A green and solvent-free process for preparation of high-purity (-)-borneol from leaves of Blumea balsamifera (L) DC

Abstract

Purpose: To develop a simple and low cost process for the preparation of high-purity (-)-borneol from leaves of Blumea balsamifera (L.) DC. Methods: An improved hydrodistillation (IHD) equipped with a vertical condenser tube was designed for extracting the volatiles (crude (-)-borneol) without solvent, and comparing with hydrodistillation-solvent extraction (HDSE) and simultaneous distillation and extraction (SDE). The sublimation was used to separated high-purity (-)-borneol. The purities of (-)-borneol products were quantitatively analyzed by gas chromatography (GC), and the (-)-borneol product was analyzed by optical activity and nuclear magnetic resonance (NMR), and the antimicrobial activity was evaluated. Results: The (-)-borneol content of the volatiles was 82 % in IHD, and much higher than that of HDSE (45 %) and SDE (44 %). After sublimation, the purity of separated (-)-borneol was 92 %, and the recovery was 96 %. The NMR spectral data confirmed that the product was (-)-borneol, and the specific rotation was -36.4° (20 °C, ethanol). Meanwhile, the performances of the (-)-borneol product and standard (-)-borneol were the same in antimicrobial activity. Conclusion: The work provides a green, efficient and solvent-free process for preparation of high-purity natural (-)-borneol from B. balsamifera leaves. © Pharmacotherapy Group, Faculty of Pharmacy, University of Benin, Benin City, 300001 Nigeria. All rights reserved.