rosin and maleopimaric-acid

A series of rosin based esters have been synthesized from dehydroabietic acid and maleopimaric acid, respectively. Their structures were confirmed by FT-IR, (1)H NMR, (13)C NMR and single crystal X-ray diffraction. Their antifeedant activities against armyworm were examined by leaf plate method. Methyl ester of dehydroabietic acid and maleopimaric acid were crystallized in orthorhombic system with cell dimensions of a = 26.352 [5] Å, b = 6.1020 [12] Å, c = 11.812 [2] Å and a = 7.9216 [11] Å, b = 11.9912 [16] Å, c = 23.425 [3] Å, respectively. They contained classic tricyclic hydrophenanthrene skeleton. The antifeedant results indicated that most rosin-based esters exhibited significant antifeedant activities at a concentration of 0.01 g mL(-1). Their feeding deterrence values were above 70% after 24h. The antifeedant activities for rosin-based esters increased with the growth of chain length of alcohol except (Ia). Some armyworm were found dead during the antifeedant activity test, by which we speculated that these synthetic rosinbased esters had stomach poison activities against armyworm.

Topics: Animals; Crystallography, X-Ray; Esters; Insecticides; Models, Molecular; Molecular Structure; Resins, Plant; Spodoptera; Triterpenes

This study was directed to look at the chemical composition of maleo-pimaric and fumaro-pimaric rosins made of unmodified rosin with maleic anhydride (MA) or fumaric acid (FA). The results showed that one peak of a maleopimaric acid (MPA) adduct on the chromatogram was obtained when a sample of this reaction product was injected into a Gas liquid chromatography (GLC) or Gas chromatograph-Mass spectrometer (GC-MS) system. Identification of this adduct using a GC-MS showed that a reaction product of rosin and MA produced endo-maleopimaric acid methyl ester. This peak of the adduct had a similar profile as in a previous study with a base peak at m/z =146 and prominent ions at m/z = 386, m/z = 187 and at m/z = 121. In the making of MPA and fumaropimaric acid (FPA) adducts, the increase in molar ratio for both reaction temperatures of 125 and 2000C and all rosin samples used in the reaction process gave a higher yield of endo maleopimaric acid. The largest amount of this product was obtained at a molar ratio of 1:10 with the reaction at 200 degrees C. Among the origin of the rosin used in this experiment, rosin from Central Java produced the highest MPA, while the highest FPA was achieved by using rosin from North Sumatra. The relationship between the molar ratio and the concentration of MPA or FPA could be expressed as a quadratic equation. From the equation, one could predict the best molar ratio to produce the highest MPA or FPA adducts at a suitable molar ratio. Using the equation Y = -0.8475 X2 + 10.448X - 9.7125, at the reaction temperature 200 degrees C, the highest MPA (around 22.50%) could be achieved by using a molar ratio of rosin and MA of 1:6.2.

Topics: Anhydrides; Diterpenes; Fumarates; Gas Chromatography-Mass Spectrometry; Maleic Anhydrides; Models, Chemical; Pinus; Resins, Plant; Temperature; Time Factors; Triterpenes

Endo-maleopimaric acid (MPA) is a contact allergen formed when colophonium is "modified" with maleic anhydride or fumaric acid. Previous patch testing showed a higher allergic response to petrolatum (pet.) preparations of MPA in amorphous form compared to MPA in crystalline form. In the present study, the impact of the physical form of MPA on the allergic response was investigated. Since the amorphous form is difficult to standardize, crystalline MPA mechanically incorporated or dissolved in pet. was used. A lower eliciting capacity was obtained from crystalline MPA, compared to that obtained from dissolved MPA, in guinea pigs intradermally induced with MPA. Using 3H-MPA a 3X difference in the dissolution into synthetic sweat from MPA dissolved in pet., compared to MPA mechanically incorporated, was demonstrated. A difference in bio-availability between dissolved and crystalline MPA could therefore be assumed. Crystalline MPA had a low sensitizing capacity compared to that seen for amorphous MPA in previous studies. The amorphous form of MPA is likely to have a larger surface area than crystalline MPA, with less ordered molecules, resulting in a higher dissolution rate and a greater bio-availability. Modified colophonium exists as amorphous solids and as viscous liquids. Thus, exposure will probably be to non-crystalline MPA and cases of contact allergy could be overlooked when screening with crystalline MPA.

Topics: Allergens; Animals; Biological Availability; Crystallization; Dermatitis, Allergic Contact; Female; Guinea Pigs; Patch Tests; Petrolatum; Resins, Plant; Skin; Solubility; Triterpenes

Most rosin (colophony) used today is chemically modified. Will contact allergy to modified rosin be overlooked when testing is performed with only unmodified rosin in the standard series? 2 components from modified rosins, maleopimaric acid (MPA) and glyceryl I-monoabietate (GMA), earlier identified as contact allergens, were added to the patch test standard series. Some commonly-used modified rosin products were also tested. Positive reactions were observed to the modified components MPA and GMA. Of the patients with positive reactions to MPA and GMA, several did not react to unmodified rosin in the standard series. No reaction was observed to the modified rosin products without a concomitant reaction to unmodified rosin. The positive reactions observed to the modified rosins may be due to residual unmodified material in the product, but a possible contribution from allergenic modified rosin components cannot be disregarded. When a patient's history indicates a rosin allergy, but a negative response to unmodified rosin in the standard series is observed, additional testing with GMA and MPA or, second best, with glycerol-esterified rosin and maleic-anhydride-modified rosin is recommended. Some modified rosin products, which could be used for additional testing, are suggested.

Topics: Abietanes; Dermatitis, Allergic Contact; Diterpenes; Esterification; Glycerol; Humans; Patch Tests; Portugal; Resins, Plant; Sweden; Triterpenes

Topics: Abietanes; Allergens; Animals; Diterpenes; Resins, Plant; Skin Tests; Triterpenes

Gäfvert, E. 1994. Allergenic components in modified and unmodified rosin. Chemical characterization and studies of allergenic activity. Acta Dermato-Venereologica. Suppl. 184. 36pp. Uppsala. Unmodified rosin (colophony) is a well-known cause of contact allergy (delayed type hypersensitivity). Rosin is obtained from coniferous trees and consists mainly of diterpenoid resin acids. Most rosin used in technical products is chemically modified. In the common modification of rosin with maleic anhydride, the major product formed is maleopimaric acid (MPA). MPA was identified in experimental sensitization studies as a potent contact allergen. MPA is also formed when rosin is modified with fumaric acid at high temperature and with prolonged heating. The amounts of MPA in technical quality rosins modified with maleic anhydride or fumaric acid might be enough to sensitize individuals handling these rosins. The major product of the modification of rosin with fumaric acid, fumaropimaric acid (FPA), did not elicit any reactions in the animals tested. In another common rosin modification, glycerol esterification, the major product formed was identified as glyceryl triabietate (GTA). In an experimental sensitization study none of the animals reacted to GTA. However, a minor product formed, glyceryl 1-monoabietate (GMA) showed sensitizing capacity. The presence of new contact allergens due to the modification, together with remaining unmodified material, contributes to the risk of developing allergy from contact with these types of rosin. A new main contact allergen in unmodified rosin was identified; 13,14(beta)-epoxyabietic acid. The allergenicity of this epoxide was comparable to that of an earlier identified rosin allergen, 15-hydroperoxyabietic acid (15-HPA). The allergens were detected as their methyl esters. Experimental sensitization and cross-reactivity of oxidation products of resin acids were studied. A pattern of cross-reactivity was observed which indicates that the hydroperoxide of abietic acid (15-HPA) may react to form a complete antigen via two different routes. One route seems to be via the formation of epoxides which then react with skin protein to form the complete antigen, and the other, via radical formation due to cleavage of the peroxide bond. The radical formed may then react with skin protein, so producing the complete antigen. Few other studies have shown results indicating the formation of several antigens from one hapten.

Topics: Abietanes; Allergens; Animals; Chromatography, High Pressure Liquid; Complement Inactivator Proteins; Cross Reactions; Dermatitis, Allergic Contact; Diterpenes; Epoxy Compounds; Female; Glycerol; Guinea Pigs; Humans; Patch Tests; Resins, Plant; Tars; Triglycerides; Triterpenes

Two groups of patients were studied, one with known contact allergy to colophony and hand eczema, 'colophony patients', and the other consisted of patients who suspected that their eczema was caused by contact with paper, 'paper patients'. The 'colophony patients' were patch tested with samples of newsprint paper, while the 'paper patients' were tested with samples of their own paper. Extracts of the paper and paper were applied. Testing with paper caused no reactions. All 'colophony patients' showed strong reactions to the tested extracts of newsprint paper. None of the 'paper patients' reacted to the extracts of their own paper, except those patch-test positive to colophony or maleopimaric acid, the main component of one type of modified colophony in paper size and shown experimentally to be a potent sensitizer. Colophony in paper may contribute to hand eczema in sensitized patients and the use of cotton gloves when in contact with paper might alleviate the dermatitis.

Topics: Abietanes; Dermatitis, Contact; Diterpenes; Female; Fibrinolytic Agents; Hand Dermatoses; Humans; Male; Newspapers as Topic; Occupational Diseases; Paper; Patch Tests; Phenanthrenes; Resins, Plant; Triterpenes

The allergenicity of the maleic-modified rosins and their esters has been studied. The unesterified resins are mainly used in paper size and the esters in printing inks, varnishes and adhesives. The levopimaric-maleic anhydride Diels-Alder adduct (maleopimaric acid) is the main component obtained in the maleic-modified rosins. This compound was synthesized and its structure was determined. Its sensitizing potential was investigated in guinea pigs according to different methods. It was shown that maleopimaric acid is a very potent sensitizer, comparable with the strongest allergen isolated from unmodified gum rosin. The allergen may also be present after esterification unless the process is carried out to completion. The animals sensitized to maleopimaric acid did not react to unmodified rosin, which shows that maleopimaric acid is structurally different from the allergens in rosin.

Topics: Allergens; Animals; Chemical Phenomena; Chemistry; Dermatitis, Contact; Guinea Pigs; Patch Tests; Resins, Plant; Triterpenes