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Highlights • Off-line multi-hyphenated methods to screen iNOS inhibitors were developed. • Two types of ingredients in Radix Ophiopogonis were obtained as iNOS ligands. • Three Ophiopogonins were confirmed with obvious iNOS inhibitory activities. Abstract Off-line multi-hyphenated methods including affinity-ultrafiltration mass spectrometry, molecular docking, and reverse-phase high-performance liquid chromatography-fluorescence detection (RP-HPLC-FD) were used to rapidly screen and identify natural inducible nitric oxide synthase (iNOS) inhibitors isolated from Ophiopogon japonicus (Thunb.) Ker-Gawl. Ultrafiltration high-performance liquid chromatography quadrupole time-of-flight mass spectrometry was used to screen and identify the potential ligands with high binding affinity to iNOS. Seven compounds (three saponins and four flavonoids) were found in Radix Ophiopogonis. Molecular docking identified the binding sites and found that the binding affinity of the three ophiopogonis ligands was higher than that of the four homoisoflavonoids. Pre-column derivatization of l -citrulline and RP-HPLC-FD verified that the in vitro inhibition activity of the three ophiopogonis compounds was stronger than that of the four homoisoflavonoids, which was similar to the screened results. In conclusion, combining an in vitro iNOS inhibition assay and affinity-ultrafiltration mass spectrometry with molecular docking was a powerful tool for rapid screening and identification of iNOS inhibitors isolated from this traditional Chinese medicine. [ABSTRACT FROM AUTHOR]

In the storage of Radix Ophiopogonis, browning often happens to cause potential risk with regard to safety. Previously few reports investigate the browning of Radix Ophiopogonis. In this research, the causes and mechanisms of the browning of Radix Ophiopogonis were preliminarily elucidated. Content determination by high-performance liquid chromatography (HPLC) and spectrophotometry, enzyme activity determination by colorimetry, and morphological observation by electron microscopy were performed in the present study. Uniform design and three-dimensional response surfaces were applied to investigate the relationship between browning and storage factors. The cortex cell wall of browned Radix Ophiopogonis was ruptured. Compared with the normal Radix Ophiopogonis, cellulase and polyphenol oxidase enzymes were activated, the levels of 5-hydroxymethylfurfural (5-HMF), total sugars, and reducing sugars were increased, while the levels of polysaccharides and methylophiopogonanone A were decreased in browned Radix Ophiopogonis. The relationship between the storage factors and degree of browning ( Y ) could be described by following correlation equation: Y = − 0.625 4 + 0.020 84 × X 3 + 0.001 514 × X 1 × X 2 − 0.000 964 4 × X 2 × X 3 . Accompanied with browning under storage conditions, the chemical composition of Radix Ophiopogonis was altered. Following the activation of cellulase, the rupture of the cortex cell wall and the outflow of cell substances flowed out, which caused the Radix Ophiopogonis tissue to become soft and sticky. The main causes of the browning were the production of 5-HMF, the activation of polyphenol oxidase, Maillard reactions and enzymatic browning. Browning could be effectively prevented when the air relative humidity (HR), temperature, and moisture content were under 25% RH, 12 °C and 18%, respectively. [ABSTRACT FROM AUTHOR]

A competitive enzyme-linked immunosorbent assay (ELISA) was developed to determine ruscogenin (RUS) by using the monoclonal antibody (McAb). The monoclonal antibody against RUS, secreted from the established hybridoma cell lines, was identified as being of the IgG 1 isotype. The McAb exhibited high specificity to RUS, showing a very slight cross reactivity with diosgenin (15.7%), and no cross-reactivity to sarsasapogenin, diammonium glycyrrhizinate, oleanolic acid and notoginsenoside R1. The established ELISA, at an IC 50 value of 157.55 ng . mL −1 and a detection limit (IC 20 ) of 20.57 ng·mL −1 , was compared with HPLC analyses, and a good correlation between ELISA and HPLC-ELSD analyses of RUS in the extract of Radix Ophiopogonis was obtained. The experimental data indicated that the ELISA method exhibits more advantages over HPLC-ELSD, such as low detection limit, high specificity, low background, and no requirement for sample pre-treatment, and is more suitable for the determination of natural components in Chinese traditional medicines and in biological samples for pharmacokinetic studies. [ABSTRACT FROM AUTHOR]

Abstract: This work aimed to improve the clinical application of Radix Ophiopogonis polysaccharide (ROP), a natural anti-myocardial ischemic fructan with Mw of 4.80kDa, by mono-PEGylation. Three mono-PEGylated ROPs were prepared by a moderate coupling reaction between amino-terminated methoxy-PEG (20-, 30-, or 40-kDa) and excessive hydroxyl-activated ROP. After being fully characterized by proton nuclear magnetic resonance as well as high-performance gel permeation chromatography and anthrone–sulfuric acid colorimetry coupled assay, they were evaluated for pharmacokinetics and anti-myocardial ischemic activities in rats with coronary artery ligation. The results showed that mono-PEGylated ROPs were successfully and effectively prepared. Compared with ROP, the three mono-PEGylated ROPs showed approximately 32-, 85-, and 100-fold prolonged retention in systemic circulation with plasma half-lives reaching 16.1, 42.4, and 49.8h, respectively. Studies on anti-myocardial ischemic effects of the conjugates showed that administrated at the same molar dose of 4μmol/kg per injection as ROP, they could achieve comparable or even better therapeutic effects although their administration intervals were 2- to 6-fold longer than that of ROP. These findings confirm that PEGylation would be a promising approach to markedly reducing the injection-administered frequency of ROP and hence patient compliance without sacrifice of the therapeutic efficacy by significantly improving its pharmacokinetics. [Copyright &y& Elsevier]

Abstract: Chromatographic fingerprinting has been recommended as a potential and reliable strategy for the quality control of herbal medicines. Although varieties of chromatographic techniques, particularly HPLC, have been widely employed, hyphenated chromatographic approach has not been sufficiently exploited in chromatographic fingerprinting. In this work, LC/MS fingerprinting of Shenmai injection was developed. Thirty ginsenosides as well as seven ophioponins were selected to construct the LC/MS fingerprint using selective ion monitoring (SIM) mode, while previous HPLC fingerprint [H.J. Zhang, Y.J. Wu, Y.Y. Cheng, J. Pharm. Biomed. Anal. 31 (2003) 175–183] only represents the ginsenosides. Subsequently, the proposed LC/MS fingerprints were applied to identifying the product manufacturers. All the samples were accurately classified based on their LC/MS fingerprints in conjunction with principal components analysis (PCA). This study would be potentially helpful to improve the quality control ability of fingerprinting-based strategy for complex herbal medicines. [Copyright &y& Elsevier]