Geschmack ist vorhersagbar: Mit FlavorMiner. FlavorMiner heißt das Tool, das IPB-Chemiker und Partner aus Kolumbien jüngst entwickelt haben. Das Programm kann, basierend auf maschinellem Lernen (KI), anhand der…
Seit Februar 2021 bietet Wolfgang Brandt, ehemaliger Leiter der Arbeitsgruppe Computerchemie am IPB, sein Citizen Science-Projekt zur Pilzbestimmung an. Dafür hat er in regelmäßigen Abständen öffentliche Vorträge zur Vielfalt…
Pyrofomins A-D, four polyoxygenated sesquiterpenoids have been isolated from the methanolic extract of the fruit bodies of Pyrofomes demidoffii. Their structures are elucidated by IR, HR-FTICR-MS, and 2D NMR spectroscopy. Furthermore, the cedrane carbon skeleton of pyrofomin A (1) is confirmed by X-ray crystallographic analysis. The sesquiterpenoids 1–4 show neither cytotoxicity against KB cells nor antimicrobial activity.
Publikation
Myint Khine, M.; Franke, K.; Arnold, N.; Porzel, A.; Schmidt, J.; Wessjohann, L. A.;A new cardenolide from the roots of Streptocaulon tomentosumFitoterapia75779-781(2004)DOI: 10.1016/j.fitote.2004.06.007
A new cardenolide, (17α)-H-periplogenin-3-O-β-d-glucopyranosyl-(1–4)-2-O-acetyl-3-O-methyl-β-fucopyranoside (1), was isolated from the roots of Streptocaulon tomentosum.
Publikation
Xu, H.; Wang, Z.-X.; Schmidt, J.; Heide, L.; Li, S.-M.;Genetic analysis of the biosynthesis of the pyrrole and carbamoyl moieties of coumermycin A1 and novobiocinMol. Gen. Genomics268387-396(2002)DOI: 10.1007/s00438-002-0759-1
The aminocoumarin antibiotic coumermycin A1 contains a central and two terminal pyrrole moieties. The coumermycin gene cluster in Streptomyces rishiriensis contains three genes (couN3, couN4 and couN5) that show sequence similarity to genes involved in the biosynthesis of the pyrrole moieties of pyoluteorin in Pseudomonas fluorescens and of undecylprodiginine in S. coelicolor. The gene couN3, which codes for a putative L-prolyl-S-PCP dehydrogenase, and the gene couN4, which encodes a putative L-prolyl-AMP ligase, were disrupted using in-frame deletion and insertional inactivation, respectively. HPLC analysis of culture extracts showed that formation of the two terminal pyrrole moieties was abolished in the couN3 - und couN4 - mutants. The mutants accumulated coumermycin D, which contains only the central pyrrole moiety. This result not only confirmed the involvement of couN3 and couN4 in the biosynthesis of the terminal pyrrole-2-carboxylic acid moieties of coumermycin A1, but also indicated, for the first time, that the central 3-methylpyrrole-2,4-dicarboxylic acid unit of the coumermycins is formed by a biosynthetic pathway that differs from that used to assemble the terminal pyrrole moieties. novN, a putative carbamoyl transferase gene from the gene cluster for novobiocin biosynthesis in S. spheroides was expressed in the couN3 - mutant. This led to the formation of bis-carbamoylated coumermycin D, a novel compound of the coumermycin series.
Publikation
Blitzke, T.; Masaoud, M.; Schmidt, J.;Constituents of Aloe rubroviolaceaFitoterapia7278-79(2001)DOI: 10.1016/S0367-326X(00)00239-2