In vivo transformations of dihydroartemisinic acid in Artemisia annua plants

Brown, Geoffrey D.; Sy, Lai‐King

doi:10.1016/j.tet.2003.11.070

Cited by 148 publications

(134 citation statements)

References 45 publications

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“…Although the enzymatic steps involved in production of the nonphytotoxic precursors amorpha-4,11-diene (A-4,11-D) and dihydroartemisinic acid (DHAA) have been elucidated (12)(13)(14)(15) and the associated genes have been shown to be highly expressed in both the apical and subapical cells of the glandular secretory trichomes (3,16), the final steps in the conversion of DHAA to artemisinin are considered to be nonenzymatic and may be extracellular (17,18). Therefore, microbial-based "complete" synthetic biology routes to artemisinin may never be achievable.…”

mentioning

confidence: 99%

Artemisia annua mutant impaired in artemisinin synthesis demonstrates importance of nonenzymatic conversion in terpenoid metabolism

Czechowski

Larson

Catania

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

101

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Artemisinin, a sesquiterpene lactone produced by Artemisia annua glandular secretory trichomes, is the active ingredient in the most effective treatment for malaria currently available. We identified a mutation that disrupts the amorpha-4,11-diene C-12 oxidase (CYP71AV1) enzyme, responsible for a series of oxidation reactions in the artemisinin biosynthetic pathway. Detailed metabolic studies of cyp71av1-1 revealed that the consequence of blocking the artemisinin biosynthetic pathway is the redirection of sesquiterpene metabolism to a sesquiterpene epoxide, which we designate arteannuin X. This sesquiterpene approaches half the concentration observed for artemisinin in wild-type plants, demonstrating high-flux plasticity in A. annua glandular trichomes and their potential as factories for the production of novel alternate sesquiterpenes at commercially viable levels. Detailed metabolite profiling of leaf maturation time-series and precursor-feeding experiments revealed that nonenzymatic conversion steps are central to both artemisinin and arteannuin X biosynthesis. In particular, feeding studies using 13 C-labeled dihydroartemisinic acid (DHAA) provided strong evidence that the final steps in the synthesis of artemisinin are nonenzymatic in vivo. Our findings also suggest that the specialized subapical cavity of glandular secretory trichomes functions as a location for both the chemical conversion and the storage of phytotoxic compounds, including artemisinin. We conclude that metabolic engineering to produce high yields of novel secondary compounds such as sesquiterpenes is feasible in complex glandular trichomes. Such systems offer advantages over single-cell microbial hosts for production of toxic natural products.artemisinin | p450 oxidase | terpenoid | sesquiterpene | Artemisia annua

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mentioning

confidence: 99%

Artemisia annua mutant impaired in artemisinin synthesis demonstrates importance of nonenzymatic conversion in terpenoid metabolism

Czechowski

Larson

Catania

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

101

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“…Also other authors report that dihydroartemisinic acid is the precursor of artemisinin in A. annua (Brown and Sy 2004). These authors also showed that there is no significant desaturation of dihydroartemisinic acid at C11-C13 to yield artemisinic acid, and claim that the reverse reaction, the reduction of artemisinic acid at the C11-C13 position to yield dihydroartemisinic acid, also has never been demonstrated (Brown and Sy 2004). Our biochemical experiments also show that there is no direct enzymatic conversion of artemisinic acid into dihydroartemisinic acid.…”

supporting

confidence: 74%

“…Subsequently, the alcohol could be oxidized two additional times at C12 by either cytochrome P450 enzymes or dehydrogenases, yielding the corresponding acid, artemisinic acid (Funk and Croteau 1994;De Kraker et al 2001;Sangwan et al 1993b;West 1980 Compounds: 1, -copaene;2, -caryophyllene;3, trans--farnesene;5, selina-4,11-diene;6, germacrene D;9, bicyclogermacrene;10, germacrene A;14, amorpha-4,11-diene. From (Bouwmeester et al 1999b) yielding dihydroartemisinic acid, which was shown by others to be converted non-enzymatically to artemisinin (Abdin et al 2003;Brown and Sy 2004;Wallaart et al 1999a;Wallaart et al 1999b). Alternatively, the C11-C13 double-bond reduction may occur in artemisinic alcohol or artemisinic aldehyde, yielding dihydroartemisinic alcohol or dihydroartemisinic aldehyde as intermediates, respectively.…”

Section: Biosynthetic Pathway Beyond Amorpha-411-dienementioning

confidence: 98%

“…Dihydroartemisinic aldehyde is further oxidized to dihydroartemisinic acid in a second dehydrogenase reaction (Figure 1, step 5). Also other authors report that dihydroartemisinic acid is the precursor of artemisinin in A. annua (Brown and Sy 2004). These authors also showed that there is no significant desaturation of dihydroartemisinic acid at C11-C13 to yield artemisinic acid, and claim that the reverse reaction, the reduction of artemisinic acid at the C11-C13 position to yield dihydroartemisinic acid, also has never been demonstrated (Brown and Sy 2004).…”

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confidence: 98%

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Research to Improve Artemisinin Production for use in the Preparation of Anti-Malarial Drugs

Bouwmeester

Bertea²,

Kraker³

et al.

Medicinal and Aromatic Plants

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Abstract. An important group of antimalarial drugs consists of the endoperoxide sesquiterpene lactone artemisinin and its semi-synthetically prepared derivatives. Because of the development of resistance against other malarial drugs, the demand for artemisinin has rapidly increased during the past decade. However, the supply of artemisinin is troublesome as neither total nor semi-synthesis are economically feasible and the only plant species known to produce artemisinin, Artemisia annua L., contains only low amounts of this compound. For a directed strategy to improve artemisinin production, one of the first requirements is to have insight into the regulation of its biosynthesis. Surprisingly, until some years ago hardly anything was known about the biosynthesis of artemisinin, particularly about the early enzymatic steps leading to (dihydro)artemisinic acid. To elucidate this important missing part in the pathway, we have analysed the terpenoids in A. annua leaves and the presence of sesquiterpene synthases, the enzyme class that should theoretically catalyse the first step in the formation of artemisinin. This led to the discovery of amorpha-4,11-diene synthase, which indeed catalyses the first step in artemisinin biosynthesis and for which the corresponding gene was cloned shortly afterwards. A subsequent search for oxidized derivatives of amorpha-4,11-diene -which could be postulated to be intermediates en route to artemisinin -revealed the presence of artemisinic alcohol, dihydroartemisinic alcohol, artemisinic aldehyde, dihydroartemisinic aldehyde and dihydroartemisinic acid. We also demonstrated the presence of the biosynthetic enzymes amorpha-4,11-diene hydroxylase, artemisinic alcohol dehydrogenase, artemisinic aldehyde reductase and dihydroartemisinic aldehyde dehydrogenase in A. annua. From these results, we conclude that the early steps in artemisinin biosynthesis involve: cyclization of farnesyl diphosphate by amorpha-4,11-diene synthase to amorpha-4,11-diene, hydroxylation of amorpha-4,11-diene to artemisinic alcohol, oxidation of artemisinic alcohol to artemisinic aldehyde, reduction of the C11-C13 double bond yielding dihydroartemisinic aldehyde, and oxidation of dihydroartemisinic aldehyde to dihydroartemisinic acid. During this biochemical research we have also managed to develop a trichome isolation protocol which has not only accelerated our biochemical work but also enables us to clone -in a very directed way -the genes that encode the enzymes responsible for artemisinin production. This should in the next few years result in several approaches to boost artemisinin production. 276H. BOUWMEESTER ET AL.

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“…Based on these results, they proposed that dihydroartemisinic acid rather than artemisinic acid is the immediate precursor of artemisinin, and also suggested that conversion from dihydroartemisinic acid to artemisinin may represent one of the rate-limiting steps during artemisinin biosynthesis. Brown and Sy (2004) fed A. annua with the isotope-labeled dihydroartemisinic acid and detected 16 kinds of 12-carboxyamorphane and cadinane sesquiterpenes including a small proportion of labeled artemisinin. Furthermore, they also confirmed that the committed product of dihydroartemisinic acid is an allylic hydroperoxide originated from non-enzymatic catalysis.…”

Section: Glandular Trichomes Are Dominant Sites Storing Artemisininmentioning

confidence: 99%

An ecological implication of glandular trichome-sequestered artemisinin: as a sink of biotic/abiotic stress-triggered singlet oxygen

Jiang

Gao

Liao

et al. 2015

Preprint

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Artemisinin is accumulated in wormwood (Artemisia annua) with uncertain ecological implications. Here, we suggest that artemisinin is generated in response to biotic/abiotic stress, during which dihydroartemisinic acid, a direct artemisinin precursor, quenches singlet oxygen ( 1 O2), one kind of reactive oxygen species. Evidence supporting artemisinin as a sink of 1 O2 emerges from that volatile isoprenoids protect plants from biotic/abiotic stress; biotic/abiotic stress induces artemisinin biosynthesis; and stress signaling pathways are involved in the biosynthesis of volatile isoprenoids among plants as well as the biosynthesis of artemisinin in A. annua. In this review, we address the ecological implication of glandular trichome-sequestered artemisinin as a sink sink of biotic/abiotic stress-triggered 1 O2, and also summarize the cumulating data on the transcriptomic and metabolic profiling of stress-enhanced artemisinin production upon eliciting 1 O2 omission from chloroplasts and initiating retrograde 1 O2 signaling from chloroplasts to nuclei.

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In vivo transformations of dihydroartemisinic acid in Artemisia annua plants

Cited by 148 publications

References 45 publications

Artemisia annua mutant impaired in artemisinin synthesis demonstrates importance of nonenzymatic conversion in terpenoid metabolism

Artemisia annua mutant impaired in artemisinin synthesis demonstrates importance of nonenzymatic conversion in terpenoid metabolism

Research to Improve Artemisinin Production for use in the Preparation of Anti-Malarial Drugs

An ecological implication of glandular trichome-sequestered artemisinin: as a sink of biotic/abiotic stress-triggered singlet oxygen

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