and O.M. the hydrochlorides of these alkaloids (1C10) were prepared by reported method [10]. As shown in Physique 2, common LC-MS chromatograms for a standard solution mixture under UV (260 nm) and MS detections by electrospray ionization (ESI) MS under the positive mode demonstrated good baseline separation for all those peaks. Each peak was observed at the following retention time Mouse monoclonal to EhpB1 and quasimolecular ion peak ([M + H]+) (296), 2 (39.5 min, 282), 3 (29.7 min, 282), 4 (21.3 min, 268), 5 (13.9 min, 312), 6 (16.9 min, 314), 7 (15.9 min, 300), 8 (9.9 min, 300), 9 (8.3 min, 286), and 10 (18.8 min, 286)). These peaks were unambiguously assigned by comparison of their retention times with those of authentic specimens [2]. Open in Nandrolone propionate a separate window Physique 2 A typical LC-MS chromatogram of a standard solution mixture (each 10 g/mL) of alkaloids (1C10). (a) SIM chromatogram (positive ESI); (b) HPLC chromatogram (UV: 260 nm). Prior to analysis, extraction conditions were examined to optimize the extracts quality in association with the contents of the alkaloids (1C10). The extraction efficacies were compared for three solvent systems (methanol, 50% aqueous methanol, and water) under two different conditions (reflux for 120 min or sonication for 30 min, each twice). As shown in Table 2, reflux in methanol afforded the highest contents of the active alkaloids (1C10). Therefore, all the analytical samples were prepared by employing the method reflux in methanol for 120 min. Table 2 Extraction efficiently of alkaloids (1C10) from lotus flower. is the peak area and x is the concentration of the analyte. The detection Nandrolone propionate and quantitation limits were estimated to be 0.17C0.90 and 0.51C2.65 ng, respectively, indicating sufficient sensitivity of this method. The relative standard deviation (RSD) values were 0.25%C1.36% for intra-day and 0.39%C1.40% for inter-day assays. Accuracy was decided in recovery experiments using the methanol extract of NN-1. As shown in Table 4, recovery rates of 92.3%C105.8% were obtained, with RSD values of lower than 1.6%. Table 3 Linearities, detection and quantitation limits, and precisions for alkaloids (1C10) in lotus flower. = 7477635? 13020.99980.170.510.250.59Nornuciferine (2)= 2698708? 109411.00000.712.160.790.43= 7054297+ 2439610.99960.320.991.361.40Asimilobine (4)= 2076494? 360210.99990.702.130.630.57Pronuciferine (5)= 3522995+ 1013280.99980.732.180.951.08Armepavine (6)= 2076494? 360210.99990.320.970.681.10Norarmepavine (7)= 1998354? 152960.99990.812.470.540.73= 1595194+ 533140.99990.902.710.590.86Coclaurine (9)= 1878370+ 168380.99990.441.330.980.39Norjuziphine (10)= 1745634+ 152401.00000.882.650.640.66 Open in a separate window a Nandrolone propionate In the regression equation, is the concentration of the analyte solution (g/mL), and is the peak area of the analyte; b values are the amount of the analyte injected on-column and c precision of the analytical method were tested using the methanol extract of NN-1 (= 5). Table 4 Recoveries for alkaloids (1C10) from lotus flower. = 3). According to the protocol thus established, contents of the alkaloids (1C10) collected in two different regions (NN-1 in Thailand; NN-5 in Taiwan) were measured. The assay was found to be reproducible, precise, and readily applicable to the quality evaluation of lotus flowers extracts. As shown in Table 5, were lower than those of the flower buds (NN-1 and NN-5) (Table S1). Table 5 Contents of alkaloids (1C10) in the methanol extracts from Nandrolone propionate lotus flower. Formation from the Free Alkaloid 282.1483 [M ? C19H18NO4]+ (calcd for C18H20O2, 282.1489) in the positive ESI mode; however, a signal due to the carbamate group was not detected in the unfavorable ESI mode. Fortunately, the unfavorable ion a part of 2 could be confirmed as the.