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1.
J Nat Prod ; 81(8): 1869-1876, 2018 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-30070829

RESUMO

Streptococcus agalactiae is a hazardous pathogen that can cause great harm to humans and fish. In the present study, the known fungal metabolite helvolic acid (10), seven new helvolic acid derivatives named 16- O-deacetylhelvolic acid 21,16-lactone (2), 6- O-propionyl-6,16- O-dideacetylhelvolic acid 21,16-lactone (3), 1,2-dihydro-6,16- O-dideacetylhelvolic acid 21,16-lactone (4), 1,2-dihydro-16- O-deacetylhelvolic acid 21,16-lactone (5), 16- O-propionyl-16- O-deacetylhelvolic acid (6), 6- O-propionyl-6- O-deacetylhelvolic acid (7), and 24- epi-6ß,16ß-diacetoxy-25-hydroxy-3,7-dioxo-29-nordammara-1,17(20)-diene-21,24-lactone (9), and two known ones (1 and 8) were isolated from the marine-derived fungus Aspergillus fumigatus HNMF0047 obtained from an unidentified sponge from Wenchang Beach, Hainan Province, China. The structures and the absolute configurations of the new compounds were unambiguously elucidated by spectroscopic data and electronic circular dichroism (ECD) spectroscopic analyses along with quantum ECD calculations. In addition, the spectroscopic data of compound 1 are reported here for the first time, the configuration of C-24 of known compound 8 was revised based on comparison of its ROESY data with its C-24 epimer 9, and the absolute configuration of 8 was also determined for the first time. Compounds 6, 7, and 10 showed stronger antibacterial activity than a tobramycin control against S. agalactiae with MIC values of 16, 2, and 8 µg/mL, respectively.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Aspergillus fumigatus/química , Ácido Fusídico/análogos & derivados , Streptococcus agalactiae/efeitos dos fármacos , Dicroísmo Circular , Ácido Fusídico/química , Ácido Fusídico/farmacologia , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Microbiana , Conformação Molecular , Estrutura Molecular , Tobramicina/farmacologia
2.
Fitoterapia ; 128: 20-25, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29723562

RESUMO

Five new amide alkaloids (1-3, 5-6) were isolated from the seeds of Clausena lansium together with one new natural product (4) and four known analogues (7-10). The structures of the new amide alkaloids were elucidated based on a comprehensive spectroscopic data analysis including 1D and 2D NMR as well as HRESIMS, and by comparison with the literature. The bioactivity results showed that compound 8 expressed potent nematicidal activity against Panagrellus redivevus, with IC50 value of 0.12 mM, while compounds 3 and 5 presented moderate nematicidal activity with IC50 values of 2.75 and 3.93 mM, respectively (abamectin as the positive control with IC50 value of 1.05 mM).


Assuntos
Alcaloides/isolamento & purificação , Amidas/isolamento & purificação , Anti-Helmínticos/isolamento & purificação , Clausena/química , Sementes/química , Alcaloides/farmacologia , Amidas/farmacologia , Animais , Anti-Helmínticos/farmacologia , Estrutura Molecular , Tylenchida/efeitos dos fármacos
3.
Fitoterapia ; 122: 1-6, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28807715

RESUMO

Five new meroterpenoids, chrodrimanins O-S (1-5), as well as a known one (6), were isolated from the fermentation broth of Penicillium sp. SCS-KFD09 isolated from a marine worm, Sipunculusnudus, from Haikou Bay, China. The structures including the absolute configurations of the new compounds were unambiguously elucidated by spectroscopic data and ECD spectra analysis along with quantum ECD calculations. Among them, compound 1 represents the first example of an unusual trichlorinated meroterpenoid with an unique dichlorine functionality. Compounds 1 and 4-6 displayed inhibitory activity of protein tyrosine phosphatase 1B (PTP1B) with IC50 values of 71.6, 62.5, 63.1, and 39.6µM, respectively, and showed no apparent activity against three tumor cell lines (A549, HepG2, and Hela) and human umbilical vein endothelial cells (HUVEC) at 10µM.


Assuntos
Nematoides/química , Penicillium/química , Proteína Tirosina Fosfatase não Receptora Tipo 1/antagonistas & inibidores , Terpenos/química , Animais , Linhagem Celular Tumoral , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Humanos , Estrutura Molecular , Terpenos/isolamento & purificação
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