RESUMO
Seven new compounds, namely talaromanloid A (1), talaromydene (2), 10-hydroxy-8-demethyltalaromydine and 11-hydroxy-8-demethyltalaromydine (3 and 4), talaromylectone (5), and ditalaromylectones A and B (6 and 7), together with seven known compounds were identified from a marine-derived fungus, Talaromyces mangshanicus BTBU20211089, which was isolated from a sediment sample collected from the South China Sea. Their chemical structures were determined using spectroscopic data, including HRESIMS, 1D, and 2D NMR techniques. The absolute configurations of 1 and 2 were elucidated by comparing experimental and calculated ECD spectra. Compounds 1, 2, 6, and 7 are new compounds possessing a novel carbon skeleton. Compound 6 is a dimeric molecule of 3 and 9. Compound 7 shared a unique structure of the cyclized dimer of 3 and 4. All the compounds were tested for their bioactivities against Staphylococcus aureus, Escherichia coli, and Candida albicans.
Assuntos
Anti-Infecciosos/farmacologia , Sedimentos Geológicos/microbiologia , Talaromyces/metabolismo , Anti-Infecciosos/isolamento & purificação , Candida albicans/efeitos dos fármacos , China , Escherichia coli/efeitos dos fármacos , Oceanos e Mares , Metabolismo Secundário , Staphylococcus aureus/efeitos dos fármacosRESUMO
Two new spiro-heterocyclic γ-lactam derivatives, cephalimysins M (1) and N (2), were isolated from the fermentation cultures of the marine-derived fungus Aspergillus fumigatus CUGBMF17018. Two known analogues, pseurotin A (3) and FD-838 (4), as well as four previously reported helvolic acid derivatives, 16-O-propionyl-16-O-deacetylhelvolic acid (5), 6-O-propionyl-6-O-deacetylhelvolic acid (6), helvolic acid (7), and 1,2-dihydrohelvolic acid (8) were also identified. One-dimensional (1D), two-dimensional (2D) NMR, HRMS, and circular dichroism spectral analysis characterized the structures of the isolated compounds.
Assuntos
Organismos Aquáticos/química , Aspergillus fumigatus/química , Furanos/química , Imidazóis/química , Lactamas/química , Pirrolidinonas/química , Compostos de Espiro/química , Dicroísmo Circular , Ácido Fusídico/análogos & derivados , Ácido Fusídico/química , Espectroscopia de Ressonância Magnética , Estrutura MolecularRESUMO
This study describes an investigation into secondary metabolites that are produced by a marine red alga, Symphyocladia latiuscula, which was collected from coastal waters off Qingdao, China. A combination of normal, reversed phase, and gel chromatography was used to isolate six citric acid derived natural products, aconitates A-F (1-6), together with two known and ten new polybrominated phenols, symphyocladins C/D (7a/b), and symphyocladins H-Q (8a/b, 9a/b and 10-15), respectively. Structure elucidation was achieved by detailed spectroscopic (including X-ray crystallographic) analysis. We propose a plausible and convergent biosynthetic pathway involving a key quinone methide intermediate, linking aconitates and symphyocladins.
Assuntos
Fenóis/química , Rodófitas/química , Animais , Organismos Aquáticos , China , Cristalografia por Raios X , Espectroscopia de Ressonância MagnéticaRESUMO
Hydrogel wound dressing for irregular shape and deep wound repair is a research hotspot. Herein, a multifunctional and self-adaptive double-layer hydrogel was constructed, which was comprised of chitosan-based inner layer hydrogel and gellan gum-based outer layer hydrogel. Various properties of inner layer hydrogel were systematically investigated, including injectability, shape-adaptability, solid-liquid phase transition, biocompatibility, hemostasis, antibacterial performance and anti-inflammatory. Thanks to the phase-transition from solid to liquid at body temperature, inner layer hydrogel exhibited stronger adaptability to fill irregular and deep wounds, in which chitosan was liquefied and its therapeutic effect was maximized. Outer layer hydrogel was fabricated by calcium ions and gellan gum, whose certain mechanical strength could provide protection and a moister environment for wounds. Because of these characteristics, double-layer hydrogel markedly promoted skin tissue regeneration and wound closure and thereby possessed potential clinical application prospect as wound dressing for deep wounds.
Assuntos
Quitosana , Hidrogéis , Hidrogéis/farmacologia , Antibacterianos/farmacologia , Bandagens , Temperatura CorporalRESUMO
This study describes an investigation into polybromocatechol conjugates isolated from a marine red alga, Symphyocladia latiuscula (Harvey) Yamada, collected from coastal waters off Qingdao, China. We report on the isolation and characterisation of eight undescribed aconitic acid conjugates, symphyocladins R-X, including a likely solvolysis artifact of symphyocladin S, and an undescribed furanoyl conjugate, symphyocladin Y. Structure elucidation was achieved by detailed spectroscopic analysis. A plausible biosynthetic pathway linking all these co-metabolites through a cascade of quinone methide additions is proposed.
Assuntos
Ácido Aconítico/química , Catecóis/química , Furanos/química , Rodófitas/química , Ácido Aconítico/farmacologia , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Catecóis/farmacologia , China , Furanos/farmacologia , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Microbiana , Estrutura Molecular , Rodófitas/metabolismo , Espectrometria de Massas por Ionização por ElectrosprayRESUMO
Since pyrithiobac (PTB) is a successful commercial herbicide with very low toxicity against mammals, it is worth exploring its derivatives for an extensive study. Herein, a total of 35 novel compounds were chemically synthesized and single crystal of 6-6 was obtained to confirm the molecular structure of this family of compounds. The novel PTB derivatives were fully evaluated against various biological platforms. From the bioassay results, the best AHAS inhibitor 6-22 displayed weaker herbicidal activity but stronger anti-Candida activity than PTB did. For plant pathogenic fungi, 6-26 showed excellent activity at 50â¯mg/L dosage. Preliminary insecticidal activity and antiviral activity were also observed for some title compounds. Strikingly, 6-5 exhibited a promising inhibitory activity against SARS-CoV Mpro with IC50 of 4.471⯵M and a low cellular cytotoxicity against mammalian 293â¯T cells. Based on the results of molecular modeling, HOMO-1 was considered to be a factor that affects AHAS inhibition and a possible binding mode of 6-5 with SARS-CoV Mpro was predicted. This is the first time that PTB derivatives have been studied as biological agents other than herbicides. The present research hence has suggested that more attentions should be paid to compounds belonging to this family to develop novel agrochemicals or medicines.
Assuntos
Benzoatos/síntese química , Benzoatos/farmacologia , Fungos/efeitos dos fármacos , Herbicidas/síntese química , Acetolactato Sintase/antagonistas & inibidores , Antivirais/síntese química , Antivirais/farmacologia , Benzoatos/química , Desenho de Fármacos , Herbicidas/farmacologia , Herbicidas/uso terapêutico , Modelos Moleculares , Estrutura Molecular , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/efeitos dos fármacosRESUMO
One new diphenyl ether, diorcinol K (1), along with three known compounds, diorcinols D (2), F (3) and I (4) were isolated from the fermentation media of a marine-derived fungus Aspergillus sp. CUGB-F046 which was isolated from a sediment sample collected from the Bohai Sea, China. Their structures were elucidated by detailed spectroscopic methods. Compounds 1, 2 and 4 displayed significant antibacterial activities against Staphylococcus aureus and methicillin-resistant S. aureus with MIC values of 3.125, 6.25 and 6.25 µg/mL, respectively.