Date Published: March 18, 2018
Publisher: Tabriz University of Medical Sciences
Author(s): Farshid Rezaei, Rashid Jamei, Reza Heidari.
Purpose: The aim of the present study was to investigate the chemical properties of wild Tagetes minuta L. (family Astreacea) collected from Northern Iran during the flowering period concerning the chemical combination of the essential oil along with its antioxidant properties and composition of fatty acids.
Tagetes minuta from sunflower (Asteraceae – Helenieae) family is a species native to South America but is now a widespread weed in most parts of the world.1 T. minuta is reported to contain a number of bioactive metabolites of high medicinal, industrial and nutritional value.2,3 The majority of published studies of T. minuta focused on the chemodiversity of volatile oils, flavonoids and thiophenes.4 Etheric oils are a source of bioactive and valuable molecules that are used in many fields such as aromatherapy, cosmetic, pharmaceutical, nutrition, agronomic and perfume industries.5 The essential oil compositions of T. minuta has been studied previously in Iran and other parts of the world.6-11 From these findings, it could be seen that the variation in Tagetes oil depends on several environmental as well as genetic factors.12,13 In addition, according to different activities of various bioactive compounds, these differences between components of the essential oil will be important in pharmaceutical and nutritional uses.14 All these scientific facts, make a thorough evaluation necessary of the native “Tagetes oil” at regional level. Scientific evidence suggests that vegetable oils as another important class of phytochemicals play a vital role in a healthful diet.15They provide energy and essential fatty acids (linoleic and linolenic acids), which are necessary for good health. The oils are also crucial to the absorption of the fat-soluble vitamins A, D, E, and K.15 The amount of unsaturated fats is one of the most important parameter of different edible vegetable oils.16 On the other hand, the influence of common environment and genes on the fatty acid composition of plants has been demonstrated by several researchers.17,18 Previously published investigations on Tagetes species have demonstrated strong antioxidant properties.19,20 Phenol and related compounds occur in food products, especially those of plant origin and are known to be responsible for the antioxidant activities. These secondary metabolites are the subject of increasing scientific interest because of their importance in human health.21 In recent years, a number of researchers have reported that environmental factors (soil type, sun exposure and rainfall) can widely affect phenolic compounds of the foods.21 However, since the biosynthesis of volatile compounds are affected by geographical variation and there is no report on the composition of the essential oil of T.minuta from North of Iran, also no study has been carried out previously on phenolic and fatty acid compounds of this plant grown in Iran, therefore this work was carried out; to identification and compare volatile constituents by GC-MS; to analyze the phenolic acids by HPLC and finally; to investigate quantification of fatty acids in the oil extracted of Tagetes minuta by GC which may be used as initial materials for medical purposes and use in relevant industries.
The present study demonstrates that the volatile oil of Tagetes minuta is rich in monoterpenes with two major components dihydrotagetone and spathulenol. The oil tested shows significant quantitative and qualitative variations when compared with previous reports from Iran and abroad. The differences could be possibly due to genetic variation and environmental factors. This research also revealed that the aerial parts of this aromatic plant are various sources of oily components, especially the essential ones, as well as of good natural sources of unsaturated fatty acids (such as linoleic acid). On the other hand, it was found that the native Tagetes oil is a non negligible source of phenolic compounds. Therefore, in addition to traditional uses this medicinal Plant can also be grown and utilized in Pharmaceutical and food industries.
The authors would like to express their gratitude to Scientific Research Projects Coordination Unit of Urmia University for financial support (Project Number: 996/2015/D30).
The authors declare no conflict of interest.