Determining Antiradical Capacity of Medicinal Plant Extract Individual Constituents Using Post-Column Reaction Method.

The post-column reaction method enables the evaluation of the antiradical capacity of individual components in a mixture by separating the components using HPLC and measuring stable free radical (e.g., DPPH●) scavenging that occurs after the chromatography column. The equipment typically consists of two detectors. The first records signals of the analytes leaving the column. The second records radical scavenging by the analytes, which appears as a negative band. The recorded signals are found on two separate chromatograms, which must be combined to interpret the results. In this study, a single DAD detector was used behind the post-column reactor, enabling the simultaneous recording of the analyte bands and negative signals, indicating radical scavenging. The objective of this study was to evaluate the antiradical capacity of key compounds found in two herbal raw materials used in traditional Chinese medicine. Saposhnikovia divaricata roots contain phenolic acids, chromones, and furanocoumarins. Chlorogenic acid, rosmarinic acid, and imperatorin demonstrated strong radical scavenging, while prim-O-glucoslocimifugin showed a weaker response, both in standards and in root extracts. However, scavenging was not observed for cimifugin and 4'-O-ß-D-glucosyl-5-O-methylvisamminol. Astragalus mongholicus roots contain astragalosides I-IV (triterpene saponins). None of these showed DPPH● scavenging. Furthermore, additional signals were observed, indicating the presence of unidentified radical scavenging compounds.

Leucaena leucocephala toxicity in Brazilian horses.

Leucaena leucocephala poisoning is reported in horses in different Brazilian regions. The poisoning occurred one month after the horses were introduced into paddocks invaded by the plant or after 10 days of consuming cut Leucaena administered as the only food. Affected horses showed moderate to severe hair loss on the mane and tail, orthokeratotic hyperkeratosis with marked follicular telogenization, and hyperplasia of thyroid follicular cells. Mimosin concentration in leaves (5.5 mg/g) was determined by a new HLPC-UV method which is also reported.

Assessment of Bioactive Phytochemicals and Utilization of Rosa canina Fruit Extract as a Novel Natural Antioxidant for Mayonnaise.

The oxidation of food emulsions causes rancidity, which reduces their shelf life. To prevent rancidity, synthetic antioxidants are widely used in the food industry. However, due to their potential health risks, researchers are exploring natural alternatives. This study aimed to investigate whether Rosa canina fruit extract (RCFE) could be used as a natural antioxidant to extend the shelf life of mayonnaise. Mayonnaise containing varying concentrations of RCFE [0.125% (T1), 0.25% (T2), 0.50% (T3), 0.75% (T4)] was compared to a mayonnaise control sample (C1) and a mayonnaise sample containing 0.02% BHT (C2) for 60 days of storage at 4 °C. RCFE was found to have high levels of total phenols content (52.06 ± 1.14 mg GAE g-1), total flavonoids content (26.31 ± 1.03 mg QE g-1), and free radical scavenging activity. The GC-MS analysis of RCFE revealed 39 different peaks, whereas the HPLC analysis showed the presence of 13 polyphenolic compounds in RCFE. The pH values of T2, T3, and T4 mayonnaise samples substantially declined as storage progressed; however, the reduction was less than that of C1 and C2. After 60 days, mayonnaise samples T2, T3, and T4 had greatly reduced peroxide and free fatty acid levels compared to C1 and C2. The mayonnaise enriched with RCFE (T3 and T4) had the most potent antioxidative ability and the lowest value of lipid hydroperoxides (peroxide value, POV) and the lowest value of thiobarbituric-acid-reactive substances (TBARS). The sensory evaluation revealed that the T3 sample exhibited the highest overall acceptability. In conclusion, this study recommends that RCFE could be used as a natural preservative to enhance the shelf life of functional foods.

Pharmacokinetics of the Anti-Inflammatory Drug Meloxicam after Single 1.5 mg/kg Intramuscular Administration to Undulate Skates (Raja undulata).

The therapy database currently used in elasmobranchs is still mostly based on empirical data, and there are few efficacy and safety studies supporting clinical practice. In this study, meloxicam pharmacokinetics (PK) were evaluated after a single 1.5 mg/kg IM administration to a group of seven clinically healthy adult undulate skates (Raja undulata Lacepède, 1802). Blood samples were collected before administration and at 15, 30, 60 and 90 min and 2, 4, 8, 12, 24 and 48 h after the IM injection. The meloxicam concentrations in plasma were determined using high-performance liquid chromatography, and PK parameters were calculated using a non-compartmental model approach. The mean ± SEM values of the main PK values were 1.84 ± 0.31 µg/mL for peak plasma concentration, 1.5 ± 0.24 h for time to maximum plasma concentration, 11.43 ± 2.04 h·µg/mL for area under the plasma concentration vs. time curve, 3.55 ± 0.65 h for elimination half-life, and 5.37 ± 0.94 h for mean residency time. No adverse reactions were detected. The relatively high plasma concentration and short time to maximum plasma concentration suggest that meloxicam could turn into an efficient analgesic and anti-inflammatory candidate drug to be used in skates. Further efficacy, pharmacodynamic, and multiple-dose studies with meloxicam are needed in elasmobranchs.

On-column nitrosation of amines observed in liquid chromatography impurity separations employing ammonium hydroxide and acetonitrile as mobile phase.

The availability of high performance liquid chromatography (HPLC) columns capable of operation at pH values up to 12 has allowed a greater selectivity space to be explored for method development in pharmaceutical analysis. Ammonium hydroxide is of particular value in the mobile phase because it is compatible with direct interfacing to electrospray mass spectrometers. This paper reports an unexpected N-nitrosation reaction that occurs with analytes containing primary and secondary amines when ammonium hydroxide is used to achieve the high pH and acetonitrile is used as the organic modifier. The nitrosation reaction has generality. It has been observed on multiple columns from different vendors and with multiple amine-containing analytes. Ammonia was established to be the source of the nitroso nitrogen. The stainless steel column frit and metal ablated from the frit have been shown to be the sites of the reactions. The process is initiated by removal of the chromium oxide protective film from the stainless steel by acetonitrile. It is hypothesized that the highly active, freshly exposed metals catalyze room temperature oxidation of ammonia to NO but that the actual nitrosating agent is likely N(2)O(3).

Content Determination of Gallic Acid in Tea Pigment Injection by RP - HPLC / 中国药房

OBJECTIVE: To develop a method for the determination of gallic acid in tea pigment injection. METHODS: RP HLPC method was adopted in which the separation of gallic acid was performed on C18 chromatographic column with a column temperature of 20℃; the mobile phase was composed of acetic acid - McOH - DMF - H2O(2 : 8 : 30 : 160) with a flow rate of 0.5ml/ mm and detection wavelength of 280nm .RESULTS: The linear range of gallic acid was 8.4-92.4?g/ ml( r = 0.9 997),the average recovery rate was 99.13% (RSD = 1.55%) .CONCLUSION: The method developed in the present study is of high specificity .sensitivity .precision,recovery and reproducibility and it can provide a basis for the formulation of quality control method for tea pigment injection.

Bioequiavailability of Ampicillin and Probenecid Capsules in Human Body / 中国药房

0.05) . CONCLUSION: Ampicillin and probenecid capsules are of bioe-quiavailability.

Content determination of Rutin in Hibiscus mutabilis L by HLPC / 重庆医科大学学报

Objective; To establish a method for content determinate of Rutin in H ibiscus mutabilis L by RT- HLPC. Methods; The chromatographic conditions were as follows; Column; Ubondpak C18; the column temperature was 25℃and the detection wavelength was 370nm;Mobil phase consisted of 0.02mol/L KH2PO4 solution cotaining 1.0% glacial acetic acid -methanol (73:27, v:v). The flow rate was 1.0ml/min. SPD -2ASUV detector was used. The standard sample was used as control. Results; Good linearity was obtained for Rutin and other components in the range of (0.5-5) ?g/20?l. Peak area was favorable liner between the concentration of Rutin in range . The regression equation was Y =0.0001X +0. 1208,correlation coefficient r = 99.8% ,The recovery rate was 99. 88% , RSD was 1. 54% (n = 5 ). Conclusion; The method is convenient, precise, resulting in high separate efficacy, and suited for the content determination of Rutin in H ibiscus mutabilis L.