Cycloheximide congeners produced by Streptomyces sp. SC0581 and photoinduced interconversion between (E)- and (Z)-2,3-dehydroanhydrocycloheximides

• Li Yang,
• Ping Wu,
• Jinghua Xue,
• Huitong Tan,
• Zheng Zhang and
• Xiaoyi Wei

Beilstein J. Org. Chem. 2017, 13, 1039–1049, doi:10.3762/bjoc.13.103

• Phytophthora infestans. Bioassay-guided fractionation of the extract led to the isolation of three new cycloheximide congeners (Figure 1), 2,3-dehydro-α-epi-isocycloheximide (1), (E)- and (Z)-2,3-dehydroanhydrocycloheximides (2 and 3), and one known but new naturally occurring cycloheximide congener

Glyco-gold nanoparticles: synthesis and applications

• Federica Compostella,
• Olimpia Pitirollo,
• Alessandro Silvestri and
• Laura Polito

Beilstein J. Org. Chem. 2017, 13, 1008–1021, doi:10.3762/bjoc.13.100

• , on the base of different expression level of the bacterial lectin FimH with a colorimetric assay. A simple and fast bioassay has been developed by Lee et al. [83] to recognize cholera toxin (CT), a protein secreted by the Vibrio cholerae bacterium which is responsible for cholera disease. A thiol

Biomimetic synthesis and HPLC–ECD analysis of the isomers of dracocephins A and B

• Viktor Ilkei,
• András Spaits,
• Anita Prechl,
• Áron Szigetvári,
• Zoltán Béni,
• Miklós Dékány,
• Csaba Szántay Jr,
• Judit Müller,
• Árpád Könczöl,
• Ádám Szappanos,
• Attila Mándi,
• Sándor Antus,
• Ana Martins,
• Attila Hunyadi,
• György Tibor Balogh,
• György Kalaus (†),
• Hedvig Bölcskei,
• László Hazai and
• Tibor Kurtán

Beilstein J. Org. Chem. 2016, 12, 2523–2534, doi:10.3762/bjoc.12.247

• the other hand, the possibility for neuroprotective activity could not be tested with the applied experimental setup. As an additional bioassay on compounds 2a–d and 3a–d, their potential to interfere with the function of P-glycoprotein (P-gp) was tested. By transporting a wide variety of compounds

Natural products from microbes associated with insects

• Christine Beemelmanns,
• Huijuan Guo,
• Maja Rischer and
• Michael Poulsen

Beilstein J. Org. Chem. 2016, 12, 314–327, doi:10.3762/bjoc.12.34

• associated with protective Actinobacteria belonging in most attine ant genera to the genus Pseudonocardia, which grow on species-specific areas of the cuticle [73][74][75][76]. In vitro bioassay-guided screening of one of the Pseudonocardia symbionts afforded the antimicrobial cyclic depsipeptide

• ][139] and high resolution NMR systems have been developed and optimized [7][18]. These technologies allow the identification in minute concentrations of the chemical entities moderating insect–microbial interactions and at least partially eliminate the need for bioassay-guided fractionation for the

New depsidones and isoindolinones from the mangrove endophytic fungus Meyerozyma guilliermondii (HZ-Y₂) isolated from the South China Sea

• Senhua Chen,
• Zhaoming Liu,
• Yayue Liu,
• Yongjun Lu,
• Lei He and
• Zhigang She

Beilstein J. Org. Chem. 2015, 11, 1187–1193, doi:10.3762/bjoc.11.133

• . Bioassay-guided fractionation of the bioactive extract led to the isolation of three new depsidones belonging to the analogues of the botryorhodines A–D [6], botryorhodines E–G (1–3), and two new isoindolinones, meyeroguillines A and B (7 and 9), together with five known compounds (4–6, 8 and 10) (Figure 1

Preparation of neuroprotective condensed 1,4-benzoxazepines by regio- and diastereoselective domino Knoevenagel–[1,5]-hydride shift cyclization reaction

• László Tóth,
• Yan Fu,
• Hai Yan Zhang,
• Attila Mándi,
• Katalin E. Kövér,
• Tünde-Zita Illyés,
• Attila Kiss-Szikszai,
• Balázs Balogh,
• Tibor Kurtán,
• Sándor Antus and
• Péter Mátyus

Beilstein J. Org. Chem. 2014, 10, 2594–2602, doi:10.3762/bjoc.10.272

• strengths. Boltzmann distributions were estimated from the ZPVE-corrected B3LYP/6-31G(d) energies in the gas-phase calculations and from the B3LYP/TZVP energies in the PCM ones. The MOLEKEL [28] software package was used for visualization of the results. Bioassay on neuroprotective activity: SH-SY5Y cells

Synthesis and biological evaluation of novel N-α-haloacylated homoserine lactones as quorum sensing modulators

• Michail Syrpas,
• Ewout Ruysbergh,
• Christian V. Stevens,
• Norbert De Kimpe and
• Sven Mangelinckx

Beilstein J. Org. Chem. 2014, 10, 2539–2549, doi:10.3762/bjoc.10.265

• . Furthermore, the biological QS activity of the synthetic AHL analogues compared to the natural AHLs was evaluated. Halogenated analogues demonstrated a reduced activity in the Escherichia coli JB523 bioassay, with the α-iodo lactones being the less active ones and the α-chloro AHLs the most potent QS agonists

• as percentage of relative fluorescence. The activity of these compounds was compared with fluorescence induced by 50 nM of N-3-oxohexanoyl homoserine lactone (OHHL), the most active autoinducer in the Escherichia coli bioassay. Most of the natural AHLs 3a–f showed agonistic activity in the whole

• bioassay to evaluate their ability to disrupt QS (Table 2). None of the α-chloro lactones 11 showed a significant reduction of QS regulated GFP-production in the tested concentration range (50–0.05 μΜ). Brominated analogues 6 demonstrated a small decrease in the activity. Among these analogues, compounds

New sesquiterpene hydroquinones from the Caribbean sponge Aka coralliphagum

• Qun Göthel and
• Matthias Köck

Beilstein J. Org. Chem. 2014, 10, 613–621, doi:10.3762/bjoc.10.52

• (4) exhibited mild antiproliferation activity against L929 mouse fibroblast, KB-31 epidermoid carcinoma, and MCF-7 breast cancer cell lines, while siphondictyal E3 (3) and cyclosiphonodictyol A (5) showed moderate activity against Gram-positive bacteria. Keywords: Aka coralliphagum; bioassay

Synthesis and quantitative structure–activity relationship study of substituted imidazophosphor ester based tetrazolo[1,5-b]pyridazines as antinociceptive/anti-inflammatory agents

• Wafaa M. Abdou,
• Neven A. Ganoub and
• Eman Sabry

Beilstein J. Org. Chem. 2013, 9, 1730–1736, doi:10.3762/bjoc.9.199

• experimental section, the general procedures, the experimental data, the results of the analyses, and the bioassay procedures are included in Supporting Information File 1. Supporting Information File 284: Full experimental details. Acknowledgements The authors would like to thank the Central Lab, School of

Zanthoxoaporphines A–C: Three new larvicidal dibenzo[de,g]quinolin-7-one alkaloids from Zanthoxylum paracanthum (Rutaceae)

• Fidelis N. Samita,
• Louis P. Sandjo,
• Isaiah O. Ndiege,
• Ahmed Hassanali and
• Wilber Lwande

Beilstein J. Org. Chem. 2013, 9, 447–452, doi:10.3762/bjoc.9.47

• , P.O. Box 812 Yaoundé, Cameroon Behavioural and Chemical Ecology Department, International Centre for Insect Physiology and Ecology, P.O. Box 30772, Nairobi 00100, Kenya 10.3762/bjoc.9.47 Abstract The bioassay-guided purification of Zanthoxylum paracanthum (Rutaceae) extracts led to the isolation of

• often harmful to nontarget organisms, including human beings, and have negative environmental impacts. We herein report the bioassay-guided isolation of four compounds including three new ones and the larvicidal activity of two of them. Results and Discussion Stem bark of Z. paracanthum was successively

Synthesis and testing of the first azobenzene mannobioside as photoswitchable ligand for the bacterial lectin FimH

• Vijayanand Chandrasekaran,
• Katharina Kolbe,
• Femke Beiroth and
• Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2013, 9, 223–233, doi:10.3762/bjoc.9.26

• the azobenzene moiety and the tyrosine gate at the entrance of the CRD, though in different ways. The only difference that is seen is that, apparently, the interactions of mannobioside 2 with the open-gate conformation of FimH are advantageous over those with the closed-gate form. From the bioassay in

• 56: Photoisomerization studies, UV–vis spectra, NMR spectra, bioassay and docking results. Acknowledgements Financial support by the DFG (collaborative network SFB677) and FCI (Fonds der Chemischen Industrie) is gratefully acknowledged. We thank Max Britz for technical assistance.

Similarity analysis, synthesis, and bioassay of antibacterial cyclic peptidomimetics

• Workalemahu M. Berhanu,
• Mohamed A. Ibrahim,
• Girinath G. Pillai,
• Alexander A. Oliferenko,
• Levan Khelashvili,
• Farukh Jabeen,
• Bushra Mirza,
• Farzana Latif Ansari,
• Ihsan ul-Haq,
• Said A. El-Feky and
• Alan R. Katritzky

Beilstein J. Org. Chem. 2012, 8, 1146–1160, doi:10.3762/bjoc.8.128

• bis(S-acylcysteine) 36 forming the pyridine–cysteine-containing macrocycle 40 in 70% yield (Scheme 3, see Supporting Information File 1 for experimental details). Bioassay Screening for antibacterial activity was performed for two cyclic peptidomimetics belonging to scaffold 37, namely 37a and 37b

Volatile organic compounds produced by the phytopathogenic bacterium Xanthomonas campestris pv. vesicatoria 85-10

• Teresa Weise,
• Marco Kai,
• Anja Gummesson,
• Armin Troeger,
• Stephan von Reuß,
• Silvia Piepenborn,
• Francine Kosterka,
• Martin Sklorz,
• Ralf Zimmermann,
• Wittko Francke and
• Birgit Piechulla

Beilstein J. Org. Chem. 2012, 8, 579–596, doi:10.3762/bjoc.8.65

• concentrations. Surprisingly, undecan-2-one (31) promoted the growth of R. solani by 10–15% at concentrations from 0.01 to 10 μmol in 50 μL and dodecan-2-one (38) at 0.01 and 0.1 μmol in 50 μL. 10-Methylundecan-2-one (34) had no effect on the growth of R. solani. An additional bioassay, performed with a mixture

• experimental design of the bioassay was not appropriate or other volatiles account for the inhibitory effects. In the literature, contradictory results were found for undecan-2-one (31). It is likely to be involved in the inhibition of sapstain fungi [40], while Sclerotinia sclerotiorum was not affected by 31

• mixture (0.09–9 μmol) were applied on filter paper (1 cm2), which was deposited at the other compartment of the Petri dish. Control experiments were performed with pentane alone. Similarly to the cocultivation test, the bioassay with individual compounds was performed at 20 °C in the dark. Every 24 h the

Conserved and species-specific oxylipin pathways in the wound-activated chemical defense of the noninvasive red alga Gracilaria chilensis and the invasive Gracilaria vermiculophylla

• Martin Rempt,
• Florian Weinberger,
• Katharina Grosser and
• Georg Pohnert

Beilstein J. Org. Chem. 2012, 8, 283–289, doi:10.3762/bjoc.8.30

• -HETE 3 (1.7 µg/g agar), and a 1/1 mixture of 5 and 6 (total 8.2 µg/g agar). To evaluate the response of the sea snail E. peruviana towards the algal compounds, we developed a new bioassay based on the avoidance reaction of the snail. When the snails were put on a Petri dish that was partially filled

• 6) were incorporated into agar matrices in natural concentrations and the response of the snails was tested by using the attachment bioassay, as described above. Of the tested metabolites only 7,8-di-HETE (3) was active when applied at concentrations corresponding to those detected in wounded G

Multicomponent synthesis of artificial nucleases and their RNase and DNase activity

• Anton V. Gulevich,
• Lyudmila S. Koroleva,
• Olga V. Morozova,
• Valentina N. Bakhvalova,
• Vladimir N. Silnikov and
• Valentine G. Nenajdenko

Beilstein J. Org. Chem. 2011, 7, 1135–1140, doi:10.3762/bjoc.7.131

• ), r.t.; b. Pd/C, 5%, HCOONH4, MeOH/H2O, reflux. Supporting Information Supporting Information File 306: General information, procedures, spectral data of all compounds, results of bioassay, and copies of selected NMR spectra. Acknowledgements The study was partly supported by SB RAS-83, 88 and RFBR-09

Novel synthesis of pseudopeptides bearing a difluoromethyl group by Ugi reaction and desulfanylation

• Jingjing Wu,
• Hui Li and
• Song Cao

Beilstein J. Org. Chem. 2011, 7, 1070–1074, doi:10.3762/bjoc.7.123

• reported of the preparation and bioassay of pseudopeptides and peptidomimetics bearing difluoromethyl groups. For example, compound I can act as bradykinin B1 antagonist or inverse agonist and can be used in the prevention of inflammation and pain [19]. Compound II is an inhibitor of microsomal

(−)-Complanine, an inflammatory substance of marine fireworm: a synthetic study

• Kazuhiko Nakamura,
• Yu Tachikawa and
• Daisuke Uemura

Beilstein J. Org. Chem. 2009, 5, No. 12, doi:10.3762/bjoc.5.12

• actual toxic substance of these animals has remained unknown. We recently isolated a novel amphipathic substance, named complanine (Figure 1), from an amphinomid polychaete, Eurythoe complanata (Figure 2). Complanine has been identified as an inflammatory substance by bioassay-guided separations; and the

A facile synthesis and fungicidal activities of 2-(alkylamino)-5,6-dimethylthieno[2,3-d]pyrimidin- 4(3H)-ones

• Yang-Gen Hu,
• Ai-Hua Zheng,
• Xu-Zhi Ruan and
• Ming-Wu Ding

Beilstein J. Org. Chem. 2008, 4, No. 49, doi:10.3762/bjoc.4.49

• many cases compares favorably with other existing methods. The preliminary bioassay of the compounds indicated that the 2-amino-5,6-dimethylthieno[2,3-d]pyrimidin-4(3H)-ones can be used as lead structure for developing novel fungicides. Further bioassay, optimization and structure-activity