Integrated Extraction Optimization and HPLC-based Quality Evaluation of Thiophenes from Tagetes erecta Roots

Area of Science:

• Phytochemistry
• Natural Product Chemistry
• Pharmacognosy

Background:

• Tagetes erecta flowers are known for lutein, but roots contain unique, bioactive thiophenes.
• Thiophenes from T. erecta roots show potential for benign prostatic hyperplasia treatment.
• No optimized extraction or quality control methods exist for thiophene-rich T. erecta roots.

Purpose of the Study:

• To develop an optimized extraction strategy for thiophene-rich Tagetes erecta roots.
• To ensure chemical consistency using validated HPLC quantification and chromatographic fingerprint analysis.
• To provide a basis for process development and quality control of T. erecta root thiophenes.

Main Methods:

• Isolation and structural confirmation of three major thiophenes: 5-(4-hydroxybut-1-ynyl)-2,2'-bithiophene (1), 5-(4-acetoxybut-1-ynyl)-2,2'-bithiophene (2), and 5-(3-buten-1-ynyl)-2,2'-bithiophene (3).
• Optimization of extraction variables including solvent, plant part, method, sample amount, and time.
• Validated High-Performance Liquid Chromatography with Photodiode Array detection (HPLC-PDA) for quantification using purified standards.
• Chromatographic fingerprint similarity analysis to assess chemical consistency.

Main Results:

• Ultrasonic extraction using 95% ethanol for 2 hours with 5g of root powder yielded optimal results.
• The validated HPLC method demonstrated excellent linearity (R² > 0.999), precision (RSD < 1%), and recovery (93.20%-105.24%).
• Chromatographic fingerprint analysis of 13 common peaks showed high similarity (0.984-1.000), indicating stable chemical profiles.

Conclusions:

• A reliable and validated workflow for extracting and analyzing thiophenes from Tagetes erecta roots has been established.
• The study confirms the significant bioactivity and pharmaceutical potential of root-derived thiophenes.
• This research provides a practical foundation for the future standardization and quality control of thiophene-rich Tagetes erecta root extracts.