The coumarins of ptaeroxylon obliquum

Dean, F. M.; Parton, Brian; Somvichien, Nongyow; Taylor, David A.

doi:10.1016/s0040-4039(00)90785-8

Cited by 26 publications

(4 citation statements)

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“…The spectrum of 7hydroxy-6-methoxycoumarin shows two singlets for protons at positions 5 and 8 at 6.8 and 7.25 ppm, respectively, whereas the same two protons in 6-hydroxy-7-methoxycoumarin overlap and appear as a two-proton singlet at 7.03 ppm. The UV spectra of the two isomers are also different, particularly in alkaline solvents (1,9,10). The isomers give identical UV spectra in neutral solvents (Fig.…”

Section: Downloaded Frommentioning

confidence: 96%

Novel Biotransformations of 7-Ethoxycoumarin by Streptomyces griseus

Sariaslani

Rosazza

1983

Appl Environ Microbiol

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Biotransformation of 7-ethoxycoumarin by Streptomyces griseus resulted in the accumulation of two metabolites which were isolated and identified as 7hydroxycoumarin and 7-hydroxy-6-methoxycoumarin. A novel series of biotransformation reactions is implicated in the conversion of the ethoxycoumarin substrate to these products, including 0-deethylation, 6-hydroxylation to form a 6,7-dihydroxycoumarin catechol, and subsequent 0-methylation. Either 7-hydroxycoumarin or 6,7-dihydroxycoumarin was biotransformed to 7-hydroxy-6methoxycoumarin by S. griseus. Trace amounts of the isomeric 6-hydroxy-7methoxycoumarin were detected when 6,7-dihydroxycoumarin was used as the substrate. Efforts to obtain a cell-free catechol-O-methyltransferase enzyme system from S. griseus were unsuccessful. However, [methyl-14C]methionine was used with cultures of S. griseus to form 7-hydroxy-6-[14C]methoxycoumarin. Streptomyces griseus (UT 1158, NRRL 8090) catalyzes a wide array of oxidative biotransformation reactions with simple aromatic compounds (23), alkaloids (7, 8, 16, 17, 20, 21), and terpene substrates (5). Reactions common for S. griseus include 0-and N-dealkylations, aromatic hydroxylation, epoxidation, and carbon-car

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Section: Downloaded Frommentioning

confidence: 96%

Novel Biotransformations of 7-Ethoxycoumarin by Streptomyces griseus

Sariaslani

Rosazza

1983

Appl Environ Microbiol

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“…Acid diterpenes of kaurenes bulk (ent-15β-E-cinnamoyloxy-kaur-16-en-19-oic, ent-15β-Z-cinnamoyloxy-kaur-16-en-19-oic and ent-kaur-16-en-19-oic acids) were identified by IR, 1 H and 13 C NMR spectra and the data were compared with thoses reported in the literature (Silverstein et al, 1994;VichnewskiI et al, 1977;Reed et al, 1993;Velandia et al, 1998;Ohno et al, 1979;Yamasaki et al, 1976). Scopoletin coumarin was identified by IR, 1 H and 13 C NMR spectra and mass espectometry and the data were compared with the ones found in literature (Dean, et al, 1967;Nascimento, Oliveira, 2001 C NMR spectra and mass espectometry and the data were compared with thoses reported in the literature (Pauli et al, 1998;Merfort, 1992;Sánchez-Rabaneda, et al, 2003;Santos, 2004;Harborne, et al, 1986;Fabre, et al;Erlend, Dag, 2002).…”

Section: Resultsmentioning

confidence: 97%

Phytochemical study of Mikania pseudohoffmanianna G. M. Barroso ex W. C. Holmes

Souza

Contini

Oliveira

2006

Rev. Bras. Cienc. Farm.

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“…It may be mentioned here that obliquetin, 6-methoxy-7-hydroxy-8-(1 ,l -dimethylallyl) coumarin, an isomer of celerin and obliquetol, a demethylated derivative o f obliquetin, have earlier becn isolated from Ptaeroxylon obliqcrum [5]. …”

Section: Be( Rin Antmentioning

confidence: 90%

Celerin, a New Coumarin from Apium graveolens

Garg¹,

Sharma²

1980

Planta Med

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The isolation of cclcrin, LI ncw coumari~l from chc petrol extrncr of A p b m graveolens sccds is rcporred.As a part of our programme for the systematic chemical investigation of some Indian medicinal plants, we reported [I-31 the isolation of several coumarins from Apiurn graveolens LINN (Apiaceae) seeds commonly known as celery seeds. The present communication deals with the isolation and structural elucidation of another new coumarin, celerin (I), from the petrol extract of the seeds. Spectral studies of I (M+ 260; C, jH,,,Od and its methyl ether I1 concluded the pre sence of a coumarin skeleton unsubstitutel at 3, 4 and 5 positio~ls and having a hy droxyl, a methoxyl and a l,l-dimethyl ally1 group in it. Negative GIBBS test [ 4~ of I a n d , & demethylated derivative 111, suggested 6 and 7 positions for hydroxyl and rnechoxyl groups and limited the placement of 1,l-dimethylaJJyl group at 8 position in T. The absence of a bathochromic shift in the UV maxima of I on addi-' tion of sodium acetate precluded the pos~i-bilicy of a free hydroxyl at 7 Downloaded by: University of British Columbia. Copyrighted material.

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The coumarins of ptaeroxylon obliquum

Cited by 26 publications

References 0 publications

Novel Biotransformations of 7-Ethoxycoumarin by Streptomyces griseus

Novel Biotransformations of 7-Ethoxycoumarin by Streptomyces griseus

Phytochemical study of Mikania pseudohoffmanianna G. M. Barroso ex W. C. Holmes

Celerin, a New Coumarin from Apium graveolens

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