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  • 5-methoxypodophyllotoxin  (3)
  • bioconversions  (2)
  • 1
    ISSN: 1573-5044
    Keywords: Mucuna pruriens ; entrapped plant cells ; bioconversions ; catechols ; isolation ; mass spectrometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Alginate-entrapped cells ofM. pruriens were able to convert a number of parasubstituted monophenolic compounds into the corresponding catechols. All catechols produced were released into the medium, which offered the opportunity to isolate these products via a relatively simple procedure. Prepurification was performed on a Sephadex G10 gel and catechols were concentrated on Affigel 601. The identity of all products was confirmed with combined liquid chromatography/mass spectrometry (LC/MS) or MS using the desorption chemical ionization technique, depending on the catechol. For the entrapped cells and for a cell homogenate prepared of the same cell line ofM. pruriens the substrate specificities were qualitatively identical when judged on initial rates of synthesis calculated on protein basis.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1573-5044
    Keywords: 3-aminotetralins ; bioconversions ; catechols ; entrapped plant cells ; mass spectrometry ; Mucuna pruriens L.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Although alginate-entrapped cells of Mucuna pruriens L. possess a low substrate specificity, only para-substituted monocyclic phenols have been ortho-hydroxylated into catechols so far. In this study, compounds with more complex chemical structures were found to be substrates using entrapped cells of M. pruriens as well as the partially purified Mucuna-phenoloxidase. Thus, 5-, 6- and 7-hydroxylated 2-aminotetralins and a tricyclic compound, 9-hydroxy N-n-propyl hexahydronaphthoxazine, were converted into catechols. After isolation using preparative HPLC, the identity of the products was confirmed by MS. In general, for the entrapped cells and the enzyme preparation identical substrate specificities were found.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Plant cell, tissue and organ culture 20 (1990), S. 81-87 
    ISSN: 1573-5044
    Keywords: anti-tumour activity ; elicitation ; lignan biosynthesis ; 5-methoxypodophyllotoxin ; phenylalanine ammonia lyase ; phenylpropanoid pathway
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Cell suspension cultures of Linum flavum L., routinely grown on a NAA-containing medium, accumulated low levels of the phenylpropanoid-derived lignan 5-methoxypodophyllotoxin (5-MPT), up to 0.004% on a dry weight basis. Feeding experiments with the precursor L-phenylalanine resulted in a 3–5-fold increase in 5-MPT levels, but caused the levels of PAL activity to fall. Treatment of the cultures with the elicitor Nigeran, either alone or in combination with phenylalanine, caused the 5-MPT production to cease, even though PAL activity was rapidly enhanced by these treatments. Transfer of the cultures to NAA-free medium resulted in a 40–50 fold higher level of 5-MPT accumulation, the PAL activity levels being lowered compared to the routinely grown cells. With these more differentiated cultures, phenylalanine feeding and elicitor treatment, both on its own and in combination with the precursor, had no effect on 5-MPT production, even though the PAL activity levels were higher than in the untreated cells. It can be concluded that in lignan-accumulating cultures of L. flavum, PAL activity is nearly always detectable and seems to show a reciprocal relationship with 5-MPT accumulation.
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Plant cell, tissue and organ culture 27 (1991), S. 115-121 
    ISSN: 1573-5044
    Keywords: Linum flavum ; 5-methoxypodophyllotoxin ; optimization ; phenylpropanoids ; production ; root culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A new, morphologically root-like cell line of Linum flavum was selected and used for the optimization of the production of 5-methoxypodophyllotoxin. The omittance of naphthaleneacetic acid from the medium resulted in further root formation, which was accompanied with a 2.6 fold increase of 5-methoxypodophyllotoxin levels. The feeding of the phenylpropanoids L-tyrosine and L-phenylalanine resulted in enhanced 5-methoxypodophyllotoxin contents. After the removal of vitamins together with the phytohormone from the medium, 5-methoxypodophyllotoxin levels were enhanced 6 times. The maximal content ever found using this production medium was 1.01% on a dry weight basis. The application of higher sucrose concentrations led to proportional biomass increase, cells grown on 6% sucrose resulted in the highest yield, 121.4 mg l-1 5-methoxypodophyllotoxin.
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  • 5
    ISSN: 1573-5044
    Keywords: Glucosides ; Linum flavum ; 5-methoxypodophyllotoxin ; podophyllotoxin ; Podophyllum hexandrum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The bioconversion of the lignan desoxypodophyllotoxin by cell suspensions of Linum flavum and of Podophyllum hexandrum was investigated. The apolar substrate could be easily dissolved in the culture medium at a concentration of 2 mM by complexation with dimethyl-β-cyclodextrin. Growth parameters of the cell suspensions were not affected by either the addition of cyclodextrin itself, or when cyclodextrin-complexed desoxypodophyllotoxin was present in the medium. The complexed lignan disappeared from the medium within 7 days for both cell cultures. Cellularly only small amounts of desoxypodophyllotoxin were found. After feeding of desoxypodophyllotoxin, the cell culture of L. flavum accumulated 5-methoxypodophyllotoxin and 5-methoxypodophyllotoxin-β-D-glucoside. After 7 days a total maximal content of 2.38% on a dry weight basis of 5-methoxypodophyllotoxin was formed, corresponding with 249 mg l-1 suspension. The highest bioconversion percentage of 52.3% was found at day 14. The desoxypodophyllotoxin-fed culture of P. hexandrum accumulated podophyllotoxin and its β-D-glucoside with a maximal content of 2.87% on a dry weight basis after 9 days, corresponding with 192 mg 1-1 suspension. The highest bioconversion percentage of 33.2% was also found at day 9.
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