Umwandlung von Krötengiften (Bufadienoliden) durch Mikroorganismen III. 12β‐Hydroxymarinobufagin. 13. Mitteilung über Reaktionen mit Mikroorganismen

Schüpbach, Michaël; Tamm, Ch.

doi:10.1002/hlca.19640470816

Cited by 8 publications

(1 citation statement)

References 22 publications

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“…Analysis of the 1D and 2D NMR (MeOH- d 4 ) data for 7 (Tables , , and S7), including HMBC correlations from H 3 -18 (δ H 0.71) to the oxymethine C-12 (δ C 75.5), COSY correlations from H 2 -11 to the oxymethine H-12 (δ H 3.42), and a J 11β,12 (11.5 Hz) value consistent with an axially disposed H-12, unambiguously identified 7 as 12β-hydroxymarinobufagenin. Although not known as a natural product, 12β-hydroxymarinobufagenin was reported in 1964 as a Fusarium lini biotransformation product of 1 and 4 and in 2005 as a Mucor polymorphosporus biotransformation product of 4 . A recent review revealed that cinobufagin, resibufogenin, and bufalin were also biotransformed by several species of fungi to 12β-hydroxylated products, but no 11α-hydroxylated products were detected .…”

Section: Resultsmentioning

confidence: 99%

Microbiome-Mediated Biotransformation of Cane Toad Bufagenins

2017

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Cane toads are an invasive pest species in which all life stages employ cardiotoxic bufagenins as a chemical defense against predators. Curiously, the bufagenin profiles of eggs and tadpoles are more complex than those of parotoid secretion, the principle mechanism of toxin delivery in adult toads. In an effort to understand this complexity, we determined that selected strains of adult toad parotoid-gland-associated Gram-positive bacteria, Bacillus spp., were capable of biotransforming secreted bufagenins, marinobufagenin (1), telocinobufagenin (2), bufalin (3), and resibufagenin (4), to hydroxylated scaffolds commonly encountered in cane toad eggs and tadpoles. Scaled-up cultivation, preparative chromatography, and detailed spectroscopic analysis identified Bacillus sp. CMB-TD29 biotransformation products of 1, as 11α-hydroxymarinobufagenin (6), 12β-hydroxymarinobufagenin (7), and 17α-hydroxymarinobufagenin (8). Comparative bufagenin profiles across the cane toad life cycle suggest that bacterial biotransformation mediates the oxidative adaptation of adult toad bufagenins to hydroxylated bufagenins encountered in eggs and tadpoles. We speculate that knowledge of a relationship between the cane toad microbiome and bufagenin chemical defenses could inspire the development of a natural, nontoxic, environmentally sustainable bacterial biocontrol for this toxic invasive species.

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Section: Resultsmentioning

confidence: 99%

Microbiome-Mediated Biotransformation of Cane Toad Bufagenins

2017

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Identifizierung der als «6β, 15α‐Dihydroxyprogesteron», «11α, 15β‐Dihydroxyprogesteron» und «12α, 15β‐Dihydroxyprogesteron» beschriebenen Steroide mit 12α, 15β‐Dihydroxyprogesteron

Dodson

Langbein

Muir

et al. 1965

Helvetica Chimica Acta

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1933207. Identifizierung der als (( 6,!?, 15a-Dihydroxyprogesteron D, Dihydroxyprogesteron n beschriebenen Steroide mit 12p, 15a-Dihydroxyprogesteronl) von R. M. Dodson2), G. Langbein3), R. D. Muira), A . Schubert3), R. Siebert3), Ch. Tamm5) und E. Weiss-Berg5) (13. X. 65) (( lla, 15P-Dihydroxyprogesteron )) und 12p, 15p-Vor einiger Zeit erhielten TAMM et al. [4] bei der Umsetzung von Progesteron rnit Xulturen von Fusarium lini (BOLLEY) neben dem bekannten 15a-Hydroxyprogesteron ein neues Dihydroxylierungsprodukt vom Smp. 192-203" und [a]'," = + 130" (Chloroform), dem sie provisorisch die Konstitution des noch unbekannten 68,15a-Dihydroxyprogesterons erteilten. Die beiden neuen Hydroxylgruppen waren leicht acetylierbar. Mit CrO, in Eisessig bei 20" lieferte dieses (t6fi, 15a-Dihydroxyprogesteron )) ein Monohydroxy-triketon, dessen 1R.-Spektrum eine neue Carbonylschwingung eines Funfringketons aufwies. Da dieses Oxydationsprodukt nicht die Eigenschaften einer 8-Dicarbonylverbindung aufwies, konnte fur die neue Ketogruppe die 16-Stellung ausgeschlossen werden. Infolgedessen enthalt es eine 15-Ketogruppe. Damit war die 15-Stellung der einen Hydroxylgruppe des Dihydroxylierungsproduktes gesichert. Die 15a-Konfiguration war auf Grund der Tatsache, dass Fzzsarium lini bei Steroiden der Androstan-und Pregnanreihe, deren Ringe C und D trans-standig verknupft sind, 15a-Hydroxylierung bewirkt [4], nicht bewiesen, doch sehr wahrscheinlich. Zweifel an der 6@-Stellung des zweiten Hydroxyls tauchten auf, als SATO et aZ. [5] bei der selektiven Oxydation von 6@,15P-Dihydroxyprogesteron rnit CrO, 6B-Hydroxy-A*pregnentrion-(3,15,20) (4) erhielten, dessen Struktur eindeutig bewiesen war, dessen physikalische Eigenschaften aber von denjenigen unseres Praparates stark abwichen (vgl. Tab.

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Magnetische Protonenresonanz‐Spektroskopie der Bufadienolide (steroidartigen Krötengifte)

Gsell¹,

Tamm²

1969

Helvetica Chimica Acta

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13. 1. GO) .Su?izmrcvy. Thc NMK. spectra of nearly all bufddienolides (stcroidal toad poisons) of known structure (aglycones and acetyl derivatives) were measured (some in various solvents) and cvaluated. The results obtained allow thc application of the principle of the self-consistent chcniical shift values ('rule of additivity') for the calculation of thc chemical shifts of the 18-and 19methyl groups. The frequencies of resonancc and thc coupling of the protons of the 17P-pentadienolick ring and oi the a-protons of the functional groups were analysed. For the determination of the XMR. spectra of polyhydroxylatcd bufadienolides and cardenolides d,-diincthyIsulfoxidc provcd to be thc most suitablc solvcnt. In this solvent not only the nature but also the rclativc positions of several hydroxyl groups can be recognized, thc rule of additivity being also applicablc.On thc basis of the data recorded the position and stereochemistry of functional groups in steroidal toad poisons of unknown structure can be determined with a high degree of probability.") Rbweichungen von Inchr als 0,02 ppm zivischcn den gefundenen untl bcrechneten 1j.u tcn ") Abweichungen zwischen den gefundenen und berechnctcn Wcrtcn ") These Wertc \x crden ziii Rcrechnung der uhrigcn \\'crtc cingcsetit ") Werte von HUBER et (11 113'.

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Umwandlung von Krötengiften (Bufadienoliden) durch Mikroorganismen III. 12β‐Hydroxymarinobufagin. 13. Mitteilung über Reaktionen mit Mikroorganismen

Cited by 8 publications

References 22 publications

Microbiome-Mediated Biotransformation of Cane Toad Bufagenins

Microbiome-Mediated Biotransformation of Cane Toad Bufagenins

Identifizierung der als «6β, 15α‐Dihydroxyprogesteron», «11α, 15β‐Dihydroxyprogesteron» und «12α, 15β‐Dihydroxyprogesteron» beschriebenen Steroide mit 12α, 15β‐Dihydroxyprogesteron

Magnetische Protonenresonanz‐Spektroskopie der Bufadienolide (steroidartigen Krötengifte)

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