caryophyllene and bisabolol

Topics: Anti-Bacterial Agents; Antineoplastic Agents, Phytogenic; Antiprotozoal Agents; Brazil; Gas Chromatography-Mass Spectrometry; Humans; Lauraceae; Leishmania; Monocyclic Sesquiterpenes; Oils, Volatile; Plant Leaves; Polycyclic Sesquiterpenes; Sesquiterpenes

Plants store volatile compounds in specialized organs. The properties of these storage organs prevent precarious evaporation and protect neighbouring tissues from cytotoxicity. Metabolic engineering of plants is often carried out in tissues such as leaf mesophyll cells, which are abundant and easily accessible by engineering tools. However, these tissues are not suitable for the storage of volatile and hydrophobic compound such as sesquiterpenes and engineered volatiles are often lost into the headspace. In this study, we show that the seeds of Arabidopsis thaliana, which naturally contain lipid bodies, accumulate sesquiterpenes upon engineered expression. Subsequently, storage of volatile sesquiterpenes was achieved in Nicotiana benthamiana leaf tissue, by introducing oleosin-coated lipid bodies through metabolic engineering. Hereto, different combinations of genes encoding diacylglycerol acyltransferases (DGATs), transcription factors (WRINKL1) and oleosins (OLE1), from the oil seed-producing species castor bean (Ricinus communis) and Arabidopsis, were assessed for their suitability to promote lipid body formation. Co-expression of α-bisabolol synthase with Arabidopsis DGAT1 and WRINKL1 and OLE1 from castor bean promoted storage of α-bisabolol in N. benthamiana mesophyll tissue more than 17-fold. A clear correlation was found between neutral lipids and storage of sesquiterpenes, using synthases for α-bisabolol, (E)-β-caryophyllene and α-barbatene. The co-localization of neutral lipids and α-bisabolol was shown using microscopy. This work demonstrates that lipid bodies can be used as intracellular storage compartment for hydrophobic sesquiterpenes, also in the vegetative parts of plants, creating the possibility to improve yields of metabolic engineering strategies in plants.

Topics: Alkyl and Aryl Transferases; Arabidopsis; Arabidopsis Proteins; Diacylglycerol O-Acyltransferase; Lipid Droplets; Lipid Metabolism; Lipids; Metabolic Engineering; Monocyclic Sesquiterpenes; Nicotiana; Plant Leaves; Plants, Genetically Modified; Polycyclic Sesquiterpenes; Seeds; Sesquiterpenes

The chemical composition of the essential oil obtained from aerial parts of Nepeta graciliflora was analysed, for the first time, by GC-FID and GC-MS. A total of 27 compounds were identified, constituting over 91.44% of oil composition. The oil was strongly characterised by sesquiterpenes (86.72%), with β-sesquiphellandrene (28.75%), caryophyllene oxide (12.15%), α-bisabolol (8.97%), α-bergamotene (8.51%), β-bisabolene (6.33%) and β-Caryophyllene (5.34%) as the main constituents. The in vitro activity of the essential oil was determined against four micro-organisms in comparison with chloramphenicol by the agar well diffusion and broth dilution method. The oil exhibited good activity against all tested organisms.

Topics: Anti-Bacterial Agents; Bridged Bicyclo Compounds; Gas Chromatography-Mass Spectrometry; Microbial Sensitivity Tests; Monocyclic Sesquiterpenes; Nepeta; Oils, Volatile; Polycyclic Sesquiterpenes; Sesquiterpenes

The chemical composition of the essential oils obtained by hydrodistillation of different parts of Eremanthus erythropappus, including leaves, branches and inflorescences, was investigated by Gas Chromatography and Gas Chromatography/Mass Spectrometry. The antimicrobial activity of the oils was assessed by the disc diffusion and microdilution methods, while the antioxidant activity was evaluated by DPPH and reducing power tests. The main compounds found in the essential oils derived from the inflorescences and leaves were β-caryophyllene, germacrene-D, α-copaene and β-pinene. α-Bisabolol was the major component in the branches. The oils were active against Staphylococcus aureus, Streptococcus pyogenes and fungi, but not Escherichia coli and Pseudomonas aeruginosa. The MIC values ranged from 0.01 to 0.50 mg/mL. Using the DPPH test, the IC50 values ranged from 38.77 ± 0.76 to 102.24 ± 1.96 μg/mL, while the reducing power test produced IC50 values between 109.85 ± 1.68 and 169.53 ± 0.64 μg/mL. The results revealed that the E. erythropappus oils are new promising potential sources of antimicrobial and antioxidant compounds with good future practical applications for human health.

Topics: Anti-Infective Agents; Antioxidants; Asteraceae; Escherichia coli; Microbial Sensitivity Tests; Monocyclic Sesquiterpenes; Oils, Volatile; Polycyclic Sesquiterpenes; Pseudomonas aeruginosa; Sesquiterpenes; Sesquiterpenes, Germacrane; Staphylococcus aureus; Streptococcus pyogenes

The chemical composition of the essential oil obtained from the aerial parts of Betonica grandiflora Willd., growing wild in Iran, was analysed by gas chromatography-mass spectrometry for the first time. Overall, 40 volatile components were identified on the basis of their mass spectra characteristics and retention indices in which ledol (21.8%), myrtenyl acetate (21.7%), eudesm-7(11)-en-4-ol (6.5%), trans-caryophyllene (5.5%), α-bisabolol (4.9%) and isolongifolol (4.5%) were the major constituents. Oxygenated sesquiterpenes, monoterpene hydrocarbons and sesquiterpene hydrocarbons were the main groups of compounds with 45.6%, 23.1% and 18.4%, respectively. The oil was moderately active against Bacillus subtilis and Staphylococcus aureus and inactive against Enterococcus faecalis and Klebsiella pneumoniae.

Topics: Anti-Bacterial Agents; Bacillus subtilis; Enterococcus faecalis; Gas Chromatography-Mass Spectrometry; Iran; Klebsiella pneumoniae; Microbial Sensitivity Tests; Monocyclic Sesquiterpenes; Monoterpenes; Oils, Volatile; Plant Components, Aerial; Polycyclic Sesquiterpenes; Sesquiterpenes; Stachys; Staphylococcus aureus