Toward a More Sustainable Sample Preparation in Phytochemistry: Case Studies in Four Subclasses of Alkaloids.
Lucas Apolinário Chibli, Bruna Ribeiro de Lima, Ariadne Magalhães Carneiro, Harley Cardoso Figueiró, Serhat Sezai Cicek, Verena Spiegler, Cristiano Soleo Funari
Journal of natural products March 22, 2024 DOI: 10.1021/acs.jnatprod.3c01048 via PubMed
Summary
AI-generated from the abstractAlkaloid extraction traditionally relies on hazardous chemicals like HCl and CH₂Cl₂. This work tested whether that practice is justified by superior recovery. In three laboratories, alkaloids harmine, boldine, vincamine, and mescaline were extracted from four medicinal plants. Replacing HCl with citric acid maintained or improved extraction performance. Ethyl acetate could fully replace CH₂Cl₂ in three of four cases and partially in the fourth without loss. The alternative solvents tert-amyl methyl ether and n-butyl acetate also enhanced alkaloid extraction. These findings suggest natural products laboratories can adopt greener solvents and processes, aligning with current pharmaceutical industry practices.
Study at a glance
| Characteristics | Experimental study Peer reviewed |
|---|---|
| Population | Alkaloids harmine, boldine, vincamine, and mescaline extracted from Banisteriopsis caapi, Peumus boldus, Vinca minor, and Trichocereus macrogonus var. pachanoi |
| Intervention | TAME |
| Keywords | Sustainable chemistry Natural compounds Plant extracts Green extraction Medicinal plants |
| Citations | 4 |
| Key finding | Citric acid can replace HCl, and ethyl acetate can replace CH₂Cl₂ in alkaloid extraction without harming efficiency, with alternative solvents TAME and BuOAc further enhancing extraction. |
Abstract
The fact that alkaloids are bases has been the most explored chemical feature of their extraction and purification procedures. The main drawback of these procedures is that they employ undesirable chemicals, with HCl and CH2Cl2 probably being the most commonly employed chemicals in their subsequent steps. This work tested the hypothesis that advantages in recovery efficiency support this common practice. Experiments were conducted in three laboratories, monitoring the alkaloids harmine (1), boldine (2), vincamine (3), and mescaline (4) extracted from Banisteriopsis caapi, Peumus boldus, Vinca minor, and Trichocereus macrogonus var. pachanoi, respectively. The research demonstrated that HCl could be replaced with citric acid (CA) without loss or even better extraction performance. The recommended EtOAc could completely replace CH2Cl2 in three out of four study cases and partially in the fourth case without harming the extraction efficiency. In addition, the alternative solvents tert-amyl methyl ether (TAME) and n-butyl acetate (BuOAc) could enhance the extraction of alkaloids. These results might incentivize natural products laboratories to consider sustainability more routinely, thus being closer to current practices in the pharmaceutical industry, which has been replacing solvents and processes with greener ones.