ABSTRACT
Six compounds were isolated from the crude extract of the liquid culture of Alternaria sp. W-1 by silica gel column chromatography, Sephadex LH-20 gel column chromatography, and HPLC. They were identified as 6-iso-tricycloalternarene 6a (1), tricycloalternarene 6a (2), tricycloalternarene B (3), uracil (4), 5-methyluracil (5), and lumichrome (6) through HR-MS, NMR and literature comparison. 6-iso-Tricycloalternarene 6a (1) is a new compound which has never been reported in the literature. In cytotoxicity assay, compounds 1-3 showed weak inhibition activity to human hepatoma cell line SMMC-7721 and human gastric cell line SGC-7901.
ABSTRACT
Isolation and purification of chemical constituents of liquid culture of symbiotic Chaetomium globosum ML-4 of oyster was performed through silica gel column chromatography, gel filtration over Sephadex LH-20, preparative TLC and HPLC. Five compounds were obtained and their structures were determined as chaetoglobosin V(1), chaetoglobosin Vb(2), tyrosol(3), 5-methyluracil(4)and uracil(5), respectively, based on HR-MS and NMR data and comparison with literatures. In vitro cytotoxicity of compounds against human hepatocellular carcinoma cell line SMMC-7721 were measured byMTT method, and results showed that compound 1 could obviously inhibit the proliferation of SMMC-7721 cells with an IC₅₀ value of 60.5 mg•L⁻¹, while the IC₅₀ value of positive control cisplatin was 19.96 mg•L⁻¹. Further studies discovered that compound 1 could lead to G2 phase arrest in SMMC-7721 cells and induce SMMC-7721 cells apoptosis. The ratio of Bcl-2/Bax in SMMC-7721 cells was decreased. The expression of protein Caspases-3,-8,-9 was improved and the expression and phosphorylation level of Akt were reduced. Aforementioned results revealed that in vitro antitumor activity of compound 1 against SMMC-7721 cells were related to G2 phase cell cycle arrest and induced-apoptosis. The induced-apoptosis was involved in both the mitochondrial pathway and the death receptor pathway and connected with activity decline of PI3K/Akt signaling pathway.
ABSTRACT
AIM@#To isolate new and/or bioactive constituents from EtOAc extract of liquid culture of endophyte Guignardia sp. from the leaves of Undaria pinnatifida (Harv.) Sur.@*METHODS@#Isolation and purification were performed through silica gel column chromatograph, Sephadex LH-20 and reversed-phase ODS column and the structures of the compounds obtained were identified through a combination of spectral and chemical methods (IR, MS, (1)H and (13)C NMR). In vitro bioactive assays including antifungal activity against three human pathogenic fungi Microsporum canis, Tricophyton rubrum and Epidermophyton floccosom and cytotoxic activity against the human nasopharyngeal epidermoid tumor KB cell line were evaluated.@*RESULTS@#Seven compounds have been obtained from the liquid culture of the title endophyte: ergosterol peroxide (6, 22-diene-5, 8-epidioxyergosta-3-ol) (1), ergosterol (2), cyclo-(Tyr-Leu) (3), cyclo-(Phe-Phe) (4), cyclo-(Val-Leu) (5), cyclo-(Phe-Pro) (6) and cyclo-(Leu-Ile) (7). Compounds 1-3 and 6 inhibited the growth of M. canis with MICs of 10.0, 20.0, 50.0 and 5.0 μg·mL(-1), respectively and compounds 1, 2 and 6 against T. rubrum with MICs of 15.0, 20.0 and 10.0 μg·mL(-1), respectively and 1 and 6 against E. floccosom with MICs of 20.0 and 50.0 μg·mL(-1), respectively. In addition, compounds 1, 3 and 6 exhibited cytotoxic activity against KB cell line with IC(50) of 20.0, 10.0, 10.0 μg·mL(-1), respectively.@*CONCLUSION@#Compounds 1-7 were obtained from Guignardia sp. of U. pinnatifida for the first time, and compounds 1 and 6 had potent cytotoxic and antifungal activity.