Glycosylated coumarins, flavonoids, lignans and phenylpropanoids from Wikstroemia nutans and their biological activities

• Meifang Wu,
• Xiangdong Su,
• Yichuang Wu,
• Yuanjing Luo,
• Ying Guo and
• Yongbo Xue

Beilstein J. Org. Chem. 2022, 18, 200–207, doi:10.3762/bjoc.18.23

• diversity of the secondary metabolites from the genus Wikstroemia. Keywords: coumarin glucosides; flavonoids; lignans; structure elucidation; Wikstroemia nutans; Introduction The genus Wikstroemia (Thymelaeaceae) contains approximately 62 species, which are widespread throughout the subtropical regions of

• Asia and Oceania [1]. Nineteen species of the genus Wikstroemia are found to be domestic in China, such as W. nutans, W. indica, and W. canescens [2]. Previous investigations have not only reported diverse secondary metabolites from the genus, but also promising pharmacological activities of the

Synthesis and late stage modifications of Cyl derivatives

• Phil Servatius and
• Uli Kazmaier

Beilstein J. Org. Chem. 2022, 18, 174–181, doi:10.3762/bjoc.18.19

• , such as histone deacetylases. Keywords: chelated enolate; Claisen rearrangement; HDAC inhibitor; peptide; late stage modification; Introduction Among natural products, peptidic structures have entered the limelight due to their extraordinary biological activities [1]. Often found as secondary

• metabolites for self-defense in different microorganisms, peptidic natural products are assembled either by ribosomal synthesis or by non-ribosomal peptide synthetases (NRPS) [2]. Macrocyclic peptides are pervasive throughout this class of natural products and often show improved stability against proteolytic

Tenacibactins K–M, cytotoxic siderophores from a coral-associated gliding bacterium of the genus Tenacibaculum

• Yasuhiro Igarashi,
• Yiwei Ge,
• Tao Zhou,
• Amit Raj Sharma,
• Enjuro Harunari,
• Naoya Oku and
• Agus Trianto

Beilstein J. Org. Chem. 2022, 18, 110–119, doi:10.3762/bjoc.18.12

• . They instead harbour diverse and abundant microbes on their body surface or in the tissues [2][3] and are believed to utilize secondary metabolites from the symbionts as protectants from attacks by predators, competitors, or pathogens. The ecological functions as such make marine microorganisms an

• available on the secondary metabolites from this genus [17][18]. In our continuing search for bioactive compounds from underexplored marine bacteria [19][20][21], a Tenacibaculum strain, isolated from a stony coral, was found to produce three metabolites, which turned out to be new cytotoxic hydroxamate

• attractive resource of new therapeutics, which are not found from terrestrial bioresources [4][5][6]. While a large majority of marine microbe-derived natural products are from fungi and actinomycetes, less attention has been paid to non-actinomycetal bacteria [6][7][8][9]. Particularly, secondary

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

• relationships in this chemotype. Keywords: acyl Pictet–Spengler reaction; alkaloids; antiproliferative activity; benzyltetrahydroisoquinolines; ion channels; protective group; total synthesis; Introduction The benzylisoquinoline alkaloids are a large and diverse class of plant secondary metabolites including

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

• microbial sources led to the isolation of Pseudomonas sp. UIAU-6B from sediments collected from the Oyun river in North Central Nigeria. Herein, we report the isolation and structure elucidation of seven secondary metabolites including five new (1–5), and two known phenolic siderophores (6 and 7) [28][36

• secondary metabolites 1–5 including pseudomonin A–C (1–3) and pseudomobactins A and B (4 and 5). The two known compounds, pseudomonine (6) and salicylic acid (7) were also isolated as the major constituents of the extracts and their structures were determined by analysis of HRESIMS, 1D and 2D NMR data (see

Phenolic constituents from twigs of Aleurites fordii and their biological activities

• Kyoung Jin Park,
• Won Se Suh,
• Da Hye Yoon,
• Chung Sub Kim,
• Sun Yeou Kim and
• Kang Ro Lee

Beilstein J. Org. Chem. 2021, 17, 2329–2339, doi:10.3762/bjoc.17.151

• A. fordii have shown Epstein–Barr virus activation effects and an enhancement of HTLV-I-induced colony formation of lymphocytes [8]. As an ongoing search for bioactive secondary metabolites from Korean medicinal sources, we investigated the methanolic extract of the twigs of A. fordii which resulted

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

• marine environment is now attracting attention as a promising source for actinomycetes potentially producing new secondary metabolites [4][5]. Indeed, a large number of pharmaceutically worthy new compounds has been found from marine actinomycetes in various niches including sediments, sea water, marine

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

• microbial competitors, symbionts or predators. Here we exemplarily summarize our current knowledge on identified secondary metabolites of the pathogenic fungus Aspergillus fumigatus and their defensive function against (microbial) predators. Keywords: amoeba predation; Aspergillus fumigatus; fungal ecology

• , physiological adaptations and chemical defence mechanisms to optimize their living conditions and resist competitors, parasites and predators [3][4][5]. These bioactive compounds are often considered as secondary metabolites (SM) which are involved in communication, symbiotic interactions, pathogenicity or

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

• characterization. Results Structure elucidation of the secondary metabolites 2–6 Preparative HPLC of the supernatant crude extract of a submerged cultivation of Marasmius sp. strain MFLUCC 14-0681 in ZM½ media led to the isolation of six carotane sesquiterpenoids, fulvoferruginins A–F (1–6, Figure 1). The first

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

• by DddW, DddP, DddQ, DddL, DddY or DddK, and C) structures of DHPS and sulfur-containing secondary metabolites. Synthesis of sulfur-containing compounds detected in the Celeribacter headspace extracts. A) Synthesis of 2-(methyldisulfanyl)benzothiazole (41) and B) synthesis of ethyl (Z)- and (E)-3

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

• address: MSD UK Discovery Centre, Francis Crick Institute, 1 Midland Road, London, NW1 1AT, United Kingdom 10.3762/bjoc.17.31 Abstract A one-flask, two-step procedure from 3-amino-2-methyl-5,6,7,7a-tetrahydro-1H-pyrrolizin-1-one affords the Streptomyces secondary metabolites legonmycins A and B – three

• . These species include both Gram-positive and Gram-negative bacteria, indicating that pyrrolizidines are potential secondary metabolites of a variety of bacterial genera. The most recent addition to the bacterial pyrrolizidine literature also concerns their biosynthesis and addresses the origin of the

¹⁹F NMR as a tool in chemical biology

• Diana Gimenez,
• Aoife Phelan,
• Cormac D. Murphy and
• Steven L. Cobb

Beilstein J. Org. Chem. 2021, 17, 293–318, doi:10.3762/bjoc.17.28

• tactic in the battle against antimicrobial resistance. In addition to fluorinated metabolites that are produced de novo from fluoride ions, it is possible to modify other secondary metabolites to incorporate fluorine by including fluorinated precursors in the culture medium. 19F NMR has been applied to

Chemical constituents of Chaenomeles sinensis twigs and their biological activity

• Joon Min Cha,
• Dong Hyun Kim,
• Lalita Subedi,
• Zahra Khan,
• Sang Un Choi,
• Sun Yeou Kim and
• Chung Sub Kim

Beilstein J. Org. Chem. 2020, 16, 3078–3085, doi:10.3762/bjoc.16.257

• continuing search for cytotoxic, antineuroinflammatory, and neurotrophic secondary metabolites from C. sinensis [13][14][15][21], the isolates (1–12) were tested for these biological activities. The cytotoxicity was evaluated on the basis of the growth inhibitory effects of the isolated compounds 1–12

• new drug candidates although further studies are needed. This phytochemical study on C. sinensis may exemplify, how novel secondary metabolites still remain undiscovered among the numerous well-known plant species. Experimental General experimental procedures. Optical rotation data were recorded using

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

• , Kgs. Lyngby, Denmark 10.3762/bjoc.16.248 Abstract Secondary metabolites provide Bacillus subtilis with increased competitiveness towards other microorganisms. In particular, nonribosomal peptides (NRPs) have an enormous antimicrobial potential by causing cell lysis, perforation of fungal membranes

• the principle root microbiome of maize [22]. Secondary metabolites (SMs) are believed to be important mediators of the interactions between microorganisms [23]. Many of them are well-studied in vitro, but the true ecological role of SMs is still the subject of investigations. Different opinions about

• fusiformis M5 confirmed the impact of B. subtilis-produced surfactin on the growth. Results Impact of B. subtilis secondary metabolites on taxonomic groups in semisynthetic mock communities We established soil-derived semisynthetic mock communities and supplemented them with B. subtilis WT P5_B1, the

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

• -10-1 Yurigaoka, Natori, Miyagi 981-1295, Japan Department of Marine Science, Faculty of Fisheries and Marine Science, Diponegoro University, Semarang, Central Java 50275, Indonesia 10.3762/bjoc.16.222 Abstract Chemical investigation of secondary metabolites from a marine-derived actinomycete strain

• [1]. More than 10,000 secondary metabolites have been isolated from actinomycetes, accounting for almost 45% of all known microbial secondary metabolites. Particularly, 70% of them were isolated from the genus Streptomyces, the dominant genus commonly found in terrestrial environments [2]. The number

• genomic information suggests the presence of biosynthetic genes for nonribosomal peptide synthetase and type III polyketide synthase in some Kocuria strains [18], which leaves a hope for new secondary metabolites. At present, only a few limited structural types of metabolites, including polyamine-derived

Three new O-isocrotonyl-3-hydroxybutyric acid congeners produced by a sea anemone-derived marine bacterium of the genus Vibrio

• Dandan Li,
• Enjuro Harunari,
• Tao Zhou,
• Naoya Oku and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2020, 16, 1869–1874, doi:10.3762/bjoc.16.154

• ]. Others can fix nitrogen [5], have phototrophy [6], or produce a plant hormone [7], and thus showing a higher metabolic versatility, which is also represented by 150 and more secondary metabolites discovered from this genus [8]. As part of our continuing study on the secondary metabolites of marine

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

• mining indicated that members of the underexplored genus Pseudosporangium, from which no secondary metabolites have been reported to date, may harbor the biosynthetic machinery for the formation of novel natural products. The strain RD062863, that is available at a public culture collection, was obtained

• discovery of new natural products. Keywords: DFT-based calculation; oligomycin; peptide; polyketides; Pseudosporangium; rare actinomycetes; Introduction Microbial secondary metabolites have been used as therapeutic drugs [1], veterinary medicines [2], agrochemicals [3], food preservatives/colorings [4][5

• analytical technologies, the searching process for new microbial secondary metabolites became faster and more efficient [10]. However, there existed a substantial number of unstudied bacterial genera for which secondary metabolic ability is still unknown at the genus level. The 16S rRNA gene sequences are

Pigmentosins from Gibellula sp. as antibiofilm agents and a new glycosylated asperfuran from Cordyceps javanica

• Soleiman E. Helaly,
• Wilawan Kuephadungphan,
• Patima Phainuphong,
• Mahmoud A. A. Ibrahim,
• Kanoksri Tasanathai,
• Suchada Mongkolsamrit,
• Janet Jennifer Luangsa-ard,
• Souwalak Phongpaichit,
• Vatcharin Rukachaisirikul and
• Marc Stadler

Beilstein J. Org. Chem. 2019, 15, 2968–2981, doi:10.3762/bjoc.15.293

• bioactive secondary metabolites. Herein, we report on the isolation, structure elucidation, and biological activities of six compounds from Gibellula sp. and Cordyceps javanica. Furthermore, the species-specific patterns of secondary metabolite production were studied. Results and Discussion Structure

• close to each other [23], and they produce the same secondary metabolites according to the evidence from Kadlec and co-workers [24], Jegorov and co-workers [25], and Luangsa-ard and co-workers [26]. They unveiled the existences of beauverolides and beauvericin, originally described from Beauveria, in

• numerous new secondary metabolites. In the future, chemotaxonomic studies should therefore be further expanded to other taxa in Gibellula, Cordyceps, and related genera, since this approach has been mostly restricted only to certain large ascomycete genera. Bioactivities Naphthopyrones are well-known to

Two new aromatic polyketides from a sponge-derived Fusarium

• Mada Triandala Sibero,
• Tao Zhou,
• Keisuke Fukaya,
• Daisuke Urabe,
• Ocky K. Karna Radjasa,
• Agus Sabdono,
• Agus Trianto and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2019, 15, 2941–2947, doi:10.3762/bjoc.15.289

• structurally unique secondary metabolites with various biological activities [8][9]. Specifically, sponge-associated fungi are attracting substantial attention because of their high capability of producing a wide range of bioactive compounds [5][10][11]. As a tropical country, Indonesia is known as the second

• database. HPLC/UV-guided purification of the secondary metabolites from this strain led to the isolation of two new polyketides, karimunones A (1) and B (2), together with five known compounds (3–7, Figure 1). Compound 1 was obtained as a red powder. TOF-HRESIMS analysis gave a deprotonated molecule [M − H

• summary, our chemical analysis of a sponge-derived fungus of the genus Fusarium led to the identification of two new and three known aromatic polyketides (1 and 2, and 3–5, respectively) and two sesquiterpenes (6 and 7). Although secondary metabolites of Fusarium were extensively studied in the past [26

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

• Saarbrücken, Germany 10.3762/bjoc.15.286 Abstract The argyrins are secondary metabolites from myxobacteria with antibiotic activity against Pseudomonas aeruginosa. Studying their structure–activity relationship is hampered by the complexity of the chemical total synthesis. Mutasynthesis is a promising

Skeletocutins M–Q: biologically active compounds from the fruiting bodies of the basidiomycete Skeletocutis sp. collected in Africa

• Tian Cheng,
• Clara Chepkirui,
• Cony Decock,
• Josphat C. Matasyoh and
• Marc Stadler

Beilstein J. Org. Chem. 2019, 15, 2782–2789, doi:10.3762/bjoc.15.270

• isolated and characterized five previously undescribed secondary metabolites, skeletocutins M–Q (1–5), along with the known metabolite tyromycin A (6) from the fruiting bodies of the polypore Skeletocutis sp. The new compounds did not exhibit any antimicrobial, cytotoxic, or nematicidal activities. However

• , compound 3 moderately inhibited the biofilm formation of Staphylococcus aureus (S. aureus), while compounds 3 and 4 performed moderately in the ʟ-leucine-7-amido-4-methylcoumarin (ʟ-Leu-AMC) inhibition assay. These compounds represent the first secondary metabolites reported to occur in the fruiting bodies

• ; polyporaceae; secondary metabolites; structure elucidation; Introduction Over the past years, we have been studying the secondary metabolites of African Basidiomycota that were collected in rainforests and mountainous areas of Western Kenya. These species were new to science, and proved to be a prolific

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

• : Aspergillus; biosynthesis; drimane; secondary metabolites; sesquiterpenoid; terpenes; Introduction The fungal genus Aspergillus is well recognised as a source of structurally diverse terpenoids comprising monoterpenoids [1], sesquiterpenoids [2][3][4][5], diterpenoids [6], sesterterpenoids [7][8][9

• production of terpenoids as the dominant biosynthetic class of secondary metabolites. Results and Discussion Purification and identification The metabolite profile of A. nanangensis was examined on a limited range of solid and liquid media suitable for fungal metabolite production. The metabolite profile

• Aspergillus type species) and unidentified but metabolically talented fungi (>60,000 spectra from 3,000 species) returned no similar metabolite cohorts, suggesting an unknown species. Individual retention time/UV–vis searches of the dominant 15 secondary metabolites against our in-house pure metabolite

Current understanding and biotechnological application of the bacterial diterpene synthase CotB2

• Ronja Driller,
• Daniel Garbe,
• Norbert Mehlmer,
• Monika Fuchs,
• Keren Raz,
• Dan Thomas Major,
• Thomas Brück and
• Bernhard Loll

Beilstein J. Org. Chem. 2019, 15, 2355–2368, doi:10.3762/bjoc.15.228

• [1][2][3]. Sesqui- and diterpenes are a diverse class of secondary metabolites derived predominantly from plants, marine invertebrates, fungi and some prokaryotes [4][5][6][7][8]. Properties of these natural products include antitumor, anti-oxidant, anti-inflammatory, antiviral, antimalarial

Isolation and biosynthesis of an unsaturated fatty acid with unusual methylation pattern from a coral-associated bacterium Microbulbifer sp.

• Amit Raj Sharma,
• Enjuro Harunari,
• Tao Zhou,
• Agus Trianto and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2019, 15, 2327–2332, doi:10.3762/bjoc.15.225

• secondary metabolites have received lesser attention [3]. To date, a couple of new compounds were discovered from soft coral-associated bacteria such as pseudoalteromones from Pseudoalteromonas isolated from the cultured octocoral Lobophytum crassum [4][5] and macrolactin V from Bacillus amyloliquefaciens

Synthesis of acremines A, B and F and studies on the bisacremines

• Nils Winter and
• Dirk Trauner

Beilstein J. Org. Chem. 2019, 15, 2271–2276, doi:10.3762/bjoc.15.219

• relationship with their plant hosts [1], which is mediated by secondary metabolites [2]. In 2005, Torta and co-workers reported the isolation of six meroterpenoid natural products, acremines A–F from A20, a strain of Acreonium byssoides, isolated from grapevine leaves that were artificially inoculated with