Tilivalline(1a),肺炎克雷伯菌的一种代谢产物。催产素及其衍生物1已由叠氮基磷酸二苯酯,2-恶唑啉2,L-脯氨酸衍生物5和吲哚有效地和立体选择性地合成;关键步骤是伴随完全立体选择性引入吲哚的曼尼希型分子内环化反应。此外,通过使用这种新的曼尼希型环化反应,还由乙缩醛酰胺9a和各种亲核试剂合成了11个取代的5 H-吡咯并[2,1- c ] [1,4]苯并二氮杂-5-酮(16)。。
Biosynthesis of the Enterotoxic Pyrrolobenzodiazepine Natural Product Tilivalline
作者:Elisabeth Dornisch、Jakob Pletz、Ronald A. Glabonjat、Florian Martin、Christian Lembacher-Fadum、Margit Neger、Christoph Högenauer、Kevin Francesconi、Wolfgang Kroutil、Klaus Zangger、Rolf Breinbauer、Ellen L. Zechner
DOI:10.1002/anie.201707737
日期:2017.11.13
the biosynthesis of tilivalline and show that this nonribosomal peptide assembly pathway initially generates tilimycin, a simple pyrrolobenzodiazepine with cytotoxic properties. Tilivalline results from the non-enzymatic spontaneous reaction of tilimycin with biogenetically generated indole. Through a chemical total synthesis of tilimycin we could corroborate the predictions made about the biosynthesis
Tilivalline (1), a metabolite from Klebsiella, has been efficiently and stereoselectively synthesized from diphenyl phosphorazidate (DPPA), the 2-oxazoline 2, the L-proline derivative 5, and indole: the key step is a Mannich type intramolecular cyclization accompanied with simultaneous and completely stereoselective introduction of indole.
Epimerization of tilivalline (1) at the C11-position occurred by treatment with zinc chloride to give a mixture of 1 and its 11-epimer (epi-1) in a ratio of 83 : 17. The computational chemical analysis of the thermodynamic stability of 1 and epi-1 through MM3(92) also revealed the energetic preference of 1 and the calculated equilibrium ratio of 1 and epi-1 was consistent with the experimental results
Tilivalline, a new pyrrolo[2, 1-c][1,4] benzodiazepine metabolite from klebsiella
作者:Nikolaus Mohr、Herbert Budzikiewicz
DOI:10.1016/0040-4020(82)85058-8
日期:1982.1
FromKlebsiella pneumoniae (+)(11S, 11aS) - 1,2,3,10,11,11a - hexahydro - 9 - hydroxy - 11 - (3′ - indolyl) - 5H - pyrrolo[2,1-c][1,4]benzodiazepin - 5 - one (1) has been isolated for which the name tilivalline is suggested. Structure elucidation and synthesis are reported.
来自肺炎克雷伯菌(+)(11S,11aS)-1,2,3,10,11,11a-六氢-9-羟基-11-(3'-吲哚基)-5 H-吡咯并[2,1- c ] [1,4]苯并二氮杂-5-一(1)已被隔离,其名称为tilivalline。报告了结构阐明和合成。
A tricyclic pyrrolobenzodiazepine produced by Klebsiella oxytoca is associated with cytotoxicity in antibiotic-associated hemorrhagic colitis
Cytotoxin-producing Klebsiella oxytoca is the causative agent of antibiotic-associated hemorrhagic colitis (AAHC). Recently, the cytotoxin associated with AAHC was identified as tilivalline, a known pentacyclic pyrrolobenzodiazepine (PBD) metabolite produced by K. oxytoca. Although this assertion of tilivalline's role in AAHC is supported by evidence from animal experiments, some key aspects of this finding appear to be incompatible with toxicity mechanisms of known PBD toxins. We therefore hypothesized that K. oxytoca may produce some other uncharacterized cytotoxins. To address this question, we investigated whether tilivalline alone is indeed necessary and sufficient to induce cytotoxicity or whether K. oxytoca also produces other cytotoxins. LC-MS- and NMR-based metabolomic analyses revealed the presence of an abundant tricyclic PBD, provisionally designated kleboxymycin, in the supernatant of toxigenic K. oxytoca strains. Moreover, by generating multiple mutants with gene deletions affecting tilivalline biosynthesis, we show that a tryptophanase-deficient, tilivalline-negative K. oxytoca mutant induced cytotoxicity in vitro similar to tilivalline-positive K. oxytoca strains. Furthermore, synthetic kleboxymycin exhibited greater than 9-fold higher cytotoxicity than tilivalline in TC50 cell culture assays. We also found that the biosynthetic pathways for kleboxymycin and tilivalline appear to overlap, as tilivalline is an indole derivative of kleboxymycin. In summary, our results indicate that tilivalline is not essential for inducing cytotoxicity observed in K. oxytoca-associated AAHC and that kleboxymycin is a tilivalline-related bacterial metabolite with even higher cytotoxicity.