Quantitative analysis of camptothecin derivatives in Nothapodytes foetida using 1H-NMR method

Area of Science:

• Natural Product Chemistry
• Analytical Chemistry
• Pharmacognosy

Background:

• Nothapodytes foetida is a source of valuable camptothecin derivatives and trigonelline.
• Accurate quantification of these compounds is crucial for their pharmaceutical applications.
• Existing analytical methods like HPLC can be time-consuming and require reference standards.

Purpose of the Study:

• To develop and validate a quantitative (1)H-NMR method for determining camptothecin derivatives and trigonelline.
• To compare the efficiency of the developed (1)H-NMR method with conventional HPLC.
• To highlight the advantages of the (1)H-NMR method for analyzing Nothapodytes foetida extracts.

Main Methods:

• Quantitative analysis using (1)H-NMR spectroscopy in DMSO-d(6).
• Identification and separation of specific proton signals (H-7, H-10, H-19, H-2) for target compounds.
• Quantification using an internal standard (3,4,5-trimethoxybenzaldehyde) and intensity ratios.
• Comparison of results with High-Performance Liquid Chromatography (HPLC) data.

Main Results:

• Well-separated proton signals for camptothecin, 9-methoxycamptothecin, pumiloside, and trigonelline were observed in the delta 9.5-5.5 region.
• The (1)H-NMR method provided accurate quantification when compared to HPLC.
• The method allows direct quantification from crude extracts without the need for calibration curves or pure reference compounds.

Conclusions:

• Quantitative (1)H-NMR offers a rapid and efficient alternative for analyzing camptothecin derivatives and trigonelline in Nothapodytes foetida.
• This method simplifies the analytical process, saving significant time compared to HPLC.
• The ability to analyze crude extracts directly makes this a valuable tool for natural product research and quality control.