Efficient phototrophic production of a high-value sesquiterpenoid from the eukaryotic microalga Chlamydomonas reinhardtii

The heterologous expression of terpene synthases in microbial hosts has opened numerous possibilities for bioproduction of desirable metabolites. Photosynthetic microbial hosts present a sustainable alternative to traditional fermentative systems, using freely available (sun)light and carbon dioxide as inputs for bio-production. Here, we report the expression of a patchoulol synthase from Pogostemon cablin Benth in the model green microalga Chlamydomonas reinhardtii. The sesquiterpenoid patchoulol was produced from the alga and was used as a marker of sesquiterpenoid production capacity. A novel strategy for gene loading was employed and patchoulol was produced up to 922±242 µg g⁻¹ CDW in six days. We additionally investigated the effect of carbon source on sesquiterpenoid productivity from C. reinhardtii in scale-up batch cultivations. It was determined that up to 1.03 mg L⁻¹ sesquiterpenoid products could be produced in completely photoautotrophic conditions and that the alga exhibited altered sesquiterpenoid production metabolism related to carbon source.     

Sesqui- and diterpenoids from two Japanese and three European liverworts

A new peroxy muurolane-type sesquiterpenoid was isolated from the ether extract of the Belgium liverwort Scapania undulata, together with three known ent-muurolanes. A new lepidozane-type sesquiterpenoid was isolated from the Japanese Porella subobtusa together with a known santalane- and two africane-type sesquiterpenoids. All structures were determined by means of NMR spectroscopic techniques. The chemosystematics of each species are discussed.     

Anti-inflammatory spiroaxane and drimane sesquiterpenoids from Talaromyces minioluteus (Penicillium minioluteum)

A new spiroaxane sesquiterpenoid talaminoid A (1) and two drimane sesquiterpenoid talaminoids B and C (2 and 3), together with four known compounds (4–7), were isolated from the solid culture broth of fungus Talaromyces minioluteum. The structures were determined by extensive 1D and 2D NMR and HRESIMS spectroscopic data analyses, and the absolute configuration of these new compounds were undoubtedly confirmed by X-ray crystal diffrations. Compound 1 is a rare spiroaxane sesquiterpenoid and the absolute configuration of spiroaxane sesquiterpenoid was determined for the first time. Compound 2 is the first drimane-type sesquiterpenoid containing both amino acid residue and butanediol group. Compounds 1, 4, and 5 showed significant suppressive effect on the production of NO on LPS induced BV-2 cells, with IC₅₀ values ranging from 4.97 to 7.81 μM. In addition, 1, 4, and 5 exhibited significant anti-inflammatory activities against the production of TNF-α and IL-6. Further immunofluorescence experiments revealed the mechanism of action to be inhibitory the NF- κB-activated pathway.     

Endophytic Bacterium-Triggered Reactive Oxygen Species Directly Increase Oxygenous Sesquiterpenoid Content and Diversity in Atractylodes lancea

Oxygenous terpenoids are active components of many medicinal plants. However, current studies that have focused on enzymatic oxidation reactions cannot comprehensively clarify the mechanisms of oxygenous terpenoid synthesis and diversity. This study shows that an endophytic bacterium can trigger the generation of reactive oxygen species (ROS) that directly increase oxygenous sesquiterpenoid content and diversity in Atractylodes lancea. A. lancea is a famous but endangered Chinese medicinal plant that contains abundant oxygenous sesquiterpenoids. Geo-authentic A. lancea produces a wider range and a greater abundance of oxygenous sesquiterpenoids than the cultivated herb. Our previous studies have shown the mechanisms behind endophytic promotion of the production of sesquiterpenoid hydrocarbon scaffolds; however, how endophytes promote the formation of oxygenous sesquiterpenoids and their diversity is unclear. After colonization by Pseudomonas fluorescens ALEB7B, oxidative burst and oxygenous sesquiterpenoid accumulation in A. lancea occur synchronously. Treatment with exogenous hydrogen peroxide (H₂O₂) or singlet oxygen induces oxidative burst and promotes oxygenous sesquiterpenoid accumulation in planta. Conversely, pretreatment of plantlets with the ROS scavenger ascorbic acid significantly inhibits the oxidative burst and oxygenous sesquiterpenoid accumulation induced by P. fluorescens ALEB7B. Further in vitro oxidation experiments show that several oxygenous sesquiterpenoids can be obtained from direct oxidation caused by H₂O₂ or singlet oxygen. In summary, this study demonstrates that endophytic bacterium-triggered ROS can directly oxidize oxygen-free sesquiterpenoids and increase the oxygenous sesquiterpenoid content and diversity in A. lancea, providing a novel explanation of the mechanisms of oxygenous terpenoid synthesis in planta and an essential complementarity to enzymatic oxidation reactions.     

Cis-9,10-dihydrocapsenone: A possible catabolite of capsidiol from cell suspension cultures of capsicum annuum

A new eudesmane sesquiterpenoid, cis-9,10-dihydrocapsenone, has been isolated in small amounts from unelicited cell suspension cultures of Capsicum annuum during the stationary phase of the growth cycle. It is proposed that the new sesquiterpenoid is an intermediate on the initial part of the route by which endogenous capsidiol is catabolized in pepper cultures.     

Genetic transfer of a twospotted spider mite (Acari: Tetranychidae) repellent in tomato hybrids

Lycopersicon hirsutum Dunal is very resistant to arthropod herbivory, and research on causes of resistance has often implicated trichomes and their secretions. To better understand relationships among resistance, repellency, and 2,3-dihydrofarnesoic acid, a trichome-borne sesquiterpenoid spider mite repellent, two tomato, Lycopersicon esculentum Miller, varieties were interbred with a highly resistant, spider mite repellent accession (LA1363) of L. hirsutum. Backcross and F2 generations were produced with each tomato variety. Whole leaves of 99 hybrids were bioassayed with twospotted spider mites, Tetranychus urticae Koch, allowing selection of six hybrids (two susceptible and four resistant) for each generation of each family. When these 24 hybrids were characterized for spider mite repellency with thumbtack bioassays, two hybrids had repellent leaflets, demonstrating that repellency was genetically transferred to interspecific tomato hybrids. Leaflet washes containing trichome secretions from each of three hybrids, including the two having repellent leaflets, were repellent in bridge bioassays. For the two hybrids having repellent leaflets and leaflet washes, removal of trichome secretions by dipping leaflets in methanol eliminated leaflet repellency. 2,3-Dihydrofarnesoic acid was present in trichome secretions of the hybrids having leaflet repellency, and it also was present in secretions of other hybrids, indicating that its presence is essential, but not sufficient for leaflet repellency. With regard to resistance, 16 of the hybrids tested had been identified as resistant in a whole leaf bioassay, but only two had repellent leaflets, indicating that other mechanisms of resistance are present in the resistant L. hirsutum parent.     

Charminarone,a seco-pseudoguaianolide from Parthenium hysterophorus

A novel sesquiterpenoid, charminarone, the first seco-pseudoguaianolide, has been isolated along with several known compounds from the whole plant of Parthenium hysterophorus. The structure of the new compound has been settled as 1,10-seco-dihydroisoparthenin 1,10-dione from its spectral data as well as from its conversion by reductive coupling reaction with Zn/TiCl(4) reagent to the known compound, anhydrodihydroisoparthenin. The reagent Zn/TiCl(4) has been used here for the first time to construct the seven membered ring of a pseudoguaianolide sesquiterpenoid.     

Involvement of 3-hydroxy-3-methylglutaryl coenzyme a reductase in the regulation of sesquiterpenoid phytoalexin synthesis in potato

The importance of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG-CoA reductase) in the regulation of sesquiterpenoid phytoalexin accumulation in potato (Solanum tuberosum L. cv Kennebec) was examined. Wounding of potato tubers produced a large temporary increase in HMG-CoA reductase activity of the microsomal and organelle fractions. Treatment of wounded tuber tissue with the sesquiterpenoid phytoalexin elicitor arachidonic acid further increased and prolonged the HMG-CoA reductase activity in the microsomal but not the organelle fraction. Incubation of elicitor-treated tuber tissue in white light reduced organelle and microsomal HMG-CoA reductase activity to 50% and 10%, respectively, of the activity of tissues held in darkness. Constant light also reduced overall phytoalexin accumulation 58% by greatly reducing levels of lubimin. Rishitin accumulation was not significantly altered by light. Application of nanomolar amounts of mevinolin, a highly specific inhibitor of HMG-CoA reductase, to elicitor-treated tuber tissue produced a large decline in lubimin accumulation and did not markedly alter rishitin accumulation. These results indicate that HMG-CoA reductase has a role in the complex regulation of sesquiterpenoid phytoalexin accumulation in potato.     

Nakijiquinones E and F,new dimeric sesquiterpenoid quinones from marine sponge

Two new dimeric sesquiterpenoid quinones, nakijiquinones E (1) and F (2), have been isolated from an Okinawan marine sponge, and the structures and relative stereochemistry of 1 and 2 were elucidated on the basis of the spectral data. Nakijiquinones E (1) and F (2) were the first dimeric sesquiterpenoid quinones possessing a 3-aminobenzoate moiety.     

4α-hydroxydihydroilludin M—A new sesquiterpenoid metabolite of Clitocybe illudens

The structure of the new sesquiterpenoid 4α-hydroxydihydroilludin M has been established by a combination of spectral and X-ray studies.     

Foetidin,a sesquiterpenoid coumarin from Ferula assa-foetida

A new sesquiterpenoid coumarin, foetidin, has been isolated from the roots of Ferula assa-foetida.     

The volatile phyllode oil of Acacia spirorbis

The steam volatile phyllode oil of Acacia spirorbis was found to be predominantly sesquiterpenoid in character. The most abundant sesquiterpenoids     

Isolation,Characterization, and Possible Anti‐Alzheimer's Disease Activities of Bisabolane‐Type Sesquiterpenoid Derivatives and Phenolics from the Rhizomes of Curcuma longa

One new bisabolane‐type sesquiterpenoid, together with four known bisabolane‐type sesquiterpenoid derivatives and seven phenolics, was isolated from the rhizomes of Curcuma longa. Their structures were elucidated by extensive spectroscopic (IR, HR‐ESI‐MS, and NMR) data analysis. The possible anti‐Alzheimer's disease (AD) activities of the isolated compounds were also evaluated using Caenorhabditis elegans AD pathological model, and 1β‐hydroxybisabola‐2,10‐dien‐4‐one had the highest possible anti‐AD activity.     

Methyl farnesoate and juvenile hormone production in embryos of Diploptera punctata in relation to innervation of corpora allata and their sensitivity to allatostatin

Corpora allata (CA) of embryos of Diploptera punctata have been previously shown to produce JH III. We have re-examined sesquiterpenoid biosynthesis throughout embryonic development and have found that early embryos produce both methyl farnesoate (MF) and JH III; as development proceeds, less MF and more JH is produced. The cockroach allatostatin peptide Dippu-allatostatin (AST) 7 inhibits sesquiterpenoid production by CA of mid to late embryos whereas it exerts a dose-dependent stimulatory effect in early embryos. This stimulatory effect is particularly apparent on MF biosynthesis. CA become innervated by allatostatin-containing nerves in early embryos (35% development). Shortly thereafter, the allatostatin-containing innervation of the CA appears complete.     

蒿属和千里光属植物中桉烷型倍半萜的光谱特征

本文就菊科中的两个大属蒿属和千里光属植物中一类典型倍半萜成分——桉烷型倍半萜的光谱特征进行综述.     

Natural anti-HIV agents-part I: (+)-demethoxyepiexcelsin and verticillatol from Litsea verticillata

The eudesmane sesquiterpenoid, verticillatol (1), as well as the lignan, (+)-5'-demethoxyepiexcelsin (2), and a known lignan, (+)-epiexcelsin (3), were isolated from Litsea verticillata Hance. Lignan 2 showed moderate anti-HIV activity with an IC(50) value of 16.4 microg/ml (42.7 microM), while the known lignan 3 was inactive up to a concentration of 20 microg/ml (48.3 microM). Compound 1 demonstrated weak activity with an IC(50) value of 34.5 microg/ml (144.7 microM) while being devoid of cytotoxicity at 20 microg/ml. The structures were elucidated by 1D and 2D NMR spectroscopy, and the absolute configuration of the new sesquiterpenoid was determined by the generation of Mosher esters.     

Sesquiterpenoids and iridoid glycosides from Valeriana fauriei.

A new guaiane sesquiterpenoid glycoside together with known sesquiterpenoids and iridoid glycosides have been isolated from the rhizomes and roots of Valeriana fauriei. The 13C NMR assignments of the isolated compounds are presented.     

The sesquiterpenoids and their chemotaxonomic implications in Senecio L. (Asteraceae)

Sesquiterpenoids are important characteristic compounds in Asteraceae plants. These compounds have been proposed to be potential chemotaxonomic markers, but this application has not been comprehensively investigated. In this paper, sesquiterpenoids from 149 species of the genus Senecio were investigated to assess their taxonomic utility. The presence and absence were encoded as binary taxonomic characteristics and subsequently utilised in a clustering analysis. The previously biosynthesis pathway of sesquiterpenoids was taken into account to explore the relationship among these species contained different sesquiterpenoid types. In addition, the DNA phylogeny was also considered to explore the distribution and evolution of sesquiterpenoids in genus Senecio further. As a result, seven chemical major sections within the Senecio were recognised based on the chemical character. Although with several exceptions, the biosynthesis pathway, molecular phylogeny and the geographical origin of these sesquiterpenoid were found to be related to the chemical sections, which largely confirmed the validity of our chemo-classification for genus Senecio. In conclusion, we suggest that the sesquiterpenoid character in Senecio has some value for the genus taxonomy but should be analysed carefully and critically.     

Natural disesquiterpenoids: an overview of their chemical structures,pharmacological activities,and biosynthetic pathways

Phytochemistry Reviews - Disesquiterpenoids are constructed by two sesquiterpenoid molecules, containing at least 30 carbons with various connection patterns, and numerous new skeletons have been...     

Effect of Cytokinin and Auxin Treatments on Morphogenesis,Terpenoid Biosynthesis,Photosystem Structural Organization,and Endogenous Isoprenoid Cytokinin Profile in <Emphasis Type="Italic">Artemisia alba</Emphasis> Turra In Vitro

Developmental pattern modification in essential oil bearing Artemisia alba Turra was obtained by exogenous plant growth regulator (PGRs) treatments in vitro. Enhanced rooting (in PGR-free and auxin-treated plants) led to elevation of the monoterpenoid/sesquiterpenoid ratio in the essential oils of aerials. On the contrary, root inhibition and intensive callusogenesis [combined cytokinin (CK) and auxin treatments] reduced this ratio more than twice, significantly enhancing sesquiterpenoid production. Both morphogenic types displayed sesquiterpenoid domination in the underground tissues, which however differed qualitatively from the sesquiterpenoids of the aerials, excluding the hypothesis of their shoot-to-root translocation and implying the possible role of another signaling factor, affecting terpenoid biosynthesis. Inhibited rooting also resulted in a significant drop of endogenous isoprenoid CK bioactive-free bases and ribosides as well as CK N-glycoconjugates and in decreased trans-zeatin (transZ):cis-zeatin (cisZ) ratio in the aerials. Marked impairment of the structural organization of the photosynthetic apparatus and chloroplast architecture were also observed in samples with suppressed rooting. It is well known that in the plant cell monoterpenoid and transZ-type CKs biogenesis are spatially bound to plastids, while sesquiterpenoid and cisZ production are compartmented in the cytosol. In the present work, interplay between the biosynthesis of terpenoids and CK bioactive free bases and ribosides in A. alba in vitro via possible moderation of chloroplast structure has been hypothesized.