Polymer degrading marine Microbulbifer bacteria: an un(der)utilized source of chemical and biocatalytic novelty

• Weimao Zhong and
• Vinayak Agarwal

Beilstein J. Org. Chem. 2024, 20, 1635–1651, doi:10.3762/bjoc.20.146

• classes of natural products isolated from Microbulbifer to date include alkaloids [15], fatty acid and polyketides [16][17], and non-ribosomally synthesized peptides [3][4][7]. These findings validate the potential for secondary metabolite discovery from Microbulbifer genus. This review will cover the

• from this bacterium by comparison of their 1H NMR and MS data with those reported in literature (Figure 7). Alkaloids Three new alkanoyl imidazoles 21–23 (Figure 8) were isolated from a culture extract of a Microbulbifer bacterium isolated from a scleractinian coral [15]. Their structures were

• of 32 natural products, including NRPSs, PKS, parabens, and alkaloids, have been isolated and identified from Microbulbifer bacteria. Based on the growing genomic data, it is unquestionable that the Microbulbifer genus is an untapped resource for natural products. The number of molecules described

Regio- and stereochemical stability induced by anomeric and gauche effects in difluorinated pyrrolidines

• Ana Flávia Candida Silva,
• Francisco A. Martins and
• Matheus P. Freitas

Beilstein J. Org. Chem. 2024, 20, 1572–1579, doi:10.3762/bjoc.20.140

• Lewis interactions from a natural bond orbital perspective. Keywords: anomeric effect; fluoropyrrolidine; gauche effect; stereochemistry; Introduction The pyrrolidine ring structure is prevalent in numerous natural alkaloids and is an important feature of the proline and hydroxyproline residues that

Mining raw plant transcriptomic data for new cyclopeptide alkaloids

• Draco Kriger,
• Michael A. Pasquale,
• Brigitte G. Ampolini and
• Jonathan R. Chekan

Beilstein J. Org. Chem. 2024, 20, 1548–1559, doi:10.3762/bjoc.20.138

• transcriptomic data sets, we uncover the potential distribution of split burpitide precursor peptides in Streptophyta. Metabolomic analysis of target plants confirms our bioinformatic predictions of new cyclopeptide alkaloids from both known and new sources. Keywords: burpitides; natural products; plants; RiPPs

• ]. These RiPP natural products encompass a wide range of structural scaffolds including cyclopeptide alkaloids that contain a phenolic ether-linkage and the lyciumin-type peptides that are composed of a crosslink between the Trp-indole-N and the carbon in another amino acid side chain or peptide backbone

• (HMM) for split burpitide precursor peptides. Using this approach, we assembled 700 transcriptomes and used predicted precursor peptide diversity for target discovery of new cyclopeptide alkaloids. Additionally, metabolomic analysis revealed the tissue distribution of these molecules across select

Towards an asymmetric β-selective addition of azlactones to allenoates

• Behzad Nasiri,
• Ghaffar Pasdar,
• Paul Zebrowski,
• Katharina Röser,
• David Naderer and
• Mario Waser

Beilstein J. Org. Chem. 2024, 20, 1504–1509, doi:10.3762/bjoc.20.134

• these catalysts (Table 1, entries 1–4, other cinchona alkaloid-based ammonium salt derivatives as well as free base cinchona alkaloids were tested too but did not allow for any improvement). Using the established and commercially available Maruoka catalysts B1 and B2 [39] next turned out to be more

Synthetic applications of the Cannizzaro reaction

• Bhaskar Chatterjee,
• Dhananjoy Mondal and
• Smritilekha Bera

Beilstein J. Org. Chem. 2024, 20, 1376–1395, doi:10.3762/bjoc.20.120

• -β-lactone core 73 (Scheme 21). An expedient use of the Cannizzaro reaction was exemplified in the noteworthy enantioselective synthesis towards the indole alkaloids 16-epivellosimine, (+)-polyneuridine, and (+)-macusine A as reported by Cook and coworkers [89]. This was effectively worked out from ᴅ

• intramolecular Cannizzaro reaction. Spiro-β-lactone-γ-lactam part of oxazolomycins via aldol crossed-Cannizzaro reaction. Synthesis of indole alkaloids via aldol crossed-Cannizzaro reaction. Aldol and crossed-Cannizzaro reaction towards the synthesis of ertuliflozin. Synthesis of cyclooctadieneones using a

Synthesis and optical properties of bis- and tris-alkynyl-2-trifluoromethylquinolines

• Stefan Jopp,
• Franziska Spruner von Mertz,
• Peter Ehlers,
• Alexander Villinger and
• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 1246–1255, doi:10.3762/bjoc.20.107

• which can be found in several natural and synthetic products and many of them show interesting pharmacological properties [1][2][3]. Quinine, for example, is a widely known natural product which was first isolated from the cinchona tree besides many other quinoline-containing cinchona alkaloids [4]. It

Manganese-catalyzed C–C and C–N bond formation with alcohols via borrowing hydrogen or hydrogen auto-transfer

• Mohd Farhan Ansari,
• Atul Kumar Maurya,
• Abhishek Kumar and
• Saravanakumar Elangovan

Beilstein J. Org. Chem. 2024, 20, 1111–1166, doi:10.3762/bjoc.20.98

• interrupted BH approach using Mn26 (3 mol %) and t-BuOK (50 mol %) in toluene at 130 °C for 24 h (Scheme 67). Fascinatingly, this process was used to synthesize pharmacologically active compounds like vibrindole A and turbomycin B alkaloids and natural products like gramine and dipterine analogues. Discrete

Methodology for awakening the potential secondary metabolic capacity in actinomycetes

• Shun Saito and
• Midori A. Arai

Beilstein J. Org. Chem. 2024, 20, 753–766, doi:10.3762/bjoc.20.69

• ribosomal S12 protein mutation results in increased expression of translation factors, which leads to enhanced protein synthesis in secondary metabolism [47]. Liu et al. reported activation of the production of bohemamines 11–13, bacterial alkaloids containing a pyrrolizidine core with two unusual methyl

Chemical and biosynthetic potential of Penicillium shentong XL-F41

• Ran Zou,
• Xin Li,
• Xiaochen Chen,
• Yue-Wei Guo and
• Baofu Xu

Beilstein J. Org. Chem. 2024, 20, 597–606, doi:10.3762/bjoc.20.52

• investigations, accompanied by fermentation media optimization, of a newly isolated fungus, Penicillium shentong XL-F41, led to the isolation of twelve compounds. Among these are two novel indole terpene alkaloids, shentonins A and B (1 and 2), and a new fatty acid 3. Shentonin A (1) is distinguished by an

• polyketides, alkaloids, sterol derivatives, terpenoids, and macrolides, with polyketides and alkaloids comprising 40% and 32% of the total, respectively. Alkaloids are a diverse group of compounds with multiple pharmacological activities, including anti-inflammatory, antibacterial, antiviral, insecticidal

• , and anticancer properties [6][7]. Historically, most alkaloids were isolated from higher plants, with a significant number found in the Apocynaceae family. Notable examples such as vinblastine, vinorelbine, vincristine, and vindesine have gained prominence as effective anticancer drugs [6][7][8][9][10

Entry to new spiroheterocycles via tandem Rh(II)-catalyzed O–H insertion/base-promoted cyclization involving diazoarylidene succinimides

• Alexander Yanovich,
• Anastasia Vepreva,
• Ksenia Malkova,
• Grigory Kantin and
• Dmitry Dar’in

Beilstein J. Org. Chem. 2024, 20, 561–569, doi:10.3762/bjoc.20.48

• antagonist 7 [33], and aldosterone synthase inhibitor 8 [34]) as well as natural products (e.g., new alkaloids deoxytryptoquivaline and deoxynortryptoquivaline from fungus Aspergillus clavatonanicus identified as natural cardiomyocyte-protective agents against cold ischemic injury [35] and possible natural

Pseudallenes A and B, new sulfur-containing ovalicin sesquiterpenoid derivatives with antimicrobial activity from the deep-sea cold seep sediment-derived fungus Pseudallescheria boydii CS-793

• Zhen Ying,
• Xiao-Ming Li,
• Sui-Qun Yang,
• Hong-Lei Li,
• Xin Li,
• Bin-Gui Wang and
• Ling-Hong Meng

Beilstein J. Org. Chem. 2024, 20, 470–478, doi:10.3762/bjoc.20.42

• alkaloids containing an unprecedented spiro[bicyclo[2.2.2]octane-diketopiperazine] skeleton, chevalinulins A and B, and the first cytochalasin homodimer containing a thioether bridge, verruculoid A, were identified from deep-sea cold seeps-derived fungi and were described to have potent proangiogenic and

• our attention. Several meroterpenoids, alkaloids, polyketides, and sesquiterpenoids from the species displayed various biological properties including anti-inflammatory, antimicrobial, and cytotoxic activities [7][8][9]. In the present work, two rare new examples of sulfur-containing ovalicin

Photoinduced in situ generation of DNA-targeting ligands: DNA-binding and DNA-photodamaging properties of benzo[c]quinolizinium ions

• Julika Schlosser,
• Olga Fedorova,
• Yuri Fedorov and
• Heiko Ihmels

Beilstein J. Org. Chem. 2024, 20, 101–117, doi:10.3762/bjoc.20.11

• structurally related alkaloids berberine [61][62][63][64][65] and coralyne [36][66][67] have been shown already to act as efficient photosensitizers for DNA damage. To the best of our knowledge, however, benzo[c]quinolizinium derivatives have not been investigated with respect to their DNA-photodamaging

Synthetic approach to 2-alkyl-4-quinolones and 2-alkyl-4-quinolone-3-carboxamides based on common β-keto amide precursors

• Yordanka Mollova-Sapundzhieva,
• Plamen Angelov,
• Danail Georgiev and
• Pavel Yanev

Beilstein J. Org. Chem. 2023, 19, 1804–1810, doi:10.3762/bjoc.19.132

• ], drugs used to treat cystic fibrosis and HIV infection, respectively. A plethora of 4-quinolones with various substitution patterns and biological activities have been isolated from natural sources. This includes plant-derived alkaloids such as graveoline [7], evocarpine [8], leiokinine [9], evollionine

• C [10], leptomerine [11], and punarivine [12]. The fruit of Evodia rutaecarpa is a particularly rich source of 4-quinolones with long-chain substituents at position 2. Various alkaloids isolated from this source have been shown to possess anti-Helicobacter pylori activity [13], inhibitory effects on

• monoamine oxidase [14], cytotoxicity against cancer cell lines [15], activity against nuclear factor of activated T cells [16], and anti-inflammatory activity [17]. Alkaloids with similar structure and anti-inflammatory activity have been isolated from another member of the Rutaceae family – Zanthoxylum

Synthesis of 7-azabicyclo[4.3.1]decane ring systems from tricarbonyl(tropone)iron via intramolecular Heck reactions

• Aaron H. Shoemaker,
• Elizabeth A. Foker,
• Elena P. Uttaro,
• Sarah K. Beitel and
• Daniel R. Griffith

Beilstein J. Org. Chem. 2023, 19, 1615–1619, doi:10.3762/bjoc.19.118

• Aaron H. Shoemaker Elizabeth A. Foker Elena P. Uttaro Sarah K. Beitel Daniel R. Griffith Department of Chemistry, Lafayette College, 730 High St., Easton, PA 18042, USA 10.3762/bjoc.19.118 Abstract The 7-azabicyclo[4.3.1]decane ring system, common to a number of biologically active alkaloids, was

• related 2-azabicyclo[4.4.1]undecane system, albeit in lower yield. Keywords: alkaloids; azabicycles; Heck reaction; iron complex; tropone; Introduction Azapolycycles are embedded within numerous biologically active alkaloids [1] and pharmaceuticals [2]. As such, novel approaches to the synthesis of

• these scaffolds, even though they are found within a number of biologically active alkaloids. We recently demonstrated that the readily available, bench-stable tricarbonyl(tropone)iron complex [4] (1, Scheme 1) could serve as a precursor to the previously unreported 2-azatricyclo[4.3.2.04,9]undecane

Sulfur-containing spiroketals from Breynia disticha and evaluations of their anti-inflammatory effect

• Ken-ichi Nakashima,
• Naohito Abe,
• Masayoshi Oyama,
• Hiroko Murata and
• Makoto Inoue

Beilstein J. Org. Chem. 2023, 19, 1604–1614, doi:10.3762/bjoc.19.117

• glycosides [1][2][3], flavan-3-ol glycosides [4], alkaloids [5], and phenolic glycosides [5][6]. Notably, sulfur-containing spiroketal glycosides, represented by breynins and epibreynins, have characteristic sesquiterpenoid-derived structures. The sesquiterpenoid phyllaemblic acid and its glycosides, which

• well as the HMBC correlations of H2-2 with C-3 and C-17, this substituent was identified as a (2-amino-2-oxoethyl)thio group. This substituent has been reported in several alkaloids isolated from plants in the Aristolochiaceae family [17][18]. Compound 3 had a β orientation for the sulfur-containing

Secondary metabolites of Diaporthe cameroonensis, isolated from the Cameroonian medicinal plant Trema guineensis

• Bel Youssouf G. Mountessou,
• Élodie Gisèle M. Anoumedem,
• Blondelle M. Kemkuignou,
• Yasmina Marin-Felix,
• Frank Surup,
• Marc Stadler and
• Simeon F. Kouam

Beilstein J. Org. Chem. 2023, 19, 1555–1561, doi:10.3762/bjoc.19.112

• great structural variability such as polyketides, terpenoids, polyketide synthase–nonribosomal peptide synthetase (PKS–NRPS) alkaloids, and cytochalasins, which have been considered as taxonomic markers of the genus [7][8][9][10]. However, it is worthwhile to mention that the name Phomopsis should no

N-Sulfenylsuccinimide/phthalimide: an alternative sulfenylating reagent in organic transformations

• Fatemeh Doraghi,
• Seyedeh Pegah Aledavoud,
• Mehdi Ghanbarlou,
• Bagher Larijani and
• Mohammad Mahdavi

Beilstein J. Org. Chem. 2023, 19, 1471–1502, doi:10.3762/bjoc.19.106

• (Scheme 46) [79]. By testing several alkaloids as organocatalysts for the transformation, cinchonidine G proved to be the best catalyst for C–H sulfenylation and selenenylation of substrates in toluene at −20 or 0 °C. The reaction occurred in shorter times in the presence of N-(arylsulfanyl)succinimide

Aromatic C–H bond functionalization through organocatalyzed asymmetric intermolecular aza-Friedel–Crafts reaction: a recent update

• Anup Biswas

Beilstein J. Org. Chem. 2023, 19, 956–981, doi:10.3762/bjoc.19.72

• 2020, Pedrosa and co-workers devised a chiral heterogenous thiourea catalyst that was applied in an enantioefficient aza-Friedel–Crafts process. A series of heterogenous catalysts were prepared by condensation between alkaloids and polystyrene-derived isothiocyanates. These polymer-supported materials

Photoredox catalysis enabling decarboxylative radical cyclization of γ,γ-dimethylallyltryptophan (DMAT) derivatives: formal synthesis of 6,7-secoagroclavine

• Alessio Regni,
• Francesca Bartoccini and
• Giovanni Piersanti

Beilstein J. Org. Chem. 2023, 19, 918–927, doi:10.3762/bjoc.19.70

• photocatalyst. Keywords: decarboxylative cyclization; DMAT; ergot alkaloids; photoredox catalysis; radicals; Introduction Visible-light photoredox catalysis is rapidly changing the way organic chemists approach the design and synthesis of molecules by offering new synthetic disconnection opportunities that

• : 1) it functions as the central intermediate in the biosynthetic pathways leading to numerous prenylated indole alkaloids, such as ergot alkaloids in normal biosynthesis and clavicipitic acid in derailment biosynthesis [68][69][70][71]; and 2) the mechanism of the fundamental central C-ring formation

• of all ergot alkaloids, specifically the decarboxylative cyclization of DMAT, is still a puzzle even though a radical mechanism has been proposed (Figure 1a) [72][73]. Results and Discussion Herein, we propose that visible light irradiation of the cationic iridium photocatalyst Ir[dF(CF3)ppy]2(dtbbpy

Non-peptide compounds from Kronopolites svenhedini (Verhoeff) and their antitumor and iNOS inhibitory activities

• Yuan-Nan Yuan,
• Jin-Qiang Li,
• Hong-Bin Fang,
• Shao-Jun Xing,
• Yong-Ming Yan and
• Yong-Xian Cheng

Beilstein J. Org. Chem. 2023, 19, 789–799, doi:10.3762/bjoc.19.59

• activity have revealed the presence of antimicrobial peptides [5], defensive alkaloids [6], and defensive long chain alcohol acetates [7]. Historically, in China, numerous records documented the utilization of animals like arthropods for medicinal purposes. Millipedes hereby represent a traditional Chinese

Total synthesis: an enabling science

• Bastien Nay

Beilstein J. Org. Chem. 2023, 19, 474–476, doi:10.3762/bjoc.19.36

• syntheses ever published in the Beilstein Journal of Organic Chemistry, such as those of frog indolizidine alkaloids [5][6]. However, no thematic issue specifically related to total synthesis has been published before, and we thought it would be time to fill this gap. Although innovative developments are

Identification and determination of the absolute configuration of amorph-4-en-10β-ol, a cadinol-type sesquiterpene from the scent glands of the African reed frog Hyperolius cinnamomeoventris

• Angelique Ladwig,
• Markus Kroll and
• Stefan Schulz

Beilstein J. Org. Chem. 2023, 19, 167–175, doi:10.3762/bjoc.19.16

• composition of the gular gland blend, including always 14. Diet-dependent uptake of compounds by frogs usually results in individual differences in compound composition, as has been observed, e.g., for skin alkaloids of Madagascan poison frogs [26]. Finally, experiments with mantellines showed that at least

Combining the best of both worlds: radical-based divergent total synthesis

• Kyriaki Gennaiou,
• Antonios Kelesidis,
• Maria Kourgiantaki and
• Alexandros L. Zografos

Beilstein J. Org. Chem. 2023, 19, 1–26, doi:10.3762/bjoc.19.1

• products by chemoselective redox reactions. Divergent total synthesis of Galbulimima alkaloids (Shenvi 2022) [62]: Members of the Galbulimima alkaloids extracted from rainforest canopy trees were found to possess neuroactive properties, such as antagonistic activity at muscarinic receptors [63

• reduction steps allowed the total synthesis of GB13 (8), himgaline (126), and GB22 (125) in only one third of the number of steps of prior syntheses (Scheme 10). Concise syntheses of eburnane alkaloids (Qin 2018) [68][69]: Eburnane indole alkaloids comprise a highly diverse class of natural products mainly

• distributed in Southeast Asia and China [70]. Compounds of this class are traditionally used for detoxification and as anti-inflammatory agents in Chinese medicine [71]. Qin and co-workers reported the asymmetric total syntheses of several eburnane alkaloids. Therein, they relied on one of their previous

Synthesis of (−)-halichonic acid and (−)-halichonic acid B

• Keith P. Reber and
• Emma L. Niner

Beilstein J. Org. Chem. 2022, 18, 1629–1635, doi:10.3762/bjoc.18.174

• assays have not yet been investigated. Our group was particularly interested in the structure of halichonic acid ((+)-1), which shares the same bridged bicyclic ring system found in many of the Aristotelia alkaloids [6]. Since our lab recently reported a synthesis of the natural product aristoquinoline

Synthetic study toward the diterpenoid aberrarone

• Liang Shi,
• Zhiyu Gao,
• Yiqing Li,
• Yuanhao Dai,
• Yu Liu,
• Lili Shi and
• Hong-Dong Hao

Beilstein J. Org. Chem. 2022, 18, 1625–1628, doi:10.3762/bjoc.18.173

• tetracyclic carbon skeleton yet-to-be found in Pseudopterogorgia elisabethae species, although related cyclohexane-angularly-fused triquinane systems have been found in waihoensene (3), conidiogenone (4), lycopodium alkaloids magellamine (5) and lycojaponicumin C (6) (Figure 1). Its seven stereogenic centers