A diterpene quinone from the bark of Cryptomeria japonica

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.

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

Forest operations and wood industry generate large amounts of residues that are discarded in the field and cause environmental pollution. However, these biomass residues are still raw materials to obtain value-added products, such as essential oils, organic/aqueous extracts and resins that are among the great natural sources of bioactive metabolites. Thus, in recent years, the scientific community is giving special attention to their valorization. To date, different uses of biomass residues have been proposed, such as a source of renewable energy, fertilizers, animal feed and bioactive molecules. In this context, Cryptomeria japonica biomass residues (e.g., bark and its exudate, heartwood, sapwood, leaves, cones and roots) represent a source of diverse specialized metabolites (e.g., sesqui-, di-, tri- and sesquarterpenes, flavonoids, lignans and norlignans) with potential application in different fields, particularly in the agrochemical, food, cosmeceutical, pharmaceutical, phytomedicine and esthetic, due to their valuable multi-bioactivities determined over the last decades. Thus, this review provides an overview of the reported biological activities of organic extracts/fractions and their specialized metabolites obtained from different parts of C. japonica, in order to encourage the alternative uses of C. japonica wastes/byproducts, and implement a sustainable and circular bioeconomy.

Antioxidant Activity of Natural Hydroquinones

Secondary metabolites derived from hydroquinone are quite rare in nature despite the original simplicity of its structure, especially when compared to other derivatives with which it shares biosynthetic pathways. However, its presence in a prenylated form is somewhat relevant, especially in the marine environment, where it is found in different algae and invertebrates. Sometimes, more complex molecules have also been identified, as in the case of polycyclic diterpenes, such as those possessing an abietane skeleton. In every case, the presence of the dihydroxy group in the para position gives them antioxidant capacity, through its transformation into para-quinones.This review focuses on natural hydroquinones with antioxidant properties referenced in the last fifteen years. This activity, which has been generally demonstrated in vitro, should lead to relevant pharmacological properties, through its interaction with enzymes, transcription factors and other proteins, which may be particularly relevant for the prevention of degenerative diseases of the central nervous system, or also in cancer and metabolic or immune diseases. As a conclusion, this review has updated the pharmacological potential of hydroquinone derivatives, despite the fact that only a small number of molecules are known as active principles in established medicinal plants. The highlights of the present review are as follows: (a) sesquiterpenoid zonarol and analogs, whose activity is based on the stimulation of the Nrf2/ARE pathway, have a neuroprotective effect; (b) the research on pestalotioquinol and analogs (aromatic ene-ynes) in the pharmacology of atherosclerosis is of great value, due to their agonistic interaction with LXRα; and (c) prenylhydroquinones with a selective effect on tyrosine nitration or protein carbonylation may be of interest in the control of post-translational protein modifications, which usually appear in chronic inflammatory diseases.

Bioactive Dimeric Abietanoid Peroxides from the Bark of Cryptomeria japonica

Three new dimeric abietane-type diterpenoids, abieta-6,8,11,13-tetraen-12-yl 12-hydroxyabieta-8,11,13-trien-7α-yl peroxide (1), abieta-6,8,11,13-tetraen-12-yl 12-hydroxyabieta-8,11,13-trien-7β-yl peroxide (2), and 12-hydroxyabieta-8,11,13-trien-7β-yl 7-oxoabieta-5,8,11,13-tetraen-12-yl peroxide (3), together with four known abietane-type diterpenoids (4–7) were isolated from the methanol extract of the bark of Cryptomeria japonica. Their structures were elucidated on the basis of spectroscopic analysis and comparison of NMR data with those of known analogues. At a concentration of 50 μM, compounds 1, 2, and 3 showed 26.2%, 23.6%, and 35.7% inhibition towards xanthine oxidase enzyme, respectively. In addition, compound 3 also showed 24.9% inhibition toward angiotensin-converting enzyme (ACE).

New Abietane-type Diterpenoids from the Bark of Cryptomeria japonica

Two new abietane-type diterpenoids, 15-hydroxy-12- O-methylsugiol (1) and 2a-hydroxy-12- O-methylsugiol (2) were isolated from the methanol extract of the bark of Cryptomeria japonica. Their structures were elucidated on the basis of spectroscopic analysis and comparison of NMR data with those of known analogues. Compounds 2 showed 13.5% inhibition towards xanthine oxidase enzyme at the concentration of 75 μM

A Pair of Enantiomeric Bis- seco-abietane Diterpenoids from Cryptomeria fortunei

(±)-Cryptomeriolide, a pair of racemic bis- seco-abietane diterpenoids, were isolated from the bark of Cryptomeria fortunei. The separation of enantiomers was achieved by using chiral stationary phase HPLC. Their structures including the absolute configuration and conformations in solution and solid state were determined by extensive analysis of spectroscopic data, single-crystal X-ray diffraction, and comparison of calculated and experimental electronic circular dichroism data. A bioinspired one-pot enantiomeric synthesis of 1a and 1b was accomplished via a readily made intermediate orthoquinone from sugiol. All compounds including the synthetic intermediates were assayed for their cytotoxic activities on human cancer cell lines HL-60, A549, and SGC7901.

Two New Abietane-type Diterpenes from the Bark of Cryptomeria japonica

Phytochemical investigation of the methanol extract of the bark of Cryptomeria japonica has led to the isolation of two new abietane-type diterpenoids, 7a-(2’-butoxyethoxy)deoxocryptojaponol (1) and 7p-(2’-butoxyethoxy)deoxocryptojaponol (2). Their structures were established by means of 1D and 2D NMR spectra and HR-EI-MS, as well as on comparison with the reported data.

Whitening and antioxidant activities of bornyl acetate and nezukol fractionated from Cryptomeria japonica essential oil

OBJECTIVES

The aim of this study was to investigate the whitening and antioxidant activities of essential oils from Cryptomeria japonica by determining their tyrosinase inhibition, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and superoxide dismutase (SOD)-like activities.

METHODS

Essential oils of C. japonica leaves were extracted with distilled water, and after condensation of volatile constituents, the condensates were extracted with ethyl acetate. Crude essential oils of C. japonica were divided into six fractions by thin layer chromatography and open column chromatography, and their chemical analysis was performed by GC/MS. Major compounds of fractions were composed of kaurene, bornyl acetate, nezukol, (-)-4-terpineol, δ-cadinene, α-terpineol, γ-eudesmol, α-eudesmol and elemol.

RESULTS

For tyrosinase inhibitory activity using two substrates, l-tyrosine and 3,4-dihydroxyphenylalanine (l-DOPA), kaurene, bornyl acetate and nezukol were highly effective. In antioxidant activity, (-)-4-terpinenol and δ-cadinene showed high DPPH radical scavenging activity, and bornyl acetate and nezukol indicated extremely high SOD-like activity.

CONCLUSION

Therefore, bornyl acetate and nezukol fractionated from C. japonica essential oil, which showed highly active whitening and antioxidant activities, have potential applications in cosmeceutical materials.

New sesquiterpene and triterpene from the fruits of Cryptomeria fortunei

A new sesquiterpene (1) and a new triterpene (2) along with 25 known compounds were isolated from the fruits of Cryptomeria fortunei (Taxodiaceae). Their structures were elucidated on the basis of spectroscopic analysis.

[Synthesis of dihydroquinopymaric acid conjugates with amino acids]

Synthesis of dihydroquinopymaric acid amides and their 2beta-succinyl and 2beta-phthalyl derivatives containing residues of amino acids was carried out for the first time. Antiviral properties of the compounds synthesized were investigated.

Bioactivity of latifolin and its derivatives against termites and fungi

Latifolin (1) and its derivatives were investigated with the aim of confirming the correlation between bioactivity (antitermite and antifungal activity) and chemical structure. Termite mortality in response to the derivatives 2'-O-methyllatifolin (2), latifolin dimethyl ether (4), and latifolin diacetate (5) increased 2-fold compared to compound 1. The mortality rate from 5-O-methyllatifolin (3) was not different from 1. The mass loss (feed consumption by termite) in response to compounds 3-5 was 3 times greater than compound 1, and the mass loss from compound 2 was twice as great as compound 1. The mortality rate from compounds 4 and 5 increased sharply 7 days after initial exposure. In assessing the antifungal activity of these compounds, it was found that the inhibition rates of white- and brown-rot fungi in response to all derivatives were less than that for compound 1. Our findings indicate that the phenolic hydroxyl group at C-5 of the A ring provides antitermite activities (mortality and mass loss). In addition, both C-5 and C-2' phenolic hydroxyl groups in the A and B rings have antifungal activity against white- and brown-rot fungi. In conclusion, the bioactivity of compound 1 depends upon the position of phenolic hydroxyl groups.

Antitermitic activities of abietane-type diterpenes from Taxodium distichum cones

Eight known abietane-type diterpenes were isolated from the weak acidic fraction of the n-hexane extract from cones of Taxodium distichum, one of the extant, living fossil conifers. They were identified as 6,7-dehydroroyleanone (1), taxodal (2), taxodione (3), salvinolone (4), 14-deoxycoleon U (5), 5,6-dehydrosugiol (6), sandaracopimaric acid (7), and xanthoperol (8). The structures of these compounds were determined by comparison of NMR spectral data with published data. The antitermitic (termicidal and antifeedant) activities of the compounds 1-8 against the subterranean termite, Reticulitermes speratus Kolbe, were evaluated. Compounds 1 and 3 showed potent termicidal activity, and 5 and 8 showed potent antifeedant activity. Compound 1 was found to be one of the representative bioactive compounds in the n-hexane extract of T. distichum cones. Compounds 1-8, with the exception of 7, were oxides of ferruginol (9). Therefore, the presence of various oxidation forms of the abietane-type structure reflects their various bioactivities.

Isolation and structure elucidation of three neo-clerodane diterpenes from Teucrium fruticans L. (LABIATAE)

Recently, the isolation from Teucrium fruticans of neo-clerodanes, namely 7beta-hydroxyfruticolone, 11-hydroxyfruticolone, deacetylfruticolone and 6-acetyl-10-hydroxyteucjaponin B, in addition to fruticolone, isofruticolone and 8beta-hydroxyfruticolone (three out of the four previously reported ones), and 6-acetylteucjaponin B (isolated from T. scordium and T. grisebachii) was reported. Minor compounds presumably of neo-clerodane nature were shown by HPLC analysis on a new extract. Three new compounds, difuranofruticol, deoxyfruticolone and 10-hydroxyteucjaponin B, and the known 7,8-didehydrofruticolone were unambiguously elucidated based on extensive NMR spectral studies (one- and two-dimensional experiments). The compounds were assayed for their antifeedant activity against Spodoptera littoralis and for their antifungal activity against Rhizoctonia solani. Compounds 9-11 showed low antifeedant activity and the feeding ratio of 12 was moderate-low. None of the tested compounds displayed significant activity against R. solani.