In continuing studies on enzyme-catalyzed cyclization of synthetic dibenzylbutanolides to members of the podophyllotoxin family, experiments which involve the biotransformation of such synthetic substrates with horseradish peroxidase and with enzymes produced by the cell culture of Nicotiana sylvestris are presented.Cyclization of synthetic 3 to the desired 5 proceeds efficiently with purified horseradish peroxidase enzyme but with the acetone powder.A much preferred route to 5, in gram scale synthesis, involves the biotransfonnation of 3 with the enzymes produced by the cell culture of Nicotiana sylvestris.This stable cell line, when grown in bioreactors, produces sufficient quantities of enzyme for efficient multi-gram synthesis in short time incubations (5-30 min).The application of this methodology for production of podophyllotoxins utilized as starting materials in etoposide synthesis is under study in our laboratory.The podophyllotoxin family of natural products and particularly those members which bear the "classical" fivemembered lactone system (see 1) have been extensively studied over the years.Several excellent recent reviews1.2provide a summary of the chemistry and syntheses of these compounds.The development of the clinical anti-cancer drug, Etoposide (VP-16) ( z ) , ~-~ continues to stimulate further studies directed at improved
The microbial degradation of the lichen antibiotic (+)-usnic acid (1) by means of the fungal isolate Mucorglobosus has been studied. It is shown that this organism provides the metabolite (+)-2-desacetylusnic acid (2) as a major component via a novel deacylation reaction.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Total Synthesis of dl-Dihydrocleavamine, dl-Carbomethoxydihydrocleavamine, dl-Coronaridine, and dl-Dihydrocatharanthine. A General Entry into the Iboga and Vinca AlkaloidsJames P. Kutney, Walter J. Cretney, Philip Le Quesne, Bruce McKague, and Edward PiersCite this: J. Am. Chem. Soc. 1966, 88, 20, 4756–4757Publication Date (Print):October 1, 1966Publication History Published online1 May 2002Published inissue 1 October 1966https://pubs.acs.org/doi/10.1021/ja00972a061https://doi.org/10.1021/ja00972a061research-articleACS PublicationsRequest reuse permissionsArticle Views158Altmetric-Citations13LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTotal synthesis of dregamine and epidregamine. A general route to 2-acylindole alkaloidsJames P. Kutney, Gunter K. Eigendorf, Hajime Matsue, Akio Murai, Kiyoshi Tanaka, Wing L. Sung, Kojiro Wada, and Brian R. WorthCite this: J. Am. Chem. Soc. 1978, 100, 3, 938–943Publication Date (Print):February 1, 1978Publication History Published online1 May 2002Published inissue 1 February 1978https://pubs.acs.org/doi/10.1021/ja00471a047https://doi.org/10.1021/ja00471a047research-articleACS PublicationsRequest reuse permissionsArticle Views495Altmetric-Citations35LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTIndole alkaloid biosynthesis. IIIJames P. Kutney, Vern R. Nelson, and Donald C. WigfieldCite this: J. Am. Chem. Soc. 1969, 91, 15, 4278–4279Publication Date (Print):July 1, 1969Publication History Published online1 May 2002Published inissue 1 July 1969https://pubs.acs.org/doi/10.1021/ja01043a042https://doi.org/10.1021/ja01043a042research-articleACS PublicationsRequest reuse permissionsArticle Views274Altmetric-Citations25LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts
Polyurethane foam supports immobilization of Mortierella isabellina ATCC 38063, a zygomycete that hydroxylates and thereby detoxifies resin acids found in certain pulp mill effluents. The fungus becomes entrapped as it threads growing mycelia through the open foam matrix. The tenacity of binding and the amount of biomass bound depend on initial spore numbers and nutrient concentration. Optimal dehydroabietic acid transformation occurs with early-stationary-phase foam-bound mycelia suspended in buffer at pH 6.5 to 8.5 with aeration >0.1 liter liter −1 min −1 and near a temperature maximum of 33°C. Neither a greater number of similarly loaded foam cubes nor a greater surface area for similar amounts of biomass increased transformation rates. Compared to free mycelial cultures, foam presence retards growth and decreases the rate of precursor transformation but does not alter the nature of the metabolites formed from dehydroabietic acid, abietic acid, or isopimaric acid. Diffusional barriers or binding of substrates in an inaccessible manner may cause the observed inhibitions. Overall, foam immobilization stabilizes enzymic activity and is a facile laboratory process with scaleup potential.
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