4-dehydroxyepisarcovagine A,a new steroidal alkaloid from Sarcococca pruniformis Lindl.

A new steroidal alkaloid, 4-dehydroxyepisarcovagine A (1), along with seven known alkaloids, sarcovagine D (2), sarcovagenine C (3), epoxysarcovagenine D (4), Pachysamine L (5), Pachysamine E (6), sarcovagine A (7) and sarcovagine B (8), was isolated from the roots and stems of Sarcococca pruniformis Lindl. The structure of compound 1 was elucidated by means of spectroscopic analysis.     

New transformation pathway and cytotoxic derivatives from the acid hydrolysis of timosaponin B III

Timosaponin B III is a major bioactive steroidal saponin isolated from Anemarrhena asphodeloides Bge. To potentially discover derivatives with better biological activity, timosaponin B III was structurally modified via acid hydrolysis to yield one new (2, timopregnane A I) C₂₁ steroidal glycoside and seven known compounds. Their structures were elucidated on the basis of NMR spectroscopy and mass spectrometry. All eight compounds were evaluated for cytotoxic activity against MCF7, SW480, HepG2, and SGC7901 cell lines in vitro. As a result, compounds 6 and 7 showed significant activity (IC₅₀ 2.94–12.2?μM) against all tested cell lines. Structure–activity relationships of these compounds were investigated and the preliminary conclusions were provided. Moreover, a new transformation pathway was discovered in the acid hydrolysis of timosaponin B III for the first time.     

Optimization of the Ultrasonic-Assisted Extraction Technology of Steroidal Saponins from Polygonatum kingianum Collett & Hemsl and Evaluating Its Quality Planted in Different Areas

Polygonatum kingianum Collett & Hemsl is one of the famous traditional Chinese herbs with satisfactory therapeutic effects on invigorating Qi, nourishing Yin and moistening lungs, in which steroidal saponins are one class of important active substances. The main purpose is to determine the optimal extraction technology of steroidal saponins and evaluate the quality of P. kingianum planted in five different areas. The optimal ultrasonic-assisted extraction (UAE) technology was established by using single-factor experiments and the response surface methodology (RSM), and the determination method of high-performance liquid chromatography (HPLC) for dioscin and diosgenin, two primary types of acid-hydrolyzed steroidal saponins, was constructed with good linear range and precision. The results showed that UAE was an efficient extraction method for steroidal saponins, and the extraction yield was significantly affected by the liquid-solid ratio. The optimal extraction technology was generated following a liquid-solid ratio of 10:1 (mL/g), an ethanol concentration of 85% (v/v), an extraction time of 75 min, an extraction temperature of 50 °C and three extractions, of which these parameters were in line with the predicted values calculated by RSM. Considering only dioscin and diosgenin, the quality of P. kingianum planted at five sample plots presented non-significant difference. However, the content of diosgenin in Pingbian Prefecture (PB) was higher than that of the other four areas with a value of 0.46 mg/g. Taken together, the optimal UAE technology for P. kingianum steroidal saponins was determined via RSM. The quality evaluation revealed that there was a non-significant difference among P. kingianum planted in different areas based on the contents of the sum of dioscin and diosgenin. This work has important reference value for the exploitation and utilization of P. kingianum.     

Simultaneous quantitation of etoricoxib, salicylic acid, valdecoxib, ketoprofen, nimesulide and celecoxib in plasma by high-performance liquid chromatography with UV detection

A specific, accurate, precise and reproducible high performance liquid chromatography (HPLC) method was developed and validated for the simultaneous quantitation of etoricoxib, salicylic acid, valdecoxib, ketoprofen, nimesulide and celecoxib in human plasma. The method employed a simple liquid-liquid extraction of etoricoxib, salicylic acid, valdecoxib, ketoprofen, nimesulide and celecoxib and internal standard (IS, DRF-4367) from human plasma (500 microL) into acetonitirile. The organic layer was separated and evaporated under a gentle stream of nitrogen at 40 degrees C. The residue was reconstituted in the mobile phase and injected onto a Kromasil KR 100-5C18 column (4.6 x 250 mm, 5 microm). The chromatographic separation was achieved by gradient elution consisting of 0.05 M formic acid (pH 3)-acetonitrile-methanol-water at a flow rate of 1.0 mL/min. The eluate was monitored using an ultraviolet (UV) detector set at 235 nm. The ratio of peak area of each analyte to IS was used for quantification of plasma samples. Nominal retention times of etoricoxib, salicylic acid, valdecoxib, ketoprofen, nimesulide, IS and celecoxib were 15.63, 17.20, 21.66, 24.95, 26.27, 30.24 and 32.22 min, respectively. The standard curve for etoricoxib, salicylic acid, valdecoxib, ketoprofen and celecoxib was linear (r2 > 0.999) in the concentration range 0.1-50 microg/mL and for nimesulide (r2 > 0.999) in the concentration range 0.5-50 microg/mL. Absolute recovery was >83% from human plasma for all the analytes and IS. The lower limit of quantification (LLOQ) of nimesulide was 0.5 microg/mL and for etoricoxib, salicylic acid, valdecoxib, ketoprofen and celecoxib the LLOQ was 0.1 microg/mL. The inter- and intra-day precisions in the measurement of QC samples, 0.1, 0.3, 15.0 and 40.0 microg/mL (for all analytes except nimesulide), were in the range 2.29-9.37% relative standard deviation (RSD) and 0.69-10.28% RSD, respectively. For nimesulide the inter- and intra-day precisions in the measurement of quality control (QC) samples, 0.5, 1.5, 15.0 and 40.0 microg/mL, were in the range 3.21-7.37% RSD and 0.97-7.06% RSD, respectively. Accuracy in the measurement of QC samples for all analytes was in the range 91.03-106.38% of the nominal values. All analytes including IS were stable in the battery of stability studies, viz. bench top, autosampler and freeze-thaw cycles. Stability of all analytes was established for 21 days at -20 degrees C. The application of the assay in an oral pharmacokinetic study in rats co-administered with celecoxib and valdecoxib is described.     

Characterization of chemical components of Periplocae Cortex and their metabolites in rats using ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry

Periplocae Cortex, named Xiang-Jia-Pi in China, has been widely used to treat autoimmune diseases, especially rheumatoid arthritis. However, the in vivo substances of Periplocae Cortex remain unknown yet. In this study, an ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry was used for profiling the chemical components and related metabolites of Periplocae Cortex. A total of 98 constituents were identified or tentatively characterized in Periplocae Cortex: 42 C21 steroidal glycosides, 10 cardiac glycosides, 23 organic acids, 4 aldehydes, 7 triterpenes, and 12 other types. Among them, 18 components were unambiguously identified by comparison with reference standards. In addition, 176 related xenobiotics (34 prototypes and 142 metabolites) were screened out and characterized in rats’ biosamples (plasma, urine, bile, and feces) after the oral administration of Periplocae Cortex. Moreover, the metabolic fate of periplocoside S-4a, a C21 steroidal glycoside, was proposed for the first time. In summary, phase II reactions (methylation, glucuronidation, and sulfation), phase I reactions (hydrolysis reactions, oxygenation, and reduction), and their combinations were the predominant metabolic reactions of Periplocae Cortex in rat. It is the first report to reveal the in vivo substances and metabolism feature of Periplocae Cortex. This study also provided meaningful information for further pharmacodynamics study of Periplocae Cortex, as well as its quality control research.     

7-位取代的甾体类化合物生物活性研究进展

7-位取代的甾体类化合物是一类具有良好生物活性的化合物,在抗炎、抗肿瘤等领域发挥着重要作用.本文以7-位取代的甾体类化合物为研究对象,按照不同的留体母核进行分类,对近年来有关7-位取代的甾体类化合物的生理活性研究进行综述,并为此类化合物的发展趋势和应用作了展望,以期为抗肿瘤药物的研发提供一定的理论基础.     

Steroidal saponins and pregnane glycosides from Smilax microphylla

Six steroidal saponins and two pregnane glycosides were isolated from the BuOH subfraction of 70% EtOH extract of Smilax microphylla C.H.Wright, among them two were new compounds (1 and 7). Pregnane glycosides were firstly isolated from the genus Smilax (Smilacaceae). Structures of the new compounds were determined on the basis of HR‐ESI‐MS, 1D and 2D NMR spectroscopic analysis. Copyright © 2012 John Wiley & Sons, Ltd.     

Study on steroidal saponins in crude and stir‐fried Fructus Tribuli by ultra‐high‐performance liquid chromatography‐mass spectrometry coupled with multivariate statistical analysis

Fructus Tribuli is a traditional Chinese medicine used clinically for many years. Crude Fructus Tribuli and stir‐fried Fructus Tribuli are recorded in the Pharmacopoeia of the People′s Republic of China. However, the differences between steroidal saponins in crude Fructus Tribuli and stir‐fried Fructus Tribuli have not been compared. In this study, ultra‐high‐performance liquid chromatography quadrupole time‐of‐flight mass spectrometry along with multivariate statistical analysis was developed to discriminate the chemical profiles and identify the steroidal saponins of crude Fructus Tribuli and stir‐fried Fructus Tribuli. Additionally, an ultra‐high‐performance liquid chromatography triple‐quadrupole mass spectrometer was used for the simultaneous quantification of nine major steroidal saponins to analyze the variations between crude Fructus Tribuli and stir‐fried Fructus Tribuli. Finally, a total of 30 steroidal saponins whose structures or contents changed significantly after processing were found and identified. The mechanism of structural transformations deduced indicated that during the stir‐frying of Fructus Tribuli, C‐22 hydroxy furostanol saponins were converted to the corresponding furostanol saponins containing C‐20‐C‐22 double bonds by dehydroxylation and deglycosylation reactions that occurred in the spirostanol saponins causing the generation of steroidal sapogenins. This study was successfully applied to the global analysis of crude Fructus Tribuli and stir‐fried Fructus Tribuli. The results of this research will be beneficial to explore the processing mechanism of Fructus Tribuli.     

Two new 14, 15-secopregnane-type steroidal glycosides from the roots of Cynanchum limprichtii

Two new steroidal glycosides 1 and 2, along with three known ones (3–5), were isolated from the 95% ethanol extract of the roots of Cynanchum limprichtii Schltr. The structure of the new compounds was elucidated as 3-O-α-L-diginopyranosyl-(1→4)-β-D-digitoxopyranosyl-(1→4)-β-D-cymaropyranosyl-(1→4)-β-D-thevetopyranosyl-14, 16:15, 20:18, 20-triepoxy-14, 15-secopregn-4, 6, 8 (14)-triene (1) and 3-O-α-L-cymaropyranosyl-(1→4)-β-D-digitoxopyranosyl- (1→4)-β-D-3-demethyl-2-deoxythevetopyranosyl-14, 16: 15, 20: 8, 20-triepoxy-14, 15-secopregn-5, 8 (14)-diene (2) on the basis of spectroscopic analysis together with acidic hydrolysis. All compounds showed cytotoxic activity against the human cancer cell line HL60, with IC₅₀ values of 55.36, 65.41, 17.88, 17.68 and 33.5 μM, respectively. While, only compound 3 showed cytotoxicity against the Caco-2 cell line, with an IC₅₀ value of 67.47 μM.     

Peculiar side-chain fission of steroidal glycosides

The characteristic novel steroidal glycosides of the 23,26-oxygenated spirostanol-type and 16,22-dicarbonyl cholestanol-type obtained in our laboratory underwent the peculiar reactions of side-chain fission between C-22 and C-23 of the steroidal skeleton by acid or alkaline hydrolysis. These reactions would be applied to the structural determination of these sorts of glycosides and suggest the biogenetic pathway of the occurrence of C-22 lactone-type glycosides.