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Concept: Anacardic acid


This tutorial review could serve as an introduction of cardanol into the world of soft nanomaterials; it is a biobased lipid-mixture obtained from the plant Anacardium occidentale L. Cardanol is a renewable raw material derived from a byproduct of cashew nut processing industry: Cashew Nut Shell Liquid (CNSL). Cardanol is a rich mixture of non-isoprenoic phenolic compounds that is a valuable raw material for generating a variety of soft nanomaterials such as nanotubes, nanofibers, gels and surfactants. These nanostructures may then serve as templates for the synthesis of additional nanomaterials. The wealth and diversity of cardanol-derived functional nanomaterials has urged us to present an article that will give readers a taste of a new class of cardanol-derived functional amphiphiles, along with their ability to generate hierarchical functional nanomaterials through non-covalent soft-chemical routes. In this concise review, we discuss selected examples of novel biobased surfactants, glycolipids, and polymers derived from cardanol, and their subsequent self-assembly into functional soft materials.

Concepts: Nut, Cashew, Cashew nutshell liquid, Anacardic acid


Antianxiety drugs currently in use are associated with a number of serious side effects. Present study was designed to evaluate the efficacy of anacardic acids (AAs) isolated from cashew nut (Anacardium occidentale L.) shell liquid (CNSL) to treat anxiety as well as its role in oxidative stress in mice model. Anxiolytic effect of AA was evaluated using rota-rod and a set of behavioral tests in male Swiss albino mice at the doses of 10, 25, and 50 mg/kg. Flumazenil was used to evaluate the possible involvement of GABAergic system in the mechanism of action of AA. The effect of AA on oxidative stress in mice was evaluated by determining the concentration of malondialdehyde (MDA), reduced glutathione, and catalase (CAT) activity. The detection of DNA damage of the treated animals was performed using alkaline comet test in the hippocampus and frontal cortex of the animals. The results demonstrated that AA did not produce myorelaxant and sedative effects, nor did it cause a decrease in locomotor activity. The anxiolytic effect of AA was well-evident in all tests, especially at higher dose levels (25 and 50 mg/mg). Flumazenil reversed the anxiolytic effect of AA at all doses. In addition, AA reduced oxidative stress by decreasing the concentration of MDA and increasing the levels of reduced glutathione (GSH) and CAT activity. Statistical analysis by Pearson’s correlation indicated a positive correlation between anxiolytic effect of AA to its antioxidant and lipid peroxidation inhibitory activity. Furthermore, increased CAT activity and GSH concentrations in the hippocampus and frontal cortex of mice was also complementary to the reduced genotoxic damage observed in the study. In comet assay, AA did not increase in DNA damage. In conclusion, the results supported that AA possesses GABAAreceptor mediated anxiolytic activity with the lack of myorelaxation and genotoxicity. © 2018 IUBMB Life, 2018.

Concepts: Antioxidant, Oxidative stress, Reactive oxygen species, Glutathione, Nut, Cashew, Anacardic acid, Anacardiaceae


Cashew nuts are important both nutritionally and industrially, but can also cause food allergies in some individuals. The present study aimed to assess the effect(s) of industrial processing on anacardic acids and allergens present in cashew nuts. Sample analyses were performed using liquid chromatography coupled with mass spectrometry, SDS-PAGE and immunoassay. The anacardic acid concentration ranged from 6.2 to 82.6mg/g during processing, and this variation was attributed to cashew nut shell liquid incorporation during storage and humidification. Dehydrated and selected samples did not significantly differ in anacardic acid content, having values similar to the raw sample. SDS-PAGE and immunoassay analysis with rabbit polyclonal sera and human IgE indicated only minor differences in protein solubility and antibody binding following processing steps. The findings indicate that appreciable amounts of anacardic acid remain in processed nuts, and that changes to cashew allergens during industrial processing may only mildly affect antibody recognition.

Concepts: Immune system, Protein, Asthma, Allergy, Fruit, Cashew, Cashew nutshell liquid, Anacardic acid


Cashew nut shells are agro-wastes produced from cashew nut processing factories and contain about 30-35 wt% oil called cashew nut shell liquid (CNSL). This liquid is a mixture of four potential compounds, namely anacardic acid, cardanol, cardol and 2-methyl cardol. Various reactions have been developed to convert the components of cashew nut shell liquid into industrially important chemicals, and these materials are herein described. Such reactions employed in the transformation include transfer hydrogenation reactions, isomerization reactions, metathesis reactions, carbonylation reactions, polymerization reactions, isomerizing metathesis reaction, and isomerizing carbonylation reactions. Through these descriptions, one realizes that cashew nut shells are not a waste, but they are rather a good source of a potential liquid, CNSL, which is a promising renewable resource for synthesizing various industrial chemicals.

Concepts: Chemical reaction, Chemical substance, Mixture, Chemical compound, Chemical industry, Cashew, Cashew nutshell liquid, Anacardic acid


The cashew nut shell liquid (CNSL) from the cashew nut shell of Anacardium occidentale L. has been used to treat skin infections, cracks on soles of feet and cancerous ulcers. In this study, we have purified the technical CNSL, systematically evaluated its anticancer, antibacterial and wound healing activity. The LC-MS data revealed that the purified CNSL contains the compounds, cardanol, anacardic acid and methylcardol. It inhibited the proliferation of HeLa cells with an IC50 of 0.004%(v/v) and caused moderate mitotic block with spindle abnormality. It induced apoptosis in HeLa cells and accelerated wound closure in L929 cells. It inhibited the growth of Bacillus subtilis with an IC50 of 0.35%(v/v) and the treated cells exhibited elongated morphology indicating that suppression of cell division is one of the possible mechanisms of its action. The study suggests that the purified CNSL might have potential applications in anticancer and antibacterial drug development.

Concepts: Immune system, Cancer, Oncology, Chemotherapy, Cell cycle, Cashew, Cashew nutshell liquid, Anacardic acid


Several polyphenols from renewable sources were surveyed for dentin biomodification. However, phenols from cashew nut shell liquid (CNSL, Anacardium occidentale) and from Aroeira (Myracrodruon urundeuva) extract have never been evaluated. The present investigation aimed to compare the dentin collagen crosslinking (biomodification) effectiveness of polyphenols from Aroeira stem bark extract, proanthocyanidins (PACs) from grape-seed extract (Vitis vinifera), cardol and cardanol from CNSL after clinically relevant treatment for one minute.

Concepts: Nut, Cashew, Cashew nutshell liquid, Anacardic acid, Anacardiaceae, Anacardium, Trees of Brazil, Wild Cashew


Cashew immature and ripe peduncles (Anacardium occidentale L.) from orange- and red-colored clones CCP 76 and BRS 189, respectively, were prepared as juice or fibrous fraction and submitted to UPLC-MS analyses, while the soluble fraction was also submitted to enzymatic evaluation. Cinnamoyl glucoside was present in ripe juice samples from both cashew clones, while monogalloyl diglucoside and digalloyl glucoside were present in immature juice samples from both cashew clones. Four compounds were found at immature fiber of both clones, anacardic acids (1, 2, 3) and GA19. The phenolic biosynthetic pathway was evaluated in juice samples and phenylalanine ammonia-lyase activity decreased significantly during the development, although it was much higher in ripe CCP 76. UDP-glycosyltransferases activity differed between clones, however its product cinnamoyl glucoside was a possible chemical marker of ripe juice samples from both clones. Flavonol synthase showed the highest specific activity in both cashew clones and its product, flavonols were identified in cashew apple at immature and ripe stages.

Concepts: Enzyme, Fruit, Cashew, Anacardic acid


Anacardic acids are the main constituents of natural cashew nut shell liquid (CNSL), obtained via the extraction of cashew shells with hexane at room temperature. This raw material presents high technological potential due to its various biological properties. The main components of CNSL are the anacardic acids, salicylic acid derivatives presenting a side chain of fifteen carbon atoms with different degrees of unsaturation (monoene-15:1, diene-15:2, and triene-15:3). Each constituent was isolated by column chromatography using silica gel impregnated with silver nitrate. The structures of the compounds were characterized by nuclear magnetic resonance through complete and unequivocal proton and carbon assignments. The effect of the side chain unsaturation was also evaluated in relation to antioxidant, antifungal and anticholinesterase activities, and toxicity against Artemia salina. The triene anacardic acid provided better results in antioxidant activity assessed by the inhibition of the free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH), higher cytotoxicity against A. salina, and acetylcholinesterase (AChE) inhibition. Thus, increasing the unsaturation of the side chain of anacardic acid increases its action against free radicals, AChE enzyme, and A. salina nauplii. In relation to antifungal activity, an inverse result was obtained, and the linearity of the molecule plays an important role, with monoene being the most active. In conclusion, the changes in structure of anacardic acids, which cause differences in polarity, contribute to the increase or decrease in the biological activity assessed.

Concepts: DNA, Carbon dioxide, Proton, Atom, Nuclear magnetic resonance, Cashew, Cashew nutshell liquid, Anacardic acid


Cardanol is a phenolic lipid component of cashew nut shell liquid (CNSL), obtained as the byproduct of cashew nut food processing. Being a waste product, it has attracted much attention as a precursor for the production of high-value chemicals, including drugs. On the basis of these findings and in connection with our previous studies on cardanol derivatives as acetylcholinesterase (AChE) inhibitors, we designed a novel series of analogues by including a protonable amino moiety belonging to different systems. Properly addressed docking studies suggested that the proposed structural modifications would allow the new molecules to interact with both the catalytic active site (CAS) and the peripheral anionic site (PAS) of AChE, thus being able to act as dual binding inhibitors. To disclose whether the new molecules showed the desired profile, they were first tested for their cholinesterase inhibitory activity towards EeAChE and eqBuChE. Compound 26, bearing an N-ethyl-N-(2-methoxybenzyl)amine moiety, showed the highest inhibitory activity against EeAChE, with a promising IC50 of 6.6 μM, and a similar inhibition profile of the human isoform (IC50 = 5.7 μM). As another positive feature, most of the derivatives did not show appreciable toxicity against HT-29 cells, up to a concentration of 100 μM, which indicates drug-conform behavior. Also, compound 26 is capable of crossing the blood-brain barrier (BBB), as predicted by a PAMPA-BBB assay. Collectively, the data suggest that the approach to obtain potential anti-Alzheimer drugs from CNSL is worth of further pursuit and development.

Concepts: Chemistry, Enzyme inhibitor, Acetylcholine, Acetylcholinesterase inhibitor, Nut, Cashew, Cashew nutshell liquid, Anacardic acid


Cashew nut shells (CNS), which are agro wastes from cashew nut processing factories, have proven to be among the most versatile bio-based renewable materials in the search for functional materials and chemicals from renewable resources. CNS are produced in the cashew nut processing process as waste, but they contain cashew nut shell liquid (CNSL) up to about 30-35 wt. % of the nut shell weight depending on the method of extraction. CNSL is a mixture of anacardic acid, cardanol, cardol, and methyl cardol, and the structures of these phenols offer opportunities for the development of diverse products. For anacardic acid, the combination of phenolic, carboxylic, and a 15-carbon alkyl side chain functional group makes it attractive in biological applications or as a synthon for the synthesis of a multitude of bioactive compounds. Anacardic acid, which is about 65% of a CNSL mixture, can be extracted from the agro waste. This shows that CNS waste can be used to extract useful chemicals and thus provide alternative green sources of chemicals, apart from relying only on the otherwise declining petroleum based sources. This paper reviews the potential of anacardic acids and their semi-synthetic derivatives for antibacterial, antitumor, and antioxidant activities. The review focuses on natural anacardic acids from CNS and other plants and their semi-synthetic derivatives as possible lead compounds in medicine. In addition, the use of anacardic acid as a starting material for the synthesis of various biologically active compounds and complexes is reported.

Concepts: Alcohol, Amine, Acetic acid, Functional groups, Nut, Cashew, Cashew nutshell liquid, Anacardic acid