Variations in Essential Oil Chemical Composition and Biological Activities of Cryptomeria japonica (Thunb. ex L.f.) D. Don from Different Geographical Origins—A Critical Review

Abstract

The scientific community is paying increasing attention to plant waste valorization, and also to “greener” practices in the agriculture, food and cosmetic sectors. In this context, unused forest biomass (e.g., leaves, seed cones, branches/twigs, bark and sapwood) of Cryptomeria japonica, a commercially important tree throughout Asia and the Azores Archipelago (Portugal), is currently waste/by-products of wood processing that can be converted into eco-friendly and high added-value products, such as essential oils (EOs), with social, environmental and economic impacts. Plant-derived EOs are complex mixtures of metabolites, mostly terpenes and terpenoids, with valuable bioactivities (e.g., antioxidant, anti-inflammatory, anticancer, neuroprotective, antidepressant, antimicrobial, antiviral and pesticide), which can find applications in several industries, such as pharmaceutical, medical, aromatherapy, food, cosmetic, perfumery, household and agrochemical (e.g., biopesticides), with manifold approaches. The EOs components are also of value for taxonomic investigations. It is known that the variation in EOs chemical composition and, consequently, in their biological activities and commercial use, is due to different exogenous and endogenous factors that can lead to ecotypes or chemotypes in the same plant species. The present paper aims to provide an overview of the chemical composition, biological properties and proposals of valorization of C. japonica EO from several countries, and also to indicate gaps in the current knowledge.

Toxicity of Some Essential Oils Constituents against Oriental Fruit Fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae)

“…The findings may vary when different insect species are employed in experiments using the same essential oil. Moreover, the disparity in toxicity across the tested compounds on fruit flies could be due to the various means of EO chemical application (contact ingestion vs. topical application) and the different developmental phases of the flies studied (larvae vs. adults) [ 37 ].…”

Encapsulation of Eucalyptus largiflorens Essential Oil by Mesoporous Silicates for Effective Control of the Cowpea Weevil, Callosobruchus maculatus (Fabricius) (Coleoptera: Chrysomelidae)

“…However, some notable quantitative differences include the relatively high concentrations of 1,8-cineole (23.1–47.0%) coupled with relatively low concentrations of spathulenol (0.4–2.7%) in the previous reports. Such differences may be due to several exogenous and endogenous factors, including harvesting time, geographical position, extraction method, and genetic makeup [ 19 , 41 , 42 ]. Insecticidal properties of some components identified in the essential oil of E. largiflorens have previously been reported ( Table 3 ).…”

Variations in Essential Oil Biological Activities of Female Cones at Different Developmental Stages from Azorean Cryptomeria japonica (Thunb. ex L.f.) D. Don (Cupressaceae)

“…Currently, the main source of biomass for C. japonica EO production in the Azores is the foliage (CJF), which constitutes the bulk of the biomass waste generated by the timber industry and forestry operations. However, it should be noted that the yield, chemical composition, and biological activities of C. japonica EO and, consequently, its specific commercial applications and price, can be significantly influenced by both exogenous and endogenous factors, such as species variety; the geographical region of the plant; environmental abiotic and biotic stresses; plant age; plant parts and their developmental stages; management practices (e.g., harvest period); the post-harvest processing of plant material (e.g., drying); and the extraction process (method and protocol used), among other factors [9,[13][14][15][16]. It should also be highlighted that comparisons of data between different studies are very difficult when different raw materials, processing conditions, extraction protocols, analytical methods, and/or units of measurement were used, among other factors (e.g., experimental conditions of bioassays) [15].…”

“…The chemical characterization, yield value, and bioactivity assessment of C. japonica biomass residues' (CJBR) EOs have focused mostly on the EO from CJF. According to our critical review [13], CJF EOs from different geographical origins are typically obtained by HD, presenting a yield range of 0.5-4.7% (w/w, dry weight basis), and are mainly constituted by a complex mixture of terpenes and terpenoids. However, the CJF EO chemotype is the α-pinene type in the Azores, while in most east Asian countries, it is mainly the ent-kaurene type or elemol plus ent-kaurene type.…”

“…However, the CJF EO chemotype is the α-pinene type in the Azores, while in most east Asian countries, it is mainly the ent-kaurene type or elemol plus ent-kaurene type. Nevertheless, all these CJF EO chemotypes present antimicrobial activities (which are mostly related to the individual susceptibility of the tested microorganisms) and/or other biocidal activities (including mosquito larvicidal, acaricidal, termiticidal, molluscicidal, insect repellent properties, and toxicity against brine shrimp nauplii) [13,15] with potential application in The remarkably increasing market value of EOs could bring about new opportunities for the sustainable management of unused forestry waste, such as that from C. japonica. Currently, the main source of biomass for C. japonica EO production in the Azores is the foliage (CJF), which constitutes the bulk of the biomass waste generated by the timber industry and forestry operations.…”