- Synthesis of lyoniresinol with combined utilization of synthetic chemistry and biotechnological methods
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We have synthesized lyoniresinol with the combined utilization of synthetic chemistry and biotechnological methods, specifically using plant cell cultures as an "enzyme source."
- Takemoto, Masumi,Fukuyo, Ayako,Aoshima, Yoichi,Tanaka, Kiyoshi
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p. 226 - 229
(2007/10/03)
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- Synthesis of Ether Oligomers
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(Equation presented) Hydroxyaromatic aldehydes and ketones were used as building blocks to prepare ether oligomers. An iterative two-step protocol involving Mitsunobu coupling and carbonyl reduction provided a protecting-group-free route with high yields. Activity screening of an 84-member library against proteases led to the discovery of micromolar inhibitors for trypsin, chymotrypsin, and subtilisin.
- Renaudet, Olivier,Reymond, Jean-Louis
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p. 397 - 400
(2007/10/03)
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- Biosynthesis of yatein in Anthriscus sylvestris.
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Little is known about the biosynthesis of yatein, in spite of its importance as a typical heartwood lignan and a key biosynthetic intermediate of the antitumor lignan podophyllotoxin. The present study, based on individual administration of [13C]phenylalanine and deuterium labelled lignans and simultaneous administration of two distinct lignans labelled with deuterium atoms to Anthriscus sylvestris, established the two independent branch pathways from matairesinol, one to afford yatein via thujaplicatin, 5-methylthujaplicatin, and 4,5-dimethylthujaplicatin and the other to bursehernin via pluviatolide. The latter pathway did not lead to yatein, eliminating the presence of a metabolic grid from matairesinol to yatein.
- Sakakibara, Norikazu,Suzuki, Shiro,Umezawa, Toshiaki,Shimada, Mikio
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p. 2474 - 2485
(2007/10/03)
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- Syntheses of two cytotoxic sinapyl alcohol derivatives and isolation of four new related compounds from Ligularia nelumbifolia
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Phytochemical reinvestigation on Ligularia nelumbifolia afforded four novel sinapyl alcohol analogues named nelumols B-E (1-4) and three known sinapyl alcohol derivatives (5-7). Their structures were elucidated by NMR techniques. Total syntheses of cytotoxic geranyloxy sinapyl alcohol (6) and geranyloxy sinapyl aldehyde (7) were carried out via two different paths. The 4-O-benzyl-substituted analogues (20 and 27) as well as the 4-O-(2-methylbutenyl) derivatives (34 and 35) were also synthesized. The cytotoxicities of 6 and 7 were measured using A-549, HL-60, and KB cancer cell lines.
- Zhao, Yu,Hao, Xiaojiang,Lu, Wei,Cai, Junchao,Yu, Hong,Sevenet, Thierry,Gueritte, Francoise
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p. 902 - 908
(2007/10/03)
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- Asymmetric synthesis of lignans using oxazolidinones as chiral auxiliaries
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A simple procedure for the asymmetric synthesis of lignans via chiral β-benzyl-γ-butyrolactones has been developed. The key benzylbutyrolactone intermediates were efficiently synthesized using a six-step procedure, starting from 3,4-(methylenedioxy)cinnamic acid. The key step in this sequence was a highly diastereoselective alkylation of an N-acyloxazolidinone enolate. The resulting β-benzyl-γ-butyrolactones were subsequently transformed into the benzylidene lignans gossypifan and savinin (hibalactone) via aldol condensation-dehydration reactions, and into the dibenzylbutyrolactone lignan 4′-demethylyalein, through alkylation. Oxidation of 4′-demethylyatein with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) afforded cis- and trans-benzylidenebenzylbutyrolactones, whereas oxidation with DDQ/TFA gave 4′-demethyl-deoxyisopodophyllotoxin.
- Charlton, James L.,Chee, Gaik-Lean
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p. 1076 - 1083
(2007/10/03)
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- STUDIES WITH PLANT CELL CULTURES OF PODOPHYLLUM PELTATUM L. II. BIOTRANSFORMATION OF DIBENZYLBUTANOLIDES TO LIGNANS. DEVELOPMENT OF A "BIOLOGICAL FACTORY" FOR LIGNAN SYNTHESIS
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An efficient and versatile synthetic route to appropriate dibenzylbutanolides suitable for biotransformation to lignans as potential intermediates for the syntheses of the clinical anti-cancer drug etoposide has been developed.Biotransformation of such substrates, for example 10, with cell cultures of Podophyllum peltatum affords a potentially exciting route to this drug.Of particular significance is the development of a semi-continuous fermentation process with these plant cells wherein successive additions of substrate and isolation of end products can be pursued with a given batch of cells and over a period of several months.Biotransformation times for the conversion of 10 to 11 and 12 are short (usually 24-48 h).Although conditions have not yet optimized, this "biological factory" for lignan synthesis provides a novel approach for the use of plant cells, in combination with chemistry, for continuous and large scale production of such metabolites.
- Kutney, James P.,Chen, Yung Ping,Gao, Shixiang,Hewitt, Gary M.,Kuri-Brena, Francisco,et al.
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- Oxidative Coupling of Lignans. IV. Monophenolic Oxidative Coupling
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Oxidative coupling of the monophenolic monoester (6) gives an aryltetralin (12) which is a potential intermediate for the synthesis of clinically active monophenolic lignan lactones.In contrast, oxidative couplings of the monophenols (32) and (35), derived from matairesinol (29), give mixtures of diastereoisomeric cyclooctadiene lignans while 4'-demethyldeoxypodorhizon (26) does not cyclize.These results show that the degree of aromatic substitution in monophenolic diarylbutanes plays an important role in determining the outcome of oxidative coupling.An alternative synthesis of the lactone (57) from piperonal has been investigated.
- Burden, Jonathan K.,Cambie, Richard C.,Craw, Peter A.,Rutledge, Peter S.,Woodgate, Paul D.
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p. 919 - 933
(2007/10/02)
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- THE SYNTHESES OF (R)-(+)-β-VANILLYL-γ-BUTYROLACTONE AND OF CHIRAL LIGNANS THEREFROM
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(R)-(+)-β-vanillyl-γ-butyrolactone was obtained in 4 steps including a resolution, from vanillin and dimethyl succinate, and was used for the total syntheses of 5 naturally occurring and optically active lignans such as (+)-isolariciresinol 20.
- Brown, Eric,Daugan, Alain
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p. 1169 - 1172
(2007/10/02)
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- Biosynthesis. Part 24. Speculative Incorporation Experiments with 1-Benzylisoquinolines and a Logical Approach via C6-C2 and C6-C3 Precursors to the Biosynthesis of Hasubanonine and Protostephanine
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Many possible 1-benzyltetrahydroisoquinolines have been examined as possible advanced precursors of the alkaloids hasubanonine (1) and protostephanine (2) in Stephania japonica plants, but none was incorporated significantly.Administration of various precursor molecules having only one aromatic ring, such as tyrosine, has demonstrated that both alkaloids are derived from two different C6-C2 biogenetic units.The subsequent failure of further 1-benzyltetrahydroisoquinolines and bisphenethylamines to be incorporated suggested the intermediacy of either (a) modified 1-benzylisoquinolines or (b) trioxygenated C6-C2 building blocks.Precursors designed to examine the first possibility, such as 1-benzyl-3,4-dihydroisoquinolines or 1-benzyl-1-carboxytetrahydroisoquinolines, were not incorporated into (1) and (2) whereas two 3',4',5'-trioxygenated 2-phenylethylamines were incorporated.These findings allow further delineation of the requirements for later precursors of the alkaloids (1) and (2).
- Battersby, Alan R.,Jones, Raymond C. F.,Kazlauskas, Rymantas,Thornber, Craig W.,Ruchirawat, Somsak,Staunton, James
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p. 2016 - 2029
(2007/10/02)
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- Synthesis along Biosynthetic Pathways. Part 2. Synthesis of Protostephanine
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The dienone protostephanone (3) is synthesised by phenol coupling or by Pschorr cyclisation from readily prepared tetrahydroisoquinolines, and the corresponding dienols (17) and (18) are converted by rearrangement, fragmentation, and reduction into protostephanine (4).This sequence mimics the natural pathway to the alkaloid.
- Battersby, Alan R.,Bhatnagar, Akil K.,Hackett, Peter,Thornber, Craig W.,Staunton, James
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p. 2002 - 2009
(2007/10/02)
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