Cytochrome P450 monooxygenase-mediated tailoring of triterpenoids and steroids in plants

• Karan Malhotra and
• Jakob Franke

Beilstein J. Org. Chem. 2022, 18, 1289–1310, doi:10.3762/bjoc.18.135

• celastrol, a potent anti-obesity metabolite [42][43]. In two independent studies, transcriptome mining and functional studies in Nicotiana benthamiana were used to identify the CYPs CYP712K1, CYP712K2, CYP712K3, and CYP712K4 capable of oxidising friedelin (8) into polpunonic acid via an aldehyde

Vicinal ketoesters – key intermediates in the total synthesis of natural products

• Marc Paul Beller and
• Ulrich Koert

Beilstein J. Org. Chem. 2022, 18, 1236–1248, doi:10.3762/bjoc.18.129

• the desired α-carbonyl group. (−)-Preussochromone A In 2020, the Koert group disclosed the synthesis of (−)-preussochromone A (24), a fungal metabolite with a highly substituted tetrahydrothiopyrane core annulated to a chromenone [10]. The tetrahydrothiopyrane ring was closed by a Lewis-acid-promoted

• the cytotoxic metabolite (−)-aplaminal (96), which was isolated from the sea hare Aplysia kurodai [32]. The natural product is characterized by a triazabicyclo[3.2.1]octane, where each bridge possesses a nitrogen atom. The synthesis commenced with N-Boc-serine (93) which was converted to secondary

Synthesis of tryptophan-dehydrobutyrine diketopiperazine and biological activity of hangtaimycin and its co-metabolites

• Houchao Xu,
• Anne Wochele,
• Minghe Luo,
• Gregor Schnakenburg,
• Yuhui Sun,
• Heike Brötz-Oesterhelt and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2022, 18, 1159–1165, doi:10.3762/bjoc.18.120

• , People's Republic of China Institute of Inorganic Chemistry, University of Bonn, Gerhard-Domagk-Straße 1, 53121 Bonn, Germany 10.3762/bjoc.18.120 Abstract An improved synthesis for tryptophan-dehydrobutyrine diketopiperazine (TDD), a co-metabolite of the hybrid polyketide/non-ribosomal peptide

• ]. Another hangtaimycin co-metabolite in S. spectabilis [9] is tryptophan-dehydrobutyrine diketopiperazine (TDD, 4) that was already isolated several decades before the discovery of 1, and likewise reported to have no antibacterial activity [9]. The initially published structure was that of (E)-4 [9], but

• inactivity of 4 against bacteria was confirmed in this study, and also 2 is an inactive metabolite of S. spectabilis, while for 1 moderate growth retardation against A. baumannii and B. subtilis, and growth inhibition against PMBN-treated E. coli was observed. However, the low activity of 1 in these assays

Identification of the new prenyltransferase Ubi-297 from marine bacteria and elucidation of its substrate specificity

• Jamshid Amiri Moghaddam,
• Huijuan Guo,
• Karsten Willing,
• Thomas Wichard and
• Christine Beemelmanns

Beilstein J. Org. Chem. 2022, 18, 722–731, doi:10.3762/bjoc.18.72

• homogentisate and geranylgeranyl diphosphate [10][11]. Another intriguing Ptase, called AuaA, has been reported to catalyze the farnesylation of 2-methyl-4-hydroxyquinoline using farnesyl diphosphate (FPP), which results in the metabolite aurachin D [12][13]. Following up on our recent exploration of the

• , and a TIM barrel protein (EboE) [28]. While prior studies suggested that the enzymatic reactions carried out by EboA-E include the prenylation of an undetermined substrate by eboC (UbiA-297 homologue) and modifications of a polyhydroxylated aromatic metabolite, the enzymatic reactions carried out by

• of the enzymatic products: UHPLC-HESI-HRMS measurement was performed on a Dionex Ultimate3000 system combined with a Q-Exactive Plus mass spectrometer (Thermo Scientific) with a heated electrospray ion source (HESI). Metabolite separation was carried out by reversed-phase liquid chromatography at 40

Menadione: a platform and a target to valuable compounds synthesis

• Acácio S. de Souza,
• Ruan Carlos B. Ribeiro,
• Dora C. S. Costa,
• Fernanda P. Pauli,
• David R. Pinho,
• Matheus G. de Moraes,
• Fernando de C. da Silva,
• Luana da S. M. Forezi and
• Vitor F. Ferreira

Beilstein J. Org. Chem. 2022, 18, 381–419, doi:10.3762/bjoc.18.43

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

• been reported before. The isolated metabolite 5 represents the previously described siderophore amamistatin B [7], while compound 6 was before only known as a decomposition product of a synthetically prepared obafluorin derivative [8]. Results and Discussion To induce siderophore biosynthesis in N

• as eluent. Fractions that showed a color change in the CAS assay were pooled and subjected to semipreparative reversed-phase HPLC. This led to the isolation of six CAS active compounds (1–6; Figure 1). The major metabolite 1 (12 mg) was obtained as a slight reddish oil. High resolution (HR) ESIMS

Unsaturated fatty acids and a prenylated tryptophan derivative from a rare actinomycete of the genus Couchioplanes

• Shun Saito,
• Kanji Indo,
• Naoya Oku,
• Hisayuki Komaki,
• Masashi Kawasaki and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2021, 17, 2939–2949, doi:10.3762/bjoc.17.203

• underexplored. However, in silico genome mining identified multiple secondary metabolite biosynthetic gene clusters in selected strains from minor actinomycetes genera, implying their comparable biosynthetic capacities to those of the already proven genera [19]. Encouraged by these reports, we examined the

• Micromonosporaceae first isolated in 1994 from a sandy soil in Japan [23], was set to be the next target. While the anti-SMASH-assisted genome mining [24] in C. caeruleus DSM 43634 revealed approximately 20 secondary metabolite biosynthetic gene clusters, only one compound, heptaene macrolide 67-121C, is known to

• unused carbon (δH 177.1, C-1) and the molecular formula. A NOESY correlation between H-11 and H-12 supported an E-configuration for the C-4/C-5 double bond. The established planar structure was identical to that of a fungal metabolite phialomustin B [26], for which specific rotation, enumerated 1H and

First total synthesis of hoshinoamide A

• Haipin Zhou,
• Zihan Rui,
• Yiming Yang,
• Shengtao Xu,
• Yutian Shao and
• Long Liu

Beilstein J. Org. Chem. 2021, 17, 2924–2931, doi:10.3762/bjoc.17.201

• , hoshinoamides A, B [11] and C [12], from a microbial metabolite of marine cyanobacterium Caldora penicillata (Figure 1). Hoshinoamides A and B showed potent activities against chloroquine-sensitive Plasmodium falciparum 3D7 with IC50 values of 0.52 and 1.0 μM, respectively. Hoshinoamide C inhibited the growth

The ethoxycarbonyl group as both activating and protective group in N-acyl-Pictet–Spengler reactions using methoxystyrenes. A short approach to racemic 1-benzyltetrahydroisoquinoline alkaloids

• Marco Keller,
• Karl Sauvageot-Witzku,
• Franz Geisslinger,
• Nicole Urban,
• Michael Schaefer,
• Karin Bartel and
• Franz Bracher

Beilstein J. Org. Chem. 2021, 17, 2716–2725, doi:10.3762/bjoc.17.183

• alkaloids). The common biosynthetic origin of these alkaloids has been investigated thoroughly over decades, and (S)-norcoclaurine, a metabolite formally built up by condensation of dopamine and 4-hydroxyphenylacetaldehyde, was identified as the common intermediate. A broad range of biological activities

• in THF under reflux to give the racemic forms of the alkaloids armepavine (2a; from Rhamnus frangula [27][28][29]), laudanine (2c; from Papaver somniferum [30][31]), pseudocodamine (2d; metabolite of isoorientaline in Corydalis platycarpa makino cell species [32]), reticuline (2e; from Papaver

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

• similarity in reaction, 1-deoxy-ᴅ-xylulose-5-phosphate reductoisomerase (DXR) instead uses a retro-aldol/aldol sequence to accomplish its rearrangement of 68 to 69. c) The secondary metabolite aurachin C (71) is oxidized by the FAD-dependent monooxygenase AuaG to epoxide 72, which upon deprotonation by an

Isolation and characterization of new phenolic siderophores with antimicrobial properties from Pseudomonas sp. UIAU-6B

• Emmanuel T. Oluwabusola,
• Olusoji O. Adebisi,
• Fernando Reyes,
• Kojo S. Acquah,
• Mercedes De La Cruz,
• Larry L. Mweetwa,
• Joy E. Rajakulendran,
• Digby F. Warner,
• Deng Hai,
• Rainer Ebel and
• Marcel Jaspars

Beilstein J. Org. Chem. 2021, 17, 2390–2398, doi:10.3762/bjoc.17.156

• as a rational extension of the previously reported metabolite, pseudomonine (6), one of the major constituents of the extract from the culture broth of Pseudomonas sp. UIAU-6B. The new compounds 1–5 are interesting chemical entities consisting of scaffolds with different functionalities that could be

Nomimicins B–D, new tetronate-class polyketides from a marine-derived actinomycete of the genus Actinomadura

• Zhiwei Zhang,
• Tao Zhou,
• Taehui Yang,
• Keisuke Fukaya,
• Enjuro Harunari,
• Shun Saito,
• Katsuhisa Yamada,
• Chiaki Imada,
• Daisuke Urabe and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2021, 17, 2194–2202, doi:10.3762/bjoc.17.141

• , an antibacterial oxime derivative from Micromonospora [14]. Along the lines of these previous studies, metabolite analysis of actinomycetes from the DSW of Sagami Bay was further conducted, and three new tetronate-class polyketides, nomimicins B (1), C (2), and D (3) were found from a rare

• intramolecular Diels–Alder reaction [20][25]. Compound 3 is very likely a biosynthetic precursor of 4. This is the first report on the isolation of a biosynthetic precursor of spirotetronate antibiotics as an innate metabolite from a wild-type strain, while such an intermediate was previously obtained from a

Catalyzed and uncatalyzed procedures for the syntheses of isomeric covalent multi-indolyl hetero non-metallides: an account

• Ranadeep Talukdar

Beilstein J. Org. Chem. 2021, 17, 2102–2122, doi:10.3762/bjoc.17.137

• the indoles are less studied compared to the same through their pyrrole counterpart. The corresponding compounds are investigated for boron, nitrogen, oxygen, sulfur, and selenium as the central connecting atom. Boranes The indole alkaloid dragmacidin D is a marine secondary metabolite which was

Natural products in the predatory defence of the filamentous fungal pathogen Aspergillus fumigatus

• Jana M. Boysen,
• Nauman Saeed and
• Falk Hillmann

Beilstein J. Org. Chem. 2021, 17, 1814–1827, doi:10.3762/bjoc.17.124

• metabolites. The genetic potential for the production of secondary metabolites in fungi is high and numerous potential secondary metabolite gene clusters have been identified in sequenced fungal genomes. Their production may well be regulated by specific ecological conditions, such as the presence of

• human pathogenic fungi like A. fumigatus, one of the most common airborne fungal pathogens, might lead to new insight in virulence mechanisms and the role of SMs therein [32]. The aim of this review is to depict the fungal secondary metabolite potential and its role in an ecological context using A

• mycotoxins (A. flavus) or can cause severe infections (A. fumigatus, A. terreus). Despite their different role for humans, they commonly share a high potential for the production of secondary metabolites, measured by the predicted number of secondary metabolite gene clusters identified by numerous genome

Analogs of the carotane antibiotic fulvoferruginin from submerged cultures of a Thai Marasmius sp.

• Birthe Sandargo,
• Leon Kaysan,
• Rémy B. Teponno,
• Christian Richter,
• Benjarong Thongbai,
• Frank Surup and
• Marc Stadler

Beilstein J. Org. Chem. 2021, 17, 1385–1391, doi:10.3762/bjoc.17.97

• Marasmius spp. include the cryptoporic acids [4], marasmals, marasmones, and oreadones [5][6], the caryophyllane hebelophyllene C [7], and the carotane fulvoferruginin (1) [8] (Figure 1). The latter is the only known secondary metabolite from M. fulvoferrugineus Gilliam and displays a modest antibiotic and

• isolated metabolite (2) showed a protonated molecular ion peak at m/z 249.1477 [M + H]+ in the HRESIMS, corresponding to the molecular formula C15H20O3 (calcd for C15H21O3+, 249.1490). The 1H NMR spectrum showed signals for three methyl groups at δH 0.99 (s, H-13), 1.20 (d, J = 7.0 Hz, H-14), and 1.91 (t

• metabolite 3 (Figure 3). A third isolated compound (3) with a molecular formula of C15H18O4, derived from a protonated molecular ion peak of m/z 263.1276 [M + H]+, was named fulvoferruginin C (3). It differed from compound 2 only in the presence of a carboxyl group (δC 171.9) instead of the tertiary methyl C

A new glance at the chemosphere of macroalgal–bacterial interactions: In situ profiling of metabolites in symbiosis by mass spectrometry

• Marine Vallet,
• Filip Kaftan,
• Veit Grabe,
• Fatemeh Ghaderiardakani,
• Simona Fenizia,
• Aleš Svatoš,
• Georg Pohnert and
• Thomas Wichard

Beilstein J. Org. Chem. 2021, 17, 1313–1322, doi:10.3762/bjoc.17.91

• polar metabolite was linked to the metabolic homeostasis of Ulva lactuca during tidal cycles [30]. Choline is the precursor of the membrane constituent phosphatidylcholine [31]. We inferred that the accumulation of choline in axenic U. mutabilis germlings might correlate with the absence of the key

• statistical analysis were uploaded and are freely accessible in the Max Planck repository Edmond (https://dx.doi.org/10.17617/3.4v). Significant features analysis and metabolite identification Data analysis was conducted in MetaboAnalyst 4.0 [48] to perform univariate and multivariate statistical tests and

• , and the relative amounts of the significant features were displayed as a boxplot. The selected significant features were further searched in the raw HRMS profiles to identify those with the reliable isotopic pattern assigned to a metabolite. The m/z values were searched in the METLIN database, using a

Breakdown of 3-(allylsulfonio)propanoates in bacteria from the Roseobacter group yields garlic oil constituents

• Anuj Kumar Chhalodia and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2021, 17, 569–580, doi:10.3762/bjoc.17.51

• release sulfur volatiles [13][14] that are especially important headspace constituents from marine bacteria of the Roseobacter group [15][16][17]. In these organisms, sulfur volatiles are to a large extent generated from algal (DMSP), a metabolite that is produced in massive amounts by algae [18], thus

Biochemistry of fluoroprolines: the prospect of making fluorine a bioelement

• Vladimir Kubyshkin,
• Rebecca Davis and
• Nediljko Budisa

Beilstein J. Org. Chem. 2021, 17, 439–460, doi:10.3762/bjoc.17.40

• , such as pipecolic acid [66]. In E. coli, the catabolism of proline occurs via the action of the bifunctional enzyme putA (Figure 9B) [67]. It sequentially degrades proline to glutamate, which can be later deaminated to an essential metabolite, α-ketoglutarate, with many metabolic options, such as an

Identification of volatiles from six marine Celeribacter strains

• Anuj Kumar Chhalodia,
• Jan Rinkel,
• Dorota Konvalinkova,
• Jörn Petersen and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2021, 17, 420–430, doi:10.3762/bjoc.17.38

• ][9]. Especially in algal blooms bacteria of the roseobacter group are highly abundant [10], and here they belong to the main players involved in the enzymatic degradation of the algal sulfur metabolite 3-(dimethylsulfonio)propanoate (DMSP, Scheme 1) [11]. Its catabolism leads either through the

Secondary metabolites of Bacillus subtilis impact the assembly of soil-derived semisynthetic bacterial communities

• Heiko T. Kiesewalter,
• Carlos N. Lozano-Andrade,
• Mikael L. Strube and
• Ákos T. Kovács

Beilstein J. Org. Chem. 2020, 16, 2983–2998, doi:10.3762/bjoc.16.248

• investigate the functions and interactions of community members, such as metabolite cross-feeding interactions, and to eventually engineer them [5][6][7]. The soil is one of the five main habitats of bacteria and archaea [8]. Soil is very heterogeneous since it exhibits spatial variability in terms of

• soil and demonstrated to impact the biofilm colony development of B. subtilis [54]. Interestingly, the modulation of the biofilm development was mediated by the primary metabolite hypoxanthine secreted by L. fusiformis. Of note, the impact of B. subtilis was not noticed on L. fusiformis in the mixed

Nocarimidazoles C and D, antimicrobial alkanoylimidazoles from a coral-derived actinomycete Kocuria sp.: application of ¹J_C,H coupling constants for the unequivocal determination of substituted imidazoles and stereochemical diversity of anteisoalkyl chains in microbial metabolites

• Md. Rokon Ul Karim,
• Enjuro Harunari,
• Amit Raj Sharma,
• Naoya Oku,
• Kazuaki Akasaka,
• Daisuke Urabe,
• Mada Triandala Sibero and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2020, 16, 2719–2727, doi:10.3762/bjoc.16.222

• habitat [6][7]. Their secondary metabolite machinery is activated in the sea, as indicated by the isolation of enediyne antitumor antibiotics from marine invertebrates. Namenamicin [8] and the shishijimicins [9], the chalicheamicin-type enediyne polyketides, were isolated from a colonial tunicate. These

• metabolite of marine Verrucosispora, effective against methicillin-resistant Staphylococcus aureus (MRSA) and Mycobacterium tuberculosis [11][12]. The genus Kocuria, formerly categorized in the genus Micrococcus, is a Gram-positive unicellular coccus belonging to the family Micrococcaceae [13]. Members of

One-pot synthesis of oxazolidinones and five-membered cyclic carbonates from epoxides and chlorosulfonyl isocyanate: theoretical evidence for an asynchronous concerted pathway

• Esra Demir,
• Ozlem Sari,
• Yasin Çetinkaya,
• Ufuk Atmaca,
• Safiye Sağ Erdem and
• Murat Çelik

Beilstein J. Org. Chem. 2020, 16, 1805–1819, doi:10.3762/bjoc.16.148

• . Linezolid (3) is the first oxazolidinone drug approved in 2000 by the Food and Drug Administration (FDA) for the treatment of multidrug resistant Gram-positive bacterial infections (Scheme 1) [10]. Cytoxazone is a microbial metabolite exhibiting potent cytokine-modulating activity. Tedizolid phosphate

Synthesis of new dihydroberberine and tetrahydroberberine analogues and evaluation of their antiproliferative activity on NCI-H1975 cells

• Giacomo Mari,
• Lucia De Crescentini,
• Serena Benedetti,
• Francesco Palma,
• Stefania Santeusanio and
• Fabio Mantellini

Beilstein J. Org. Chem. 2020, 16, 1606–1616, doi:10.3762/bjoc.16.133

• of THBERs 3a chosen as representative example, reveals that these two hydrogens are in cis position (Figure 4). Therefore, the THBERs 3 show the same configuration of the metabolite cavidine that is the 13-methyltetrahydroprotoberberine alkaloid which occur in various species of Corydalis [69

Antibacterial scalarane from Doriprismatica stellata nudibranchs (Gastropoda, Nudibranchia), egg ribbons, and their dietary sponge Spongia cf. agaricina (Demospongiae, Dictyoceratida)

• Cora Hertzer,
• Stefan Kehraus,
• Nils Böhringer,
• Fontje Kaligis,
• Robert Bara,
• Dirk Erpenbeck,
• Gert Wörheide,
• Till F. Schäberle,
• Heike Wägele and
• Gabriele M. König

Beilstein J. Org. Chem. 2020, 16, 1596–1605, doi:10.3762/bjoc.16.132

• the genus Doriprismatica and scalarane-containing dictyoceratid sponges of the Spongiidae family. The results also indicate that D. stellata passes the scalarane metabolite on to its egg ribbons, most likely for protective purposes. The scalarane showed antibacterial activity against the Gram-positive

• from the previously reported scalaranes [25][29][33][42][56][61][62], the new metabolite is functionalized at C-11 instead of C-12 and has a cyclopropane ring bridging C-3, C-22 and C-4 of ring A. Scalarane sesterterpenes are considered as chemotaxonomic markers for the sponge families Thorectidae

• between nudibranchs of the genus Doriprismatica and scalarane-containing dictyoceratid sponges of the families Thorectidae and Spongiidae. This relationship is further reflected by their shared specialized metabolite 12-deacetoxy-4-demethyl-11,24-diacetoxy-3,4-methylenedeoxoscalarin, as proven in this

A cyclopeptide and three oligomycin-class polyketides produced by an underexplored actinomycete of the genus Pseudosporangium

• Shun Saito,
• Kota Atsumi,
• Tao Zhou,
• Keisuke Fukaya,
• Daisuke Urabe,
• Naoya Oku,
• Md. Rokon Ul Karim,
• Hisayuki Komaki and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2020, 16, 1100–1110, doi:10.3762/bjoc.16.97

• and subjected to metabolite analysis, which resulted in the discovery of a novel cyclopeptide, pseudosporamide (1), along with three new oligomycin-class polyketides, pseudosporamicins A–C (2–4). The unusual structure of compound 1, featured by a biaryl-bond bridging across a tripeptide scaffold, N

• widely used as an indicator of the taxonomic position of prokaryotes. It was believed that a high similarity of the 16S rRNA gene sequence implied the closeness or even the identity in other sets of genes including secondary metabolite biosynthetic genes. However, our recent analysis of Streptomyces

• species demonstrated that the distribution of secondary metabolite biosynthetic genes was not the same even in phylogenetically close species [11]. This finding became our starting point to explore the secondary metabolism in actinomycete genera from which no secondary metabolites were described. “Rare