7-Oxodehydroabietic acid

Tracing colophonium in consumer products.[Pubmed:34291483]

Contact Dermatitis. 2021 Jul 22.

BACKGROUND: Colophonium (rosin) can cause allergic contact dermatitis, mainly due to autoxidation of abietic acid (AbA). Products containing >/=0.1% colophonium should be labeled with EUH208 - "Contains rosin; colophony. May produce an allergic reaction." How should this be measured? OBJECTIVE: To compare the results from different strategies for estimating colophonium levels in consumer products: (a) from AbA, and (b) the sum of all major resin acids. To investigate the ratio of 7-Oxodehydroabietic acid (7-O-DeA)/AbA as indication of autoxidation. METHODS: Resin acids were extracted from consumer products, derivatized, and then separated by gas chromatography/mass spectrometry (GC/MS). RESULTS: Resin acids were detected in 9 of 15 products. No product contained colophonium >/=0.1%. Estimation based on AbA resulted in underestimation of the colophonium levels in four of nine products. For three products, the obtained levels from this strategy were only one of two compared to when estimating from the sum of all resin acids. The ratio 7-O-DeA/AbA varied from 74% to 1.4%. CONCLUSIONS: We propose to measure colophonium based on the sum of all detectable major resin acids, including 7-O-DeA. The ratio of 7-O-DeA/AbA should be used as a marker of autoxidation, indicating an increased risk of sensitization. The presented analytical method is simple to use and suitable for further screening studies.

Phytochemical, Antiplasmodial, Cytotoxic and Antimicrobial Evaluation of a Southeast Brazilian Brown Propolis Produced by Apis mellifera Bees.[Pubmed:34227213]

Chem Biodivers. 2021 Sep;18(9):e2100288.

Seven phenolic compounds (ferulic acid, caffeic acid, 4-methoxycinnamic acid, 3,4-dimethoxycinnamic acid, 3-hydroxy-4-methoxybenzaldehyde, 3-methoxy-4-hydroxypropiophenone and 1-O,2-O-digalloyl-6-O-trans-p-coumaroyl-beta-D-glucopyranoside), a flavanonol (7-O-methylaromadendrin), two lignans (pinoresinol and matairesinol) and six diterpenic acids/alcohol (19-acetoxy-13-hydroxyabda-8(17),14-diene, totarol, 7-Oxodehydroabietic acid, dehydroabietic acid, communic acid and isopimaric acid) were isolated from the hydroalcoholic extract of a Brazilian Brown Propolis and characterized by NMR spectral data analysis. The volatile fraction of brown propolis was characterized by CG-MS, composed mainly of monoterpenes and sesquiterpenes, being the major alpha-pinene (18.4 %) and beta-pinene (10.3 %). This propolis chemical profile indicates that Pinus spp., Eucalyptus spp. and Araucaria angustifolia might be its primary plants source. The brown propolis displayed significant activity against Plasmodium falciparum D6 and W2 strains with IC50 of 5.3 and 9.7 mug/mL, respectively. The volatile fraction was also active with IC50 of 22.5 and 41.8 mug/mL, respectively. Among the compounds, 1-O,2-O-digalloyl-6-O-trans-p-coumaroyl-beta-D-glucopyranoside showed IC50 of 3.1 and 1.0 mug/mL against D6 and W2 strains, respectively, while communic acid showed an IC50 of 4.0 mug/mL against W2 strain. Cytotoxicity was determined on four tumor cell lines (SK-MEL, KB, BT-549, and SK-OV-3) and two normal renal cell lines (LLC-PK1 and VERO). Matairesinol, 7-O-methylaromadendrin, and isopimaric acid showed an IC50 range of 1.8-0.78 mug/mL, 7.3-100 mug/mL, and 17-18 mug/mL, respectively, against the tumor cell lines but they were not cytotoxic against normal cell lines. The crude extract of brown propolis displayed antimicrobial activity against C. neoformans, methicillin-resistant Staphylococcus aureus, and P. aeruginosa at 29.9 mug/mL, 178.9 mug/mL, and 160.7 mug/mL, respectively. The volatile fraction inhibited the growth of C. neoformans at 53.0 mug/mL. The compounds 3-hydroxy-4-methoxybenzaldehyde, 3-methoxy-4-hydroxypropiophenone and 7-Oxodehydroabietic acid were active against C. neoformans, and caffeic and communic acids were active against methicillin-resistant Staphylococcus aureus.

Four new neo-clerodane diterpenes from the stem bark of Croton oligandrus.[Pubmed:31204854]

Nat Prod Res. 2021 Jan;35(2):298-304.

Four new neo-clerodanes, crotonolins C-F (3-6), were isolated from the stem bark of Croton oligandrus together with the known clerodane crotonzambefuran A, the abietanes 7-beta-hydroxydehydroabietic acid and 7-Oxodehydroabietic acid, and ferulic acid. Their structures were elucidated by spectroscopic analyses including 1D and 2D NMR and HRESIMS and by comparison with previously reported data. The cytotoxicity of the isolated compounds against A549, MCF7, PC3 and PNT2 cells was evaluated using the MTT assay. Only 7-beta-hydroxydehydroabietic acid showed a moderate level of activity against PC3 cells with an IC50 value of 68.9 +/- 6.6 microM.

Involvement of allelopathy in inhibition of understory growth in red pine forests.[Pubmed:28779633]

J Plant Physiol. 2017 Nov;218:66-73.

Japanese red pine (Pinus densiflora Sieb. et Zucc.) forests are characterized by sparse understory vegetation although sunlight intensity on the forest floor is sufficient for undergrowth. The possible involvement of pine allelopathy in the establishment of the sparse understory vegetation was investigated. The soil of the red pine forest floor had growth inhibitory activity on six test plant species including Lolium multiflorum, which was observed at the edge of the forest but not in the forest. Two growth inhibitory substances were isolated from the soil and characterized to be 15-hydroxy-7-oxodehydroabietate and 7-Oxodehydroabietic acid. Those compounds are probably formed by degradation process of resin acids. Resin acids are produced by pine and delivered into the soil under the pine trees through balsam and defoliation. Threshold concentrations of 15-hydroxy-7-oxodehydroabietate and 7-Oxodehydroabietic acid for the growth inhibition of L. multiflorum were 30 and 10muM, respectively. The concentrations of 15-hydroxy-7-oxodehydroabietate and 7-Oxodehydroabietic acid in the soil were 312 and 397muM, respectively, which are sufficient concentrations to cause the growth inhibition because of the threshold. These results suggest that those compounds are able to work as allelopathic agents and may prevent from the invasion of herbaceous plants into the forests by inhibiting their growth. Therefore, allelopathy of red pine may be involved in the formation of the sparse understory vegetation.

Conifer Diterpene Resin Acids Disrupt Juvenile Hormone-Mediated Endocrine Regulation in the Indian Meal Moth Plodia interpunctella.[Pubmed:28674826]

J Chem Ecol. 2017 Jul;43(7):703-711.

Diterpene resin acids (DRAs) are important components of oleoresin and greatly contribute to the defense strategies of conifers against herbivorous insects. In the present study, we determined that DRAs function as insect juvenile hormone (JH) antagonists that interfere with the juvenile hormone-mediated binding of the JH receptor Methoprene-tolerant (Met) and steroid receptor coactivator (SRC). Using a yeast two-hybrid system transformed with Met and SRC from the Indian meal moth Plodia interpunctella, we tested the interfering activity of 3704 plant extracts against JH III-mediated Met-SRC binding. Plant extracts from conifers, especially members of the Pinaceae, exhibited strong interfering activity, and four active interfering DRAs (7alpha-dehydroabietic acid, 7-Oxodehydroabietic acid, dehydroabietic acid, and sandaracopimaric acid) were isolated from roots of the Japanese pine Pinus densiflora. The four isolated DRAs, along with abietic acid, disrupted the juvenile hormone-mediated binding of P. interpunctella Met and SRC, although only 7-Oxodehydroabietic acid disrupted larval development. These results demonstrate that DRAs may play a defensive role against herbivorous insects via insect endocrine-disrupting activity.

Pinecone of Pinus koraiensis Inducing Apoptosis in Human Lung Cancer Cells by Activating Caspase-3 and its Chemical Constituents.[Pubmed:28027428]

Chem Biodivers. 2017 Apr;14(4).

Pinecones from Pinus koraiensisSiebold & Zucc. (Pinaceae), which have historically been treated as an undesired waste by-product in the processing of seeds, have recently been shown to contain ingredients with potent biological activities, such as polyphenols exhibiting antitumor activity. With this study, we seek to broaden our understanding of antitumor compounds contained in these pinecones beyond just polyphenols. We found that the water extract of P. koraiensis pinecones exhibits significant cytotoxic activity, with IC50 values ranging from 0.62 to 1.73 mg/ml in four human lung cancer cell lines, A549, H1264, H1299, and Calu-6, irrespective of their p53 status. We also demonstrate that pinecone water extract induces apoptosis associated with caspase-3 activation in the same cancer cell lines. Chemical investigation of the pinecone water extract revealed eight main components (1 - 8), and their structures were identified as dehydroabietic acid (1), 15-hydroxy-7-Oxodehydroabietic acid (2), 7beta,15-dihydroxydehydroabietic acid (3), beta-d-glucopyranosyl labda-8(17,13)-diene-(15,16)-lactone-19-oate (4), 7alpha,15-dihydroxydehydroabietic acid (5), (+)-(1S,2S,4R)-limonene-1,2-diol (6), sobrerol (7), and 4-hydroxybenzoic acid (8). These findings suggest a novel biological application of P. koraiensis pinecones in combatting human lung cancer, and further identify the major compounds that could contribute to this anticancer activity.

SPE and HPLC/UV of resin acids in colophonium-containing products.[Pubmed:18666177]

J Sep Sci. 2008 Aug;31(15):2784-90.

A new method, involving SPE and HPLC/UV diode-array detection (DAD), was developed for the quantification of colophonium components in different consumer products, such as cosmetics. Colophonium is a common cause of contact dermatitis since its components can oxidize into allergens on exposure to air. Three different resin acids were used as markers for native and oxidized colophonium, abietic acid (AbA), dehydroabietic acid (DeA), and 7-Oxodehydroabietic acid (7-O-DeA). The SPE method, utilizing a mixed-mode hydrophobic and anion exchange retention mechanism, was shown to yield very clean extracts. The use of a urea-embedded C(12) HPLC stationary phase improved the separation of the resin acids compared to common C(18). Concentrations higher than 2 mg/g of both AbA and DeA were detected in wax strips. In this product also 7-O-DeA, a marker for oxidized colophonium, was detected at a level of 28 microg/g. The LODs were in the range of 7-19 microg/g and the LOQs 22-56 microg/g. The method is simple to use and can be applied on many types of technical products, not only cosmetics. For the first time, a method for technical products was developed, which separates AbA from pimaric acid.

Tape-stripping as a method for measuring dermal exposure to resin acids during wood pellet production.[Pubmed:18392277]

J Environ Monit. 2008 Mar;10(3):345-52.

The purpose of this study was to develop a sensitive and specific method for quantifying dermal exposure to the resin acids 7-Oxodehydroabietic acid (7-OXO), dehydroabietic acid (DHAA), abietic acid (AA), and pimaric acid (PA). In addition the method was evaluated in occupational settings during production of wood pellets. Tape-strips were spiked with the substances to evaluate the recovery of the acids from the tape. The removal efficiency of the tape was assessed by tape-stripping a specified area on a glass plate spiked with resin acids. The recovery of the acids from human skin in vivo was evaluated by applying acids in methanol onto the skin of volunteers. Occupational dermal exposure to the resin acids was assessed by tape-stripping the skin of workers involved in the production of wood pellets. The resin acids were analyzed by liquid chromatography mass spectrometry (LC-MS). The limit of detection was 15 pg (7-OXO), 150 pg (DHAA), 285 pg (AA) and 471 pg (PA) per injection. The recovery from spiked tapes was in general 100%. The removal efficiency of the tape was 48-101%. Recovery tests from human skin in vivo showed a mean recovery of 27%. Quantifiable amounts of resin acids were observed on four different skin areas with an increase in exposure during a work shift. This study shows that occupational dermal exposure to resin acids can be assessed by tape-stripping and quantified by LC-MS.

Exposure to wood dust, resin acids, and volatile organic compounds during production of wood pellets.[Pubmed:18322870]

J Occup Environ Hyg. 2008 May;5(5):296-304.

The main aim of this study was to investigate exposure to airborne substances that are potentially harmful to health during the production of wood pellets, including wood dust, monoterpenes, and resin acids, and as an indicator of diesel exhaust nitrogen dioxide. In addition, area measurements were taken to assess background exposure levels of these substances, volatile organic compounds (VOCs), and carbon monoxide. Measurements were taken at four wood pellet production plants from May 2004 to April 2005. Forty-four workers participated in the study, and a total of 68 personal measurements were taken to determine personal exposure to wood dust (inhalable and total dust), resin acids, monoterpenes, and nitrogen dioxide. In addition, 42 measurements of nitrogen dioxide and 71 measurements of total dust, resin acids, monoterpenes, VOCs, and carbon monoxide were taken to quantify their indoor area concentrations. Personal exposure levels to wood dust were high, and a third of the measured levels of inhalable dust exceeded the Swedish occupational exposure limit (OEL) of 2 mg/m3. Parallel measurements of inhalable and total dust indicated that the former were, on average, 3.2 times higher than the latter. The data indicate that workers at the plants are exposed to significant amounts of the resin acid 7-Oxodehydroabietic acid in the air, an observation that has not been recorded previously at wood processing and handling plants. The study also found evidence of exposure to dehydroabietic acid, and exposure levels for resin acids approached 74% of the British OEL for colophony, set at 50 microg/m3. Personal exposure levels to monoterpenes and nitrogen dioxide were low. Area sampling measurements indicated that aldehydes and terpenes were the most abundant VOCs, suggesting that measuring personal exposure to aldehydes might be of interest. Carbon monoxide levels were under the detection limit in all area measurements. High wood dust exposure levels are likely to have implications for worker health; therefore, it is important to reduce exposure to wood dust in this industry.

Direct exposure electron ionization mass spectrometry and gas chromatography/mass spectrometry techniques to study organic coatings on archaeological amphorae.[Pubmed:15739159]

J Mass Spectrom. 2005 May;40(5):675-87.

Two different analytical approaches, direct exposure electron ionization mass spectrometry (DE-MS) and gas chromatography/mass spectrometry (GC/MS), were compared in a study of archaeological resinous materials. DE-MS was found to be an efficient fingerprinting tool for the fast screening of organic archaeological samples and for providing information on the major components. GC/MS appeared to be more efficient in unravelling the sample composition at a molecular level, despite the long analysis time and the need for a wet chemical pretreatment. Both procedures were applied to characterize the organic material present as coatings in Roman and Egyptian amphorae. DE-MS successfully identified abietanic compounds, hence a diterpenic resinous material could be identified and its degree of oxidation assessed. GC/MS enabled us to identify dehydroabietic acid, 7-Oxodehydroabietic acid, 15-hydroxy-7-Oxodehydroabietic acid, 15-hydroxydehydroabietic acid, retene, tetrahydroretene, norabietatriene, norabietatetraene and methyl dehydroabietate. These oxidized and aromatized abietanes provided evidence that the amphorae examined were waterproofed with a pitch produced from resinous wood of plants from the Pinaceae family. The chemometric evaluation of the GC/MS data highlighted significant chemical differences between the pitches found in the two archaeological sites, basically related to differences in the production techniques of the materials and in their degradation pathways.

New abietane-type diterpenes from the heartwood of Picea morrisonicola.[Pubmed:15256710]

Chem Pharm Bull (Tokyo). 2004 Jul;52(7):861-3.

New abietane-type diterpenes, 15-acetoxy-7-Oxodehydroabietic acid (1), picealactones A (2), B (3), and C (4), together with the known 7-Oxodehydroabietic acid (5) were isolated and identified from the heartwood of Picea morrisonicola. The structures of 1-4 were determined on the basis of spectral data explanation. Compounds 2-4 possessed a rare 5-dehydro-18, 6-olide functionality. Compounds 1 and 2 were first isolated from natural source.