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.

Azorean Cryptomeria japonica is widely used for local wood production, generating large amounts of aerial-part biomass residues that can be a sustainable source of value-added bioproducts. This comparative study aimed (i) to determine the yield and chemical profile of the essential oils (EOs) extracted by hydrodistillation from Azorean C. japonica foliage, leaves, male cones (MCs), and female cones (FCs), and (ii) to investigate the antimicrobial and brine shrimp lethality (BSL) effects of the obtained EOs and some major components. The EOs yield revealed a wide range (ca. 1–3%, w/d.w.) and their chemical composition, analysed by GC–MS and GC–FID, showed the presence of seventy-one components. Monoterpene hydrocarbons (38–71%) dominated in all the studied EOs, mainly α-pinene (17–45% of total EOs), decreasing as follows: cone EOs > leaf EOs > foliage EOs. Oxygen-containing monoterpenes (mainly terpinen-4-ol) also dominated in cone EOs. Contrariwise, oxygen-containing sesquiterpenes (mainly elemol) and diterpene hydrocarbons (mainly phyllocladene) dominated in foliage/leaf EOs. The studied EOs exhibited activity against Gram-positive bacteria but no activity against Gram-negative bacteria. A similar trend was displayed by α-pinene. Only the cone EOs showed antifungal activity against Penicillium chrysogenum, but this was significantly lower than those of α-pinene and terpinen-4-ol. Moreover, FC EO should also be considered for further investigation due to its high toxicity on BSL bioassay. In conclusion, this study demonstrated the variability of yield, chemical profile, and bioactivities in the EOs from different parts of the Azorean C. japonica, expanding the knowledge of the potentialities of C. japonica aerial-part EOs, particularly the ones from the cone samples.

The reproductive cycle of an Alvania species is studied for first time. Alvania mediolittoralis Gofas, 1989 is an endemic Azorean rissoid very common in sheltered places and particularly abundant among the algal turf covering the lower half of the intertidal and upper subtidal rocky shores. This species reproduces throughout the year, with two spawning peaks, one during early spring and the other in late autumn. In an attempt to relate to current paleobiogeographical studies, inferences are made regarding the ecological advantages of species with a continuous type of reproduction, on Azorean shores, during glacial episodes.