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Rita M. Moraes - One of the best experts on this subject based on the ideXlab platform.

  • Correspondence
    2015
    Co-Authors: Kent E. Cushman, Rita M. Moraes, Ebru Bedir, Ikhlas A. Khan, Patrick D. Gerard, Bladimiro Silva, Kent Cushman
    Abstract:

    Dried leaves of Podophyllum peltatum were ground to a fine powder and stored at room temperature protected from light and moisture in tightly closed glass or plastic bottles. Aqueous extraction: 40 mg of powdered tissue were mixed with 0.6 mL of 25 mM potassium phosphate, pH 7.0, and incubated at 22 °C with rocking for 30 min. Incubation continued for another 5 min after addition of 0.6 mL of ethyl acetate. After separating the aqueous and organic phases by centrifugation, the latter was collected, the solvent evaporated, and the residue dissolved in 0.8 mL of methanol. Extracts (10 µL) were analyzed by isocratic HPLC of 20 min at 1 mL/min, followed by a 5-min methanol wash and re-equilibration for 15 min. Column: 4.6 × 150 mm Hypersil C-18, 5 µm particle size; mobile phase: 28 parts acetonitrile and 72 parts 0.025 % trifluoroacetic acid. Absorbance was measured at 220 nm. The identity of podophyllotoxin and its glucoside wa

  • Propagule Type and Planting Time for Field-established
    2015
    Co-Authors: Muhammad Maqbool, Kent E. Cushman, Rita M. Moraes
    Abstract:

    The American mayapple (Podophyllum peltatum L.; Berberidaceae) is a rhizomatous perennial species found throughout eastern North America. The species has received attention recently due to pharmaceutical compounds found in its leaves. Podophyllotoxin, along with α-peltatin, and β-peltatin, are aryltetralin lignan

  • rapid analysis of lignans from leaves of Podophyllum peltatum l samples using uplc uv ms
    Biomedical Chromatography, 2011
    Co-Authors: Bharathi Avula, Rita M. Moraes, Yanhong Wang, Ikhlas A. Khan
    Abstract:

    A new rapid UPLC-UV-MS method has been developed that permits the analysis of four lignans (4′-O-demethylpodophyllotoxin, podophyllotoxin, α-peltatin and β-peltatin) in P. peltatum L. Podophyllotoxin is a natural lignan that is being used as a precursor for the semi-synthetic anti-cancer drugs etoposide, teniposide and etopophos. The chromatographic separation was achieved using a reversed-phase C18 column with a mobile phase of water and acetonitrile, both containing 0.05% formic acid. Analyses of P. peltatum leaves collected from different colonies within a single site indicated a significant variation in 4′-O-demethylpodophyllotoxin, α-peltatin, podophyllotoxin and β-peltatin content. Within 3.0 min four main lignans could be separated with detection limits of 0.1, 0.3, 0.3 and 0.2 μg/mL, respectively. 4′-O-demethylpodophyllotoxin and α-peltatin appeared most prominently among the lignans obtained. The podophyllotoxin content was found in the range of 0.004–0.77% from 16 samples collected from 6 colonies within the same site. The content of podophyllotoxin is directly proportional to the content of 4′-O-demethylpodophyllotoxin and inversely proportional to α-peltatin and β-peltatin content. LC-mass spectrometry coupled with electrospray ionization (ESI) interface method is described for the identification of four lignans in various populations of plant samples. By applying principal component analysis and hierarchical cluster analysis, Podophyllum samples collected from various colonies within a location were distinguished. Copyright © 2011 John Wiley & Sons, Ltd.

  • rapid analysis of lignans from leaves of Podophyllum peltatum l samples using uplc uv ms
    Planta Medica, 2011
    Co-Authors: Bharathi Avula, Rita M. Moraes, Yanhong Wang, Ikhlas A. Khan
    Abstract:

    A new rapid UPLC-UV-MS method has been developed that permits the analysis of four lignans (4'-O-demethylpodophyllotoxin, podophyllotoxin, α-peltatin and β-peltatin) in P. peltatum L. Podophyllotoxin is a natural lignan that is being used as a precursor for the semi-synthetic anti-cancer drugs etoposide, teniposide and etopophos. The chromatographic separation was achieved using a reversed-phase C18 column with a mobile phase of water and acetonitrile, both containing 0.05% formic acid. Analyses of P. peltatum leaves collected from different colonies within a single site indicated a significant variation in 4'-O-demethylpodophyllotoxin, α-peltatin, podophyllotoxin and β-peltatin content. Within 3.0 min four main lignans could be separated with detection limits of 0.1, 0.3, 0.3 and 0.2 μg/mL, respectively. 4'-O-demethylpodophyllotoxin and α-peltatin appeared most prominently among the lignans obtained. The podophyllotoxin content was found in the range of 0.004-0.77% from 16 samples collected from 6 colonies within the same site. The content of podophyllotoxin is directly proportional to the content of 4'-O-demethylpodophyllotoxin and inversely proportional to α-peltatin and β-peltatin content. LC-mass spectrometry coupled with electrospray ionization (ESI) interface method is described for the identification of four lignans in various populations of plant samples. By applying principal component analysis and hierarchical cluster analysis, Podophyllum samples collected from various colonies within a location were distinguished.

  • in vitro germplasm conservation of Podophyllum peltatum l under slow growth conditions
    In Vitro Cellular & Developmental Biology – Plant, 2010
    Co-Authors: Hemant Lata, Rita M. Moraes, Bianca Waleria Bertoni, Ana Maria Soares Pereira
    Abstract:

    Germplasm conservation of Podophyllum peltatum L. was attempted by using synthetic seed technology and media supplemented with osmotic agents. Excised buds from in vitro cultures were encapsulated in calcium alginate beads and cultured on different substrates then stored at 5, 10, and 25°C for up to 8 mo. Survival and vigor in re-growth were the parameters used to evaluate the germplasm storage conditions. Vigor in re-growth was measured by number of buds induced after storage, which was achieved on a substrate containing water solidified with 1% w/v agar under 10°C. In vitro storage of shoot cultures was also evaluated by supplementing osmotic agents, mannitol, or sorbitol to the media. Such treatment had a negative impact on post-storage re-growth (at 25°C), even though the inclusion of 2% w/v sorbitol and mannitol each to the media increased plantlet survival during 10°C storage treatment. A deleterious effect was noticed among cultures in re-growth when higher concentrations of these supplements were added to the media. Genetic stability was assessed following 8 mo of storage using a PCR-based multilocus DNA fingerprinting technique, amplified fragment-length polymorphism. No differences in the DNA fragment patterns were observed using eight primer combinations in stored clones. However, a polymorphic band was noticed in the accession that served as explant source, suggesting that the mutation has occurred prior to this study perhaps during the 9 years of in vitro cultivation.

Ikhlas A. Khan - One of the best experts on this subject based on the ideXlab platform.

  • Correspondence
    2015
    Co-Authors: Kent E. Cushman, Rita M. Moraes, Ebru Bedir, Ikhlas A. Khan, Patrick D. Gerard, Bladimiro Silva, Kent Cushman
    Abstract:

    Dried leaves of Podophyllum peltatum were ground to a fine powder and stored at room temperature protected from light and moisture in tightly closed glass or plastic bottles. Aqueous extraction: 40 mg of powdered tissue were mixed with 0.6 mL of 25 mM potassium phosphate, pH 7.0, and incubated at 22 °C with rocking for 30 min. Incubation continued for another 5 min after addition of 0.6 mL of ethyl acetate. After separating the aqueous and organic phases by centrifugation, the latter was collected, the solvent evaporated, and the residue dissolved in 0.8 mL of methanol. Extracts (10 µL) were analyzed by isocratic HPLC of 20 min at 1 mL/min, followed by a 5-min methanol wash and re-equilibration for 15 min. Column: 4.6 × 150 mm Hypersil C-18, 5 µm particle size; mobile phase: 28 parts acetonitrile and 72 parts 0.025 % trifluoroacetic acid. Absorbance was measured at 220 nm. The identity of podophyllotoxin and its glucoside wa

  • rapid analysis of lignans from leaves of Podophyllum peltatum l samples using uplc uv ms
    Biomedical Chromatography, 2011
    Co-Authors: Bharathi Avula, Rita M. Moraes, Yanhong Wang, Ikhlas A. Khan
    Abstract:

    A new rapid UPLC-UV-MS method has been developed that permits the analysis of four lignans (4′-O-demethylpodophyllotoxin, podophyllotoxin, α-peltatin and β-peltatin) in P. peltatum L. Podophyllotoxin is a natural lignan that is being used as a precursor for the semi-synthetic anti-cancer drugs etoposide, teniposide and etopophos. The chromatographic separation was achieved using a reversed-phase C18 column with a mobile phase of water and acetonitrile, both containing 0.05% formic acid. Analyses of P. peltatum leaves collected from different colonies within a single site indicated a significant variation in 4′-O-demethylpodophyllotoxin, α-peltatin, podophyllotoxin and β-peltatin content. Within 3.0 min four main lignans could be separated with detection limits of 0.1, 0.3, 0.3 and 0.2 μg/mL, respectively. 4′-O-demethylpodophyllotoxin and α-peltatin appeared most prominently among the lignans obtained. The podophyllotoxin content was found in the range of 0.004–0.77% from 16 samples collected from 6 colonies within the same site. The content of podophyllotoxin is directly proportional to the content of 4′-O-demethylpodophyllotoxin and inversely proportional to α-peltatin and β-peltatin content. LC-mass spectrometry coupled with electrospray ionization (ESI) interface method is described for the identification of four lignans in various populations of plant samples. By applying principal component analysis and hierarchical cluster analysis, Podophyllum samples collected from various colonies within a location were distinguished. Copyright © 2011 John Wiley & Sons, Ltd.

  • rapid analysis of lignans from leaves of Podophyllum peltatum l samples using uplc uv ms
    Planta Medica, 2011
    Co-Authors: Bharathi Avula, Rita M. Moraes, Yanhong Wang, Ikhlas A. Khan
    Abstract:

    A new rapid UPLC-UV-MS method has been developed that permits the analysis of four lignans (4'-O-demethylpodophyllotoxin, podophyllotoxin, α-peltatin and β-peltatin) in P. peltatum L. Podophyllotoxin is a natural lignan that is being used as a precursor for the semi-synthetic anti-cancer drugs etoposide, teniposide and etopophos. The chromatographic separation was achieved using a reversed-phase C18 column with a mobile phase of water and acetonitrile, both containing 0.05% formic acid. Analyses of P. peltatum leaves collected from different colonies within a single site indicated a significant variation in 4'-O-demethylpodophyllotoxin, α-peltatin, podophyllotoxin and β-peltatin content. Within 3.0 min four main lignans could be separated with detection limits of 0.1, 0.3, 0.3 and 0.2 μg/mL, respectively. 4'-O-demethylpodophyllotoxin and α-peltatin appeared most prominently among the lignans obtained. The podophyllotoxin content was found in the range of 0.004-0.77% from 16 samples collected from 6 colonies within the same site. The content of podophyllotoxin is directly proportional to the content of 4'-O-demethylpodophyllotoxin and inversely proportional to α-peltatin and β-peltatin content. LC-mass spectrometry coupled with electrospray ionization (ESI) interface method is described for the identification of four lignans in various populations of plant samples. By applying principal component analysis and hierarchical cluster analysis, Podophyllum samples collected from various colonies within a location were distinguished.

  • frequency and timing of leaf removal affect growth and podophyllotoxin content of Podophyllum peltatum in full sun
    Planta Medica, 2006
    Co-Authors: Kent E. Cushman, Rita M. Moraes, Ebru Bedir, Patrick D. Gerard, Bladimiro Silva, Ikhlas A. Khan
    Abstract:

    Podophyllotoxin is a pharmaceutical compound found in leaves and rhizomes of American mayapple (P. peltatum L.), a species being investigated as an alternative to that of the Indian mayapple (P. emodi). Leaves alone can serve as a renewable source of podophyllotoxin (and other lignans) leaving rhizomes undisturbed to produce leaf biomass in subsequent years. It is not known, however, how frequently or severely plants can be defoliated without adversely affecting future plant growth, lignan content, or podophyllotoxin yield (gm -2 ). This study compared harvest strategies that were mild to severe in frequency and timing of leaf removal. A wild population in full sun was subjected to leaf removal treatments of varying frequency (every year, every 2 nd or 3 rd year) and timing (early or late). Control plots not previously harvested were included every year. Plots were 1.0 m 2 and established during spring of 2001. Duration of the study was four years. P. peltatum plants did not tolerate the most severe harvest treatment: annual harvest frequency in combination with early harvest time. Early annual harvests reduced total leaf dry mass and total leaf area in a consistent and linear manner. In contrast, plants tolerated annual harvests when conducted late in the growing season and tolerated early harvests when conducted every 2 nd or 3 rd year. The number of sexual shoots was reduced to zero by early annual harvests. Podophyllotoxin content was 2.7 to 6.5 times greater in leaves harvested early compared to those harvested late, though content was significantly greater in only two out of four years. In conclusion, we can recommend leaf removal every year from well-established P. peltatum populations grown in full sun if harvests are conducted late in the growing season. This harvest strategy ensures maximum podophyllotoxin yield without jeopardizing future leaf biomass yield. Leaves harvested early appear to have greater podophyllotoxin content, but we discourage early harvest every year. Instead, our results indicate that leaves can be harvested early every other year without reducing long-term performance of P. peltatum populations.

  • arbuscular mycorrhiza improves acclimatization and increases lignan content of micropropagated mayapple Podophyllum peltatum l
    Plant Science, 2004
    Co-Authors: Rita M. Moraes, Ebru Bedir, Ikhlas A. Khan, Zita De Andrade, Franck E Dayan, Hemant Lata, Ana Maria Soares Pereira
    Abstract:

    Abstract In vitro propagated plants are delicate and lacking vigor to survive the acclimatization shock with great losses observed frequently. Comparison of potting substrates showed that survival of Podophyllum peltatum plantlets was higher (97%) in a non-sterile soil (NS)–sand (2:1 v/v) substrate than in Miracle–Gro potting mix®-sand (2:1 v/v) with or without inocula of arbuscular mycorrhiza (AM). The non-sterile soil substrate was collected from areas of P. peltatum wild-grown colonies located on the University of Mississippi Campus. Within the group of plantlets grown in the Miracle–Gro potting mix®-sand substrate, the survival rate was significantly higher in plantlets inoculated with AM fungi. Plantlets inoculated with Entrophospora colombiana had a superior survival rate (73%) than plantlets inoculated with Glomus mosseae, Gigaspora ramisporophora or Scutellospora fulgida (57%). Ex vitro G. ramisporophora inoculated plants yielded more podophyllotoxin and related lignans than the control, non-inoculated plants.

Norman G Lewis - One of the best experts on this subject based on the ideXlab platform.

  • next generation sequencing in predicting gene function in podophyllotoxin biosynthesis
    Journal of Biological Chemistry, 2013
    Co-Authors: Joaquim V Marques, Michael A Costa, Laurence B Davin, Kyewon Kim, Choonseok Lee, Gregory D May, John A Crow, Norman G Lewis
    Abstract:

    Podophyllum species are sources of (−)-podophyllotoxin, an aryltetralin lignan used for semi-synthesis of various powerful and extensively employed cancer-treating drugs. Its biosynthetic pathway, however, remains largely unknown, with the last unequivocally demonstrated intermediate being (−)-matairesinol. Herein, massively parallel sequencing of Podophyllum hexandrum and Podophyllum peltatum transcriptomes and subsequent bioinformatics analyses of the corresponding assemblies were carried out. Validation of the assembly process was first achieved through confirmation of assembled sequences with those of various genes previously established as involved in podophyllotoxin biosynthesis as well as other candidate biosynthetic pathway genes. This contribution describes characterization of two of the latter, namely the cytochrome P450s, CYP719A23 from P. hexandrum and CYP719A24 from P. peltatum. Both enzymes were capable of converting (−)-matairesinol into (−)-pluviatolide by catalyzing methylenedioxy bridge formation and did not act on other possible substrates tested. Interestingly, the enzymes described herein were highly similar to methylenedioxy bridge-forming enzymes from alkaloid biosynthesis, whereas candidates more similar to lignan biosynthetic enzymes were catalytically inactive with the substrates employed. This overall strategy has thus enabled facile further identification of enzymes putatively involved in (−)-podophyllotoxin biosynthesis and underscores the deductive power of next generation sequencing and bioinformatics to probe and deduce medicinal plant biosynthetic pathways.

  • secoisolariciresinol dehydrogenase mode of catalysis and stereospecificity of hydride transfer in Podophyllum peltatum
    Organic and Biomolecular Chemistry, 2006
    Co-Authors: Syed G A Moinuddin, Michael A Costa, Gregory L Helms, Buhyun Youn, Diana L. Bedgar, Laurence B Davin, Chulhee Kang, Norman G Lewis
    Abstract:

    Secoisolariciresinol dehydrogenase (SDH) catalyzes the NAD+ dependent enantiospecific conversion of secoisolariciresinol into matairesinol. In Podophyllum species, (−)-matairesinol is metabolized into the antiviral compound, podophyllotoxin, which can be semi-synthetically converted into the anticancer agents, etoposide, teniposide and Etopophos®. Matairesinol is also a precursor of the cancer-preventative “mammalian” lignan, enterolactone, formed in the gut following ingestion of, for example, various high fiber dietary foods, as well as being an intermediate to numerous defense compounds in vascular plants. This study investigated the mode of enantiospecific Podophyllum SDH catalysis, the order of binding, and the stereospecificity of hydride abstraction/transfer from secoisolariciresinol to NAD+. SDH contains a highly conserved catalytic triad (Ser153, Tyr167 and Lys171), whose activity was abolished with site-directed mutagenesis of Tyr167Ala and Lys171Ala, whereas mutagenesis of Ser153Ala only resulted in a much reduced catalytic activity. Isothermal titration calorimetry measurements indicated that NAD+ binds first followed by the substrate, (−)-secoisolariciresinol. Additionally, for hydride transfer, the incoming hydride abstracted from the substrate takes up the pro-S position in the NADH formed. Taken together, a catalytic mechanism for the overall enantiospecific conversion of (−)-secoisolariciresinol into (−)-matairesinol is proposed.

  • secoisolariciresinol dehydrogenase purification cloning and functional expression implications for human health protection
    Journal of Biological Chemistry, 2001
    Co-Authors: Michael A Costa, Helene C Pelissier, Laurence B Davin, Norman G Lewis
    Abstract:

    Abstract Matairesinol is a central precursor in planta in the biosynthesis of numerous lignans, including that of the important antiviral and anticancer agent, podophyllotoxin. In this study, the ∼32-kDa NAD-dependent secoisolariciresinol dehydrogenase, which catalyzes the enantiospecific conversion of (−)-secoisolariciresinol into (−)-matairesinol in Forsythia intermedia, was purified >6,000-fold to apparent homogeneity. The 831-base pair cDNA clone encoding this 277-amino acid protein was next obtained from a library constructed from F. intermedia stem tissue, whose fully functional recombinant protein, produced by expression of this cDNA in Escherichia coli, catalyzed the same enantiospecific conversion via the corresponding lactol intermediate. A homologous secoisolariciresinol dehydrogenase gene was also isolated from a Podophyllum peltatum rhizome cDNA library, whose 834-base pair cDNA clone encoded a 278-amino acid protein with a calculated molecular mass of ∼32 kDa. Expression of this protein in E. coli produced a fully functional recombinant protein that also catalyzed the enantiospecific conversion of (−)-secoisolariciresinol into (−)-matairesinol via the intermediary lactol. Various kinetic parameters were defined and established conversion of the intermediary lactol as being rate-limiting. With this overall enzymatic conversion now unambiguously defined, the entire biochemical pathway to the lignans, secoisolariciresinol and matairesinol, has been elucidated. Last, both secoisolariciresinol and matairesinol are metabolized in the gut of mammals, following digestion of high fiber dietary grains, seeds, and berries, into the so-called “mammalian” lignans, enterodiol and enterolactone, respectively; these in turn confer significant protection against the onset of breast and prostate cancers.

  • dirigent mediated podophyllotoxin biosynthesis in linum flavum and Podophyllum peltatum
    Phytochemistry, 2000
    Co-Authors: Zhiqiang Xia, Michael A Costa, Laurence B Davin, John Proctor, Norman G Lewis
    Abstract:

    Given the importance of the antitumor/antiviral lignans, podophyllotoxin and 5-methoxypodophyllotoxin, as biotechnological targets, their biosynthetic pathways were investigated in Podophyllum peltatum and Linum flavum. Entry into their pathways was established to occur via dirigent mediated coupling of E-coniferyl alcohol to afford (+)-pinoresinol; the encoding gene was cloned and the recombinant protein subsequently obtained. Radiolabeled substrate studies using partially purified enzyme preparations next revealed (+)-pinoresinol was enantiospecifically converted sequentially into (+)-lariciresinol and (-)-secoisolariciresinol via the action of an NADPH-dependent bifunctional pinoresinol/lariciresinol reductase. The resulting (-)-secoisolariciresinol was enantiospecifically dehydrogenated into (-)-matairesinol, as evidenced through the conversion of both radio- and stable isotopically labeled secoisolariciresinol into matairesinol, this being catalyzed by the NAD-dependent secoisolariciresinol dehydrogenase. (-)-Matairesinol was further hydroxylated to afford 7'-hydroxymatairesinol, this being efficiently metabolized into 5-methoxypodophyllotoxin. Thus much of the overall biosynthetic pathway to podophyllotoxin has been established, that is, from the dirigent mediated coupling of E-coniferyl alcohol to the subsequent conversions leading to 7'-hydroxymatairesinol.

Camilo Canel - One of the best experts on this subject based on the ideXlab platform.

  • Podophyllum peltatum possesses a β glucosidase with high substrate specificity for the aryltetralin lignan podophyllotoxin
    Biochimica et Biophysica Acta, 2003
    Co-Authors: Franck E Dayan, Camilo Canel, Jeanne M Kuhajek, Susan B Watson, Rita M. Moraes
    Abstract:

    Abstract A β-glucosidase with high specificity for podophyllotoxin-4-O-β- d -glucopyranoside was purified from the leaves of Podophyllum peltatum. The 65-kDa polypeptide had optimum activity at pH 5.0 and was essentially inactive at pH 6.5 or above. Maximum catalytic activity of this glucosidase was obtained at 45 °C, but the enzyme was not heat stable. This β-glucosidase displayed higher substrate specificity for podophyllotoxin-4-O-β- d -glucopyranoside than for the other lignans tested, and for the (1→3) linkage of laminaribiose than for other glucosidic linkages.

  • Evaluation of Podophyllum peltatum accessions for podophyllotoxin production.
    Planta Medica, 2002
    Co-Authors: Rita M. Moraes, Ebru Bedir, Holly Barrett, Charles L. Burandt, Camilo Canel, Ikhlas A. Khan
    Abstract:

    In an effort to develop a sustainable source of podophyllotoxin for the production of anticancer drugs such as etoposide, teniposide and etopophos, Podophyllum peltatum accessions with podophyllotoxin-rich leaf biomass were identified and transplanted to different growing conditions by vegetative cuttings. Results indicate that the lignan profile in leaves does not change over time or due to environment conditions. Podophyllotoxin and alpha-peltatin content in the blades seems to be stable with an inverse relationship of concentration between these compounds. A podophyllotoxin-rich leaf accession showed low biosynthetic capability to synthesize alpha- and beta-peltatin and the converse was also true, indicating that selection and cultivation of high-yielding podophyllotoxin leaf biomass may reduce production costs.

  • high yield of podophyllotoxin from leaves of Podophyllum peltatum by in situ conversion of podophyllotoxin 4 o beta d glucopyranoside
    Planta Medica, 2001
    Co-Authors: Camilo Canel, Charles L. Burandt, Ikhlas A. Khan, Markus Ganzera, Franck E Dayan, Agnes M Rimando, Rita M. Moraes
    Abstract:

    Rehydration of powdered tissues of Podophyllum peltatum L. prior to extraction with an organic solvent allows endogenous beta-glucosidases to hydrolyze lignan 4-O-beta-D-glucosides in situ and increase the yield of podophyllotoxin. Aqueous extraction of rhizomes and leaves of P. peltatum yielded 4- to 10-fold greater quantities of podophyllotoxin than the traditional ethanolic extraction. Most significantly, leaves were shown to contain over 52 mg of podophyllotoxin per g of dry weight (5.2%), exceeding levels previously reported from any source. These results point to the use of leaves harvested from cultivated P. peltatum as an attractive alternative to the destructive collection of natural populations.

  • High yield of podophyllotoxin from leaves of Podophyllum peltatum by in situ conversion of podophyllotoxin 4-O-β-D-glucopyranoside
    Planta Medica, 2001
    Co-Authors: Camilo Canel, Charles L. Burandt, Ikhlas A. Khan, Markus Ganzera, Franck E Dayan, Agnes M Rimando, Rita M. Moraes
    Abstract:

    Rehydration of powdered tissues of Podophyllum peltatum L. prior to extraction with an organic solvent allows endogenous beta-glucosidases to hydrolyze lignan 4-O-beta-D-glucosides in situ and increase the yield of podophyllotoxin. Aqueous extraction of rhizomes and leaves of P. peltatum yielded 4- to 10-fold greater quantities of podophyllotoxin than the traditional ethanolic extraction. Most significantly, leaves were shown to contain over 52 mg of podophyllotoxin per g of dry weight (5.2%), exceeding levels previously reported from any source. These results point to the use of leaves harvested from cultivated P. peltatum as an attractive alternative to the destructive collection of natural populations.

  • the american mayapple revisited Podophyllum peltatum still a potential cash crop
    Economic Botany, 2000
    Co-Authors: Rita M. Moraes, Charles L. Burandt, Ikhlas A. Khan, Markus Ganzera, L I Xingli, Camilo Canel
    Abstract:

    Podophyllum peltatum, was reexamined for its potential use in the commercial production of podophyllotoxin, a lignan used in the semisynthesis of important anticancer drugs. A survey of the natural population of the American mayapple, Podophyllum peltatum, was conducted in order to identify high-yielding genotypes. Plants were collected from the eastern and central United States. The lignan content of leaf blades and rhizome material of the collected specimens was characterized by aqueous extraction followed by HPLC analysis. Podophyllotoxin and α-peltatin appeared most prominently among the lignans obtained. Leaf blades were generally richer in podophyllotoxin than rhizomes. Several high-yielding accessions were identified, the blades of which contained 4.0–5.6% podophyllotoxin. A negative correlation was observed between podophyllotoxin and peltatin content in the blades. The combination of high biosynthetic capacity and preferential accumulation of podophyllotoxin in leaves of mayapple makesthis plant an excellent candidate for agricultural production of podophyllotoxin.

Charles L. Burandt - One of the best experts on this subject based on the ideXlab platform.

  • Evaluation of Podophyllum peltatum accessions for podophyllotoxin production.
    Planta Medica, 2002
    Co-Authors: Rita M. Moraes, Ebru Bedir, Holly Barrett, Charles L. Burandt, Camilo Canel, Ikhlas A. Khan
    Abstract:

    In an effort to develop a sustainable source of podophyllotoxin for the production of anticancer drugs such as etoposide, teniposide and etopophos, Podophyllum peltatum accessions with podophyllotoxin-rich leaf biomass were identified and transplanted to different growing conditions by vegetative cuttings. Results indicate that the lignan profile in leaves does not change over time or due to environment conditions. Podophyllotoxin and alpha-peltatin content in the blades seems to be stable with an inverse relationship of concentration between these compounds. A podophyllotoxin-rich leaf accession showed low biosynthetic capability to synthesize alpha- and beta-peltatin and the converse was also true, indicating that selection and cultivation of high-yielding podophyllotoxin leaf biomass may reduce production costs.

  • high yield of podophyllotoxin from leaves of Podophyllum peltatum by in situ conversion of podophyllotoxin 4 o beta d glucopyranoside
    Planta Medica, 2001
    Co-Authors: Camilo Canel, Charles L. Burandt, Ikhlas A. Khan, Markus Ganzera, Franck E Dayan, Agnes M Rimando, Rita M. Moraes
    Abstract:

    Rehydration of powdered tissues of Podophyllum peltatum L. prior to extraction with an organic solvent allows endogenous beta-glucosidases to hydrolyze lignan 4-O-beta-D-glucosides in situ and increase the yield of podophyllotoxin. Aqueous extraction of rhizomes and leaves of P. peltatum yielded 4- to 10-fold greater quantities of podophyllotoxin than the traditional ethanolic extraction. Most significantly, leaves were shown to contain over 52 mg of podophyllotoxin per g of dry weight (5.2%), exceeding levels previously reported from any source. These results point to the use of leaves harvested from cultivated P. peltatum as an attractive alternative to the destructive collection of natural populations.

  • High yield of podophyllotoxin from leaves of Podophyllum peltatum by in situ conversion of podophyllotoxin 4-O-β-D-glucopyranoside
    Planta Medica, 2001
    Co-Authors: Camilo Canel, Charles L. Burandt, Ikhlas A. Khan, Markus Ganzera, Franck E Dayan, Agnes M Rimando, Rita M. Moraes
    Abstract:

    Rehydration of powdered tissues of Podophyllum peltatum L. prior to extraction with an organic solvent allows endogenous beta-glucosidases to hydrolyze lignan 4-O-beta-D-glucosides in situ and increase the yield of podophyllotoxin. Aqueous extraction of rhizomes and leaves of P. peltatum yielded 4- to 10-fold greater quantities of podophyllotoxin than the traditional ethanolic extraction. Most significantly, leaves were shown to contain over 52 mg of podophyllotoxin per g of dry weight (5.2%), exceeding levels previously reported from any source. These results point to the use of leaves harvested from cultivated P. peltatum as an attractive alternative to the destructive collection of natural populations.

  • the american mayapple revisited Podophyllum peltatum still a potential cash crop
    Economic Botany, 2000
    Co-Authors: Rita M. Moraes, Charles L. Burandt, Ikhlas A. Khan, Markus Ganzera, L I Xingli, Camilo Canel
    Abstract:

    Podophyllum peltatum, was reexamined for its potential use in the commercial production of podophyllotoxin, a lignan used in the semisynthesis of important anticancer drugs. A survey of the natural population of the American mayapple, Podophyllum peltatum, was conducted in order to identify high-yielding genotypes. Plants were collected from the eastern and central United States. The lignan content of leaf blades and rhizome material of the collected specimens was characterized by aqueous extraction followed by HPLC analysis. Podophyllotoxin and α-peltatin appeared most prominently among the lignans obtained. Leaf blades were generally richer in podophyllotoxin than rhizomes. Several high-yielding accessions were identified, the blades of which contained 4.0–5.6% podophyllotoxin. A negative correlation was observed between podophyllotoxin and peltatin content in the blades. The combination of high biosynthetic capacity and preferential accumulation of podophyllotoxin in leaves of mayapple makesthis plant an excellent candidate for agricultural production of podophyllotoxin.

  • In vitro propagation of Podophyllum peltatum.
    Planta medica, 1998
    Co-Authors: Rita M. Moraes-cerdeira, Charles L. Burandt, Jairo Kenupp Bastos, N. P. Dhammika Nanayakkara, James D. Mcchesney
    Abstract:

    The lignan podophyllotoxin, occurring in Podophyllum emodi Wall, ex Royale and Podophyllum peltatum. L., is the starting compound for the semi-synthesis of the anticancer drugs etoposide and teniposide. In this study, we evaluate development of an in vitro propagation protocol to rapidly produce high yielding Podophyllum peltatum plants. Rhizome tips were inoculated on MS medium supplied with 4.4 microM N(6)-benzyladenine and 0.025% (w/v) activated charcoal. These explants formed terminal buds, similar to the ones found in nature. These buds were sources of in vitro bud cultures. These bud cultures were classified as: apical, axillary, and adventitious and the effects of various N(6)-benzyladenine concentrations on the three types of bud cultures were evaluated through bud, leaf, and root inductions. Cultures of axillary and adventitious buds were more proliferous for bud induction. Podophyllotoxin contents of in vitro rooted bud and plantlet cultures were similar to the content found in the wild. Plantlets and buds were acclimatized under controlled environment conditions.