The utilization of metalloporphyrins as bioinspired oxidation catalysts is an evolving topic of research. By understanding the cytochrome P-450 mechanism of action, chemists have been able to successfully mimic several types of oxidation reactions using metalloporphyrins as catalysts. At first, homogeneous systems presented the most amenable strategy for oxidizing a vast array of substrates; however, current environmental concerns have directed research in this field to the design, synthesis, and application of heterogeneous catalysts, as well as avoiding the use of highly pollutant co-oxidants and/or co-catalysts. Herein, we review the past decade (from 2008) concerning the use of solely molecular oxygen as an environmentally benign oxidant source, in oxidation reactions catalyzed by bioinspired metalloporphyrin analogues. We did not intend to create a comprehensive review; instead we highlight the most important and illustrative examples for this period. We emphasize the application of such catalysts on...

Metalloporphyrins: Bioinspired Oxidation Catalysts

Fuel and chemicals from wet lignocellulosic biomass waste streams by hydrothermal carbonization

Citrus production generates a large quantities of residues which can be used in the production of intermediate compounds for the production of value added products which can be used in the synthesis of industrial fine chemicals, fragrances, flavorings, herbicides, pharmaceutical products among others. This work presents a study to increase the value added of essential oils obtained from orange peel producing p-cymene and pectin. Techno-economic and environmental assessments were developed demonstrating that computer-aided process engineering tools can be used to evaluate the feasibility of integrated processes. Two scenarios were evaluated (with and without electricity generation) obtaining 9.22 and 42.63 kg/h with purities of 97 and 81 % of p-cymene and pectin respectively. In the scenario with electricity generation, 99.81 kWh was obtained, covering all requirements in the process. The techno-economic analysis showed that the most appropriate scheme was that without electricity generation reaching a production cost of 5.27 and 3.53 USD/kg of p-cymene and pectin respectively. Environmental analysis reveals that the potential environmental impact was lowest for the scenario without electricity generation.

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Techno-economic and Environmental Assessment of p-Cymene and Pectin Production from Orange Peel

The objective of this study was to test the hypothesis that p-cymene can attenuate acute lung injury induced by lipopolysaccharide (LPS) in vivo. In the mouse model of LPS-induced acute lung injury, intraperitoneal preconditioning with p-cymene resulted in a significant reduction of pro-inflammatory cytokines (TNF-α, IL-1β and IL-6), lung water gain, inflammatory cell infiltration, lung tissue myeloperoxidase activity. In addition, p-cymene blocked the phosphorylation of IκBα protein and mitogen-activated protein kinases (MAPK) signaling pathway activation. Histopathologic examination of lung tissue indicated that p-cymene treatment markedly decreased focal thickening, congestion, pulmonary edema, and inflammatory cells infiltration. The results showed that p-cymene had a protective effect on LPS-induced ALI in mice.

https://www.mdpi.com/1420-3049/17/7/8159/pdf

p-Cymene Protects Mice Against Lipopolysaccharide-Induced Acute Lung Injury by Inhibiting Inflammatory Cell Activation

The transformation of α-limonene into p -cymene over oxide catalysts (γ-Al 2 O 3 , TiO 2 , SiO 2 , MCM-41) has been studied under H 2 and He atmosphere in the temperature range 200–300 °C using a fixed bed micro-reactor working under atmospheric pressure. The catalysts were characterized using various physicochemical techniques (N 2 adsorption–desorption, NH 3 -TPD, XRD, TPR, HR-TEM). We demonstrated that an almost complete transformation of α-limonene into p -cymene can be obtained at 300 °C over a high surface area anatase (Alfa Aesar) in helium atmosphere. The high surface area titania was also proved a very stable catalyst. The high catalytic performance of this oxide could be attributed to a good balance between the acidity and surface reducibility exhibited by this material. The aforementioned properties are, respectively, relevant to the isomerization and disproportionation/dehydrogenation steps involved in the mechanism of title reaction. Based on the yields obtained for p -cymene and by-products we proposed a mechanistic scheme for the title reaction over the high surface area titania.

Transformation of α-limonene into p-cymene over oxide catalysts: A green chemistry approach

Application of ultrasonic spraying in preparation of p-cymene by industrial dipentene dehydrogenation

The invention discloses a terpene resin and a preparation method thereof. The preparation method comprises steps as follows: terpene substances are used as a raw material, AlCl3 in the presence of an aromatic solvent is used as a main catalyst, and a cocatalyst is used in the reaction; polymerization is carried out at low temperature to prepare the crude terpene resin product; and the crude terpene resin product is washed and distilled under reduced pressure to obtain the terpene resin product. The cocatalyst is trimethylchlorosilane, triethylchlorosilane, tripropylchlorosilane or tributylchlorosilane, and accounts for 1-5% of the total mass of the terpene substance raw material; the main catalyst AlCl3 accounts for 4-12% of the total mass of the terpene substance raw material; the elemental chlorine content in the prepared terpene resin product is less than 100mg/kg, and the metallic aluminum content is less than 10mg/kg; the terpene resin product does not contain metallic antimony; and the residue level of the volatile solvent is less than 25mg/kg. The product reaches to the food level.

Terpene resin and preparation method thereof

The invention discloses a preparation method of the Alpha hyphen Terpinene with high purity, which comprises the following steps: first, synthesizing Alpha hyphen Terpinene: the turpentine oil or one of the Alpha hyphen pinene or Beta hyphen pinene of industrial grade is mixed with the organic solvent and the water and one or two or the mixture of the sulphuric acid, the phosphoric acid, the p-toluene sulfonic acid and the chloroactic acid or the macropore cation exchange resin are used ascatalysts to directly react with water to generate Alpha hyphen Terpinene reaction product; the generation of the Gamma hyphen Terpinene are reduced by the method of controlling the mixture ratio and the reaction temperature of the Terpinene, the organic solvent and the water to form the transparent homogeneous solution system; second, separating the Alpha hyphen Terpinene with high purity. The invention forms the transparent homogeneous solution system through the turpentine oil or one of the Alpha hyphen pinene or Beta hyphen pinene of industrial grade and the organic solvent and water, therefore effectively inhibiting the generation of the main impurity- Gamma hyphen Terpinene.

Method of manufacturing high purity alpha-terpineol

The present invention provides a preparation method of pimaric type acid, comprising the following steps: (1) putting refined resin acid, turpentine or colophony and maleic anhydride into a reaction bottle according to proportion by weight being 1:0.3-1.5, having the addition reaction by microwave auxiliary heating or direct heating after the materials are dissolved by C1-C10 lower fatty acid solvent, proportion by weight between the C1-C10 lower fatty acid solvent and the refined resin acid is 0.05-30:1, cooling, crystallizing, filtering and washing the resultant of reaction after the reaction; and (2) merging the filtrate collected from the step (1), distilling at reduced pressure so as to remove the solvent and obtain crude product of pimaric type acid which is dissolved into sodium hydroxide water solution to prepare pimaric type resinate water solution, and adjusting the pH-value to 6-14 by mineral acid or organic acid during stirring, and directly purifying the deposition or firstly acidifying and secondly purifying the deposition to obtain the product of pimaric type acid. The invention has the advantages of high yield, high content, low cost and less pollution, etc.

Method of preparing pimaric type acid

The invention discloses a preparation method for rosin-based hyperbranched polyester and application of the rosin-based hyperbranched polyester to epoxy resin. The method comprises the following steps of: under the protection of nitrogen, reacting maleopimaric acid with a glycidol monomer in a molar ratio of (0.05-10):1 in an aprotic solvent at the temperature of 50 to 150 DEG C for 0.5 to 24 hours; adding a strong acid catalyst into the aprotic solvent, tracking and checking until an acid value is less than or equal to 10mg/g, reducing pressure at the vacuum degree of 0.1 to 100kPa, and continuously reacting for 0.5 to 5 hours to obtain an initial product; and precipitating, filtering, separating, and performing vacuum drying to obtain the rosin-based hyperbranched polyester. The method is simple, expensive equipment and complicated operation are not needed, and the obtained polymer contains a large number of end groups, can be dissolved in various organic solvents, and can be directly applied to the epoxy resin.

Dongmei Li

Papers

Application of ultrasonic spraying in preparation of p-cymene by industrial dipentene dehydrogenation

Terpene resin and preparation method thereof

Method of manufacturing high purity alpha-terpineol

Method of preparing pimaric type acid

Preparation method for rosin-based hyperbranched polyester and application of rosin-based hyperbranched polyester to epoxy resin