Isolation and biosynthesis of daturamycins from Streptomyces sp. KIB-H1544

• Yin Chen,
• Jinqiu Ren,
• Ruimin Yang,
• Jie Li,
• Sheng-Xiong Huang and
• Yijun Yan

Beilstein J. Org. Chem. 2022, 18, 1009–1016, doi:10.3762/bjoc.18.101

• daturamycins was identified through gene knockout and biochemical characterization experiments and the biosynthetic pathway of daturamycins was proposed. Keywords: biosynthesis; diarylcyclopentenone; polyporic acid synthetase; p-terphenyl; Streptomyces; Introduction Natural products containing a terphenyl

• DatA, which catalyzes the Claisen–Dieckmann condensation of phenylpyruvic acid (7) to generate the key intermediate polyporic acid (8). Finally, we proposed a biosynthetic pathway for daturamycins. Results and Discussion Daturamycin A (1), a yellow powder, possessed a molecular formula of C19H16O5 with

• . Diarylcyclopentenones, characteristic constituents of mushrooms [23], were rarely discovered in Streptomyces species. These components exhibit redox activity and are involved in reducing ferric (Fe3+) in the Fenton-based biological decomposition of lignocellulose [24][25]. The biosynthetic pathway of p-terphenyl was

Anti-inflammatory aromadendrane- and cadinane-type sesquiterpenoids from the South China Sea sponge Acanthella cavernosa

• Shou-Mao Shen,
• Qing Yang,
• Yi Zang,
• Jia Li,
• Xueting Liu and
• Yue-Wei Guo

Beilstein J. Org. Chem. 2022, 18, 916–925, doi:10.3762/bjoc.18.91

• -dependent density functional theory/electronic circular dichroism (TDDFT-ECD) calculations or X-ray diffraction analysis. A plausible biosynthetic pathway of these sesquiterpenoids and their internal correlation were proposed and discussed. In an in vitro bioassay, (+)-aristolone (3) exhibited promising

• anti-inflammatory activity by the inhibition of LPS-induced TNF-α and CCL2 release in RAW 264.7 macrophages. Keywords: Acanthella cavernosa; anti-inflammatory; biosynthetic pathway; chiral separation; marine sponge; sesquiterpenoid; Introduction Marine sponges of the genus Acanthella (class

• with five related known ones [2, 3, (−)-4, 6, and 7] (Figure 1), were obtained. Herein, we report the isolation, chiral separation of racemic mixtures of 4 and 5, structural elucidation, plausible biosynthetic pathway, and biological evaluation of these isolated compounds. Results and Discussion By the

Efficient production of clerodane and ent-kaurane diterpenes through truncated artificial pathways in Escherichia coli

• Fang-Ru Li,
• Xiaoxu Lin,
• Qian Yang,
• Ning-Hua Tan and
• Liao-Bin Dong

Beilstein J. Org. Chem. 2022, 18, 881–888, doi:10.3762/bjoc.18.89

• production of terpentetriene. The medium screening for terpentetriene production as well as the elucidation of terpentetriene biosynthetic pathway in K. griseola DSM 43859 are underway in our lab. Thus, all essential genes (phoN, ipk, idi, ggdps, tdps, and ttes) for a truncated artificial pathway to produce

• the clerodane diterpene, terpentetriene, were fully collected. The biosynthetic pathway towards ent-kaurene resembles that of terpentetriene. First, a class II DTS catalyzes the cyclization of GGDP into a diphosphate intermediate, ent-copalyl diphosphate (ent-CPP). Next, a class I DTS further cyclizes

The stereochemical course of 2-methylisoborneol biosynthesis

• Binbin Gu,
• Anwei Hou and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2022, 18, 818–824, doi:10.3762/bjoc.18.82

• processing through (R)-2-Me-LPP [23]. The GPP methyltransferase (GPPMT) and the 2-methylisoborneol synthase (2MIBS) and their coding genes were discovered and functionally characterized, giving further evidence for the biosynthetic pathway to compound 1 [23][24][25]. As we have recently demonstrated, the

Sesquiterpenes from the soil-derived fungus Trichoderma citrinoviride PSU-SPSF346

• Wiriya Yaosanit,
• Vatcharin Rukachaisirikul,
• Souwalak Phongpaichit,
• Sita Preedanon and
• Jariya Sakayaroj

Beilstein J. Org. Chem. 2022, 18, 479–485, doi:10.3762/bjoc.18.50

• . Structures of compounds 1–7 isolated from Trichoderma citrinoviride PSU-SPSF346. 1H-1H COSY, key HMBC, and NOEDIFF data of compounds 1 and 2. ECD spectra of compounds 1 and 3 in MeOH. Proposed biosynthetic pathway for compound 2. The NMR data of compounds 1 and 2 in CD3OD. Supporting Information Supporting

Amamistatins isolated from Nocardia altamirensis

• Till Steinmetz,
• Wolf Hiller and
• Markus Nett

Beilstein J. Org. Chem. 2022, 18, 360–367, doi:10.3762/bjoc.18.40

• reductive degradation of amamistatin-type siderophores. Compound 6 represents a possible shunt product of amamistatin biosynthesis. A similar molecule and its putative biosynthetic pathway were recently described by Jaspars et al. [12]. In accordance with this proposal, salicylic acid and ʟ-threonine would

α-Ketol and α-iminol rearrangements in synthetic organic and biosynthetic reactions

• Scott Benz and
• Andrew S. Murkin

Beilstein J. Org. Chem. 2021, 17, 2570–2584, doi:10.3762/bjoc.17.172

• a biosynthetic pathway for the novel steroid asperflotone (72), it was suggested that its source was asperfloroid (73), a similar steroid isolated from the same source fungus, Aspergillus flocculosus [23]. First, reduction of the C8–C9 double bond and oxidation at C15 would provide α-ketol 74

• of proposed intermediate 78, occurs with base (M = K or Cs), but dehydration to 81 occurs with acid. c) Substrate scope of similar Cs2CO3-catalyzed α-ketol rearrangements. Proposed biosynthetic pathway converting acylphloroglucinol (87) to isolated elodeoidins A–H 92–96. Oxidation at C3 followed by α

Synthesis of O⁶-alkylated preQ₁ derivatives

• Laurin Flemmich,
• Sarah Moreno and
• Ronald Micura

Beilstein J. Org. Chem. 2021, 17, 2295–2301, doi:10.3762/bjoc.17.147

• in the biosynthetic pathway of the hypermodified tRNA nucleoside queuosine (Q) (Scheme 1) [5]. The core structure of the nucleobase is 7-aminomethyl-7-deazaguanine, a pyrrolo[2,3-d]pyrimidine also termed prequeuosine base (preQ1) [6][7]. In many bacteria, preQ1 binds to specific mRNA domains and

• residue in huimycin and to a 2-[4'-(4''-O-methyl-ß-ᴅ-glucopyranosyl)-6'-deoxy-α-ᴅ-glucopyranosyl] moiety in dapiramicin A [19][20]. In the biosynthetic pathway, the conversion of preQ0 into huimycin requires methylation of preQ0 and attachment of the N-acetylglucosamine moiety as final steps [18]. The

Beyond ribose and phosphate: Selected nucleic acid modifications for structure–function investigations and therapeutic applications

• Christopher Liczner,
• Kieran Duke,
• Gabrielle Juneau,
• Martin Egli and
• Christopher J. Wilds

Beilstein J. Org. Chem. 2021, 17, 908–931, doi:10.3762/bjoc.17.76

• Damha [208]. Zhou reasoned that because 3'-O-β-glucosylated nucleocidin, an intermediate in the biosynthetic pathway of nucleocidin, was stable, they may be able to successfully achieve the synthesis of the 4'-F-rU phosphoramidite through a selective protection of the hydroxy groups in stages [211

Synthesis of legonmycins A and B, C(7a)-hydroxylated bacterial pyrrolizidines

• Wilfred J. M. Lewis,
• David M. Shaw and
• Jeremy Robertson

Beilstein J. Org. Chem. 2021, 17, 334–342, doi:10.3762/bjoc.17.31

• pxaAB gene cluster in E. coli, and analysis of the metabolites by differential 2D NMR spectroscopy, led to the isolation and characterization of pyrrolizixenamide A (9) and, subsequently, pyrrolizixenamides B–D (10–12). Ultimately, an analogous biosynthetic pathway to that proposed for the legonmycins

3-Acetoxy-fatty acid isoprenyl esters from androconia of the ithomiine butterfly Ithomia salapia

• Florian Mann,
• Daiane Szczerbowski,
• Lisa de Silva,
• Melanie McClure,
• Marianne Elias and
• Stefan Schulz

Beilstein J. Org. Chem. 2020, 16, 2776–2787, doi:10.3762/bjoc.16.228

• . The position of the double bonds in the acyl chain of the esters can be explained by a biosynthetic pathway described in detail in Scheme 5. The double bond distribution is consistent with both desaturases acting on palmitic acid, leading to the respective hexadecenoic acids. These acids are the

• % HBraq, toluene, 24 h, 110 °C, 79%; b) IBX, EtOAc, 60 °C, 3.15 h, 90%; c) C5H11PPh3Br, LDA, THF, −78 °C, 12 h, 84%; d) i) Mg, 21, THF, ii) (S)-22, Cu(I)I, THF, –30 °C, 12 h, 79%; e) SnOBu2, 140°C, 36 h, 65%; f) Ac2O, pyridine, DMAP, CH2Cl2, 12 h rt, 74%. Proposed biosynthetic pathway of fatty acids

Synthesis of C-glycosyl phosphonate derivatives of 4-amino-4-deoxy-α-ʟ-arabinose

• Lukáš Kerner and
• Paul Kosma

Beilstein J. Org. Chem. 2020, 16, 9–14, doi:10.3762/bjoc.16.2

• were inactive towards enzyme upstream of the biosynthetic pathway to undecaprenyl Ara4N, the peracetylated 4-azido derivative showed modest reduction of Ara4N incorporation into the lipid A part of Salmonella typhimurium [8]. We have recently set out to study the substrate specificity of ArnT enzymes

Terpenes

• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2019, 15, 2966–2967, doi:10.3762/bjoc.15.292

• products. Their remarkable structural complexity and diversity is a result of a unique biosynthetic pathway invented by nature that starts with the formation of only a few acyclic precursors termed oligoprenyl diphosphates. These precursors containing multiple olefinic double bonds can be ionised to

Chemical synthesis of tripeptide thioesters for the biotechnological incorporation into the myxobacterial secondary metabolite argyrin via mutasynthesis

• David C. B. Siebert,
• Roman Sommer,
• Domen Pogorevc,
• Michael Hoffmann,
• Silke C. Wenzel,
• Rolf Müller and
• Alexander Titz

Beilstein J. Org. Chem. 2019, 15, 2922–2929, doi:10.3762/bjoc.15.286

• antipseudomonal activity. The biosynthetic pathway for argyrin production in Cystobacter sp. SBCb004 (Arg1, radical SAM-dependent methyltransferase; Arg2/Arg3, nonribosomal peptide synthetases; Arg4, O‑methyltransferase; Arg5, tryptophan 2,3-dioxygenase). The initial tripeptide of the biosynthesis of the argyrins

Bacterial terpene biosynthesis: challenges and opportunities for pathway engineering

• Eric J. N. Helfrich,
• Geng-Min Lin,
• Christopher A. Voigt and
• Jon Clardy

Beilstein J. Org. Chem. 2019, 15, 2889–2906, doi:10.3762/bjoc.15.283

• potential with molecular structure is severely restricted. The canonical terpene biosynthetic pathway uses a single enzyme to form a cyclized hydrocarbon backbone followed by modifications with a suite of tailoring enzymes that can generate dozens of different products from a single backbone. This

Nanangenines: drimane sesquiterpenoids as the dominant metabolite cohort of a novel Australian fungus, Aspergillus nanangensis

• Heather J. Lacey,
• Cameron L. M. Gilchrist,
• Andrew Crombie,
• John A. Kalaitzis,
• Daniel Vuong,
• Peter J. Rutledge,
• Peter Turner,
• John I. Pitt,
• Ernest Lacey,
• Yit-Heng Chooi and
• Andrew M. Piggott

Beilstein J. Org. Chem. 2019, 15, 2631–2643, doi:10.3762/bjoc.15.256

• bacteria, fungi, mammalian cells and plants. Bioinformatics analysis, including comparative analysis with other acyl drimenol-producing Aspergilli, led to the identification of a putative nanangenine biosynthetic gene cluster that corresponds to the proposed biosynthetic pathway for nanangenines. Keywords

• analyses above, a biosynthetic pathway to the nanangenines was proposed (Figure 3). Unlike the ast cluster, where there are multiple HAD-like enzymes encoded (one terpene synthase and two phosphatases), the putative nanangenine cluster only encodes one such enzyme, FE257_006542. However, given that

• biosynthetic gene cluster in A. nanangensis MST-FP2251 and homologs identified in other drimane sesquiterpenoid-producing species of Aspergillus section Usti. Gene models are drawn to scale; shaded boxes that link gene models represent amino acid identity (0% transparent; 100% black). Putative biosynthetic

Analysis of sesquiterpene hydrocarbons in grape berry exocarp (Vitis vinifera L.) using in vivo-labeling and comprehensive two-dimensional gas chromatography–mass spectrometry (GC×GC–MS)

• Philipp P. Könen and
• Matthias Wüst

Beilstein J. Org. Chem. 2019, 15, 1945–1961, doi:10.3762/bjoc.15.190

• (+)-valencene from germacrene A [11]. This biosynthetic pathway could also be confirmed by feeding experiments. The formation of the three aforementioned sesquiterpene hydrocarbons takes place without deuterium loss, so that with the use of d3-MVL as precursor (Scheme 5) nine deuterium atoms and with the use of

• described by Steele et al. for the formation of guaia-6,9-diene and δ-selinene via germacrene C could also be confirmed by feeding experiments (Scheme 7) [9]. Biosynthesis of (E)-β-caryophyllene and α-humulene The biosynthetic pathway postulated by Boland and Garms for the formation of (E)-β-caryophyllene

• from farnesyl pyrophosphate (FPP) is consistent with our feeding experiments (Scheme 8) [29]. The incorporation of deuterium atoms into (E)-β-caryophyllene during biosynthesis is shown by the following mass spectra (Figure 11). The assumed biosynthetic pathway for the formation of (E)-β-caryophyllene

Targeting the Pseudomonas quinolone signal quorum sensing system for the discovery of novel anti-infective pathoblockers

• Christian Schütz and
• Martin Empting

Beilstein J. Org. Chem. 2018, 14, 2627–2645, doi:10.3762/bjoc.14.241

• [38]. HQNO acts through inhibition of complex III in the respiratory chain of bacteria and mitochondria of eukaryotes and, hence, it can be considered a general cytotoxic agent. DHQ, a shunt product of the PQS biosynthetic pathway, is important for P. aeruginosa virulence in a Caenorhabditis elegans

Volatiles from three genome sequenced fungi from the genus Aspergillus

• Jeroen S. Dickschat,
• Ersin Celik and
• Nelson L. Brock

Beilstein J. Org. Chem. 2018, 14, 900–910, doi:10.3762/bjoc.14.77

• biosynthetic pathway from linoleic acid via its hydroperoxide has been suggested [24][25][26], and if the same biosynthetic steps would proceed from linolenic acid, this would result in the assigned structure of 2 (Scheme 1B). The other compounds identified in the headspace extracts of A. fischeri were all

Volatiles from the xylarialean fungus Hypoxylon invadens

• Jeroen S. Dickschat,
• Tao Wang and
• Marc Stadler

Beilstein J. Org. Chem. 2018, 14, 734–746, doi:10.3762/bjoc.14.62

• -dimethylphenol (11), B) 2-hydroxy-4-methylbenzaldehyde (12), C) 3,4-dimethoxytoluene (15), D) 2-methoxy-4-methylbenzaldehyde (17), E) 2-methoxy-5-methylphenol (14), F) 5-hydroxy-2-methylchroman-4-one (18), and G) 5-hydroxy-2-methyl-4H-chromen-4-one (19). Proposed common biosynthetic pathway to volatile aromatic

Volatiles from the tropical ascomycete Daldinia clavata (Hypoxylaceae, Xylariales)

• Tao Wang,
• Kathrin I. Mohr,
• Marc Stadler and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2018, 14, 135–147, doi:10.3762/bjoc.14.9

• structure could be assigned to each of the eight peaks observed in this analysis, again confirming the structure of (4R,5R,6S)-11a for the natural product from D. clavata (Figure 4). The 13C NMR data of all four stereoisomers 11a–d are summarised in Table 2. A proposed biosynthetic pathway to (4R,5R,6S)-11a

Herpetopanone, a diterpene from Herpetosiphon aurantiacus discovered by isotope labeling

• Xinli Pan,
• Nicole Domin,
• Sebastian Schieferdecker,
• Hirokazu Kage,
• Martin Roth and
• Markus Nett

Beilstein J. Org. Chem. 2017, 13, 2458–2465, doi:10.3762/bjoc.13.242

• resemblance to cadinane-type sesquiterpenes from plants, but is structurally entirely unprecedented in bacteria. Based on its molecular architecture, a possible biosynthetic pathway is postulated. Keywords: genome mining; herpetopanone; Herpetosiphon; isotope labeling; terpene; Introduction Terpenoids

Enzymatic synthesis of glycosides: from natural O- and N-glycosides to rare C- and S-glycosides

• Jihen Ati,
• Pierre Lafite and
• Richard Daniellou

Beilstein J. Org. Chem. 2017, 13, 1857–1865, doi:10.3762/bjoc.13.180

• aggression. Their biosynthetic pathway requires the action of a S-GT (UGT74B1) that catalyses the reaction between a thiohydroximate acceptor and UDP-α-D-glucose as sugar donor to yield the corresponding desulfoglucosinolate (Figure 2) [20][21]. UGT74B1 from A. thaliana is a versatile enzyme in terms of

The chemistry and biology of mycolactones

• Matthias Gehringer and
• Karl-Heinz Altmann

Beilstein J. Org. Chem. 2017, 13, 1596–1660, doi:10.3762/bjoc.13.159

• C14’. The first and currently only mycolactone originating from a genetically engineered biosynthetic pathway was isolated by Leadlay and co-workers in 2007 [63]. Thus, the cloning of a CYP450 hydroxylase gene from a related strain into the M. marinum DL045 strain produced a mycolactone F variant with

Biosynthetic origin of butyrolactol A, an antifungal polyketide produced by a marine-derived Streptomyces

• Enjuro Harunari,
• Hisayuki Komaki and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2017, 13, 441–450, doi:10.3762/bjoc.13.47

• ; pink, PKS for polyketide backbone of 1; yellow, genes for biosynthesis of hydroxymalonyl-ACP; gray, transporter. Biosynthetic pathway of hydroxymalonyl-ACP. Adapted from [24]. Incorporation of L-valine-d8 into 1. (a) 1H NMR spectrum of natural 1 and 2H NMR spectrum of L-valine-d8-labeled 1. (b) ESIMS

• produced by a Streptomyces strain collected from deep sea water of the Toyama Bay, Japan. In order to get insight into the construction of the above-mentioned unusual structures, we performed an in silico analysis of the biosynthetic genes of 1 through draft genome sequencing and proposed its biosynthetic

• pathway [22]. In this study, biosynthetic precursors of 1 were investigated for further genetic and enzymatic studies. Results and Discussion It was obvious from its structure that 1 was synthesized through the malonate pathway. First, [1,2-13C2]acetate was fed to the culture to ensure the alignment of