RESUMEN
Fifteen polyketides, including four new compounds, isoversiol F (1), decumbenone D (2), palitantin B (7), and 1,3-di-O-methyl-norsolorinic acid (8), along with 11 known compounds (3-6 and 9-15), were isolated from the deep-sea-derived fungus Aspergillus versicolor SH0105. Their structures and absolute configurations were determined by comprehensive spectroscopic data, including 1D and 2D NMR, HRESIMS, and ECD calculations, and it is the first time to determine the absolute configuration of known decumbenone A (6). All of these compounds were evaluated for their antimicrobial activities against four human pathogenic microbes and five fouling bacterial strains. The results indicated that 3,7-dihydroxy-1,9-dimethyldibenzofuran (14) displayed obvious inhibitory activity against Staphylococcus aureus (ATCC 27154) with the MIC value of 13.7 µM. In addition, the antioxidant assays of the isolated compounds revealed that aspermutarubrol/violaceol-I (15) exhibited significant 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity with the IC50 value of 34.1 µM, and displayed strong reduction of Fe3+ with the ferric reducing antioxidant power (FRAP) value of 9.0 mM under the concentration of 3.1 µg/mL, which were more potent than ascorbic acid.
Asunto(s)
Antibacterianos/farmacología , Aspergillus/metabolismo , Depuradores de Radicales Libres/farmacología , Policétidos/farmacología , Antibacterianos/aislamiento & purificación , Depuradores de Radicales Libres/aislamiento & purificación , Sedimentos Geológicos/microbiología , Pruebas de Sensibilidad Microbiana , Policétidos/aislamiento & purificación , Conformación Proteica , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/crecimiento & desarrollo , Relación Estructura-ActividadRESUMEN
A novel perylenequinone-related compound, alternatone A (1), with an unprecedented tricyclo[6.3.1.02,7] dodecane skeleton, together with three known perylenequinones, altertoxin I (2), stemphyperylenol (3), and alterperylenol (4), was isolated from the soft-coral-derived fungus Alternaria alternata L3111'. Their structures including absolute configurations were elucidated on the basis of comprehensive spectroscopic analysis, electronic circular dichroism calculations, and X-ray diffraction data. Compound 4 showed cytotoxicity against A-549, HCT-116, and HeLa cell lines with IC50 values of 2.6, 2.4, and 3.1 µM, respectively. A possible biosynthetic pathway of 1 was proposed.
Asunto(s)
Alternaria/química , Antozoos/microbiología , Perileno/análogos & derivados , Quinonas/química , Quinonas/farmacología , Animales , Antibacterianos/química , Antibacterianos/farmacología , Antibióticos Antineoplásicos/química , Antibióticos Antineoplásicos/farmacología , Línea Celular Tumoral , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Pruebas de Sensibilidad Microbiana , Modelos Moleculares , Estructura Molecular , Perileno/química , Perileno/farmacología , Difracción de Rayos XRESUMEN
Six new sordarin tetracyclic diterpene glycosides, moriniafungins B-G (1-6), and a new sordaricin tetracyclic diterpene, sordaricin B (8), together with two known analogues, moriniafungin (7) and sordaricin (9), were isolated from the zoanthid-derived fungus Curvularia hawaiiensis TA26-15. The structures of the new compounds were elucidated by comprehensive analyses of spectroscopic data, including 1D and 2D NMR and MS data. Compounds 1-6 represent the first case of sordarins from marine-derived fungi possessing a sordarose with a spiro 1,3-dioxolan-4-one ring, which is rare in the nature. Compound 4 showed antifungal activity against Candida albicans ATCC10231 with an MIC value of 2.9 µM.
Asunto(s)
Ascomicetos/química , Dioxolanos/química , Diterpenos/aislamiento & purificación , Glicósidos/química , Indenos/aislamiento & purificación , Diterpenos/química , Indenos/química , Estructura Molecular , Análisis Espectral/métodosRESUMEN
Two new naphthalenones, corynenones A and B (1 and 2), and one new depsidone, corynesidone E (3), together with one known depsidone, corynesidone A (4) and two known diphenyl ethers, corynethers A (5) and B (6), were isolated from the sponge-derived fungus Corynespora cassiicola XS-20090I7. Their structures including absolute configurations were determined by spectroscopic data and electronic circular dichroism (ECD) spectra. Compounds 4 and 5 showed cytotoxicity against human promyelocytic leukemia HL-60 and human cervical carcinoma HeLa cell lines.
Asunto(s)
Depsidos/aislamiento & purificación , Lactonas/aislamiento & purificación , Naftalenos/aislamiento & purificación , Poríferos/microbiología , Saccharomycetales/química , Animales , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Dicroismo Circular , Depsidos/química , Depsidos/farmacología , Células HL-60 , Células HeLa , Humanos , Lactonas/química , Lactonas/farmacología , Estructura Molecular , Naftalenos/química , Naftalenos/farmacologíaRESUMEN
The inversion of substrate size specificity is an evolutionary roadblock for proteins. The Duf4243 dioxygenases GedK and BTG13 are known to catalyze the aromatic cleavage of bulky tricyclic hydroquinone. In this study, we discover a Duf4243 dioxygenase PaD that favors small monocyclic hydroquinones from the penicillic-acid biosynthetic pathway. Sequence alignments between PaD and GedK and BTG13 suggest PaD has three additional motifs, namely motifs 1-3, distributed at different positions in the protein sequence. X-ray crystal structures of PaD with the substrate at high resolution show motifs 1-3 determine three loops (loops 1-3). Most intriguing, loops 1-3 stack together at the top of the pocket, creating a lid-like tertiary structure with a narrow channel and a clearly constricted opening. This drastically changes the substrate specificity by determining the entry and binding of much smaller substrates. Further genome mining suggests Duf4243 dioxygenases with motifs 1-3 belong to an evolutionary branch that is extensively involved in the biosynthesis of natural products and has the ability to degrade diverse monocyclic hydroquinone pollutants. This study showcases how natural enzymes alter the substrate specificity fundamentally by incorporating new small motifs, with a fixed overall scaffold-architecture. It will also offer a theoretical foundation for the engineering of substrate specificity in enzymes and act as a guide for the identification of aromatic dioxygenases with distinct substrate specificities.
Asunto(s)
Secuencias de Aminoácidos , Dioxigenasas , Especificidad por Sustrato , Dioxigenasas/metabolismo , Dioxigenasas/genética , Dioxigenasas/química , Cristalografía por Rayos X , Hidroquinonas/metabolismo , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/química , Secuencia de Aminoácidos , Modelos Moleculares , Alineación de SecuenciaRESUMEN
AIM: To clarify the role of inducible nitric oxide synthase (iNOS) in blood-retinal barrier (BRB) injury after acute high intraocular pressure (IOP) in rats. METHODS: Forty-two Sprague-Dawley (SD) rats were randomized into 7 groups [control (Cont), 3, 6, 12, 24, 48, and 72h, n=6]. Except Cont group, other groups' retina tissue was obtained at corresponding time points after a model of acute high IOP have been established in rats. The expression of iNOS and tight junction protein zonula occludens (ZO)-1 was detected by Western blotting. Evans blue (EB; 3% ) was injected into the great saphenous vein to detect the leakage of EB by spectrophotometer. Nine rats were divided into Cont, 6h, 12h groups, the expression of iNOS was localized by immunofluorescence. In order to verify the role of iNOS in the damage to BRB, thirty-six rats were randomly divided into 4 groups [Cont, Cont+inhibitor (Inh), 6h and 6h+Inh, n=9]. After treatment with the iNOS-specific inhibitor 1400W, the expression of iNOS and ZO-1 and the leakage of BRB were detected again. RESULTS: The immunofluorescence results showed that the expression of iNOS was observed in the Cont group and 6h group, but not in the 12h group. iNOS was mainly expressed in the retinal nerve fiber layer, ganglion cell layer and inner nuclear layer and that it did not colocalize with the retinal ganglion cell marker NeuN but was co-expressed with the vascular endothelial cell marker CD31. Western blotting showed that in the early period (3h, 6h) after acute high IOP, the expression of iNOS was upregulated, then the down-regulation of iNOS were tested in the follow-up timing spots. ZO-1 expression showed a continuous down-regulation after 6h. The quantitative results for EB showed that the amount of EB leakage began to increase at 3h after acute high IOP. At 6h, the leakage of EB was lower, but at 12h, the leakage of EB was highest, after which it gradually recovered but remained higher than that in the Cont group. The expression of iNOS was down-regulated after 1400W treatment. ZO-1 expression was not significantly changed in the Cont+Inh group and the 6h group, and significantly down-regulated in the 6h+Inh group, and the leakage of EB was significantly increased after 1400W treatment. CONCLUSION: These results suggest that the upregulation of iNOS expression in the early stage after acute high IOP may have a protective effect on BRB injury.
RESUMEN
Six new sorbicillinoids, trichoreeseione A (1) and B (2), trichodermolide B (3), 13-hydroxy-trichodermolide (4), 24-hydroxy-trichodimerol (5), 15-hydroxy-bisvertinol (7), together with three known analogs, trichodimerol (6), 24-hydroxy-bisvertinol (8), and bisvertinol (9), were isolated from the sponge-derived fungus Trichoderma reesei (HN-2016-018). Their structures including absolute configurations were elucidated by analysis of NMR, MS data, and calculated ECD spectra. Compounds 1 and 2 with a characteristic naphthalene-trione ring were firstly reported in sorbicillinoid family. Compounds 3 and 4 were two rare sorbicillinoids containing a unique bicycle [3.2.1] lactone skeleton, while 3 with a propan-2-one moiety was also recorded first time in this family. Compound 5 displayed cytotoxic activity against A549, MCF-7, and HCT116 cell lines with the IC50 values of 5.1, 9.5, and 13.7 µM, respectively.
RESUMEN
Two new harziane diterpene lactones, possessing a 6/5/7/5-fused carbocyclic core containing a lactone ring system, harzianelactones A and B (1 and 2), and five new harziane diterpenes, harzianones A-D (3-6) and harziane (7), were isolated from the soft coral-derived fungus Trichoderma harzianum XS-20090075. Their structures were determined by extensive NMR spectroscopic data, ECD and OR calculations, as well as X-ray diffraction. The isolated compounds exhibited potent phytotoxicity against seedling growth of amaranth and lettuce. Harziane diterpenes were rarely reported for their remarkably bioactivities, and it was the first report to study the phytotoxicity of harziane diterpenes, which provide a new application of such compounds in agriculture for future research.
Asunto(s)
Amaranthus/crecimiento & desarrollo , Diterpenos/química , Herbicidas/farmacología , Lactuca/crecimiento & desarrollo , Toxinas Biológicas/farmacología , Trichoderma/química , Amaranthus/efectos de los fármacos , Animales , Antozoos/microbiología , Diterpenos/aislamiento & purificación , Lactonas/química , Lactonas/aislamiento & purificación , Lactuca/efectos de los fármacos , Espectroscopía de Resonancia Magnética , Estructura Molecular , Malezas/efectos de los fármacos , Difracción de Rayos XRESUMEN
Two new compounds penibenzophenones A-B (1-2), and the synthetic α,ß-unsaturated amide alkaloid (E)-tert-butyl(3-cinnamamidopropyl)carbamate (4), newly identified as a natural product, alone with three known ones (3, 5-6) were isolated from the EtOAc extract of the endophytic fungus Penicillium citrinum HL-5126 isolated from the mangrove Bruguiera sexangula var. rhynchopetala collected in the South China Sea. Compound 1 was a chlorinated benzophenone. The structures of 1-6 were elucidated by extensive NMR spectral interpretation, MS data and X-ray analysis. The new compound 2 displayed cytotoxic activity against human A549 cell lines with an IC50 value of 15.7 µg/mL, and 1 showed antibacterial activity against Staphylococcus aureus with a MIC value of 20 µg/mL.
Asunto(s)
Alcaloides/farmacología , Antibacterianos/farmacología , Benzofenonas/farmacología , Penicillium/química , Células A549 , Alcaloides/química , Alcaloides/aislamiento & purificación , Amidas/química , Antibacterianos/aislamiento & purificación , Benzofenonas/aislamiento & purificación , Cristalografía por Rayos X , Evaluación Preclínica de Medicamentos/métodos , Endófitos/química , Humanos , Espectroscopía de Resonancia Magnética , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Rhizophoraceae/microbiología , Staphylococcus aureus/efectos de los fármacos , HumedalesRESUMEN
One new cytochalasin metabolite [11]-cytochalasa-5(6),13-diene-1,21-dione-7,18-dihydroxy-16,18-dimethyl-10-phenyl-(7S*,13E,16S*,18R*) (1), together with three known compounds (2-4) were obtained from the EtOAc extract of the endophytic fungus Daldinia eschscholtzii HJ001 isolated from the mangrove Brguiera sexangula var. rhynchopetala collected in the South China Sea. Their structures were elucidated by the detailed analysis of comprehensive spectroscopic data. Compounds 1 and 2 were evaluated for their antibacterial and cytotoxic activities.
Asunto(s)
Citocalasinas/química , Xylariales/metabolismo , Antibacterianos/química , Antibacterianos/farmacología , Antineoplásicos/química , Antineoplásicos/farmacología , Línea Celular Tumoral , Citocalasinas/metabolismo , Citocalasinas/farmacología , Endófitos/química , Endófitos/metabolismo , Células Hep G2 , Humanos , Espectroscopía de Resonancia Magnética , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Humedales , Xylariales/químicaRESUMEN
OBJECTIVE: To observe the effect of electroacupuncture (EA) stimulation of "Xiaohai" (SI 8) and "Xiajuxu" (ST 39) on serum TNF-α and duodenal high mobility group protein B 1 (HMGB 1) levels in rats with duodenal ulcer (DU), so as to analyze its underlying mechanism in improving DU. METHODS: Forty SD rats were randomly divided into normal control, model, Xiaohai (SI 8) and Xiajuxu (ST 39) groups (n=10 in each group). The DU model was established by intramuscular injection of 10% Cysteamine hydrochloride (300 mg/kg), followed by taking water containing 1% Cysteamine hydrochloride for 48 h. EA (10 Hz/50 Hz, 1-3 mA) was applied to bilateral SI 8 and ST 39 for 30 min, once a day for 10 days. The DU score (0-5 score) was evaluated according to Moraes' method. Serum TNF-α content was determined by ELISA and duodenal HMGB 1 expression was measured by immunohistochemistry. RESULTS: Compared to the normal control group, the DU score, serum TNF-α content, and duodenal HMGB 1 expression level of the model group were significantly higher (P<0.01). Following EA intervention, the increased DU score, serum TNF-α content, and duodenal HMGB 1 expression level were considerably down-regulated in the two EA groups in comparison with the model group (P<0.01, P<0.05) except HMGB 1 in the SI 8 group (P>0.05), and the effect of EA of "Xiajuxu" (ST 39), the lower-He point, was remarkably superior to that of "Xiaohai" (SI 8) in reducing DU score and TNF-α content (P<0.01). CONCLUSION: EA stimulation of SI 8 and ST 39 can improve duodenal ulceration in DU rats, which may be related to its effect in down-regulating serum TNF-α and duodenal HMGB 1 expression. The therapeutic effect of ST 39 is markedly better than SI 8 in relieving duodenal ulceration.