Phytochemical analysis- Biological properties of Heliotropium procubens from Panama

Abstract

Heliotropium (Boraginaceae) consists of approx. 300 species widespread worldwide, used widely in folk medicine (against inflammations, skin diseases etc) [1]. H. procumbens Mill. is an annual weedy herb, native in America and E to the West Indies. In the framework of our phytochemical studies on Boraginaceae plants, we report herein the chemical profile of the plant, revealing the presence of pyrrolizidine alkaloids, (LC-MS) among which several new natural products such as: helifoline and hydroxy-platynecine isomers (both saturated necine), 9-angleloyl-heliotridine (possessing a double bond in the 1,2-position -ring B), all in the forms of N-oxides and phenolic metabolites: flavonoids of luteolin, quercetin, kaempferol type and caffeic acid derivatives. All chemical structures were determined by spectral means (NMR).Antioxidant properties of methanol (ME) and water (WE) extracts were assessed via five different assays. Enzyme inhibition potential against key clinical enzymes involved in neurodegenerative diseases AChE and BChE, diabetes (α-amylase and α-glucosidase) and skin whitening (tyrosinase) were assayed. The extracts displayed considerable free radical scavenging activity against DPPH and ABTS radicals, with potential values for ME: 46.88, 68.31 and WE: 93.43 and 131.48 mg TE/g extr, respectively. H. procubens was found to harbor bioactive metabolites and hence could be served as a source of biological activities which could be further explored and exploited for potential applications.