NMR-based stability evaluation of (E)-1-(3',4'-dimethoxyphenyl)butadiene (DMPBD) from Zingiber cassumunar Roxb. rhizome.

INTRODUCTION: The active compound (E)-1-(3',4'-dimethoxyphenyl)butadiene (DMPBD) isolated from the rhizomes of Zingiber cassumunar Roxb. has potent anti-inflammatory and anticancer activities. Although DMPBD is one of the promising drug candidates for phytomedicine, its limited stability impedes its widespread use. For the development of new drugs, the assessment of their chemical stability is essential, ensuring they maintain their properties within specified limits throughout the period from production until use. OBJECTIVE: In the present study, we aimed to evaluate the stability of DMPBD under various conditions, including different solvents, temperatures, and lighting conditions, to identify the factors affecting stability and optimize the storage and handling conditions. METHODOLOGY: DMPBD samples subjected to the different conditions tested were monitored by quantitative 1H NMR (qHNMR), using an internal standard for the determination of the absolute quantity of DMPBD as a function of time and the changes thereof within 1 month. RESULTS: Significant decomposition of DMPBD was observed in chloroform-d1, whereas its content remained constant in methanol-d4. The content of DMPBD was maintained upon storage at temperatures below 4°C, both as methanolic solution and in the crude extract. Exposure to light had a slight negative impact on its contents. Some degradation products could be identified as resulting from O2-induced cleavage of the diene moiety. CONCLUSIONS: For pharmacological/therapeutic applications, DMPBD should be stored in the form of the crude extract or as a purified material in methanolic solution. Ideally, the storage temperature should be below 4°C and O2 should be excluded.

Simultaneous HPLC analysis of crebanine, dicentrine, stephanine and tetrahydropalmatine in Stephania venosa

ABSTRACT Stephania venosa (Blume) Spreng., Menispermaceae, has been traditionally used as tonic drug and treatment of various diseases in South East Asian countries. In order to evaluate the quality and standardization of S. venosa roots, the HPLC method for quantification of the content of major components in S. venosa was developed and validated. The chromatographic separation was performed on a Hypersil BDS C18 column using gradient system of 100 mM ammonium acetate in water and methanol with flow rate 1 ml/min. Detection wavelength was set at 210 nm for tetrahydropalmatine, 280 nm for dicentrine and crebanine, and 270 nm for stephanine. The validated method showed good sensitivity, linearity, precision, and accuracy. The suitable solvent that yielded highest alkaloids contents from the matrix was optimized. S. venosa samples collected from various locations were analyzed. The present study provided comprehensive overview of major components in S. venosa. A remarkable variation in the accumulation of alkaloids in each population and the between individual in the same population could be observed. Our results showed the heterogeneity of S. venosa in Thailand which would need a further study for species delimitations.