Activity assays of NnlA homologs suggest the natural product N-nitroglycine is degraded by diverse bacteria

• Kara A. Strickland,
• Brenda Martinez Rodriguez,
• Ashley A. Holland,
• Shelby Wagner,
• Michelle Luna-Alva,
• David E. Graham and
• Jonathan D. Caranto

Beilstein J. Org. Chem. 2024, 20, 830–840, doi:10.3762/bjoc.20.75

• antibiotic activity towards Gram-negative bacteria. An NNG degrading heme enzyme, called NnlA, has recently been discovered in the genome of Variovorax sp. strain JS1663 (Vs NnlA). Evidence is presented that NnlA and therefore, NNG degradation activity is widespread. To achieve this objective, we

• producers and of NNG is unknown. Additionally, NNG’s physiological function is unknown, but it is toxic to plants, mice, and Gram-negative bacteria [25][26]. While there is no direct evidence of the mechanism of this toxicity, NNG has been shown to competitively inhibit succinate dehydrogenase, a component

• often exhibit antibiotic activity and it has been shown that NNG exhibits antibiotic activity towards Gram-negative bacteria (0.18 to 25 μg/mL) [24]. Moreover, the nitramine functional group has potential to serve as a potent warhead in an antibiotic. For example, a cytochrome P450 homolog, XplA

New variochelins from soil-isolated Variovorax sp. H002

• Jabal Rahmat Haedar,
• Aya Yoshimura and
• Toshiyuki Wakimoto

Beilstein J. Org. Chem. 2024, 20, 692–700, doi:10.3762/bjoc.20.63

• fatty acyl groups. Furthermore, the variochelin biosynthetic gene cluster was identified through draft genome sequencing and gene knockout experiments. Compounds 1–5 exhibited antimicrobial activities against Gram-negative bacteria, including several soil-isolated plant pathogens. Keywords

• variochelins [20]. Biological activity The antimicrobial activities of 1–5 were evaluated against several Gram-negative and Gram-positive bacteria (Table 1). As a result, 1–5 inhibited the growth of the Gram-negative bacteria Escherichia coli and Burkholderia multivorans, but lacked activity against Bacillus

• triplicate, according to the Clinical Laboratory Standards Institute testing standard, in 96-well plate microbroth dilution assays. Compounds were tested against Gram-negative bacteria (Escherichia coli JW5503, Bukholderia multivorans NBRC 102086 and Bukholderia plantarii NBRC 104884) and Gram-positive

A new analog of dihydroxybenzoic acid from Saccharopolyspora sp. KR21-0001

• Rattiya Janthanom,
• Yuta Kikuchi,
• Hiroki Kanto,
• Tomoyasu Hirose,
• Arisu Tahara,
• Takahiro Ishii,
• Arinthip Thamchaipenet and
• Yuki Inahashi

Beilstein J. Org. Chem. 2024, 20, 497–503, doi:10.3762/bjoc.20.44

• ). Antioxidant activity of 1 was measured via the DPPH radical. 1 showed potent DPPH radical scavenging activity with an IC50 value of 5.0 μg·mL−1, which is lower than that of trolox (IC50; 7.5 μg·mL−1) (Table 2). In contrast, 1 did not show antimicrobial activity against Gram-positive and Gram-negative bacteria

• -positive bacteria, Kocuria rhizophila ATCC 9341 and Bacillus subtilis ATCC 6633; two strains of Gram-negative bacteria, Escherichia coli Europe NIHJ and Xanthomona campestis pv. oryzae KB 88; and two strains of fungi, Candida albicans ATCC 64548 and Mucor racemosus IFO 4581. All strains were tested by

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

• most prominent examples in this regard are the fluoroquinolone antimicrobials [3] – a remarkably successful drug class, used to treat bacterial infections caused by both Gram-positive and Gram-negative bacteria [4]. Other notable 4-quinolones of synthetic origin are ivacaftor [5] and elvitegravir [6

Synthesis and biological evaluation of Argemone mexicana-inspired antimicrobials

• Jessica Villegas,
• Bryce C. Ball,
• Katelyn M. Shouse,
• Caleb W. VanArragon,
• Ashley N. Wasserman,
• Hannah E. Bhakta,
• Allen G. Oliver,
• Danielle A. Orozco-Nunnelly and
• Jeffrey M. Pruet

Beilstein J. Org. Chem. 2023, 19, 1511–1524, doi:10.3762/bjoc.19.108

• (five Gram-positive and four Gram-negative bacteria, and three fungi). Additionally, the crystal structures of two berberine variants are described. Several berberine variants show enhanced antibacterial activity compared to the unaltered plant-derived molecule. We also report promising preliminary

• cereus, Bacillus subtilis, Staphylococcus epidermidis, Corynebacterium pseudodiphtheriticum), four Gram-negative bacteria (Escherichia coli, Proteus mirabilis, Enterobacter aerogenes, Enterobacter cloacae), and three fungi (Saccharomyces cerevisiae, Candida albicans, Penicillium chrysogenum). The goal of

• these compounds have been reported before, they were still of interest, as neither compound has been thoroughly assessed for its antimicrobial activity. Our initial pool of berberine variants was screened against 12 microbial organisms (five Gram-positive and four Gram-negative bacteria, and three fungi

Intermediates and shunt products of massiliachelin biosynthesis in Massilia sp. NR 4-1

• Till Steinmetz,
• Blaise Kimbadi Lombe and
• Markus Nett

Beilstein J. Org. Chem. 2023, 19, 909–917, doi:10.3762/bjoc.19.69

• biosynthetic intermediates or shunt products of massiliachelin. Their bioactivity was tested against one Gram-positive and three Gram-negative bacteria. Keywords: Massilia; massiliachelin; siderophore; structure elucidation; Introduction Iron is crucial for many important biological processes, such as

• signal at δH 7.62 ppm characteristic for an amide. In vitro tests were conducted for all compounds to assess their antibacterial activities against three Gram-negative bacteria (Escherichia coli, Agrobacterium tumefaciens and Pseudomonas fluorescens) and one Gram-positive bacterium (Bacillus subtilis

Synthesis of imidazo[1,2-a]pyridine-containing peptidomimetics by tandem of Groebke–Blackburn–Bienaymé and Ugi reactions

• Oleksandr V. Kolomiiets,
• Alexander V. Tsygankov,
• Maryna N. Kornet,
• Aleksander A. Brazhko,
• Vladimir I. Musatov and
• Valentyn A. Chebanov

Beilstein J. Org. Chem. 2023, 19, 727–735, doi:10.3762/bjoc.19.53

• microorganisms (see Table 3 for details). Both Gram-positive and Gram-negative bacteria (specifically, strains of E. coli and B. subtilis) were equally inhibited in their growth. Compound 7o, in particular, was able to inhibit the growth of B. subtilis at a concentration of 125 mg/L. Bacteriostatic activity

Strategies to access the [5-8] bicyclic core encountered in the sesquiterpene, diterpene and sesterterpene series

• Cécile Alleman,
• Charlène Gadais,
• Laurent Legentil and
• François-Hugues Porée

Beilstein J. Org. Chem. 2023, 19, 245–281, doi:10.3762/bjoc.19.23

• -positive and Gram-negative bacteria (Scheme 31B). 4.4 Photocatalyzed oxidative ring expansion: alternative radical chemistry for pleuromutilin scaffold construction Following the advent of photoredox catalysis in ring-opening and ring-expansion chemistry [75], a new route was proposed by Foy and Pronin to

Nostochopcerol, a new antibacterial monoacylglycerol from the edible cyanobacterium Nostochopsis lobatus

• Naoya Oku,
• Saki Hayashi,
• Yuji Yamaguchi,
• Hiroyuki Takenaka and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2023, 19, 133–138, doi:10.3762/bjoc.19.13

• -hexane. The resulting three layers were tested against four Gram-positive bacteria, five Gram-negative bacteria, six fungi, and two yeasts, which detected antibacterial activity against two Gram-positive bacteria, Bacillus subtilis and Staphylococcus aureus, from the 90% aqueous MeOH layer. The

Digyalipopeptide A, an antiparasitic cyclic peptide from the Ghanaian Bacillus sp. strain DE2B

• Adwoa P. Nartey,
• Aboagye K. Dofuor,
• Kofi B. A. Owusu,
• Anil S. Camas,
• Hai Deng,
• Marcel Jaspars and
• Kwaku Kyeremeh

Beilstein J. Org. Chem. 2022, 18, 1763–1771, doi:10.3762/bjoc.18.185

• promising antimicrobial properties in comparison to the laboratory standards ampicillin and amphotericin B. Compound 1 produced interesting biological activity against the Gram-negative bacteria Shigella sonnei, Shigella flexneri and the multidrug resistant Gram-positive Staphylococcus aureus with IC50 of

Cyclometalated iridium complexes-catalyzed acceptorless dehydrogenative coupling reaction: construction of quinoline derivatives and evaluation of their antimicrobial activities

• Hongling Shui,
• Yuhong Zhong,
• Renshi Luo,
• Zhanyi Zhang,
• Jiuzhong Huang,
• Ping Yang and
• Nianhua Luo

Beilstein J. Org. Chem. 2022, 18, 1507–1517, doi:10.3762/bjoc.18.159

• -triazoquinoline derivatives, and the biological activity evaluation showed that most of the compounds had a higher antibacterial activity (the optimal MIC value was 6.25 mg/mL) against Gram-positive bacteria, Gram-negative bacteria and all tested fungi than the standard ciprofloxacin (Figure 1a). Bodke's group

• and other compounds showed similar or lower antifungal activity than norfloxacin. Unfortunately, all compounds were less effective against Gram-negative bacteria (MIC > 128 μg/mL) than the parent drug norfloxacin. To sum up, the synthesized compounds exhibited enhanced antibacterial activity against

On drug discovery against infectious diseases and academic medicinal chemistry contributions

• Yves L. Janin

Beilstein J. Org. Chem. 2022, 18, 1355–1378, doi:10.3762/bjoc.18.141

Cholyl 1,3,4-oxadiazole hybrid compounds: design, synthesis and antimicrobial assessment

• Anas J. Rasras,
• Mohamed El-Naggar,
• Nesreen A. Safwat and
• Raed A. Al-Qawasmeh

Beilstein J. Org. Chem. 2022, 18, 631–638, doi:10.3762/bjoc.18.63

• acid with the heterocyclic moiety 1,3,4-oxadizole was synthesized, and tested for antimicrobial activity against Gram-positive, Gram-negative bacteria, and fungi. Among the synthesized compounds, the most potent derivatives against S. aureus were 4t, 4i, 4p, and 4c with MIC values between 31 and 70 µg

• for their in vitro antibacterial potential against Staphylococcus aureus and Bacillus subtilis as examples of Gram-positive bacteria as well as against Escherichia coli and Proteus vulgaris as examples of Gram-negative bacteria [35]. They were also evaluated for their in vitro antifungal activity

• , compound 4d showed the highest activity against Gram-negative bacteria Proteus vulgaris followed by compounds 4c, 4t, 4b, 4n, 4s, 4l, 4p, 4q, 4i, 4o, 4g and 4j, respectively. All tested compounds exhibited lower activities compared to the tested reference drugs. On the other hand, the order of

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

• metabolites from Gram-negative bacteria are still quite limited, despite the predominance of this group in the marine environment [10][11]. The genus Tenacibaculum belongs to the family Flavobacteriaceae within the phylum Bacteroidetes. Members of this genus are Gram-negative, aerobic, motile by gliding, and

Total synthesis of the O-antigen repeating unit of Providencia stuartii O49 serotype through linear and one-pot assemblies

• Tanmoy Halder and
• Somnath Yadav

Beilstein J. Org. Chem. 2021, 17, 2915–2921, doi:10.3762/bjoc.17.199

• polysaccharides are one of the important constituents of the surface lipopolysaccharides (LPS) of the cell wall of Gram-negative bacteria. These antigens are responsible for several functions that include adhesion to the host cells and are also found to contribute to the evasion of the host immune responses

• ]. Providencia is a genus of Gram-negative bacteria that belongs to the enterobacteria family and is responsible for causing several enteric infections including urinary tract infections. Providencia includes mainly five virulent species – P. alcalifaciens, P. rettgeri, P. rustigianii, P. stuartii, and P

Biological properties and conformational studies of amphiphilic Pd(II) and Ni(II) complexes bearing functionalized aroylaminocarbo-N-thioylpyrrolinate units

• Samet Poyraz,
• Samet Belveren,
• Sabriye Aydınoğlu,
• Mahmut Ulger,
• Abel de Cózar,
• Maria de Gracia Retamosa,
• Jose M. Sansano and
• H. Ali Döndaş

Beilstein J. Org. Chem. 2021, 17, 2812–2821, doi:10.3762/bjoc.17.192

• anti(myco)bacterial and antifungal activity of newly prepared organometallic compounds were investigated against some Gram-positive, Gram-negative bacteria, M. tuberculosis H37Rv strains and C. albicans, C. tropicalis, C. glabrata fungi. The screened novel complexes showed different degrees of

Double-headed nucleosides: Synthesis and applications

• Vineet Verma,
• Jyotirmoy Maity,
• Vipin K. Maikhuri,
• Ritika Sharma,
• Himal K. Ganguly and
• Ashok K. Prasad

Beilstein J. Org. Chem. 2021, 17, 1392–1439, doi:10.3762/bjoc.17.98

• double-headed nucleosides was assessed through in vitro studies on Gram-positive bacteria Staphylococcus aureus, Listeria inovanii and Gram-negative bacteria Klebsiella pneumoniae, Salmonella sp., and Escherichia coli [20]. Triazolyl double-headed nucleosides showed efficacy against eosinophil-derived

β-Lactamase inhibition profile of new amidine-substituted diazabicyclooctanes

• Zafar Iqbal,
• Lijuan Zhai,
• Yuanyu Gao,
• Dong Tang,
• Xueqin Ma,
• Jinbo Ji,
• Jian Sun,
• Jingwen Ji,
• Yuanbai Liu,
• Rui Jiang,
• Yangxiu Mu,
• Lili He,
• Haikang Yang and
• Zhixiang Yang

Beilstein J. Org. Chem. 2021, 17, 711–718, doi:10.3762/bjoc.17.60

• increasing day by day thereby indicating the strength of these pathogens in compromising the efficacy of new antibiotics after a certain period of time. Recently, the WHO warned about the seriousness of carbapenemase-resistant Gram-negative bacteria as a global threat and urged for the development of new

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

• . 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

Selected peptide-based fluorescent probes for biological applications

• Debabrata Maity

Beilstein J. Org. Chem. 2020, 16, 2971–2982, doi:10.3762/bjoc.16.247

• chondroitin sulphate. Sensores 10 and 11 even could detect heparin selectively from their mixtures and have been utilized for heparin detection in diluted bovine serum. Lipopolysaccharide detection Endotoxic lipopolysaccharide (LPS) is an important component in the outer cell membrane of Gram-negative

• bacteria [57]. It is a glycolipid consisting of a variable polysaccharide domain connected to a conserved glucosamine-based phospholipid called lipid A. It is highly negatively charged due to two phosphorylated groups in the lipid A part and carboxylated groups in the polysaccharide part. It is amphiphilic

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

• the same as those for 1 (Table 1). The antimicrobial activity of 1–4 was tested against Gram-positive bacteria Kocuria rhizophila and Staphylococcus aureus, Gram-negative bacteria Escherichia coli and Rhizobium radiobacter, a yeast Candida albicans, and two fungi Glomerella cingulata and Trichophyton

• rubrum (Table 2). All compounds exhibited moderate activity against Gram-positive bacteria with MICs of 6.25–12.5 μg/mL but were inactive against Gram-negative bacteria. The compounds 1–4 were also active against the yeast and fungi, with MIC values ranging from 6.25–25 μg/mL. In addition, the compounds

4-Hydroxy-3-methyl-2(1H)-quinolone, originally discovered from a Brassicaceae plant, produced by a soil bacterium of the genus Burkholderia sp.: determination of a preferred tautomer and antioxidant activity

• Dandan Li,
• Naoya Oku,
• Yukiko Shinozaki,
• Yoichi Kurokawa and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2020, 16, 1489–1494, doi:10.3762/bjoc.16.124

• rutaceous plants [9]. Examples from microbes include chymase inhibitors SF2809-I to VI from an actinomycete of the genus Dactylosporangium [10], a quorum sensing signaling molecule 2,4-dihydroxyquinoline (DHQ, 4) from Gram-negative bacteria Pseudomonas aeruginosa and Burkholderia thailandensis, [7], and 4-O

• aureus FDA209P JC-1 (Gram-positive bacterium), Rhizobium radiobacter NBRC14554, Ralstonia solanacearum SUPP1541, Tenacibaculum maritimum NBRC16015 (Gram-negative bacteria), Candida albicans NBRC0197, and Saccharomyces cerevisiae S100 (yeasts). Oxidative burst, which is a transient production of massive

Fabclavine diversity in Xenorhabdus bacteria

• Sebastian L. Wenski,
• Harun Cimen,
• Natalie Berghaus,
• Sebastian W. Fuchs,
• Selcuk Hazir and
• Helge B. Bode

Beilstein J. Org. Chem. 2020, 16, 956–965, doi:10.3762/bjoc.16.84

• against the tested Gram-positive and Gram-negative bacteria in the other strains analyzed (Table 3). Whether this bioactivity is due to individual members of the fabclavines or whether all of them have a comparable activity must be studied in the future after the isolation of the individual derivatives

• . Nevertheless, synergistic effects with other compound classes, enhancing the overall inhibitory activity, cannot be excluded. As an example, X. indica and X. cabanillasii showed an additional bioactivity against Gram-negative bacteria even without fabclavine production (Table 3). This bioactivity might be

Light-controllable dithienylethene-modified cyclic peptides: photoswitching the in vivo toxicity in zebrafish embryos

• Sergii Afonin,
• Oleg Babii,
• Aline Reuter,
• Volker Middel,
• Masanari Takamiya,
• Uwe Strähle,
• Igor V. Komarov and
• Anne S. Ulrich

Beilstein J. Org. Chem. 2020, 16, 39–49, doi:10.3762/bjoc.16.6

• Gram-positive bacteria, Gram-negative bacteria, HeLa cells, and human erythrocytes) and were able to rationalize the specific impact of our modifications onto cell selectivity indices. Though all compounds demonstrated distinctly different cell toxicities in the ring-open and the ring-closed photoforms

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

• mechanisms of pathogenic Gram-negative bacteria against antibiotics, such as polymyxin B and colistin [3]. The main effect of Ara4N incorporation into the lipid A part – and, less frequently, into the inner core region of LPS [4] – is thought to originate from blocking the electrostatic interaction of