An effective urobilin clearance strategy based on paramagnetic beads facilitates microscale proteomic analysis of urine.

Urine provides an ideal source for disease biomarker discovery. High-adhesion contaminants such as urobilin, which are difficult to remove from urine, can severely interfere with urinary proteomic analysis. Here, we aimed to establish a strategy based on single-pot, solid-phase-enhanced sample preparation (SP3) technology to prepare samples for urinary proteomics analysis that almost completely eliminates the impact of urobilin. A systematic evaluation of the effects of two urinary protein precipitation methods, two types of protein lysis buffers, and different ratios of magnetic digestion beads on the identification and quantification of the microscale urinary proteome was conducted. Our results indicate that methanol-chloroform precipitation, coupled with efficient lysis facilitated by urea, and subsequent enzymatic digestion using a mix of hydrophilic and hydrophobic magnetic beads offers the best performance. Further applying this strategy to the urine of patients with benign prostatic hyperplasia, prostate cancer and healthy individuals, combined with a narrow window of data-independent acquisition, FGFR4, MYLK, ORM2, GOLM1, SPP1, CD55, CSF1, DLD and TIMP3 were identified as potential biomarkers to discriminate benign prostatic hyperplasia and prostate cancer patients.

Correction: Pentacyclic spermidine alkaloids with radioprotective and anti-inflammatory activities from Orychophragmus violaceus.

Correction for 'Pentacyclic spermidine alkaloids with radioprotective and anti-inflammatory activities from Orychophragmus violaceus' by Zan-Xin Xu et al., Org. Biomol. Chem., 2021, 19, 9844-9848, DOI: 10.1039/D1OB01973B.

Pentacyclic spermidine alkaloids with radioprotective and anti-inflammatory activities from Orychophragmus violaceus.

Two pairs of novel pentacyclic spermidine alkaloid enantiomers, (±)-orychoviolines A and B ((±)-1 and (±)-2), were isolated from the seeds of Orychophragmus violaceus and represented the first example of a 2-piperidinone-fused hydrodibenzofuran skeleton, constructed from a 6/5/6/6 tetracyclic system and an 18 atomic ring. The most unexpected novelty was the formation of one more piperidinone ring by a connection between C-6 and N-7. Their structures and absolute configurations were determined by spectroscopic analyses, X-ray crystallography, and ECD analysis. Compared to Ex-RAD (sodium salt of 4-carboxystyryl-4-chlorobenzylsulfone), (-)-1 exhibited a significant radioprotective effect on cell survival and DNA damage. (-)-1 also exhibited remarkable anti-inflammatory activity by inhibiting the production of NO in RAW 264.7 cells activated by lipopolysaccharide with an IC50 value of 20.3 ± 1.58 µM, which was equivalent to that of dexamethasone.

Chemical constituents from the aerial parts of Orychophragmus violaceus.

A new alkaloid, demethylorychophragine A (1), together with 18 known compounds was isolated from the aerial parts of Orychophragmus violaceus. Structure of the new compound was identified by extensive spectroscopic techniques. 2 and 3 were isolated from nature for the first time. Known compounds were identified by comparison with data reported in the literature. All compounds were evaluated for anti-radiation activities against X-ray irradiation in HUVEC cell line. Results showed that 10, 12, and 15 showed excellent anti-radiation activity. All compounds were tested for cytotoxic activity against SH-SY5Y and HeLa cell lines. 16 exhibited significant cytotoxicity activity against SH-SY5Y cells, with IC50 value of 23.86 ± 0.38 µM (p = 0.045). The anti-inflammatory effects of all compounds were assessed by determining their ability to inhibit the production of NO, which was induced by stimulating the RAW264.7 murine macrophage cell line with lipopolysaccharide. 16 markedly decreased NO to a level of 27.34 ± 1.29 µM.