no substituents at C-2 or C-3 of the quinonoid ring must be considered potentially strong allergens.

Topics: Allergens; Animals; Dermatitis, Allergic Contact; Disease Models, Animal; Guinea Pigs; Patch Tests; Phenanthrenes; Structure-Activity Relationship

This article explores protein conjugation of 7-oxodehydroabietic acid, a resin acid found in both aerosol from soldering with rosin flux and in rosin solids. In a murine model, conjugation (haptenation) of resin acids to proteins is required to generate antibodies against rosin. Hydroperoxy resin acids are dermal sensitizers, with haptenation thought to occur via radical mechanisms. Dermal sensitization to 7-oxodehydroabietic acid has been observed, although no radical haptenation mechanism has been proposed to explain the sensitizing properties of this compound. Conjugation of L-lysine to 7-oxodehydroabietic acid was predicted, with a Schiff base (or imine) linkage formed between C-7 of the resin acid and a free amino group of lysine. Fast atom bombardment mass spectrometry provided evidence of the conjugate; a small peak was seen for the conjugate (M+H)+ ion in aqueous ethanol with 20 mM concentrations of the free resin and amino acids. A larger conjugate peak was observed with addition of tertiary amine as a mild basic catalyst, and the intensity of the conjugate peak exceeded that of the precursors upon replacement of the ethanol with benzene. Resin acids accumulate in the plasma membrane, a non-aqueous environment apparently conducive to conjugation of 7-oxodehydroabietic acid with lysine side chains of membrane proteins. The result would be dehydroabietic acid covalently bound to protein, which could lead to interaction with immune cells having resin acid specificity. The haptenation mechanism presented may be involved in allergic contact dermatitis and occupational asthma observed from exposure to resin acid solids and aerosols. As sampling and analytical methods have been previously demonstrated for 7-oxodehydroabietic acid, this compound may be a useful exposure marker with relevance to negative health effects such as occupational asthma.

Topics: Abietanes; Asthma; Dermatitis, Allergic Contact; Diterpenes; Haptens; Humans; Lysine; Occupational Diseases; Occupational Exposure; Phenanthrenes; Resins, Plant

In order to investigate the contact allergens in the unmodified colophony (rosin) used in routine patch testing, preparative chromatographic techniques were used to separate its components which were then patch tested on colophony-sensitive individuals. The chemical structure of the dermatologically active components was elucidated using mass spectrometry, nuclear magnetic resonance and infra-red techniques. The study shows that oxidized resin acids are stronger sensitizers than the resin acids themselves, the most potent contact allergen being 7-oxydehydroabietic acid (purity 92%). At naturally occurring concentrations (relative to abietic acid) all unoxidized resin acids were found to play an insignificant part, individually, in colophony dermatitis, except abietic acid (purity 99%), which was found to be a weak but important allergen. The commercial Trolab abietic acid preparation (unknown purity) was found to be dermatologically more active than purified abietic acid.

Topics: Abietanes; Adult; Allergens; Chromatography, High Pressure Liquid; Dermatitis, Allergic Contact; Diterpenes; Female; Humans; Male; Middle Aged; Patch Tests; Phenanthrenes; Resins, Plant

As part of the investigation of sources of exposure to rosin allergens, disposable diapers (napkins) common on the Swedish market were analyzed, using gas chromatography, to detect the main rosin compounds. Rosin components were detected in all diapers, the highest amounts in those from the 2 major producers. In these diapers, more rosin was found in the top layer, which is in close contact with the skin than in the fluff. Despite the possibly minimal risk of induction of sensitization to rosin allergens in diapers, there is a real risk of elicitation of dermatitis in sensitive individuals, especially since penetration is enhanced by occlusion and irritation. Such material is not only used for infant diapers, but also for adult incontinence products and feminine hygiene products.

Topics: Abietanes; Adult; Allergens; Chromatography, Gas; Dermatitis, Allergic Contact; Diterpenes; Humans; Incontinence Pads; Infant; Infant Care; Irritants; Menstrual Hygiene Products; Phenanthrenes; Resins, Plant; Risk Factors; Sweden

Topics: Abietanes; Adhesives; Adult; Dermatitis, Allergic Contact; Diterpenes; Female; Humans; Phenanthrenes; Plastics; Resins, Plant; Urticaria

A connection between patch test reactions to paper extracts and contact allergy to rosin (colophony) has been demonstrated.. We wanted to determine whether a difference in the allergenic activity of various types of paper is related to a difference in the pulp.. Patients with dermatitis who were frequently exposed to paper were patch tested with extracts from various papers and the standard series. The extracts were also tested in volunteers with or without contact allergy to rosin and in animals. The rosin compounds in the papers were analyzed by gas chromatography.. The subjects reacting to paper extracts also reacted to rosin. Most reactions were found to the papers produced from mechanical pulps, which contained the highest analyzed amounts of rosin compounds. Animals sensitized to rosin reacted only to paper from mechanical pulp.. Papers based on mechanical pulps that are considered to be environmentally friendly have a greater potential to elicit positive patch test reactions than papers made from other pulps. The increased use of mechanical pulps in different applications may increase the incidence of rosin-related hand eczema.

Topics: Abietanes; Allergens; Animals; Dermatitis, Allergic Contact; Dermatitis, Irritant; Dermatitis, Occupational; Diterpenes; Eczema; Female; Guinea Pigs; Hand Dermatoses; Humans; Immunization; Male; Paper; Patch Tests; Phenanthrenes; Resins, Plant

Adhesives and bandages containing zinc oxide (ZnO) and rosin are often used for treatment of ulcers. The aim of this work was to study a possible inhibitory effect of ZnO on the elicitation of allergic contact reactions to rosin and to determine whether such an effect might be due to the formation of zinc resinates. Patch testing in rosin-sensitive patients was performed with mixes of ZnO and rosin. The eliciting capacities of one mix in which zinc resinates might be formed and another mix in which the formation of zinc resinates was prevented, were compared to the eliciting capacity of rosin alone. If a reduction of the allergic response was observed for the mix in which zinc resinates might form and if no reduction was observed for the mix in which formation of zinc resinates was prevented, this would support the hypothesis that the reduction in eliciting capacity was due to formation of zinc resinates. However, we could not see any difference in eliciting capacity when comparing the 2 mixes with a test preparation of rosin. Commercial adhesives (bandages) containing ZnO and rosin were patch tested in 7 rosin-sensitive patients. The concentration of abietic acid in the adhesives was determined with HPLC. Abietic acid was detected in all but one of those declared to contain rosin. The patients reacted to the adhesives in which abietic acid was detected. For rosin-sensitive persons, the addition of ZnO to rosin-containing adhesives cannot be regarded as an appropriate measure to inhibit the elicitation of allergic reactions.

Topics: Abietanes; Adhesives; Chromatography, High Pressure Liquid; Dermatitis, Allergic Contact; Dermatologic Agents; Diterpenes; Humans; Occlusive Dressings; Patch Tests; Phenanthrenes; Resins, Plant; Spectroscopy, Fourier Transform Infrared; Tars; Zinc Oxide

Degradation of abietic, levopimaric and dehydroabietic acids after exposure to air and light over a period of one to several months, as well as examination of degraded French tall oil rosin and Portuguese colophony, led to the isolation of numerous oxidation products. These compounds were synthesized and consigned to experimental sensitization in guinea pigs. From 20 substances studied as acids or as their methyl esters, in the present and preceding paper, at least 2 can be named: 8,12-peroxydo-delta 13(14)-dihydroabietic acid and 12 alpha-hydroxyabietic acid, that contribute a great deal to colophony allergy by both their sensitizing capacity and their determined concentration in the mixture of degradation products. We recommend the preparation of a new mixture of colophony oxidation products for patch testing in the diagnosis of contact allergy to colophony.

Topics: Abietanes; Animals; Dermatitis, Allergic Contact; Diterpenes; Fibrinolytic Agents; Guinea Pigs; Methyl Ethers; Oxidation-Reduction; Patch Tests; Phenanthrenes; Plant Oils; Resins, Plant; Tars