Toward a More Sustainable Sample Preparation in Phytochemistry: Case Studies in Four Subclasses of Alkaloids.

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.

Antinociceptive and anti-inflammatory activities of the sesame oil and sesamin.

Sesame oil is widely consumed as nutritious food, cooking oil, and in pharmaceuticals and food. In this study, the antinociceptive and anti-inflammatory properties of the sesame oil and sesamin were investigated. The sesame oil and sesamin reduced the number of abdominal contortions at the doses 100, 200, or 400 mg/kg. The first and second phases of the time paw licking were inhibited by sesame oil and sesamin (100, 200, or 400 mg/kg). After 90 min of treatment, sesame oil and sesamin increased the reaction time on a hot plate (200 or 400 mg/kg). Considering the tail-immersion assay, the sesame oil and sesamin produced significant effect after 60 min at the doses of 100, 200, or 400 mg/kg. After 4 h of application of the carrageenan, the sesame oil and sesamin were effective against the paw edema. The exudate volume and leucocyte migration were also reduced by sesame oil and sesamin. These results suggest that sesamin is one of the active compounds found in sesame oil and justify the antinociceptive and anti-inflammatory properties of this product.