Two new xyloketals from the endophytic fungus Endomelanconiopsis endophytica derived from medicinal plant Ficus hirta.

Chemical examination of the liquid culture of Endomelanconiopsis endophytica A326 isolated from the Chinese folk medicine Ficus hirta resulted in the isolation of two new xyloketals named xyloketals K and L (1-2) and three known analogs (3-5) including a new natural product (5). Their structures were determined on the basis of extensive spectroscopic analysis. All compounds were evaluated for their cytotoxic activities against the SF-268, MCF-7, NCI-H460, and HepG-2 tumor cell lines. Nonetheless, no significant activity was observed.

Two New Secondary Metabolites from the Endophytic Fungus Endomelanconiopsis endophytica.

Two new secondary metabolites, endomeketals A-B (1-2), a new natural product (3), and a known compound (4) were isolated from the ethyl acetate extract of the endophytic fungus Endomelanconiopsis endophytica A326 derived from Ficus hirta. Their structures were determined on the basis of extensive spectroscopic analysis. All compounds were evaluated for their cytotoxic activities against SF-268, MCF-7, NCI-H460, and HepG-2 tumor cell lines. However, no compound showed cytotoxic activity against these human tumor cell lines.

Guignardones P-S, New Meroterpenoids from the Endophytic Fungus Guignardia mangiferae A348 Derived from the Medicinal Plant Smilax glabra.

Four new meroterpenoids, guignardones P-S (1-4), and three known analogues (5-7) were isolated from the endophytic fungal strain Guignardia mangiferae A348. Their structures were elucidated on the basis of spectroscopic analysis and single crystal X-ray diffraction. All the isolated compounds were evaluated for their inhibitory effects on SF-268, MCF-7, and NCI-H460 human cancer cell lines. Compounds 2 and 4 exhibited weak inhibitions of cell proliferation against MCF-7 cell line.

Inhibition mechanism investigation of quercetagetin as a potential tyrosinase inhibitor.

Tyrosinase is one important rate limiting enzyme in melanin synthesis, directly affecting the melanin synthesis. Quercetagetin is one active ingredient from marigold. Thence, the inhibition effects of quercetagetin against tyrosinase were investigated. The results showed quercetagetin could inhibit tyrosinase activity with IC50 value of 0.19 ± 0.01 mM and the inhibition type was a reversible mixed-type. Results of fluorescence quenching showed quercetagetin could quench tyrosinase fluorescence in static process. CD and 3D fluorescence results showed the interaction of quercetagetin to tyrosinase could change tyrosinase conformation to inhibit activity. Moreover, docking revealed details of quercetagetin's interactions with tyrosinase.

Should people with chronic liver diseases be vaccinated against COVID-19?

Hepatic impairment in coronavirus disease 2019 (COVID-19) may derive from cholangiocyte damage in the beginning, but not from direct infection of hepatocytes. Chronic liver disease patients co-infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) exhibited overexpression of angiotensin-converting enzyme 2 receptors and overwhelming cytokine storm. Consensus has been reached that we should encourage as many people as possible to be vaccinated in order to achieve herd immunity. SARS-CoV-2 vaccines can prevent or alleviate severe infection and cytokine storm. It is recommended that all adult patients with chronic liver diseases and liver transplant recipients should receive COVID-19 vaccines using the standard dose and schedule. Data is not yet sufficient to compare the efficacy of different types of vaccines used in chronic liver disease patients.