Biotransformation of valencene by cultured cells of Gynostemma pentaphyllum

Sakamaki, Hiroshi; Itoh, Ken‐ichi; Taniai, Tetsuyuki; Kitanaka, Susumu; Takagi, Yoshikazu; Chai, Wen; Horiuchi, C. Akira

doi:10.1016/j.molcatb.2004.10.004

Cited by 37 publications

(18 citation statements)

References 14 publications

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“…They obtained (+)-nootkatone with a yield of 40%. On the other hand, various biocatalysts, such as G. pentaphyllum cultures, green algae Chlorella species, fungi Bothryosphaeria dothidea, the lyophilisate of edible mushroom Pleurotus sapidus, and several bacterial cytochrome P450 enzymes have also been studied for this transformation [27][28][29][30][31][32][33][34][35]. However, the costly culture conditions, the low conversion rate and yield, the inhibition of enzymes by products, and the presence of various by-products still hamper the industrial preparation of (+)-nootkatone via biocatalysts.…”

Section: Introductionmentioning

confidence: 99%

One-Pot Synthesis of (+)-Nootkatone via Dark Singlet Oxygenation of Valencene: The Triple Role of the Amphiphilic Molybdate Catalyst

et al. 2016

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Efficient one-pot catalytic synthesis of (+)-nootkatone was performed from (+)-valencene using only hydrogen peroxide and amphiphilic molybdate ions. The process required no solvent and proceeded in three cascade reactions: (i) singlet oxygenation of valencene according to the ene reaction; (ii) Schenck rearrangement of one hydroperoxide into the secondary β-hydroperoxide; and (iii) dehydration of the hydroperoxide into the desired (+)-nootkatone. The solvent effect on the hydroperoxide rearrangement is herein discussed. The amphiphilic dimethyldioctyl ammonium molybdate, which is also a balanced surfactant, played a triple role in this process, as molybdate ions catalyzed at both Step 1 and Step 3 and it allowed the rapid formation of a three-phase microemulsion system that highly facilitates product recovery. Preparative synthesis of the high added value (+)-nootkatone was thus performed at room temperature with an isolated yield of 46.5%. This is also the first example of a conversion of allylic hydroperoxides into ketones catalyzed by molybdate ions.

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Section: Introductionmentioning

confidence: 99%

One-Pot Synthesis of (+)-Nootkatone via Dark Singlet Oxygenation of Valencene: The Triple Role of the Amphiphilic Molybdate Catalyst

et al. 2016

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“…vacuolata, Chlorella pyrenoidosa, Chlorella vulgaris, Botryosphaeria dothidea and Botryodiplodia theobromae . Kaspera et al 9 applied the fungus Chaetomium globosum to reach a 19.5% yield of nootkatone after 9 days, while the use of Gynostemma pentaphyllum by Sakamaki et al 10 afforded a 72% yield after 20 days. It is worth mentioning that pure valencene was used as starting raw material in all these works.…”

Section: Introductionmentioning

confidence: 99%

Nondegenerate π‐Donor/π‐Acceptor [2]Catenanes Containing Proton‐Ionizable 1H‐1,2,4‐Triazole Subunits: Synthesis and Spontaneous Resolution

Alcalde

Pérez‐García

Ramos

et al. 2007

Chemistry A European J

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Chirality can hold the key to inducing directionality of motion in components of molecular devices. With this idea in mind, we describe here 1) the template-directed synthesis of two [2]catenanes wherein cyclobis(paraquat-p-phenylene) is interlocked with polyether macrocycles containing, in addition to one 3,5-bis(oxymethylene)-1H-1,2,4-triazole unit, either one 1,4-dioxybenzene or one 1,5-dioxynaphthalene ring system. We also report 2) the full characterization of both [2]catenanes by fast atom bombardment mass spectrometry (FABMS), X-ray crystallography, and dynamic (1)H NMR spectroscopy. We reveal 3) the fact that the [2]catenanes not only exist, both in the solution-state and in the solid-state, as strictly one of the two possible translational isomers, but that they also exhibit spontaneous resolution on crystallization leading to formation of homochiral crystals, as indicated by X-ray crystallography and circular dichroism (CD) experiments. Finally, we comment 4) on the chances of switching these catenanes chemically.

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“…However, plants have different metabolites and different enzymes from heterotrophic microbes. Plant cultured cells are then expected to be useful biocatalysts and we have contributed to develop these areas Sakamaki et al 2005).…”

Section: Introductionmentioning

confidence: 99%

Stereoselective oxidation of racemic 1-arylethanols by basil cultured cells of Ocimum basilicum cv. Purpurascens

et al. 2007

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The biotransformation of racemic 1-phenylethanol (30 mg) with plant cultured cells of basil (Ocimum basilicum cv. Purpurascens, 5 g wet wt) by shaking 120 rpm at 25 degrees C for 7 days in the dark gave (R)-(+)-1-phenylethanol and acetophenone in 34 and 24% yields, respectively. The biotransformation can be applied to other 1-arylethanols and basil cells oxidized the (S)-alcohols to the corresponding ketones remaining the (R)-alcohols in excellent ee.

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Biotransformation of valencene by cultured cells of Gynostemma pentaphyllum

Cited by 37 publications

References 14 publications

One-Pot Synthesis of (+)-Nootkatone via Dark Singlet Oxygenation of Valencene: The Triple Role of the Amphiphilic Molybdate Catalyst

One-Pot Synthesis of (+)-Nootkatone via Dark Singlet Oxygenation of Valencene: The Triple Role of the Amphiphilic Molybdate Catalyst

Nondegenerate π‐Donor/π‐Acceptor [2]Catenanes Containing Proton‐Ionizable 1H‐1,2,4‐Triazole Subunits: Synthesis and Spontaneous Resolution

Stereoselective oxidation of racemic 1-arylethanols by basil cultured cells of Ocimum basilicum cv. Purpurascens

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