Biochemical and structural characterisation of the second oxidative crosslinking step during the biosynthesis of the glycopeptide antibiotic A47934

• Veronika Ulrich,
• Clara Brieke and
• Max J. Cryle

Beilstein J. Org. Chem. 2016, 12, 2849–2864, doi:10.3762/bjoc.12.284

• , which is generated by the actions of cytochrome P450 (Oxy) enzymes that affect the crosslinking of aromatic side chains of amino acid residues contained within the GPA heptapeptide precursor. Given the crucial role peptide cyclisation plays in GPA activity, the characterisation of this process is of

• homologues can display significantly different catalytic propensities despite their overall similarities. Keywords: crystal structure; cytochrome P450; glycopeptide antibiotic; peptide; phenolic coupling; Introduction The glycopeptide antibiotics (GPAs) are a series of highly modified heptapeptide natural

• generation GPAs in clinical use are all entirely derived from in vivo biosynthesis [1][2]. The biosynthesis of GPAs is based around the initial synthesis of the linear heptapeptide by a type-I non-ribosomal peptide synthetase (NRPS) [5][6] and its subsequent modification by cytochrome P450 monooxygenases [7

A detailed view on 1,8-cineol biosynthesis by Streptomyces clavuligerus

• Jan Rinkel,
• Patrick Rabe,
• Laura zur Horst and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2016, 12, 2317–2324, doi:10.3762/bjoc.12.225

• representing various stereoisomers and constitutional isomers with different positioning of olefinic double bonds or alcohol functions are known just for sesquiterpenes [11]. The structural diversity of terpenoids can be further increased by the action of tailoring enzymes such as cytochrome P450

Biosynthesis of oxygen and nitrogen-containing heterocycles in polyketides

• Franziska Hemmerling and
• Frank Hahn

Beilstein J. Org. Chem. 2016, 12, 1512–1550, doi:10.3762/bjoc.12.148

• polyketide with potent antitumor, antifungal, antiparasitic, pesticidal and antitrypanosomal activities (Scheme 13). In its biosynthesis, the furan-ring formation occurs on a late stage, catalysed in an unprecedented fashion by the cytochrome P450 oxidase AurH [13][62][63][64][65][66][67]. This enzyme

• intensive studies. Gene disruption experiments in the aflatoxigenic strain A. parasiticus NRRL 2999 revealed that this step is in fact catalysed by the cytochrome P450 enzyme AVR monooxygenase via an undeciphered mechanism (encoded by the gene cypX, see Scheme 16) [93]. The same study also revealed the

• and aflY) have been implied in biosynthetic studies to code for enzymes that are participating in this complex conversion [100]. Henry and Townsend suggested an oxidation–reduction–oxidation sequence mediated by putative NADPH-dependent oxidoreductase AflM and cytochrome P450 enzyme AflN [101]. Gene

From steroids to aqueous supramolecular chemistry: an autobiographical career review

• Bruce C. Gibb

Beilstein J. Org. Chem. 2016, 12, 684–701, doi:10.3762/bjoc.12.69

• peripheral to your current studies with SciFinder. Life is so much more than either your brain or an algorithm, and if you expose yourself to other chemistries going on around you might be very surprised what pops up. In my case, the Breslow paper pointed me towards the cytochrome P450 family of enzymes, or

Biosynthesis of α-pyrones

• Till F. Schäberle

Beilstein J. Org. Chem. 2016, 12, 571–588, doi:10.3762/bjoc.12.56

• and by inducing the so-called aryl hydrocarbon receptor, apoptosis is mediated by inducing cytochrome P450 1A1 [25]. For alternariol 9-methyl ether (19) and the graphislactone A (21) cytotoxic effects against the human cancer cell line SW1116 with IC50 values between 8.5 and 21 μg/mL were reported [26

Base metal-catalyzed benzylic oxidation of (aryl)(heteroaryl)methanes with molecular oxygen

• Hans Sterckx,
• Johan De Houwer,
• Carl Mensch,
• Wouter Herrebout,
• Kourosch Abbaspour Tehrani and
• Bert U. W. Maes

Beilstein J. Org. Chem. 2016, 12, 144–153, doi:10.3762/bjoc.12.16

• metabolites is therefore of great importance to facilitate the drug discovery process [42]. For this purpose chemoselective oxidation protocols are a valuable tool since they can provide us with metabolites typically generated by cytochrome P450 enzymes. Bearing this in mind we attempted to oxygenate the

Recent highlights in biosynthesis research using stable isotopes

• Jan Rinkel and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2015, 11, 2493–2508, doi:10.3762/bjoc.11.271

• diterpenoid product cyclooctat-9-en-7-ol (52). Further oxidation by the cytochrome P450-hydroxylases CotB3 and CotB4 yields the biologically active compound cyclooctatin (45) [67]. This outstanding study exemplifies the scope of isotopic labeling experiments in the elucidation of terpene biosynthesis by

Active site diversification of P450cam with indole generates catalysts for benzylic oxidation reactions

• Paul P. Kelly,
• Anja Eichler,
• Susanne Herter,
• David C. Kranz,
• Nicholas J. Turner and
• Sabine L. Flitsch

Beilstein J. Org. Chem. 2015, 11, 1713–1720, doi:10.3762/bjoc.11.186

• Paul P. Kelly Anja Eichler Susanne Herter David C. Kranz Nicholas J. Turner Sabine L. Flitsch School of Chemistry & Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, M1 7DN, Manchester, United Kingdom 10.3762/bjoc.11.186 Abstract Cytochrome P450

• low cost starting materials [1]. One of the most attractive reagents in terms of cost and environmental impact for hydrocarbon oxidation is oxygen in the presence of a catalyst. In this context enzymatic oxidations are attractive, in particular cytochrome P450 monooxygenases (P450s or CYPs) due to

Selective allylic hydroxylation of acyclic terpenoids by CYP154E1 from Thermobifida fusca YX

• Anna M. Bogazkaya,
• Clemens J. von Bühler,
• Sebastian Kriening,
• Alexandrine Busch,
• Alexander Seifert,
• Jürgen Pleiss,
• Sabine Laschat and
• Vlada B. Urlacher

Beilstein J. Org. Chem. 2014, 10, 1347–1353, doi:10.3762/bjoc.10.137

• . Regioselective oxidation of parental alkenes is a challenging task for chemical catalysts and requires several steps including protection and deprotection. Many cytochrome P450 enzymes are known to catalyse selective allylic hydroxylation under mild conditions. Here, we describe CYP154E1 from Thermobifida fusca

• -box for allylic hydroxylation in synthetic chemistry. Keywords: allylic hydroxylation; cytochrome P450; natural products; protein engineering; regiochemistry; terpenoids; Introduction Direct allylic hydroxylation yielding highly valuable allylic alcohols has been recognised for a while as one of the

• terpenoids in plants represents the most prominent example [14]. Heme-containing cytochrome P450 monooxygenases (P450 or CYP) are predominantly responsible for structural and functional diversity of terpenoids: allylic hydroxylation of parental monoterpenes leads to further diversification via sequential

Intermediates in monensin biosynthesis: A late step in biosynthesis of the polyether ionophore monensin is crucial for the integrity of cation binding

• Wolfgang Hüttel,
• Jonathan B. Spencer and
• Peter F. Leadlay

Beilstein J. Org. Chem. 2014, 10, 361–368, doi:10.3762/bjoc.10.34

• undergoes a cascade of ring opening/closing catalysed by the combined action of the unusual epoxide hydrolases MonBI and MonBII, to give the putative protein-bound intermediate dehydroxydemethylmonensin. The next steps, catalysed respectively by the cytochrome P450 hydroxylase MonD and the methyltransferase

Recent progress in the discovery of small molecules for the treatment of amyotrophic lateral sclerosis (ALS)

• Allison S. Limpert,
• Margrith E. Mattmann and
• Nicholas D. P. Cosford

Beilstein J. Org. Chem. 2013, 9, 717–732, doi:10.3762/bjoc.9.82

• , riluzole demonstrates variable drug exposure in addition to highly differential serum concentrations among ALS patients following oral administration [9]. This variability correlates with the heterogeneous patient expression of the cytochrome P450 (CYP) isoform CYP1A2, which provides the primary mechanism

Chemical–biological characterization of a cruzain inhibitor reveals a second target and a mammalian off-target

• Jonathan W. Choy,
• Clifford Bryant,
• Claudia M. Calvet,
• Patricia S. Doyle,
• Shamila S. Gunatilleke,
• Siegfried S. F. Leung,
• Kenny K. H. Ang,
• Steven Chen,
• Jiri Gut,
• Juan A. Oses-Prieto,
• Jonathan B. Johnston,
• Michelle R. Arkin,
• Alma L. Burlingame,
• Jack Taunton,
• Matthew P. Jacobson,
• James M. McKerrow,
• Larissa M. Podust and
• Adam R. Renslo

Beilstein J. Org. Chem. 2013, 9, 15–25, doi:10.3762/bjoc.9.3

• (TcCYP51), a cytochrome P450 enzyme involved in the biosynthesis of ergosterol in the parasite. Compound 4 also inhibits mammalian CYP isoforms but is trypanocidal at concentrations below those required to significantly inhibit mammalian CYPs in vitro. A chemical-proteomics approach employing an activity

• investigated are cruzain [7][8][9][10], the major cysteine protease active in the parasite, and T. cruzi CYP51 (TcCYP51), a 14-α-demethylase enzyme of the cytochrome P450 family required for ergosterol biosynthesis [11][12][13][14]. TcCYP51 is analogous to the fungal enzyme targeted by the azole class of

• , producing new lead compounds with compelling properties [37][38][39]. Inhibition of mammalian CYPs A concern with any inhibitor of TcCYP51 is the potential for cross reactivity with mammalian cytochrome P450 (CYP) enzymes, especially those CYPs involved in drug metabolism, like CYP3A4. To assess this risk

Regio- and stereoselective oxidation of unactivated C–H bonds with Rhodococcus rhodochrous

• Elaine O’Reilly,
• Suzanne J. Aitken,
• Gideon Grogan,
• Paul P. Kelly,
• Nicholas J. Turner and
• Sabine L. Flitsch

Beilstein J. Org. Chem. 2012, 8, 496–500, doi:10.3762/bjoc.8.56

• isomers in yields of up to 26%. Most interestingly, 2-(4-nitrobenzyloxy)tetrahydrofuran and 2-(4-nitrobenzyloxy)tetrahydropyran were transformed in high yields to the 4-hydroxylated and 5-hydroxylated products, respectively. Keywords: biocatalysis; cytochrome P450; hydroxylation; Rhodococcus rhodochrous

• proceeded with regio-, diastereo- and enantioselectivity. We were also interested in establishing whether the oxidising capabilities of this organism were the result of cytochrome P450 activity. Results and Discussion Transformations of THP ether derivatives The results of the biohydroxylations of the p

• enantiomers. Nature of the hydroxylating enzyme One of the aims of this study was to investigate the nature of the hydroxylating enzyme in an attempt to establish whether the catalytic protein was a cytochrome P450. Inhibition studies with 1-aminobenzotriazole and metyrapone showed that hydroxylation was

Natural product biosyntheses in cyanobacteria: A treasure trove of unique enzymes

• Jan-Christoph Kehr,
• Douglas Gatte Picchi and
• Elke Dittmann

Beilstein J. Org. Chem. 2011, 7, 1622–1635, doi:10.3762/bjoc.7.191

• glutathione and protein synthesis as well as cytochrome P450. Characteristic features of cylindrospermopsins include a guanidine moiety and a hydroxymethyluracil attached to the tricyclic carbon skeleton. According to feeding assays, the polyketide chain assembly starts with the activation of guanidinoacetate

• hectochlorin synthesis. Chain elongation is performed by a monomodular PKS and two bimodular NRPS. Two of the NRPS modules are suggested to activate 2-oxo-isovaleric acid, which is reduced by an embedded KR domain to 2-hydroxyisovaleric acid and proposed to be further oxidized by one of two cytochrome-P450

Advances in synthetic approach to and antifungal activity of triazoles

• Kumari Shalini,
• Nitin Kumar,
• Sushma Drabu and
• Pramod Kumar Sharma

Beilstein J. Org. Chem. 2011, 7, 668–677, doi:10.3762/bjoc.7.79

• agents posaconazole (12) and ravuconazole (13)) are synthetic compounds that have one or more azole rings with three nitrogen atoms in a five membered ring. They act by inhibition of the cytochrome P450-dependent conversion of lanosterol to ergosterol [42]. Triazoles act as cytochrome P450 14α

• -demethylase inhibitors. This enzyme is involved in the conversion of lanosterol to ergosterol which is helpful in the cell wall synthesis. In this mechanism the basic nitrogen of the azole ring is tightly bound to the heme iron of the fungal cytochrome P450 preventing substrate and oxygen binding. Inhibition

• , tingling or numbness in the extremities and difficulty in breathing or swallowing. Pharmacokinetics First generation triazoles The antifungal triazoles are generally well tolerated, but have significant potential for drug–drug interactions through their interference with cytochrome P450-dependent oxidative