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Botrytis allii andCollectotrichum dematium are onion pathogens which can infect in the field and cause decay in storage. Some phenolics can hinder development of these fungi, but the effect of cytokinins is not clear. Cytokinins (kinetin or 6-benzyladenine) or phenolics (caffeic or chlorogenic acids) were added to agar at concentrations of 0 to 10–3 M. Cultures were continuously irradiated with fluorescent light or maintained in the dark for 6 days. On unamended media, final mycelial elongation was 45 or 17.8 mm and sporulation was 28 or 10.6 × 104 spores/ml forBotrytis andColletotrichum, respectively. ForBotrytis, mycelial elongation was slightly (5%) but significantly increased and sporulation increased by 21% by incubation on phenolics as compared to cytokinins. Mycelial extension ofColletotrichum was not affected by amendment. Sporulation ofColletotrichum on kinetin was 16 to 28% greater than on the other amendments. As amendments concentration increased elongation of mycelia of both fungi decreased. Sporulation ofBotrytis increased by 60% as amendment concentration increased from 0 to 10–5 M and then decreased 25% at 10–3 M. As amendment concentration increased from 0 to 10–3 M, sporulation ofColletotrichum increased by 45%. Incubation in light increased mycelial extension 3 to 17% forBotrytis andColletotrichum respectively, and sporulation was increased approximately 78% for both fungi. These compounds do not appear to inhibit development of theseBotrytis orColletotrichum species in culture. 相似文献
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Four classes of Xanthomonas campestris mutants were identified with respect to pectate lyase. Pectate lyase production in the wild-type and classes I and IIb mutants was partially dependent on the growth-phase whereas in classes IIa and III it was totally dependent. Enzyme activity in some of the mutants was constitutive and resistant to catabolite repression. 相似文献
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《Bioorganic & medicinal chemistry》2020,28(22):115739
N-phenyl ureidobenzenesulfonates (PUB-SOs) is a new class of promising anticancer agents inducing replication stresses and cell cycle arrest in S-phase. However, the pharmacological target of PUB-SOs was still unidentified. Consequently, the objective of the present study was to identify and confirm the pharmacological target of the prototypical PUB-SO named 2-ethylphenyl 4-(3-ethylureido)benzenesulfonate (SFOM-0046) leading to the cell cycle arrest in S-phase. The antiproliferative and the cytotoxic activities of SFOM-0046 were characterized using the NCI-60 screening program and its fingerprint was analyzed by COMPARE algorithm. Then, human dihydroorotate dehydrogenase (hDHODH) colorimetric assay, uridine rescuing cell proliferation and molecular docking in the brequinar-binding site were performed. As a result, SFOM-0046 exhibited a mean antiproliferative activity of 3.5 μM in the NCI-60 screening program and evidenced that leukemia and colon cancer cell panels were more sensitive to SFOM-0046. COMPARE algorithm showed that the SFOM-0046 cytotoxic profile is equivalent to the ones of brequinar and dichloroallyl lawsone, two inhibitors of hDHODH. SFOM-0046 inhibited the hDHODH in the low nanomolar range (IC50 = 72 nM) and uridine rescued the cell proliferation of HT-29, HT-1080, M21 and MCF-7 cancer cell lines in the presence of SFOM-0046. Finally, molecular docking showed a binding pose of SFOM-0046 interacting with Met43 and Phe62 present in the brequinar-binding site. In conclusion, PUB-SOs and notably SFOM-0046 are new small molecules hDHODH inhibitors triggering replication stresses and S-phase arrest. 相似文献
6.
The genera Leontodon s.str. and Hedypnois are so far the only known sources of hydroxyhypocretenolides, a rare subclass of guaianolide type sesquiterpene lactones. In this study the three endemic species from the Azorean Archipelago, L. filii, L. hochstetteri, and L. rigens, were analyzed together with L. hispidus and L. × grassiorum, a hybrid originating from L. hispidus and L. hochstetteri. Flowering heads were analyzed by UHPLC-DAD-MS with regards to their phenolics' profiles, establishing qualitatively identical profiles for all taxa. The following phenolics were detected in flowering heads of all investigated taxa: caffeoyltartaric acid, cichoric acid, chlorogenic acid, 3,5-di-O-caffeoylquinic acid, luteolin, luteolin 7-O-β-d-glucopyranoside, luteolin 4′-O-β-d-glucopyranoside, and luteolin 7-O-β-d-glucuronide.In UHPLC-DAD-MS analyses of the rhizomes, no flavonoids were detected. In rhizomes, caffeoyltartaric acid was only detected in L. hispidus. However, in addition to caffeoylquinic acid derivatives already found in the flowering heads, 1,5-di-O-caffeoylquinic acid, 3,4-di-O-caffeoylquinic acid, and 4,5-di-O-caffeoylquinic acid were detected in rhizomes of all investigated taxa.The chemophenetically most interesting group of hydroxyhypocretenolides was detected in rhizomes of all investigated taxa. 11,13β-Dihydro-14-dihydroxyhypocretenolide was detected in L. filii and L. hochstetteri, while 11,13β-dihydro-14-hydroxyhypocretenolide-β-d-glucopyranoside was present in all Azorean taxa. 1,10-Epoxy-14-hydroxyhypocretenolide-β-d-glucopyranoside and 1,10-epoxy-14-hydroxyhypocretenolide-β-d-glucopyranoside-6′-O-p-hydroxyphenylacetic acid ester were restricted to the Azorean taxa and the hybrid L. × grassiorum, while the dimeric sesquiterpenoid 14-hydroxyhypocretenolide-β-d-glucopyranoside-4′,14″-hydroxyhypocretenoate ester was restricted to L. hispidus and L. × grassiorum. 相似文献
7.
Two new compounds, named leptospyranonaphthazarin A (1) and leptosnaphthoic acid A (2), together with four known compounds (3–6) were isolated from an endophytic fungus Leptosphaerulina sp. SKS032. Their structures were assigned using spectroscopic methods, computational methods, and single-crystal X-ray diffraction analysis. In the antibiotic assay, compounds 1, 2, and 6 exhibited antibacterial activities against Staphylococcus aureus with minimal inhibitory concentration (MIC) values of 25.0, 50.0, and 50.0 μg/mL, respectively. 相似文献
8.
Nevena Cvetesic Mirna Bilus Ita Gruic-Sovulj 《The Journal of biological chemistry》2015,290(22):13981-13991
Aminoacyl-tRNA synthetases catalyze ATP-dependent covalent coupling of cognate amino acids and tRNAs for ribosomal protein synthesis. Escherichia coli isoleucyl-tRNA synthetase (IleRS) exploits both the tRNA-dependent pre- and post-transfer editing pathways to minimize errors in translation. However, the molecular mechanisms by which tRNAIle organizes the synthetic site to enhance pre-transfer editing, an idiosyncratic feature of IleRS, remains elusive. Here we show that tRNAIle affects both the synthetic and editing reactions localized within the IleRS synthetic site. In a complex with cognate tRNA, IleRS exhibits a 10-fold faster aminoacyl-AMP hydrolysis and a 10-fold drop in amino acid affinity relative to the free enzyme. Remarkably, the specificity against non-cognate valine was not improved by the presence of tRNA in either of these processes. Instead, amino acid specificity is determined by the protein component per se, whereas the tRNA promotes catalytic performance of the synthetic site, bringing about less error-prone and kinetically optimized isoleucyl-tRNAIle synthesis under cellular conditions. Finally, the extent to which tRNAIle modulates activation and pre-transfer editing is independent of the intactness of its 3′-end. This finding decouples aminoacylation and pre-transfer editing within the IleRS synthetic site and further demonstrates that the A76 hydroxyl groups participate in post-transfer editing only. The data are consistent with a model whereby the 3′-end of the tRNA remains free to sample different positions within the IleRS·tRNA complex, whereas the fine-tuning of the synthetic site is attained via conformational rearrangement of the enzyme through the interactions with the remaining parts of the tRNA body. 相似文献
9.
Elisabeth Tillberg 《Plant Growth Regulation》1992,11(2):147-152
Dormancy-breaking treatment of the photosensitive Scots pine (Pinus sylvestris L.) seed by white light incubation or a 15-min exposure to red light decreased the abscisic acid content prior to radicle protrusion. Incubation in the dark or exposure to red light followed by a 5-min far-red light irradiation did not cause as great a decrease in abscisic acid content nor was the dormancy relieved. The ability of the far-red light to keep the ABA level high and to prevent germination gradually disappeared as the length of the dark period between the red and far-red treatments was increased to 24 h. ABA was quantified on a gas chromatograph with an electron capture detector. 相似文献
10.
《Bioorganic & medicinal chemistry letters》2020,30(17):127397
Herein, a boronic acid-based sensor was reported selectively to recognize Pd2+ ion. The fluorescence intensity increased 36-fold after sensor binding with 2.47 × 10−5 M of Pd2+ ion. It was carried out in the 99% aqueous solution for binding tests, indicating sensor having good water solubility. In addition, it is discernible that Pd2+ ion turned on the blue fluorescence of sensor under a UV–lamp (365 nm), while other ions (Ag+, Al3+, Ba2+, Ca2+, Cr2+, Cd2+, Co2+, Cs2+, Cu2+, Fe2+, Fe3+, K+, Li+, Mg2+, Mn2+, Na+, Ni2+ and Zn2+) did not show the similar change. Furthermore, sensor has a low limit of detection (38 nM) and high selectivity, which exhibits the potential for the development of Pd2+ recognition in practical environments. 相似文献