Sesquiterpene lactones from Tithonia diversifolia with ferroptosis-inducing activities.

Eight previously undescribed sesquiterpene lactones (1-8), together with six known ones (9-14) were isolated from the aerial parts of Tithonia diversifolia (Hemsl.) A. Gray.

Engineered nanomedicines block the PD-1/PD-L1 axis for potentiated cancer immunotherapy.

Immunotherapy, in particular immune checkpoint blockade (ICB) therapy targeting the programmed cell death-1 (PD-1)/programmed cell death ligand-1 (PD-L1) axis, has remarkably revolutionized cancer treatment in the clinic. Anti-PD-1/PD-L1 therapy is designed to restore the antitumor response of cytotoxic T cells (CTLs) by blocking the interaction between PD-L1 on tumour cells and PD-1 on CTLs. Nevertheless, current anti-PD-1/PD-L1 therapy suffers from poor therapeutic outcomes in a large variety of solid tumours due to insufficient tumour specificity, severe cytotoxic effects, and the occurrence of immune resistance.

Multiple transporters are involved in natamycin efflux in Streptomyces chattanoogensis L10.

Antibiotic-producing microorganisms have evolved several self-resistance mechanisms to prevent auto-toxicity. Overexpression of specific transporters to improve the efflux of toxic antibiotics has been found one of the most important and intrinsic resistance strategies used by many Streptomyces strains. In this work, two ATP-binding cassette (ABC) transporter-encoding genes located in the natamycin biosynthetic gene cluster, scnA and scnB, were identified as the primary exporter genes for natamycin efflux in Streptomyces chattanoogensis L10.