Chemical Composition and Pharmacological Activity of Alkaloids from the Common Periwinkle Cultured in Georgia

Abstract

The common periwinkle (Vinca minor L.) is a perennial herbaceous plant used for a long time in both classical and folk medicine for the treatment of various disorders [1, 2]. The main set of biologically active substances in this plant is represented by indole alkaloids, predominantly of the eburnamine group. It was experimentally established that alkaloids of this group favorably affect the cerebral circulation, producing a more than twofold increase in the blood flow rate [3]. Experience gained with foreign preparations based on this plant such as oxibral and vincanor (vincapan, vincaton) confirmed that the common periwinkle is a valuable medicinal plant [1, 4]. In Georgia, the common periwinkle was cultivated as a medicinal plant on an experimental field of the Institute of Pharmaceutical Chemistry at the Vashla-dzhvari village near Tbilisi. The green mass yield from the experimental field was 2 – 2.5 kg m. An attempt at transferring the common periwinkle to the field of the Experimental Center of Medicinal Plants (Shiraki, East Kakhetia) was successful, leading to an increase in the alkaloid content. The total alkaloid yield reached up to 1 and 0.8%, in which the vincamine content amounted to 0.06 and 0.04%, in the blooming and fruitage stages, respectively. The purpose of this study was to refine the chemical composition of alkaloids from the common periwinkle cultivated in Georgia and check for the pharmacological identity of the vincamine base and the active alkaloid fraction extracted from herbs. The experiments were performed with an air-dry material prepared from plants collected in the blooming period (May – April) in 1997 and 1998 on the experimental field at the Institute of Pharmaceutical Chemistry (Tbilisi). The main stages of the total alkaloid extraction and the isolation of individual alkaloid fractions are indicated in the scheme. The course of the extraction process was monitored and the homogeneity of products checked by TLC. All TLC runs demonstrated spot patterns with reproducible Rf values. Pharmaceutical Chemistry Journal Vol. 35, No. 5, 2001