An activity-directed fractionation and purification process was used to isolate antitumor compounds from the roots of Belamcanda chinensis (L.) DC. The ethyl acetate extract showed greater antitumor activities than the other extracts, consequently leading to the isolation of 18 compounds identified as -sitosterol (1), dausterol (2), quercetin (3), kampferol (4), shikimic acid (5), gallic acid (6), ursolic acid (7), betulin (8), betulonic acid (9), betulone (10), tectoridin (11), irisflorentin (12), 4′,5,6-trihydroxy-7-methoxyisoflavone (13), tectorigenin (14), irilins A (15), iridin (16), irigenin (17), and iristectongenin A (18). Compounds 3-10, 13, and 15 were isolated from B. chinensis for the first time. Compounds 4 and 7-10 showed potent cytotoxic activities against PC3, MGC-803, Bcap-37, and MCF-7 cell lines. The mechanism of the antitumor action of compound 7 was preliminarily investigated through acridine orange/ethidium bromide (AO/EB) staining, Hoechst 33258 staining, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, which indicated the growth inhibition of MGC-803 cells via the induction of tumor cell apoptosis.

The sediment samples were collected from eight sites located in the Pearl River Estuary and the Shenzhen Bay of the west coast of Shenzhen. The distributions of the seven elements Zn, Cr, Hg, Cu, Cd, Pb and As have been analyzed, and their pollution degrees, corresponding potential ecological risks and source identifications have been studied using geo-accumulation index, potential ecological risk index and integrated multivariate statistical methods, respectively. Based on the calculated geo-accumulation indices, the contamination levels of all elements in the Pearl River Estuary are similar to those in the Shenzhen Bay, reflecting that these elements in the study areas have similar sources because of the adequate seawater exchange. The calculated potential ecological risk indices suggest that Cd and Hg are at considerable and moderate risk, respectively. Multivariate statistical analyses further reveal that Zn, Hg, Cd and Pb originated from industrial wastewater, while Cr and Cu are mainly from both industrial wastewater and agricultural sources, and As is mainly from natural source. These research results provide baseline information for both the coastal environment management and the worldwide heavy metal distribution and assessment.

The synthesis of long, branched, and complex carbohydrate sequences remains a challenging task in chemical synthesis. Reported here is an efficient and modular one‐pot synthesis of a nona‐decasaccharide and shorter sequences from Psidium guajava polysaccharides, which have the potent α‐glucosidase inhibitory activity. The synthetic strategy features: 1) several one‐pot glycosylation reactions on the basis of N‐phenyltrifluoroacetimidate (PTFAI) and Yu glycosylation to streamline the chemical synthesis of oligosaccharides, 2) the successful and efficient assembly sequences (first O3′, second O5′, final O2′) toward the challenging 2,3,5‐branched Araf motif, 3) the stereoselective 1,2‐cis‐glucosylation by reagent control, and 4) the convergent [6+6+7] one‐pot coupling reaction for the final assembly of the target nona‐decasaccharide. This orthogonal one‐pot glycosylation strategy can streamline the chemical synthesis of long, branched, and complicated carbohydrate chains.

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