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

• them were identified as fusarindoles B (4) [15], dehydrocurvularin (5) [16], hydroxycurvularin (6) [17], curvularin (7) [18], curvulopyran (8) [19], (S)-6-(sec-butyl)-3-isobutylpyrazin-2(1H)-one (9) [20], 3,6-di-sec-butyl-2(1H)-pyrazinone (10) [20], daidzein (11) [21], and genistein (12) [22]. Notably

Nucleophilic and electrophilic cyclization of N-alkyne-substituted pyrrole derivatives: Synthesis of pyrrolopyrazinone, pyrrolotriazinone, and pyrrolooxazinone moieties

• Işıl Yenice,
• Sinan Basceken and
• Metin Balci

Beilstein J. Org. Chem. 2017, 13, 825–834, doi:10.3762/bjoc.13.83

• biological activities. Various microbes, reported in the literature, can accomplish the synthesis of pyrazinone derivatives [3][4][5][6]. For instance, phevalin (1) and tyrvalin (2), pyrazinone derivatives synthesized by a serious human pathogen, Staphylococcus aureus, act as protein kinase inhibitors

• photosynthesis by inhibiting electron transport (Figure 1). They are used to control grasses pre- and post-emergence [9][10]. Pyrrole-fused pyrazinone heterocycles and their synthesis are of great interest due to their natural presence and potent pharmacological and biological activities. A natural product

• + H]+ calcd for C11H12INO2, 317.99855; found, 317.99880. Structures of some natural products containing pyrazinone and aminotriazonone skeletons. Structures of some natural products containing a pyrrolopyrazinone moiety. N-alkyne substituted pyrrole esters 7a–d. Correlations of olefinic proton in 12c

Brønsted acid-mediated cyclization–dehydrosulfonylation/reduction sequences: An easy access to pyrazinoisoquinolines and pyridopyrazines

• Ramana Sreenivasa Rao and
• Chinnasamy Ramaraj Ramanathan

Beilstein J. Org. Chem. 2017, 13, 428–440, doi:10.3762/bjoc.13.46

• -diamide 9a and substituted pyrazinone 10a in 90:10 ratio. Generally, the syntheses of these types of units are very limited in the literature [31]. Under controlled experimental conditions, in the absence of NaBH4/MeOH, the ene-diamide 9a was successfully generated in 90% yield using 4 equivalents of TfOH

• in 30 minutes from 7a. While increasing the reaction time from 30 minutes to 2 h, the formation of biologically active pyrazinone 10a has been realized as a major product along with ene-diamide 9a. A literature survey revealed that sulfonamides are known to undergo hydrolysis in the presence of a

• evidence for cyclized compounds 9b and 10a was supported by single-crystal X-ray diffraction analysis (Figure 3) in addition to IR, NMR and HRMS data. To show the synthetic utility of substituted pyrazinones, we introduce a phenyl group at the C-3 position in pyrazinone derivative 10a. To begin with, the

Regiochemistry of cyclocondensation reactions in the synthesis of polyazaheterocycles

• Patrick T. Campos,
• Leticia V. Rodrigues,
• Andrei L. Belladona,
• Caroline R. Bender,
• Juliana S. Bitencurt,
• Fernanda A. Rosa,
• Davi F. Back,
• Helio G. Bonacorso,
• Nilo Zanatta,
• Clarissa P. Frizzo and
• Marcos A. P. Martins

Beilstein J. Org. Chem. 2017, 13, 257–266, doi:10.3762/bjoc.13.29

• intermediates, and from these data it was possible to explain the regiochemistry of the products obtained. Additionally, the data were a useful tool for elucidating the reaction mechanisms. Keywords: DFT-B3LYP; polyazaheterocycles; pyrazinone; pyrido[1,2-a]pyrimidinone; pyrimido[1,2-a]benzimidazole

• involved the cyclocondensation of 1,2-dicarbonyl compounds with ethylenediamine and 1,2-phenylenediamine and they obtained polyazaheterocycles with pyrazinone and quinoxalinone cores. Although there is a wide range of papers reporting on cyclocondensation reactions, only few authors have discussed the

• %, respectively, were obtained. The best reaction conditions were used for the subsequent cyclocondensation reactions between compounds 5–7 and various diamines 8a–f. The reaction time ranged from 2 to 24 h and the pyrazinone and quinoxalinone derivatives 9a–f, 10c–f, 11a–e were obtained in medium to high yield

Marine-derived myxobacteria of the suborder Nannocystineae: An underexplored source of structurally intriguing and biologically active metabolites

• Antonio Dávila-Céspedes,
• Peter Hufendiek,
• Max Crüsemann,
• Till F. Schäberle and
• Gabriele M. König

Beilstein J. Org. Chem. 2016, 12, 969–984, doi:10.3762/bjoc.12.96

• ) and 19 proved to have cytotoxic effects in the lower micromolar range against different cancer cell lines [47]. Nannozinones A (21) and B (22, Figure 9) are produced by N. pusilla strain MNa10913, isolated from a soil sample, collected in Mallorca, Spain [49]. They represent novel pyrazinone type