Methyl Abietate Research Articles

Multiple forms ofO-methyltransferase involved in the microbial conversion of abietic acid into methyl abietate byMycobacteriumsp.

Six out of seven tested strains of mycobacteria transformed abietic acid to methyl abietate in shake culture. The conversion carried out by Mycobacterium sp. MB 3683 was induced by the substrate and stimulated by methionine. Fractionation of the cell extract of Mycobacterium sp. MB 3683 on DEAE cellulose, Ultrogel AcA 44 and MONO Q resulted in the separation of three distinct methyltransferase activities which could also esterify palmitic acid. The separated forms of the methyltransferase exhibited different activities towards these two substrates.

Multiple forms of O-methyltransferase involved in the microbial conversion of abietic acid into methyl abietate by Mycobacterium sp.

Six out of seven tested strains of mycobacteria transformed abietic acid to methyl abietate in shake culture. The conversion carried out by Mycobacterium sp. MB 3683 was induced by the substrate and stimulated by methionine. Fractionation of the cell extract of Mycobacterium sp. MB 3683 on DEAE cellulose, Ultrogel AcA 44 and MONO Q resulted in the separation of three distinct methyltransferase activities which could also esterify palmitic acid. The separated forms of the methyltransferase exhibited different activities towards these two substrates.

Microbial transformation of abietic acid to methyl abietate

Abietic acid was quantitatively converted into methyl abietate in a shaken culture of Mycobacterium MB 3683 within 144 hours at the concentration of 200 mg/l.

Conversion of Abietic Acid Into Analogs of Ambergris Odorants

The conversion of methyl abietate (16) into (42) and (43), analogues of the known amber odorants (1) and (2), is reported.

Studies on Allylic Oxidation Reactions of Methyl Abietate+

Abstract Allylic oxidation reactions of methyl abietate (2) with selenium dioxide and lead tetraacetate have been studied in different solvents. Oxidation of methyl abietate (2) with selenium dioxide in acetic anhydride furnished methyl 7α-O-acetyl dehydroabietate (5b) in 68 % yield.

Contact allergy due to colophony (III). Sensitizing potency of resin acids and some related products.

7 resin acids, 3 synthetically prepared derivatives and the neutral fraction of Chinese colophony were studied by experimental sensitization using a modified FCA method. 4 resin acids, laevopimaric, abietic, podocarpic and tetrahydroabietic, proved to be weak sensitizers. Neoabietic, dehydroabietic, isopimaric acid and larixol remained negative. However, the derivatives, methyl abietate and calcium abietate, were shown to be moderate sensitizers, and the maleic-modified adduct to be a moderate to strong sensitizer. As laevopimaric acid plays only a minor rôle in colophony, abietic acid must be considered a major, even if weak, allergen in non-modified colophony. The neutral fraction of colophony is also partially involved in colophony allergy.

Dihydroabietyl alcohol (Abitol®) A sensitizer in mascara

A nickel-sensitized female patient developed a contact dermatitis reaction to her mascara that was maintained by her spectacle frames, which contained nickel. On patch testing, she reacted to dihydroabietyl alcohol (Abitol), which was present in her mascara, and to hypoallergenic adhesive tape containing methyl abietate. There was also cross-reactivity with colophony and abietic acid.

Disproportionation of Methyl Abietate by Ironpentacarbonyl

Disproportionation of methyl abietate by metal complex catalysts was studied. The catalysts used were RhCI (PPh3) 3, PdCl2 (PPh3) 2, PtCl2 (PPh3) 2, Fe (CO) 5, Cr (CO) 5, Fe (acac) 3, Co (acac) 3, Pd/C, and I2. Among these Fe (CO) 5 was the most effective catalyst at 250°C. The effects of reaction temperature and catalyst amount on the product composition were investigated, and it was found that, with 10% Fe (CO) 5 at 250°C, almost all of methyl abietate entered into the reaction in 4 hr affording methyl dehydroabietate (66%) and methyl dihydroabietates (27%). Methyl dihydroabietates were separated by chromatography and their structures were determined by NMR and mass spectrometry. From the relative amounts of two isomers of methyl dihydroabietates, selectivity in hydrogenation was recognized. In the case of I2 catalyst, 13 α- (RtDeAb 0.46) and 13 β-abiet-8-enoate (RtDeAb 0.49) were obtained in 15.0% and 22.2% yield, respectively, while in the case of Fe (CO) 5 catalyst, the yields were 6.0% and 18.1%, respectively. Further, it was found that Fe (CO) 5 was effective for the disproportionation between methyl abietate and methyl linolate.

Free-radical bromination of methyl abietate by N-bromosuccinimide and solvolysis of the products

Free-radical bromination of methyl abietate by N-bromosuccinimide and solvolysis of the products

Diterpenoids. XXIII. The synthesis of the C4 epimers of methyl abietate, methyl palustrate, and methyl dehydroabietate

Diterpenoids. XXIII. The synthesis of the C4 epimers of methyl abietate, methyl palustrate, and methyl dehydroabietate

Thermal isomerization of methyl abietate

Thermal isomerization of methyl abietate

The hydroboration-oxidation of abietic acid

Monohydroboration-oxidation of abietic acid and methyl abietate with both diborane and t-2,3-dimethylbutylborane leads to preferential attack on the 7,8-double bond to give 7-hydroxy-8(14)-enes, e.g., (IIIa). Dihydroboration-oxidation with these reagents yields mainly the 7β,14β-dihydroxy derivatives, e.g., (XIXa), with smaller amounts of the 7α, 14α-dihydroxy-compounds and a third 7,14-diol of unknown stereochemistry. The dihydroboration reactions are of interest, since it is shown that at least one of the products is derived by migration of the 13,14-double bond of abietic acid to the 8,14-position during hydroboration. Some reactions of the hydroxyabietic acid derivatives are described.

Dehydrogenation studies with tetrachloro- o-benzoquinone : Structure of a novel dehydrogenation-addition product of abietic acid

The structure of the solid adduct, obtained by treatment of methyl abietate with tetra-chloro- o-benzoquinone in xylene has been shown to be 2-[2′,2′-(5′,6′,7′,8′-tetrachloro-benzo-1′,4′ dioxano)]-ethyl-3,4,4a(α),4b,5,6,7,8,8a(α),9-decahydro-4b(β),8(β)-dimethyl-8(α)-carbomethoxyphenanthrene (Ia).

Oxidation of the Fumeric Acid—Methyl Abietate Diels—Alder Adduct with Alkaline Permanganate. Terpenes. VIII1,2

Oxidation of the Fumeric Acid—Methyl Abietate Diels—Alder Adduct with Alkaline Permanganate. Terpenes. VIII^1,2

The monooxide and dioxide of abietic acid

1. The monooxide and dioxide of abletic acid were obtained in pure form; the monooxide of methyl abietate was also obtained. 2. By reduction of the monooxide of abietic acid with lithium aluminum hydride the corresponding glycol was obtained. This same glycol was obtained by reduction of the monooxide of methyl abietate. 3. By elimination of acetic acid from the diacetate of the glycol there were obtained the acetates of the dienic alcohols: these consisted of acetates of alcohols with conjugated and with isolated systems of double bonds. 4. The presence of considerable quantities of alcohols with isolated double bonds showed that the original monooxide of abietic acid was the 7,8-oxide.