RESUMEN
Histidine kinases (HKs) are important sensor proteins in fungi and play an essential role in environmental adaptation. However, the mechanisms by which fungi sense and respond to fungivores attack via HKs are not fully understood. In this study, we utilized Neurospora crassa to investigate the involvement of HKs in responding to fungivores attack. We found that the 11 HKs in N. crassa not only affected the growth and development, but also led to fluctuations in antioxidant production. Ten mutants in the genes encoding HKs (except ∆phy1) showed increased production of reactive oxygen species (ROS), especially upon Sinella curviseta attack. The ROS burst triggered changes in conidia and perithecial beaks formation, as well as accumulation of ß-glucan, ergothioneine, ergosterol, and carotenoids. ß-glucan was increased in ∆hk9, ∆os1, ∆hcp1, ∆nik2, ∆sln1, ∆phy1 and ∆phy2 mutants compared to the wild-type strain. In parallel, ergothioneine accumulation was improved in ∆phy1 and ∆hk16 mutants and further increased upon attack, except in ∆os1 and ∆hk16 mutants. Additionally, fungivores attack stimulated ergosterol and dehydroergosterol production in ∆hk9 and ∆os1 mutants. Furthermore, deletion of these genes altered carotenoid accumulation, with wild-type strain, ∆hk9, ∆os1, ∆hcp1, ∆sln1, ∆phy2, and ∆dcc1mutants showing an increase in carotenoids upon attack. Taken together, HKs are involved in regulating the production of conidia and antioxidants. Thus, HKs may act as sensors of fungivores attack and effectively improve the adaptive capacity of fungi to environmental stimuli.
Asunto(s)
Histidina Quinasa , Neurospora crassa , Especies Reactivas de Oxígeno , Neurospora crassa/genética , Neurospora crassa/metabolismo , Histidina Quinasa/genética , Histidina Quinasa/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Esporas Fúngicas/genética , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Animales , Regulación Fúngica de la Expresión Génica , Artrópodos/genética , Artrópodos/microbiología , Mutación , Adaptación Fisiológica/genética , Ergosterol/metabolismo , beta-Glucanos/metabolismo , Antioxidantes/metabolismo , Carotenoides/metabolismo , ErgotioneínaRESUMEN
Three chromone analogs, 1-3, a chlorinated alkaloid sclerotioramine (4), together with two 11-noreremophilane-type sesquiterpenes with a conjugated enolic OH group and a brominated one, 5 and 6, respectively, were isolated from Penicillium citreonigrum (HQ738282). Compounds 1, 5, and 6 were new. Biological tests revealed that 4 exhibited a significant activity (IC50 7.32â µg/ml), and 6 showed a moderate activity (IC50 16.31â µg/ml) in vitro against HepG2 cell line, and 4 also displayed an activity comparable to that of acarbose against α-glucosidase.
Asunto(s)
Alcaloides/química , Alcaloides/farmacología , Penicillium/química , Sesquiterpenos/química , Sesquiterpenos/farmacología , Alcaloides/aislamiento & purificación , Antineoplásicos/química , Antineoplásicos/aislamiento & purificación , Antineoplásicos/farmacología , Inhibidores de la Colinesterasa/química , Inhibidores de la Colinesterasa/aislamiento & purificación , Inhibidores de la Colinesterasa/farmacología , Cristalografía por Rayos X , Inhibidores de Glicósido Hidrolasas/química , Inhibidores de Glicósido Hidrolasas/aislamiento & purificación , Inhibidores de Glicósido Hidrolasas/farmacología , Halogenación , Células Hep G2 , Humanos , Modelos Moleculares , Neoplasias/tratamiento farmacológico , Sesquiterpenos/aislamiento & purificaciónRESUMEN
A new 12-membered ring lactone, (3S),(6R)-6-hydroxylasiodiplodin (1), with two known analogues, (3R)-lasiodiplodin (2), and (3R),(5S)-5-hydroxylasiodiplodin (3) were isolated from the EtOH extracts of normal Apriona germari (Hope)-associated fungus Sarocladium kiliense grown in rice medium. The structures of compounds 1-3 were elucidated by a combination of spectroscopic data interpretation, single-crystal X-ray diffraction analysis, and modified Mosher's method.
Asunto(s)
Hypocreales/química , Lactonas/química , Zearalenona/análogos & derivados , Cristalografía por Rayos X/métodos , Difracción de Rayos X/métodos , Zearalenona/químicaRESUMEN
This study has achieved the design and diversity-oriented synthesis of novel 1,4-thiazepine derivatives embedded with carbazole, pyrazole or isoxazole motif via microwave-assisted multicomponent reactions under solvent-free condition, thus providing a green and facile access to 1,4-thiazepine derivatives with prominent features of high structural diversity, short reaction time, high yields and environmental friendliness. More importantly, these novel compounds have been subjected to the test of in vitro antioxidant and cytotoxic activities, resulting in the finding that these 1,4-thiazepine derivatives not only have significant antioxidant activity, but also exhibit remarkably selective cytotoxicity to carcinoma cell line HCT 116.
Asunto(s)
Antioxidantes/farmacología , Química Farmacéutica/métodos , Tiazepinas/síntesis química , Antineoplásicos/farmacología , Carbazoles/química , Línea Celular Tumoral , Diseño de Fármacos , Ensayos de Selección de Medicamentos Antitumorales/métodos , Células HCT116 , Humanos , Microondas , Modelos Químicos , Pirazoles/química , Solventes , Temperatura , Tiazepinas/farmacologíaRESUMEN
Sterols are one of the active classes of compounds in Inonotus obliquus for their effective therapy of many diseases. In field environment, this fungus accumulates large amount of sterols. In cultured mycelia, however, this class of compounds is less accumulated. For analyzing the factors responsible for differing sterol composition, the field-grown and cultured mycelia were extracted with 80% ethanol at room temperature and total sterols were prepared using silicon gel column chromatography followed by identification using either GC-MS or spectroscopic methods. For culturing Inonotus obliquus, the seed culture was grown either in basic medium consisting of glucose (2%), yeast extract (0.5%), KH2PO4 (0.01%), MgSO4.7H20 (0.05%) and distilled water at pH 6.5, or the basic medium supplemented with serial concentrations of AgNO3. The results indicated that field-grown mycelia contained lanosterol and inotodiol (comprised 45. 47% and 25. 36% of the total sterols, respectively) and other 10 sterols (comprising the remaining 30.17%) including ergosterol biosynthetic intermediates such as 24-methylene dihydrolanosterol, 4,4-dimethylfecosterol, 4-methyl fecosterol, fecosterol and episterol. Column chromatography also led to the isolation of lanosterol, Inotodiol, trametenolic acid, foscoparianol B and a new triterpenoid foscoparianol D in field-grown mycelia. In comparison, the cultured mycelia only contained three sterols with ergosterol as the predominant one (82.20%). Lanosterol only accounted for 3.68%. Supplementing Ag+ into the culture at 0.28 micromol x L(-1) greatly enhanced content of lanosterol (accounting for 56.81%) and decreased the content of ergosterol (18.5%) together with the presence of intermediates for ergosterol biosynthesis. These results suggested that the sterol composition in mycelia of the fungus can be diversified by supplementing substances inhibiting enzymatic process towards the synthesis of ergosterol. Harsh growth conditions in field environment (i.e. temperature variation, UV irradiation etc.) can delay the synthesis of ergosterol and hereby diversify the sterol composition in the mycelia of Inonotus obliquus.
Asunto(s)
Basidiomycota/química , Ergosterol/biosíntesis , Lanosterol/biosíntesis , Nitrato de Plata/farmacología , Basidiomycota/crecimiento & desarrollo , Medios de Cultivo/farmacología , Técnicas de Cultivo , Cromatografía de Gases y Espectrometría de Masas , Lanosterol/análogos & derivados , Micelio/químicaRESUMEN
AIM: To investigate the chemical constituents of the secondary metabolites of the roots of Daphne genkwa. METHODS: The roots of D. genkwa were extracted with 95% ethanol at 60-70 degrees C for 7 days to obtain the crude extract. The crude extract was purified by silica gel and Sephadex LH-20 column chromatography as well as the HPLC techniques. The structures of the isolates were elucidated by combined spectroscopic methods including 1D and 2D NMR, MS, UV, IR and CD. RESULTS: Three new biflavonoids were isolated from the ethanol extract of the roots of D. genkwa and their structures were identified as daphnodorin H-3-methyl ether (1), daphnodorin H-3"-methyl ether (2) and daphnodorin G-3"-methyl ether (3). CONCLUSION: Compounds 1, 2 and 3 are three new biflavonoids.
Asunto(s)
Biflavonoides/aislamiento & purificación , Daphne/química , Plantas Medicinales/química , Biflavonoides/química , Etanol , Conformación Molecular , Estructura Molecular , Raíces de Plantas/químicaRESUMEN
There is evidence that the excessive generation of reactive oxygen free radicals contributes to the brain injury associated with cerebral ischemia. In the present study, the protective effect of chronic administration of ethyl docosahexaenoate (E-DHA) against oxidative brain injury was evaluated in the gerbil model of transient cerebral ischemia. Weanling male gerbils were orally pretreated with either E-DHA (200 mg/kg) or vehicle, once a day, for 10 weeks and subjected to bilateral occlusion of common carotid arteries for 10 min. At the different reperfusion times, E-DHA pretreatment significantly inhibited the increases in the production of brain salicylate-derived 2,5-dihydroxybenzoic acid (2,5-DHBA) and content of brain malonildialdehyde (MDA). The superoxide dismutase (SOD) activity was not modified; however, pretreatment with E-DHA significantly prevented the level of brain-reduced glutathione (GSH) and activities of brain glutathione peroxidase (GSH-P(X)) and catalase (CAT) from declines caused by cerebral ischemia. Moreover, ischemia and reperfusion-induced delayed neuronal loss in the hippocampus CA1 sector and locomotor hyperactivity were also significantly attenuated by pretreatment with E-DHA. These results suggested that the neuroprotective effect of E-DHA might be due to its antioxidant property.
Asunto(s)
Isquemia Encefálica/tratamiento farmacológico , Ácidos Docosahexaenoicos/administración & dosificación , Fármacos Neuroprotectores/administración & dosificación , Animales , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Isquemia Encefálica/metabolismo , Radicales Libres/metabolismo , Gerbillinae , Masculino , Actividad Motora/efectos de los fármacos , Actividad Motora/fisiologíaRESUMEN
AIM: To investigate the chemical constituents of the roots of Daphne genkwa. METHODS: Silica gel and Sephadex LH-20 column chromatographic techniques were employed for the isolation and purification. The structure was elucidated by a combination of spectroscopic analyses. RESULTS: A new dicoumarin named isodaphnoretin was isolated and the structure was established as 7-hydroxy-6-methoxy-4-[(2-oxo-2H-1-benzopyran-7-yl)-oxyl]-2H-1-benzopyran-2-one. CONCLUSION: Isodaphnoretin is a new compound.
Asunto(s)
Cumarinas/aislamiento & purificación , Daphne/química , Plantas Medicinales/química , Cumarinas/química , Conformación Molecular , Estructura Molecular , Raíces de Plantas/químicaRESUMEN
The interaction of berberine and Human Serum Albumin (HSA) has been studied by fluorescence and UV-Vis absorption spectroscopy. With fluorescence quenching method, the binding constant K was found to be 1.168 x 10(5) L x mol(-1) and the number of binding site n was 5.26. The binding distance (R = 3.44 nm) and energy transfer efficiency (E = 0.303) were also obtained according to Förster's non-radiation energy transfer theory. The energy transfer path between tyrosine residual and tryptophan residual was cut by berberine in the site of HSA and weak fluorescence berberine-HSA complex was also observed.