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Search for "bioactivity" in Full Text gives 165 result(s) in Beilstein Journal of Organic Chemistry.
Cuevaenes C–E: Three new triene carboxylic derivatives from Streptomyces sp. LZ35ΔgdmAI
Beilstein J. Org. Chem. 2014, 10, 858–862, doi:10.3762/bjoc.10.82
- microbes at 30 μg/disc, indicating that the existence of the carboxyl group (1-COOH) is essential for the bioactivity. Previously, Liu et al. [7] reported the synthesis of cuevaene A. However, the NMR spectroscopic data of cuevaene A failed to match the published data. In a later paper, Taylor et al. [6
New sesquiterpene hydroquinones from the Caribbean sponge Aka coralliphagum
Beilstein J. Org. Chem. 2014, 10, 613–621, doi:10.3762/bjoc.10.52
- aqueous n-BuOH extract yielded the new compounds siphonodictyals E1–E4 (1–4) and cyclosiphonodictyol A (5). In this article, we describe the isolation, structural elucidation, and bioactivity of compounds 1–5 from the Aka growth form incrustans, as well as discuss the biosynthetic pathway of related
- ]. Moreover, the influence of the sulfate esters on the bioactivity has been proven by activity tests: the desulfated compounds tend to be more active [5]. Therefore, we propose that the sulfate esters act as hydroxy protecting groups. The sponges excrete the sesquiterpene hydroquinones primarily in the
- sulfated form and their activities get increased by hydrolysis of these labile groups. This would lead to a prolonged bioactivity of these metabolites and therefore to a more efficient defense against predators or pathogens. Experimental 1H and 13C NMR spectra were recorded on a Bruker Avance 600 MHz NMR
Preparation of new alkyne-modified ansamitocins by mutasynthesis
Beilstein J. Org. Chem. 2014, 10, 535–543, doi:10.3762/bjoc.10.49
- introduce a thiol linker by Huisgen-type cycloaddition which can principally be utilized to create tumor targeting conjugates. In bioactivity tests, only those new ansamitocin derivatives showed strong antiproliferative activity that bear an ester side chain at C-3. Keywords: ansamitocins; antibiotics
Tanzawaic acids I–L: Four new polyketides from Penicillium sp. IBWF104-06
Beilstein J. Org. Chem. 2014, 10, 251–258, doi:10.3762/bjoc.10.20
- Magnaporthe oryzae, one of the most devastating plant diseases on cultivated rice. Bioactivity-guided fractionation of organic extracts led to the isolation of a series of eight pure compounds, the structures of which were elucidated by 2D NMR spectroscopy as well as by mass spectrometry. Results and
- . The isolated compounds were tested for their bioactivity in a series of antimicrobial and antiproliferative assays. We found that apart from compounds 1 and 2, the other isolates (3–8) inhibited the conidial germination in Magnaporthe oryzae at concentrations of 50 µg/mL or less (Table 3) whereas the
- addition, tanzawaic acid A (7) showed weak activity in agar diffusion assays at 50 µg/filter dics against Bacillus brevis, Mucor miehei, and Paecilomyces variotii, as well as cytotoxic effects against HeLaS3 cells at a concentration of 50 µg/mL. However, none of the other compounds showed bioactivity in
Charge-transfer interaction mediated organogels from 18β-glycyrrhetinic acid appended pyrene
Beilstein J. Org. Chem. 2013, 9, 2877–2885, doi:10.3762/bjoc.9.324
- the form of free acids or aglycones, has been noted by its low toxicity, biocompatibility and bioactivity [31][32]. A wide array of papers has been published to report its anti-inflammatory, antiviral, and antitumor effects [33][34]. In recent years, it has been found that triterpenoids can serve as
SF002-96-1, a new drimane sesquiterpene lactone from an Aspergillus species, inhibits survivin expression
Beilstein J. Org. Chem. 2013, 9, 2866–2876, doi:10.3762/bjoc.9.323
- the culture fluid in the survivin promoter dependent reporter gene assay as described below. The compounds were isolated from the culture fluid by bioactivity-guided fractionation using the survivin transcriptional reporter assay in Colo 320 cells. The fermentation was stopped after 18 days, when the
- (60:40) as eluent to yield 28 mg of SF002-96-1 (tR: 13 min). During bioactivity-guided fractionation and isolation of compound SF002-96-1, no other compounds have been detected inhibiting survivin promoter activity. The purity of the isolated compound was analyzed with a Hewlett-Packard Series 1100LC
The regulation and biosynthesis of antimycins
Beilstein J. Org. Chem. 2013, 9, 2556–2563, doi:10.3762/bjoc.9.290
- utilise acyl-SNACs provides the possibility to employ feeding studies to introduce new chemistry at C-8. AntO is a lipase homologue and is predicted to install the N-formyl group resulting in the 3-formamidosalicylate moiety. AntO is required for bioactivity against the human pathogenic fungus, Candida
- bioactivity of 5-fluoroantimycins and reported they retained potent antifungal activity against Candida albicans, but were significantly reduced in cytotoxity in a leukemia P388 mouse cell line compared to the parent compounds [25]. Sandy et al. recently showed AntB can accept both acyl-CoAs and acyl-SNACs to
Cyclopamine analogs bearing exocyclic methylenes are highly potent and acid-stable inhibitors of hedgehog signaling
Beilstein J. Org. Chem. 2013, 9, 2328–2335, doi:10.3762/bjoc.9.267
- cells. An extension of this study to F-ring-modified structures shows the necessity of a rigidly positioned nitrogen atom for bioactivity as well as the presence of the C21 methyl group for acid stability and bioactivity. Keywords: cyclopamine; hedgehog signaling pathway; natural products; steroidal
- and 9 it becomes evident that the F-ring is necessary for bioactivity. The piperidine moiety provides a rather rigidly placed nitrogen atom. Nevertheless, a pyrrolidine as in compound 23 still provides the correct orientation of the nitrogen atom. Despite compounds 8 and 9 being inactive in the assay
- , both derivatives induced cytotoxicity in the concentration range tested. Very subtle changes of the conformation of the piperidine ring significantly change bioactivity: While 25-epi-exo-cyclopamine 5 shows reduced activity in comparison to exo-cyclopamine 2, bis-exo-cyclopamine 6 is the most active
The chemistry of isoindole natural products
Beilstein J. Org. Chem. 2013, 9, 2048–2078, doi:10.3762/bjoc.9.243
- -cleavable complex they prevent the replication of DNA and act as efficient antitumor compounds [21]. The extraordinary bioactivity of indolocarbazoles has drawn a lot of attention from chemists and biologists. The biosynthesis of staurosporine (26) and rebeccamycin (28), both being the most prominent
Synthesis and antibacterial activity of monocyclic 3-carboxamide tetramic acids
Beilstein J. Org. Chem. 2013, 9, 1899–1906, doi:10.3762/bjoc.9.224
- found that 3-alkoxycarbonyl and 3-carboxamide tetramic acids prefer tautomer A, while the preference of 3-acyltetramic acids depends on the N(1)-functionality. Of particular interest is that 3-carboxamide analogues, especially 2b, have shown bioactivity against various Gram-positive bacteria including
New tridecapeptides of the theonellapeptolide family from the Indonesian sponge Theonella swinhoei
Beilstein J. Org. Chem. 2013, 9, 1643–1651, doi:10.3762/bjoc.9.188
- aliphatic amino acids; ii) the abundance of N-methylated residues and iii) the presence of a macrocycle made up by more than ten amino acids. Only a few theonellapeptolides have been tested for immunosuppressive activity and they revealed a moderate potency [25]. In general, the potential bioactivity of
ML212: A small-molecule probe for investigating fluconazole resistance mechanisms in Candida albicans
Beilstein J. Org. Chem. 2013, 9, 1501–1507, doi:10.3762/bjoc.9.171
- fungal cells. A substituted indazole possessing the desired bioactivity profile was selected for further development, and initial investigation of structure–activity relationships led to the discovery of ML212. Keywords: antifungal; Candida albicans; chemosensitizer; fluconazole; Molecular Libraries
- . While bioactivity is still observed with these substances, they all appear to be only weakly active (IC50 = 2–8 μM). Conversely, the meta-substituted systems 35–38 prove to be the most conducive to potency. The methyl ether 36 is potent against CaCi-2 (IC50 = 0.7 μM) as is the N,N-dimethylamine variant
Exploration of an epoxidation–ring-opening strategy for the synthesis of lyconadin A and discovery of an unexpected Payne rearrangement
Beilstein J. Org. Chem. 2013, 9, 1179–1184, doi:10.3762/bjoc.9.132
- addition to its interesting bioactivity, lyconadin A presents a significant synthetic challenge by virtue of its unique pentacyclic skeleton, which contains six stereocenters and a pyridone ring. It is therefore not surprising that 1 has attracted the attention of the organic synthesis community. The first
Facile synthesis of functionalized spiro[indoline-3,2'-oxiran]-2-ones by Darzens reaction
Beilstein J. Org. Chem. 2013, 9, 918–924, doi:10.3762/bjoc.9.105
- ; oxindole; oxirane; spiro-epoxyoxindole; spirooxindole; Introduction The spirooxindole unit is a privileged heterocyclic motif that forms the core structure of a large family of natural alkaloids and many pharmacological agents with important bioactivity and interesting structural properties [1][2][3][4][5
Quantification of N-acetylcysteamine activated methylmalonate incorporation into polyketide biosynthesis
Beilstein J. Org. Chem. 2013, 9, 664–674, doi:10.3762/bjoc.9.75
- A-thioesters prior to their enzyme-catalyzed transfer onto the polyketide synthase. Control over the selection of malonic acid building blocks promises great potential for the experimental alteration of polyketide structure and bioactivity. One requirement for this endeavor is the supplementation of
Efficient synthesis of phenylene-ethynylene rods and their use as rigid spacers in divalent inhibitors
Beilstein J. Org. Chem. 2013, 9, 215–222, doi:10.3762/bjoc.9.25
- 24 is a mimic for DC-SIGN inhibition and its bioactivity will be tested elsewhere. Inhibition studies The inhibitory potency of 22 for LecA was studied in an ELISA type assay by using a glycochip as the solid phase [10]. In this assay an IC50 value of 0.9 μM was determined (Table 1). This compared
Thioester derivatives of the natural product psammaplin A as potent histone deacetylase inhibitors
Beilstein J. Org. Chem. 2013, 9, 81–88, doi:10.3762/bjoc.9.11
- , Schnittspahnstraβe 12, 64287 Darmstadt, Germany Cancer Research UK Biomolecular Structure Group, UCL School of Pharmacy, 29-39 Brunswick Square, London WC1N 1AX, United Kingdom 10.3762/bjoc.9.11 Abstract There has been significant interest in the bioactivity of the natural product psammaplin A, most recently as a
The multicomponent approach to N-methyl peptides: total synthesis of antibacterial (–)-viridic acid and analogues
Beilstein J. Org. Chem. 2012, 8, 2085–2090, doi:10.3762/bjoc.8.234
- cytotoxicity in a MTT assay on an undisclosed cell line [7]. Albeit that these two reports on the toxicity of extracts containing constituent 1 were very intriguing, no further biological screening of the pure substance has been performed to date. The connection between compound 1 and the bioactivity of the
- and N-methylated amino groups demanded harsher than usual conditions, upon which the desired viridic acid (1) was obtained in just 5% overall yield. The lack of sufficient amounts of isolated materials from natural sources did not allow for reliable bioactivity tests, and the demand for higher
Total synthesis and biological evaluation of fluorinated cryptophycins
Beilstein J. Org. Chem. 2012, 8, 2060–2066, doi:10.3762/bjoc.8.231
- are usually good substrates for the P-glycoprotein efflux pump resulting in a decreased bioactivity. Structures of cryptophycin-1 (1) and -52 (2). Fluorinated derivatives of cryptophycin-1 and -52 [20][21][22]. Access to the trifluoromethyl substituted unit A-building block 16. Reagents and conditions
An efficient access to the synthesis of novel 12-phenylbenzo[6,7]oxepino[3,4-b]quinolin-13(6H)-one derivatives
Beilstein J. Org. Chem. 2012, 8, 1849–1857, doi:10.3762/bjoc.8.213
- block for the synthesis of manifold biologically and pharmaceutically important compounds [25][26]. As a consequence, the remarkable bioactivity surrounding the benzoxepine moiety has elicited a significant amount of interest as demonstrated by synthetic work already published [27][28][29][30]. In light
On the proposed structures and stereocontrolled synthesis of the cephalosporolides
Beilstein J. Org. Chem. 2012, 8, 1287–1292, doi:10.3762/bjoc.8.146
- correlation between bioactivity and spiroketal stereochemistry in many natural spiroketals. For example, cephalostatin and ritterazine feature thermodynamically disfavored spiroketals that are more cytotoxic than their stereoisomers [12]. Other prominent cytotoxic spiroketals include spongistatin [7] and
Partial thioamide scan on the lipopeptaibiotic trichogin GA IV. Effects on folding and bioactivity
Beilstein J. Org. Chem. 2012, 8, 1161–1171, doi:10.3762/bjoc.8.129
- backbone modification is compatible with the preservation of its typical membrane leakage and antibiotic properties, although somewhat attenuated. Keywords: bioactivity; conformation; peptaibiotic; peptide synthesis; peptides; thiopeptides; Introduction Since their first incorporation into peptides [1
Synthesis and in silico screening of a library of β-carboline-containing compounds
Beilstein J. Org. Chem. 2012, 8, 1048–1058, doi:10.3762/bjoc.8.117
- (4) compounds 2{1,6} and 6{10} are predicted to be ligands for a total of 15 protein targets. This high number of potential protein targets may be due to the electronegative trifluoromethyl group on 2{1,6} and the effect it would have on the α,β-unsaturated amide and the purported bioactivity of the
- targets and 6,933,068 bioactivity entries from 44,682 publications and PubChem bioassays [18][19]. The Openbabel FP2 fingerprint was used as a descriptor to assess similarities between molecules [20]. Tanimoto coefficients were calculated between the compounds of the β-carboline library and the ChEMBL
- database, and only β-carboline compounds with a Tc greater than 0.60 were considered for bioactivity analysis. A lower Tc threshold was used to identify a larger number of bioactivity targets. Table 4 lists the most promising bioactive targets for the newly synthesized β-carbolines together with the
Algicidal lactones from the marine Roseobacter clade bacterium Ruegeria pomeroyi
Beilstein J. Org. Chem. 2012, 8, 941–950, doi:10.3762/bjoc.8.106
- bioactivity of the Ruegeria lactones against bacteria, fungi, and the fresh water alga Chlorella fusca. Further tests will have to be performed with marine algae, including E. huxleyi and related species, to investigate the significance of these findings within the ecological context of the bacterial lactone
Unprecedented deoxygenation at C-7 of the ansamitocin core during mutasynthetic biotransformations
Beilstein J. Org. Chem. 2012, 8, 861–869, doi:10.3762/bjoc.8.96
- mutants and mutasynthetic approaches. We suggest that the formation of these derivatives is based on elimination at C-7/C-8 followed by reduction(s) of the intermediate enone. In bioactivity tests, only ansamitocin derivatives bearing an ester side chain at C-3 showed strong antiproliferative activity
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