@article {1152, title = {Development and Validation of Stability Indicating HPLC Method for Determination of Caffeic Acid, Vitexin and Rosmarinic Acid in Thunbergia laurifolia Leaf Extract}, journal = {Pharmacognosy Journal}, volume = {12}, year = {2020}, month = {May 2020}, pages = {611-618}, type = {Research Article}, chapter = {611}, abstract = {

Thunbergia laurifolia has been a popular herb used in Thai traditional medicine for detoxification and as antipyretic. It contains rosmarinic acid (RA), caffeic acid (CA) and vitexin as major compounds. In order to control the herbal quality, the stability indicating high-performance liquid chromatography (HPLC) was developed and validated. The stability study of compounds in T. laurifolia leaf extract was investigated. The chromatographic separation was performed using a reversed-phase C18 column and mobile phase consisted of 0.5\% acetic acid and methanol using a gradient elution with 1.0 mL/min flow rate. The detection wavelength was set at 330 nm. The method was validated for its linearity, precision, accuracy, limit of detection and limit of quantitation. Forced degradation of three compounds in extract showed that they were stable in oxidative condition, but highly labile under alkaline hydrolytic conditions. All three compounds in T. laurifolia leaf extract were stable at room temperature at least 3 months while a remarkable decrease of RA, vitexin and CA in the extract were found in accelerated condition. This finding could be applied for predicting the storage recommendation and expiry of T. laurifolia extract and its related pharmaceutical products.

}, keywords = {Force degradation, Phenolic compound, Phytochemical screening, Stabilityindicating method}, doi = {10.5530/pj.2020.12.91 }, author = {Nanthakarn Woottisin and Sumet Kongkiatpaiboon and Sophida Sukprasert and Korbtham Sathirakul} } @article {1554, title = {Acetylcholinesterase inhibitory activity of didehydrostemofoline, stemofoline alkaloids and extracts from Stemona collinsiae Craib roots}, journal = {Pharmacognosy Journal}, volume = {5}, year = {2013}, pages = {56-59}, type = {Original Article}, abstract = {

Introduction: Acetylcholinesterase (AChE) inhibition is one of insect toxicity mechanisms found in many plants. Stemona collinsiae Craib, a traditional insecticidal plant, has been of interest for its AChE inhibitory activity. Methods: Powdered roots of S. collinsiae were successively extracted with hexane, dichloromethane, and methanol. The contents of major active insecticidal components, didehydrostemofoline and stemofoline alkaloids, were analyzed by HPLC. Anti-AChE activity was evaluated using Ellman\’s colorimetric method and TLC-bioautography. Results: The contents of didehydrostemofoline and stemofoline alkaloids in the hexane, dichloromethane, and methanol extracts were 3.59 and 0.18, 40.78 and 0.74, and 1.43 and 0.09\% w/w, respectively. TLC fingerprints of each extract showed major spots of didehydrostemofoline and stemofoline of which TLC bioassays indicated active AChE inhibitory activity. IC50 values on anti-AChE activities of hexane, dichloromethane and methanol extracts were 126.72, 73.78, and \>1000 mg/ml, respectively while those of didehydrostemofoline, stemofoline, and standard galanthamine were 131.3, 102.1, and 1.30 mM, respectively. Conclusion: The AChE inhibitory activity of hexane, dichloromethane and methanol extracts from S. collinsiae roots and their major alkaloids, didehydrostemofoline and stemofoline, were determined. The data support the traditional utilization of this plant as a natural insecticide.

Key words: Acetylcholinesterase inhibition, Didehydrostemofoline, Stemofoline, Stemona collinsiae, Stemonaceae.

}, keywords = {Acetylcholinesterase inhibition, Didehydrostemofoline, Stemofoline, Stemona collinsiae, Stemonaceae}, author = {Sumet Kongkiatpaiboon and Piyanuch Rojsanga, and Virote Pattarajinda, and Wandee Gritsanapan} }