Abietic Acid Derivatives Research Articles

Natural Products-Based Botanical Bactericides Discovery: Novel Abietic Acid Derivatives as Anti-Virulence Agents for Plant Disease Management.

The discovery of natural product-based pesticides is critical for agriculture. In this work, a series of novel tricyclic diterpenoid derivatives decorated with an amino alcohol moiety were elaborately prepared from natural abietic acid, and their antibacterial behavior was explored. Bioassay results indicated that compound C2 exhibited the most promising bioactivity (EC50 = 0.555 μg mL-1) against Xanthomonas oryzae pv. oryzae (Xoo), about 73 times higher than the effect of commercial thiodiazole copper (TC). Results of in vivo bioassays showed that compound C2 displayed significantly higher control of rice bacterial leaf blight (curative activity: 63.8%; protective activity: 58.4%) than TC (curative activity: 43.6%; protective activity: 40.8%), and their bioactivity could be improved maximally 16% by supplementing the auxiliaries. Antibacterial behavior suggested that compound C2 could suppress various virulence factors. Overall, these findings suggested that new botanical bactericide candidates could control intractable plant bacterial diseases by suppressing virulence factors.

Semisynthetic Abietic and Dehydroabietic Acid Derivatives and Triptoquinone Epimers Interfere with LPS-Triggered Activation of Dendritic Cells.

Abietic acid (AA), dehydroabietic acid (DHA) and triptoquinones (TQs) are bioactive abietane-type diterpenoids, which are present in many edible vegetables and medicinal herbs with health-promoting properties. Evidence suggests that beneficial effects of diterpenes operate, at least in part, through effects on cells in the immune system. Dendritic cells (DCs) are a key type of leukocyte involved in the initiation and regulation of the immune/inflammatory response and natural or synthetic compounds that modulate DC functions could be potential anti-inflammatory/immunomodulatory agents. Herein, we report the screening of 23 known semisynthetic AA and DHA derivatives, and TQs, synthesized previously by us, in a multi-analyte DC-based assay that detects inhibition of pro-inflammatory cytokine production. Based on the magnitude of the inhibitory effect observed and the number of cytokines inhibited, a variety of activities among compounds were observed, ranging from inactive/weak to very potent inhibitors. Structurally, either alcohol or methyl ester substituents on ring A along with the introduction of aromaticity and oxidation in ring C in the abietane skeleton were found in compounds with higher inhibitory properties. Two DHA derivatives and two TQs exhibited a significant inhibition in all pro-inflammatory cytokines tested and were further investigated. The results confirmed their ability to inhibit, dose dependently, LPS-stimulated expression of the co-stimulatory molecules CD40 and/or CD86 and the production of the pro-inflammatory cytokines IL-1β, IL-6, IL-12 and TNFα. Our results demonstrate that DC maturation process can be targeted by semisynthetic DHA derivatives and TQ epimers and indicate the potential of these compounds as optimizable anti-inflammatory/immunomodulatory agents.

Characterization of bark, needles and cones from silver fir (Abies alba mill.) towards valorization of biomass forestry residues

Valorization of renewable biomass forestry gains more and more interest due to the exhaustible nature of fossil based resources and their negative environment impact. Therefore, this study involves thoroughly characterization of bark, needles and cones from silver fir (Abies alba Mill.) of two different ages (40 and 100 years) to determine their potential use as source of valuable compounds. Proximate/ultimate and compositional analysis as well as thermal behavior showed that the studied materials are promising candidates for biomass valorization by torrefaction and pyrolysis. In addition, it was revealed that fir samples contain significant amounts of phenolic and flavonoid compounds. The extractive fractions were found to be rich in highly valuable compounds such as terpenes, paraffins, phenols, acids and derivatives of abietic acid. This induced good antioxidant activity of the extractive fractions, with fast scavenging of DPPH radicals. The PCA and hierarchical clustering used for exploratory data analysis offered the possibility to combine multiple information obtained from detailed characterization of samples into a global view of the system. This allowed us to observe and distinguish similarities and differences among samples according to source and age. Needles stand out from bark and cones due to the high content of terpenes in extractives. Paraffins were the main components in the extractives from cones. Saccharides were found, in small amounts, only in the extractives of bark. Differences by age were also observed. The resulted outcomes provide a promising starting point in selecting suitable sources and procedures for valorization of renewable biomass forestry into energy and value added materials.

Rosin-Related Compounds (Abietic Acid Derivatives) Concentrations in Chloroprene Rubber Products and the Amounts Eluted Into Artificial Sweat.

Division of Environmental Chemistry National Institute of Health Sciences Kawasaki, Kanagawa, Japan [email protected] The authors have no funding or conflicts of interest to declare.

Anti‐obesity effect of plant diterpenes and their derivatives: A review

Obesity is a medical condition in which excess body fat is accumulated by a combination of excessive food intake, lack of physical activity, and genetic susceptibility. Obesity increases the risk of various diseases and conditions, including cardiovascular diseases, diabetes, cancer, and depression. This review focuses on most recent reports pertaining to the antiobesity activity of plant-derived diterpenes in different databases. For this, a search (until August 2019) was conducted in the PubMed and Science Direct databases with the following keywords: "plant diterpenes" or "plant diterpenoids" paired with "obesity" or "antiobesity effects." Overall, 729 references that used the aforementioned keywords were selected, among which 34 articles have been included in this review. Results from this search suggest that a number of diterpenes and their derivatives have been found to exert antiobesity effects through various mechanisms, such as overweight reduction or modification of body mass index, protein-tyrosine phosphatase 1B inhibition, lipase activity inhibition, antiadipogenesis effect, among others. Carnosic acid, carnosol and the derivatives of abietic acid, steviol, and andrographolide are examples of important antiobesity diterpenes and their derivatives. Of note, plant-derived diterpenes may be potential candidates for managing obesity and obesity-related diseases and disorders in human and other animals.

Identification of the Residue in the Bolgar Medieval Sphero‐Conical Vessel by Gas Chromatography – Mass Spectrometry

The Golden Horde sphero‐conical vessel retrieved from the ruins of the medieval city of Bolgar (Russia, Republic of Tatarstan) during archaeological excavations, which contained residue in the form of encrustation on the bottom and the wall, was analysed in the NRC ‘Kurchatov Institute’ by X‐ray phase analysis and high‐performance liquid and gas chromatography with MS detectors (HPLC–MS, GC–MS). The GC–MS method established that the residue from the sphero‐conical vessel was comprised primarily of abietic acid derivatives (around 46%) and retene, which is polycyclic aromatic hydrocarbon (around 27%); this means that turpentine exuded from the stems of certain species of coniferous trees, called resin and subsequently heat‐treated, was poured into the vessel. Researchers have been trying to decipher the function of these mysterious vessels for 200 years, and this is the first time that resin stored in a sphero‐conical vessel has been documented. Potentially, this vessel was probably used as a personal ‘medical kit’.

A gas chromatographic study of the residual contents of a medieval sphero-conical vessel

Black deposit was discovered on the inner wall of a sphero-conical vessel found during archaeological excavations on the territory of the Volga Bulgars. Compounds from the deposit were extracted with organic solvents and studied by gas chromatography with flame ionization and mass spectrometry detectors. Abietic acid derivatives, including retene, present in the composition of soft wood turpentine were identified. The relatively high retene concentration in the remains of the spherocone and also the presence of other polycyclic aromatic hydrocarbons suggest the thermal version of their origin. Probably, the vessel was used as a part of alambik, which is an ancient distillation apparatus for the distillation of soft wood turpentine.

Identification of Gli-mediated transcription inhibitors through synthesis and evaluation of taepeenin D analogues

Abietic acid derivatives related to taepeenin D were identified as new Hh pathway inhibitors that operate downstream of Smo.

Refikite from Krásno, Czech Republic: a crystal-and molecular-structure study

AbstractThe crystal structure of the organic mineral refikite has been determined. The mineral was found in joints in bark and wood from pine trees in the 'V Borkách' peat deposit near the town of Krásno, Slavkovský les Mountains, western Bohemia, Czech Republic. It forms white to light-yellow polycrystalline crusts or randomly intergrown, transparent, colourless, very thin, acicular crystals up to 0.2–0.5 mm long. Sometimes, colourless-to-white elongated prismatic crystals up to 1–1.5 mm in size were encountered. The mineral is soft (Mohs hardness ∼1) and very brittle, with an uneven fracture. No visible cleavage was discerned. Crystals have a greasy-to-glassy lustre; fine crystal aggregates have a pearly lustre. Refikite, empirical formula C20H34O2 or C19H33COOH, is a derivative of abietic acid. It is orthorhombic, space group P21212, with a = 22.6520(7), b = 10.3328(3), c = 7.6711(2) Å, V = 1795.49(9) Å3, Z = 4. Refikite comprises two closely related compounds based on perhydrophenanthrene. The major component has two axial methyl groups, one terminal carboxylic group and one terminal propan-2-yl (isopropyl) group joined to the three fused rings in the same fashion as in abietic acid. However, the fused ring system is fully reduced (contains single bonds only). In the minor component, the terminal propan-2-yl group is replaced by a propen-2-yl (methylvinyl) group. The crystal structure is stabilized by strong O···H–O hydrogen bonds. High-resolution mass spectroscopy (HRMS) confirmed a molecular mass of 306 and the formula C20H34O2. Hydrogen-1 and carbon-13 nuclear magnetic resonance (NMR) spectroscopy showed the presence of four methyl groups in the major component; infrared (IR), Raman and NMR spectra are consistent with the structure. The HRMS, IR and Raman spectroscopy methods confirmed the presence of a minor component containing the propen-2-yl group replacing the propan-2-yl group. This is also reflected in a shortened C15–C17 single bond metric of 1.468(6) Å shown by single-crystal X-ray analysis. The trivial name of the major component of refikite is tetrahydroabietic acid or abietan-18-oic acid. This work represents the first proof of the existence of abietic acid derivatives as naturally occurring species.

Prospects of an alternative treatment against Trypanosoma cruzi based on abietic acid derivatives show promising results in Balb/c mouse model.

Chagas disease, caused by the protozoa parasite Trypanosoma cruzi, is an example of extended parasitaemia with unmet medical needs. Current treatments based on old-featured benznidazole (Bz) and nifurtimox are expensive and do not fulfil the criteria of effectiveness, and a lack of toxicity devoid to modern drugs. In this work, a group of abietic acid derivatives that are chemically stable and well characterised were introduced as candidates for the treatment of Chagas disease. In vitro and in vivo assays were performed in order to test the effectiveness of these compounds. Finally, those which showed the best activity underwent additional studies in order to elucidate the possible mechanism of action. In vitro results indicated that some compounds have low toxicity (i.e. >150 μM, against Vero cell) combined with high efficacy (i.e. <20 μM) against some forms of T. cruzi. Further in vivo studies on mice models confirmed the expectations of improvements in infected mice. In vivo tests on the acute phase gave parasitaemia inhibition values higher those of Bz, and a remarkable decrease in the reactivation of parasitaemia was found in the chronic phase after immunosuppression of the mice treated with one of the compounds. The morphological alterations found in treated parasites with our derivatives confirmed extensive damage; energetic metabolism disturbances were also registered by (1)H NMR. The demonstrated in vivo activity and low toxicity, together with the use of affordable starting products and the lack of synthetic complexity, put these abietic acid derivatives in a remarkable position toward the development of an anti-Chagasic agent.

Synthesis and biological evaluation of abietic acid derivatives

A series of C18-oxygenated derivatives of abietic acid were synthesized and evaluated for their cytotoxic, antimycotic, and antiviral activities. In general, the introduction of an aldehyde group at C18 did improve the resultant bioactivity, while the presence of an acid or alcohol led to less active compounds.

Unconventional Synthesis of Pullulan Abietates

Pullulan abietic acid esters (pullulan abietates) of different degree of substitution (DS) were synthesized homogeneously in N,N-dimethylacetamide using differently in situactivated abietic acid derivatives. In situ activation was achieved with p-toluenesulfonyl chloride, N,N‘-carbonyldiimidazole and iminium chloride formed from oxalyl chloride/N,N-dimethylformamide. The DS values of the biopolymer esters determined by acid-base titration after saponification indicated that in situ activation with p-toluenesulfonyl chloride is most efficient while in case of the in situ activation with N,N‘-carbonyldiimidazole almost no polymer degradation occured. The pullulan abietates were characterized by elemental analysis, GPC, FTIR-, 1H- and 13C NMR spectroscopy.

The synthesis of a near infrared-sensitive tackifier

A general method to prepare near infrared absorbing abietic acid derivatives is described in which the carboxylic acid of abietic acid is sterically hindered, making the seemingly simple esterification of the acid with a functional near infrared dye the most troublesome stage of the synthesis. Optimum results were obtained by constructing the chromophore from components previously attached to abietic acid. The spectral properties of the desired compound both in solution and within polymer films are discussed. The tackifiers increase the near infrared absorption, offering the potential for near infrared-activated hot-melt adhesives.

Regio- and Stereo-selective Hydroxylation of Abietic Acid Derivatives by Mucor circinelloides and Mortierella isabellina

Mucor circinelloides and Mortierella isabellina hydroxylated dehydroabietic acid (DehA). DehA was converted regio- and stereo-selectively by whole cells of Mr. circinelloides to give 2alpha-hydroxydehydroabietic acid in a 75% molar conversion yield (11 mM from 14.7 mM DehA) after 72 h in the cultivation medium containing 3% (v/v) Tween 80. With cells of Ma. isabellina, under the same conditions, 20.5 mM (6.5 g l(-1)) 2-hydroxydehydroabietic acid (alpha/beta=81/19) was formed from 26.4 mM DehA.

EFFECT OF ABIETIC ACID DERIVATIVE SURFACTANTS ON CALORIFIC VALUE AND FLOW OF CRUDE OIL AND SOME DISTILLATES

ABSTRACT A series of abietic monoester and amide have been prepared by esterification of abietic acid with long chain alcohol blend (Nafol 20+), polyethylene glycol (PEG 400, 600, 1000 and 4000) and hexadecylamine. The abietic diester derivatives were prepared by esterification of abietic–maleic anhydride adduct with Nafol 20+ only or polyethylene glycol-1000 and Nafol 20+. These reactions were carried out to prepare eight abietic acid derivatives. The products were purified and characterized by FTIR and 1H NMR analyses. The surface-active properties of these compounds were correlated with their effect on pour point and calorific values of crude oil. From the results, it has been found that the compound EA23-MN, which has the more negative value of ΔG ad, exhibited maximum pour point depression and increases the calorific values of crude oil and some distillates.

Synthetic derivatives of abietic acid with radical scavenging activity.

In this work, studies on the arylation of anilines derived from dehydroabietic acid, the main component of disproportionated rosin, are presented. The redox properties of the new diarylamines were investigated by cyclic voltammetry, and their free radical scavenging activity was tested by reduction of the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical. Three of the diarylamines with lower oxidation potential proved to be as active as isopropyldiphenylamine (IPPD) and superior to tert-butylhydroxytoluene (BHT), both commercially available synthetic antioxidants.

Diels-Alder polymerization of some derivatives of abietic acid

Diels-Alder polymerization of some derivatives of abietic acid

Diels-Alder polymerization of some derivatives of abietic acid

The Diels-Alder polymerization reaction between a bisdiene derived from abietic acid and 4,4′-diphenylmethanedimaleimide (bismaleimide) was studied. The bisdiene was the dehydrodecarboxylation product of abietic acid, denoted here as diabietyl ketone. An insoluble and infusible polymer with high molecular weight was obtained. It is a poly(ketoimide) with hydrophenanthrene moieties in the backbone. The analyses showed that the chemical structure of the polymer was different from that expected. The polymer structural unit was found to contain bismaleimide and diabietyl ketone units not in a molar ratio of 1 : 1, as expected, but in a ratio of 5–6 : 1. The phenomenon was ascribed to the difference between the rates of the two concomitant reactions in the synthesis; the homopolymerization of bismaleimide and the proper Diels-Alder polymerization. The polymer having in structure the monomer units in 1 : 1 ratio was, however, obtained by both the dehydrodecarboxylation of the diacid resulted from the Diels-Alder reaction between abietic acid and 4,4′-diphenylmethanedimaleimide and the polycondensation of the ketone of maleated abietic acid with 4,4′-diaminodiphenylmethane. The monomers and the polymers were investigated by usual physical and chemical methods. The thermal stability of polymers was evaluated by TGA. The synthesized polymers were identical heat-resistant as the crosslinked polymer obtained from 4,4′-diphenylmethanedimaleimide. They were stable in air up to 360°C. Die Diels-Alder-Polymerisation von einem aus Abietinsäure hergestellten Bisdien und 4,4′-Diphenylmethandimaleimid wurde untersucht. Das Bisdien war das Produkt der Dehydrodecarboxylierung von Abietinsäure, hier mit Diabietylketon bezeichnet. Daraus resultierte ein hochmolekulares, unlösliches und nicht schmelzbares Polymeres. Das Polymere ist ein Poly(ketoimid) mit Hydrophenanthren-Einheiten in der Hauptkette. Die Analysen zeigten, daß die Struktur des Polymeren anders ist als vorausgesagt. Das Verhältnis von Bismaleinimid zu Bisdien im Polymeren beträgt nicht 1 : 1, sondern liegt zwischen 5 : 1 und 6 : 1. Dieser Befund wurde mit der Differenz der Reaktionsgeschwindigkeiten der beiden konkurrierenden Reaktionen in der Synthese erklärt, der Homopolymerisation des Bismaleinimids und der eigentlichen Diels-Alder-Polymerisation. Das Polymere mit einem Monomerverhältnis von 1 : 1 wurde auf zwei Wegen erhalten: Zum einen durch Dehydrodecarboxilierung der Disäure aus der Diels-Alder-Reaktion von Abietinsäure und 4,4′-Diphenylmethandimaleimid, zum anderen durch Polykondensation des Ketons von maleinierter Abietinsäure mit 4,4′-Diaminodiphenylmethan. Die Monomeren und Polymeren wurden mit den gängigen physikalischen und chemischen Methoden untersucht. Die thermische Stabilität der Polymeren wurde mit der TGA bestimmt. Die synthetisierten Polymeren sind genauso hitzebeständig wie das vernetzte Polymere aus 4,4′-Diphenylmethandimaleimid. Sie sind in Luft bis 360°C stabil.

Identification of lipophilic pollutants discharged from a finnish pulp and paper mill

Lipophilic organic compounds originating from kraft pulping and papermaking were identified by straight gas chromatography/mass spectrometry (GC/MS) analyses. Samples analyzed included a primary clarifier effluent (PE) and a secondary clarifier effluent (SE) from the activated sludge treatment plant of a Finnish ECF-bleached (Elementally Chlorine Free) kraft pulp and paper mill. Liquid-liquid extraction composition of PE was compared with solid phase extraction (SPE) and dialysis of a semipermeable membrane device (SPMD) exposed to PE. Dichloromethane extracts of particulate material isolated from PE, sludges from both the primary and secondary clarifier, a sediment collected in the vicinity of the mill and whitefish subacutely exposed to the secondary treatment effluent were also investigated. Typical pulp mill-related compounds such as terpenes, terpenoids and aromatic compounds were identified in PE whereas these were non-detectable in SE. For example, thunbergene, thunbergol, squalene, longifolene and derivatives of abietic acid were observed in PE. Alkylated polycyclic aromatics were major compounds identified in the sediment sample with retene (C4-alkyl phenanthrene) as a predominant component.

The impact of contamination from a municipal solid waste landfill (Zagreb, Croatia) on underlying soil

The present study was conducted on the main landfill of the city of Zagreb which contains about 5 million tons of waste disposed of directly onto highly permeable alluvial sediments. The investigations were aimed at assessing the impact of contamination from the landfill on underlying soil and comprised the determination of a broad spectrum of inorganic and organic constituents in the samples (size fractions &amp;lt;2 mm) of solid waste, soil and aquifer sediments. Both the total content of various contaminants as well as their part which is readily leachable with water were determined in the examined samples. Compound classes identified in the landfill can be classified into the two main categories: (1) markers of biological waste and of its microbial transformation (ammonia, dissolved organic carbon, short-chain aliphatic acids, phenols, derivatives of abietic acid) and (2) markers of anthropogenic waste (toxic metals, hydrocarbons, chlorinated hydrocarbons, surfactant-derived compounds, phthalates, pharmaceutical chemicals). The complex assemblages of contaminants were shown to change dramatically during the transport from the solid waste through unsaturated zone of the soil to aquifer sediments. It was shown that, in addition to the vertical infiltration of leachate from the solid waste, the hydrological regime of groundwater has also a strong impact on the contaminant distribution in soils below the landfill.