Pseudostellarin B (cyclic peptide) was isolated and purified from the herbs of Pseudostellaria heterophylla (Miq.) Pax for the first time by high-speed counter-current chromatography (HSCCC) using a two-phase solvent system consisting of n-butanol-ethyl acetate-water (0.6:4.4:5, v/v). The technique can isolate mg levels of the target compound per run with purity better than 96%. The chemical structure of the compound has been positively confirmed by electrospray ionization time of flight (TOF) MS, (1)H-NMR, (13)C-NMR and (1)H-(13)C-COSY analyses.
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http://dx.doi.org/10.1016/j.talanta.2006.05.016 | DOI Listing |
Metabolites
June 2022
Graduate Institute of Biotechnology, National Chung Hsing University, Taichung 402, Taiwan.
GLP-1 receptor agonists stimulate GLP-1R to promote insulin secretion, whereas DPP4 inhibitors slow GLP-1 degradation. Both approaches are incretin-based therapies for T2D. In addition to GLP-1 analogs, small nonpeptide GLP-1RAs such as LY3502970, TT-OAD2, and PF-06882961 have been considered as possible therapeutic alternatives.
View Article and Find Full Text PDFInt J Mol Sci
June 2022
Institute of Biomolecular Chemistry of CNR, Padova Unit, Via F. Marzolo, 1, 35131 Padova, Italy.
The tyrosinase enzyme, which catalyzes the hydroxylation of monophenols and the oxidation of -diphenols, is typically involved in the synthesis of the dark product melanin starting from the amino acid tyrosine. Contributing to the browning of plant and fruit tissues and to the hyperpigmentation of the skin, leading to melasma or age spots, the research of possible tyrosinase inhibitors has attracted much interest in agri-food, cosmetic, and medicinal industries. In this study, we analyzed the capability of antamanide, a mushroom bioactive cyclic decapeptide, and some of its glycine derivatives, compared to that of pseudostellarin A, a known tyrosinase inhibitor, to hinder tyrosinase activity by using a spectrophotometric method.
View Article and Find Full Text PDFZhongguo Zhong Yao Za Zhi
January 2022
College of Pharmaceutical Sciences, Southwest University Chongqing 400715, China the MOE Engineering Research Center of Coptis Development & Utilization, Southwest University Chongqing 400715, China.
Four cyclic peptides were isolated from the 75% ethanol extract of the fibrous roots of Pseudostellaria heterophylla by silica gel, Sephadex LH-20 column chromatography, and semi-preparative HPLC. Through mass spectrometry, NMR and other methods, they were identified as pseudostellarin L(1), heterophyllin B(2), pseudostellarin B(3), and pseudostellarin C(4). Among them, compound 1 was a new cyclic peptide, and compounds 2-4 were isolated from the fibrous roots of P.
View Article and Find Full Text PDFNat Prod Res
July 2022
College of Pharmaceutical Sciences, Southwest University, Chongqing, China.
A new cyclic peptide, Pseudostellarin K (), together with thirteen known compounds, including two cyclic peptides ( and ), one β-carboline alkaloid (), two amides ( and ), three phenylpropanoids () and other compounds (), were isolated from the fibrous root of . Their structures were elucidated by extensive spectroscopic analysis. Compounds , -, were isolated from the genus pseudostellaria for the first time.
View Article and Find Full Text PDFBeilstein J Org Chem
May 2018
State Key Laboratory of Elemento-Organic Chemistry, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), College of Chemistry, Nankai University, Tianjin 300071, China.
The system of the hypervalent iodine(III) reagent FPID and (4-MeOCH)P was successfully applied to solid-phase peptide synthesis and cyclic peptide synthesis. Four peptides with biological activities were synthesized through SPPS and the bioactive cyclic heptapeptide pseudostellarin D was obtained via solution-phase peptide synthesis. It is worth noting that FPID can be readily regenerated after the peptide coupling reaction.
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