A new chemotype of Ocimum basilicum var. purpurascens Benth. from Madhubani district of Bihar, India and phytochemical investigations of their colchiploids

Abstract

Of the 160 species of the genus Ocimum L. (Lamiaceae), the species O. basilicum is medicinally and commercially a very significant one, as it contains a number of aromatic compounds. Various terpenes and phenols found in the species are widely used throughout the world in various ways, namely, in medicines, cosmetic materials, culinary, etc. It occurs in different climatic zones, right from the seashore to the high altitude world over. During a survey of the different aromatic compounds, especially terpenes and phenols, a new chemotype of a variety of the species, O. basilicum var. purpurascens Benth. was found in the Madhubani district which possessed three phytopharmaceutically important compounds, namely methyl cinnamate (9.61%), linalool (27.88%) and eugenol (42.67%) in leaf and methyl cinnamate (2.87%), linalool (29.35%) and eugenol (48.22%) in inflorescence detected and analyzed with the help of Gas Chromatography. The Chemotype under investigation was named Eugenol>linalool>methyl cinnamate type. Due to the importance of these three in the national economy and the lack of any effort for its genetic improvement led the above authors to carry out chromosome doubling through autopolyploidy to see augmentation of these pharmaceutically important chemicals with other terpenoids if any. Successful autopolyploids were obtained after subjecting the new chemotype understudy by colchicine treatment of the shoot apex. Phytochemical, as well, as other investigations, were made upto third polyploid generation. These polyploids achieved considerable cytogenetical normalcy and some terpenoids, such as, linalool, methyl chavicol, geraniol, αβ - terpineole and αβ - caryophyllene were observed to be in higher amounts.