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

• simple as hemolysis, and at the same time would make the data more relevant to human toxicity. Hence, we selected the zebrafish embryotoxicity assay as a potential compromise. Due to their small size, cheap husbandry and maintenance, fast embryogenesis, extracorporeal development, known genome and

• general trend, we observed a very low water solubility and tendency to aggregate. As can be seen from Figure 4, the toxicity against zebrafish embryos is higher than hemolysis for the majority of the ring-open isomers and for all ring-closed photoforms. This result suggests that the lysis of red blood

• data points are correlated quite well along the diagonal. This correspondence is in contrast to the comparison between hemolysis and HeLa cytotoxicity (Figure 5B) that had been reported in our earlier study, where the whole data set shows a systematic deviation off the diagonal. Our new in vivo data

Synthesis of novel sulfide-based cyclic peptidomimetic analogues to solonamides

• José Brango-Vanegas,
• Luan A. Martinho,
• Lucinda J. Bessa,
• Andreanne G. Vasconcelos,
• Alexandra Plácido,
• Alex L. Pereira,
• José R. S. A. Leite and
• Angelo H. L. Machado

Beilstein J. Org. Chem. 2019, 15, 2544–2551, doi:10.3762/bjoc.15.247

• range of 300–0.3 µM. None of the compounds presented antibacterial activity against S. aureus, since no MIC value could be obtained in the range of concentrations tested (MIC > 300 µM). Subsequently, a screening assay was carried out to evaluate the effect of these compounds on the hemolysis of

• Figure 2). Analogues 9e and 9g were then tested at lower concentrations (300–5 µM), and 9e was able to hamper the hemolysis by the strain at 10 µM (see Supporting Information File 1, Table S1). The antihemolytic activity of 9e and 9g was also tested in a quantitative microdilution assay using human red

• blood cells (see Supporting Information File 1, assay 3) [43]. Analogue 9e showed better capacity to inhibit the hemolysis than 9g at the same concentration (Figure 3). At concentrations of 10 µM and 200 µM of 9e, the hemolysis production by S. aureus was inhibited by 63% and 84%, respectively. Also, a

Pathoblockers or antivirulence drugs as a new option for the treatment of bacterial infections

• Matthew B. Calvert,
• Varsha R. Jumde and
• Alexander Titz

Beilstein J. Org. Chem. 2018, 14, 2607–2617, doi:10.3762/bjoc.14.239

• factors playing crucial roles in acute virulence [55]. Staphylococcus aureus infections are characterized by the toxic action of bacterial α-hemolysin, a pore forming toxin leading to hemolysis. The antibody MEDI4893, which blocks S. aureus α-hemolysin, is currently in phase II clinical trials [56

Interactions between cyclodextrins and cellular components: Towards greener medical applications?

• Loïc Leclercq

Beilstein J. Org. Chem. 2016, 12, 2644–2662, doi:10.3762/bjoc.12.261

• ). For sake of clarity, only some typical examples are reported in this section. The first well-documented effect of CDs is probably hemolysis which corresponds to the lysis of red blood cells (erythrocytes) and the release of their contents into surrounding fluid (blood plasma). In 1982, Irie and co

• -workers reported that native CDs are able to cause hemolysis of human erythrocytes [59]. This behavior occurs at relatively high concentrations (>1 mM) and that the degree of cholesterol extraction is a function of the CD used, its concentration, incubation time, temperature. For instance, in given

• conditions (isotonic solution with similar incubation time and temperature), the observed hemolysis is in the order γ-CD < α-CD < β-CD. This different effect, observed for native CDs, has been explained by Ohtani et al. in 1989 [58]. As the membrane of erythrocytes is composed of proteins (43%) associated

Multivalent display of the antimicrobial peptides BP100 and BP143

• Imma Güell,
• Rafael Ferre,
• Kasper K. Sørensen,
• Esther Badosa,
• Iteng Ng-Choi,
• Emilio Montesinos,
• Eduard Bardají,
• Lidia Feliu,
• Knud J. Jensen and
• Marta Planas

Beilstein J. Org. Chem. 2012, 8, 2106–2117, doi:10.3762/bjoc.8.237

• amylovora, Xanthomonas axonopodis pv. vesicatoria and Pseudomonas syringae pv. syringae [28][29]. BP100 displayed minimum inhibitory concentration (MIC) values in the range 2.5–7.5 μM and also showed low hemolysis (22% at 150 μM). BP143, which contains one D-amino acid, was as active, significantly less

• was determined as the ability to lyse erythrocytes in comparison to melittin. Percent hemolysis at 50 and 150 μM is included in Table 1. Results showed that the parent peptides BP100 and BP143 were not hemolytic at these concentrations. In contrast, carbopeptides 1–3 were able to lyse erythrocytes at

• preassembly may favor the formation of a more organized amphipathic peptide structure compared to the monomers, which has been correlated with a higher degree of hemolysis [14][36]. BP100 was originally designed based on an ideal α-helical Edmunson wheel and showed a moderate degree of secondary-structure

Modulating the activity of short arginine-tryptophan containing antibacterial peptides with N-terminal metallocenoyl groups

• H. Bauke Albada,
• Alina-Iulia Chiriac,
• Michaela Wenzel,
• Maya Penkova,
• Julia E. Bandow,
• Hans-Georg Sahl and
• Nils Metzler-Nolte

Beilstein J. Org. Chem. 2012, 8, 1753–1764, doi:10.3762/bjoc.8.200

• of the RcCO-W(RW)2-peptide versus killing kinetics of the (RW)3 derivative showed faster reduction of the colony forming units for the RcCO-W(RW)2-peptide, although MIC values indicated higher activity for the (RW)3-peptide. This was confirmed by growth inhibition studies. Secondly, hemolysis studies

• were tested in parallel to obtain HC50 values under identical conditions. As can be seen from these results, none of these peptides is strongly hemolytic. For example, each of the two (RW)3 compounds showed less than 50% hemolysis up to 500 µg/mL (333 µM). This value is higher from what has been

• reported before by Liu et al. (who reported 50% hemolysis at ~250 µM [53]). In fact, only the L-amino acid peptide (RW)3 showed weak hemolysis at 333 µM with 17% of the hRBCs being destroyed as compared to Triton X-100. These low hemolytic properties for both (RW)3-peptides, even up to 500 µg/mL, did not

Design of a novel tryptophan-rich membrane-active antimicrobial peptide from the membrane-proximal region of the HIV glycoprotein, gp41

• Evan F. Haney,
• Leonard T. Nguyen,
• David J. Schibli and
• Hans J. Vogel

Beilstein J. Org. Chem. 2012, 8, 1172–1184, doi:10.3762/bjoc.8.130

• minimal hemolysis, indicating that the parent peptide is not particularly cytotoxic. However, the mutation of four residues to cationic Arg residues resulted in a dramatic increase in the hemolytic activity, with significant hemolysis occurring at gp41w-4R concentrations as low as 7 μg/mL. For gp41w-KA

• gp41w concentrations below 100 μg/mL, and hemolysis was not observed at peptide concentrations lower than 500 μg/mL. The fluorescence spectroscopy results demonstrate that gp41w interacts with lipid bilayers and the Trp residues embed themselves into the membrane. The DSC data indicate that gp41w

Triterpenoid saponins from the roots of Acanthophyllum gypsophiloides Regel

• Elena A. Khatuntseva,
• Vladimir M. Men’shov,
• Alexander S. Shashkov,
• Yury E. Tsvetkov,
• Rodion N. Stepanenko,
• Raymonda Ya. Vlasenko,
• Elvira E. Shults,
• Genrikh A. Tolstikov,
• Tatjana G. Tolstikova,
• Dimitri S. Baev,
• Vasiliy A. Kaledin,
• Nelli A. Popova,
• Valeriy P. Nikolin,
• Pavel P. Laktionov,
• Anna V. Cherepanova,
• Tatiana V. Kulakovskaya,
• Ekaterina V. Kulakovskaya and
• Nikolay E. Nifantiev

Beilstein J. Org. Chem. 2012, 8, 763–775, doi:10.3762/bjoc.8.87

• composition with keyhole limpet hemocyanin-based immunogen. The availability of saponins 1 and 2 as individual pure compounds from the extract of the roots of A. gypsophiloides makes it a prospective source of immunoactive agents. Keywords: Acanthophyllum gypsophiloides; adjuvant; hemolysis; NMR; saponin

• whether traces or decomposition products of ingested saponins enter the blood stream through the permeable membranes of mucosal cells. For compounds 1, 2 and saponin from Quillaja bark (Sigma) as a reference compound, the study on in vitro hemolysis was carried out. The obtained data confirmed high

• hemolytic activity of the Quillaja bark saponin, which caused 100% of hemolysis at a minimal hemolytic concentration of 5.5 μg/mL. Saponins 1 and 2 exhibited much lower hemolytic activity (Table 3): 50% hemolysis was observed at concentrations 11–18 μg/mL. Hemolysis of 85–95% for compounds 1 and 2 was