Biological activities of organic extracts and specialized metabolites from different parts of Cryptomeria japonica (Cupressaceae) - A critical review

Essential Oil Composition and Anti-Cholinesterase Properties of Cryptomeria japonica Foliage Harvested in São Miguel Island (Azores) in Two Different Seasons

The Azorean Cryptomeria japonica forest operations and wood industry generate considerable foliage biomass residues that are used for local essential oil (EO) production. However, research on seasonal variation of C. japonica EO remains scarce. In this study, the EOs from fresh Azorean C. japonica foliage (Az-CJF) collected in autumn (Aut) and spring (Spr) were obtained via hydrodistillation and investigated for their physical properties, yield, chemical composition, and bioactivities. Both EOs presented a strong odor, a yellowish color, a density around 0.9 g·mL-1, and similar yields (approximately 1% v/w, dry matter). Nevertheless, the GC-MS analyses showed a decrease in monoterpene hydrocarbons (MH) and an increase in oxygenated sesquiterpenes (OS) contents in Spr-EO compared with Aut-EO (16% vs. 35% for MH and 45% vs. 31% for OS, respectively). In addition, the predominant components were kaur-16-ene (23%) for Spr-EO and phyllocladene (19%) for Aut-EO, revealing that both EOs were rich in diterpene hydrocarbons (29% vs. 26%). Concerning its toxicity against brine shrimp, a low mortality (0-38%) was observed at a concentration range of 100-180 μg·mL-1. Regarding the anti-cholinesterase properties, both EOs were inactive against acetylcholinesterase but showed anti-butyrylcholinesterase activity superior to (-)-α-pinene, a major compound of Az-CJF EO (IC50 values: 84, 148, and 648 μg·mL-1 for Spr-EO, Aut-EO, and α-pinene, respectively). Overall, the results indicate the potential benefit of both seasonal EOs in Alzheimer's disease treatment. In conclusion, this study demonstrated that season strongly influences the Az-CJF EO quantitative composition and thus its bioactivity, aiding in the selection of the most high-quality raw materials for use in Azorean C. japonica EO aromatherapy industry.

Sequential Separation of Essential Oil Components during Hydrodistillation of Fresh Foliage from Azorean Cryptomeria japonica (Cupressaceae): Effects on Antibacterial, Antifungal, and Free Radical Scavenging Activities

Cryptomeria japonica wood industry generates large amounts of foliage biomass residues. Due to the increasing applications and markets for essential oils (EOs), fresh Azorean C. japonica foliage (Az-CJF) residues are used for local EO production. Hydrodistillation (HD), a common process for obtaining EOs, also provides the possibility to fractionate them. Thus, this study evaluated the in vitro antimicrobial and antioxidant activities of six Az-CJF EO fractions (Frs. 1-6), collected at sequential HD timeframes (HDTs: 0-2, 2-10, 10-30, 30-60, 60-120, and 120-240 min), in comparison to the crude EO, obtained from a non-fractionated HD (0-240 min HDT). Antimicrobial activities were assessed via disc diffusion method against seven bacteria (foodborne and/or human pathogens) and two Penicillium spp. (phytopathogenic fungi), and antioxidant activity was estimated using DPPH and ABTS assays. Concerning the antibacterial activity, all the EO samples were effective only toward Gram-positive bacteria. Fractions 1-3 (<30 min HDT) were the most active, with growth inhibition zones (GIZ) of 7.0-23.3 mm (1.4-2.2 times higher than those of the crude EO), being Bacillus spp. (B. licheniformis and B. subtilis) the most sensitive, followed by Staphylococcus aureus and Micrococcus luteus. Regarding the antifungal activity, Frs. 1-3 also displayed the best activities, but only against P. italicum (GIZ around 9.0 mm), while the crude EO showed no antifungal activity. Overall, the best antimicrobial properties of Frs. 1-3 could be attributed, at least in part, to their highest content in α-pinene and bornyl acetate. On the other hand, Frs. 4-6 (>30 min HDT) exhibited the strongest antioxidant activities (EC50 values: 1.5-2.3 and 1.0-1.7 mg mL-1 for DPPH and ABTS, respectively), being at least 1.3-fold higher than those of the crude EO. The presence of nezukol, elemol, and eudesmol isomers could strongly contribute to the best free radical scavenging properties of Frs. 4-6. In conclusion, HD was found to be an efficient process for obtaining new Az-CJF EO fractions with variable and enhanced bioactivities due to their differential composition, as assessed using GC-MS. Hence, these findings could contribute to increasing the commercial potential of the C. japonica EO industry, namely, the Fr2 and Fr6, which presented the most significant activities and can have potential applications in the food, medical, and agriculture sectors.

Abietane Diterpenoids from the Bark of Cryptomeria japonica and Their Antifungal Activities against Wood Decay Fungi

Phytochemical investigation of the bark of Cryptomeria japonica led to the isolation of five new abietane diterpenoids, 5-epi-12-hydroxy-6-nor-5,6-secoabieta-8,11,13-trien-7,5-olide (1), 12-hydroxy-6β-methoxy-6,7-secoabieta-8,11,13-trien-7,6-olide (2), 6β,12-dihydroxy-7,8-secoabieta-8,11,13-trien-7,8-olide (4), 5,12-dihydroxy-7,8-secoabieta-8,11,13-trien-7,8-olide (5), and 5α,8-epoxy-12-hydroxy-7,8-secoabieta-8,11,13-trien-7-al (6), together with one known abietane diterpenoid, obtuanhydride (3). Their structures were elucidated by analysis of spectroscopic data and comparison with the spectral data of known analogs. At the concentration of 100 μg/mL, compounds 4, 5, and 6 inhibited antifungal activities against wood decay fungi activity by 18.7, 37.2, and 46.7%, respectively.

Essential Oil Variability of Azorean Cryptomeria japonica Leaves under Different Distillation Methods, Part 2: Molluscicidal Activity and Brine Shrimp Lethality

This study reports on the in vivo molluscicidal activity and Artemia salina lethality of Azorean Cryptomeria japonica leaf (CJL) essential oils (EOs) obtained by hydrodistillation (HD) and water-steam distillation (WSD) techniques, especially in light of the recent focus on the use of forestry and wood industry residues in a sustainable world economy. Molluscicidal activity was performed during several life stages of Radix peregra by the immersion method, under laboratory conditions. A first screening through a single-dose bioassay revealed that both EOs were highly active towards eggs, juveniles and adult snails (ca. 100% mortality). Concentration- and time-toxicity assays were carried out only on adult snails to determine the lethal parameters (LC50;90 and LT50;90). The LC50 values were 33 and 62 µg/mL for EO–WSD and EO–HD, respectively, after 48 h. The LT50 of EO–WSD required only 21 h for both 16 h and continous exposure periods, while that of EO–HD was slighty superior (21.8–25.6 h). Although not significant, EO–WSD was also slightly more toxic against A. salina than EO–HD (LC50 = 98 and 115 µg/mL after 24 h, respectively). In conclusion, Azorean CJL EOs, which are rich in α-pinene (mostly EO–WSD), have huge potential to be used as safe raw materials for the development of natural molluscicide products to control snails responsible for transmitting fascioliasis.

Neofusicoccum cryptomeriae sp. nov. and N. parvum Cause Stem Basal Canker of Cryptomeria japonica in China

Cryptomeria japonica D. Don is a coniferous tree species widely grown in southern China for its high ornamental value. Recently, during disease surveys in China, a symptom of dieback occurred on C. japonica in Nanjing, Jiangsu Province, China. A total of 130 trees were surveyed and more than 90% showed the same symptom. The crowns of affected trees were brown when viewing from a distance, and the bark showed no difference from the healthy ones. In this study, 157 isolates were isolated from the 3 affected plants of C. japonica, and based on the living culture on PDA, the fungal isolates were preliminarily divided into 6 groups. Thirteen representative isolates were selected for the pathogenicity test, and seven of them showed obvious pathogenicity on C. japonica, causing stem basal canker. These isolates were identified based on comparisons of the DNA sequences of the internal transcribed spacer regions (ITS), partial translation elongation factor 1-alpha (tef1), β-tubulin (tub2), and DNA-directed RNA polymerase II subunit (rpb2) and combined with their morphological characteristics. Results showed that these seven isolates belong to two taxa in Neofusicoccum, including a species new to science. The new species, Neofusicoccum cryptomeriae, was hereby described and illustrated. The other species was N. parvum. Both species were pathogens of stem basal canker of Cryptomeria japonica.