RESUMO
A new brominated pyrrolactam stylissaol A (1) together with four known analogues, 2-bromoaldisine, aldisine, spongiacidin D, and Z-hymenialdisine, were isolated from the EtOAc extract of marine sponge Stylissa massa collected in Myanmar. The absolute configuration at C-10 of 1 was determined as R by the electronic circular dichroism (ECD) data. Among the isolated compounds, 2-bromoaldisine showed anti-Viral Protein R (Vpr) activity against TREx-HeLa-Vpr cells with an effective dose of 10 µM and its potency was comparable to that of positive control damnacanthal.
Assuntos
Alcaloides/química , Antivirais/química , Poríferos/química , Alcaloides/isolamento & purificação , Alcaloides/metabolismo , Animais , Antivirais/isolamento & purificação , Antivirais/metabolismo , Dicroísmo Circular , Células HeLa , Humanos , Conformação Molecular , Mianmar , Poríferos/metabolismo , Produtos do Gene vpr do Vírus da Imunodeficiência Humana/antagonistas & inibidores , Produtos do Gene vpr do Vírus da Imunodeficiência Humana/genética , Produtos do Gene vpr do Vírus da Imunodeficiência Humana/metabolismoRESUMO
SmltD is an ATP-dependent ligase that catalyzes the condensation of UDP-MurNAc-l-Ala and l-Glu to form UDP-MurNAc-l-Ala-l-Glu, in the newly discovered peptidoglycan biosynthesis pathway of a Gram-negative multiple-drug-resistant pathogen, Stenotrophomonas maltophilia. Phytochemical investigation of the 70% ethanol extract from Woodfordia fruticosa flowers collected in Myanmar led to the identification of anti-SmltD active flavonoids, kaempferol 3-O-(6''-galloyl)-ß-d-glucopyranoside (1), astragalin (2), and juglalin (3). Among them, 1 showed the most potent SmltD inhibitory activity. An enzyme steady-state kinetic study revealed that 1 exerted competitive inhibition with respect to ATP. The results of this study provided an attractive foundation for the further development of novel inhibitors of SmltD.
Assuntos
DNA Ligase Dependente de ATP/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Flavonoides/farmacologia , Peptidoglicano/biossíntese , Woodfordia/química , DNA Ligase Dependente de ATP/metabolismo , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/química , Inibidores Enzimáticos/isolamento & purificação , Flavonoides/química , Flavonoides/isolamento & purificação , Estrutura Molecular , Peptidoglicano/química , Stenotrophomonas maltophilia/enzimologia , Relação Estrutura-AtividadeRESUMO
Jatropha multifida is a medicinal plant that belongs to the Euphorbiaceae family. Our investigation revealed that the chloroform extract of J. multifida stems showed anti-melanin deposition activity against α-melanocyte stimulating hormone (α-MSH)- and 3-isobutyl-1-methylxanthine (IBMX)-induced melanogenesis in the mouse melanoma cell line (B16-F10). Further fractionation and purification of the major constituents led to the isolation of two coumarins (1 and 2) and seven known lignoids (3-9). All isolated compounds exhibited anti-melanin deposition activities against the mouse melanoma cell line (B16-F10) with IC50 values ranging from 37.5 to 560.1 µM, without any cytotoxicity even at high concentrations, except for 8. Further mechanistic studies suggested that 9 downregulated tyrosinase mRNA expression, while the anti-melanin deposition activities of 4 and 8 appeared to be unrelated to tyrosinase inhibition and the downregulated expression of the key melanogenesis-associated mRNAs. These results suggested that J. multifida could possess potent skin whitening ingredients.
Assuntos
Jatropha/química , Melaninas/metabolismo , Melanoma Experimental/tratamento farmacológico , Extratos Vegetais/farmacologia , alfa-MSH/farmacologia , Animais , Linhagem Celular Tumoral , Regulação para Baixo/efeitos dos fármacos , Camundongos , Monofenol Mono-Oxigenase/metabolismoRESUMO
Four new bis-iridoid glycosides, saungmaygaosides A-D (1-4), and six known iridoid glycosides (5-10) were isolated from the n-butanol extract of the stems of Picrorhiza kurroa collected in Myanmar. Their structures were elucidated by extensive spectroscopic techniques. All of the isolates were assayed for anti-Vpr activity, using TREx-HeLa-Vpr cells. Among the isolates, saungmaygaoside D (4), sylvestroside IV dimethyl acetal (7), and sweroside (8) were the most potent inhibitors with effective doses of 5 and 10⯵M, respectively, without showing any notable cytotoxicities.