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Abstract. Yarmoohammadi M, Talebi SM, Nohooji MG. 2017. Infraspecific variations in essential oil and glandular trichomes in Nepeta heliotropifolia. Biodiversitas 18: 964-970. Nepeta heliotropifolia Lam. (Labiatae) is one of the perennial medicinal and aromatic plants, naturally grows in different regions of Iran. The essential oil composition of aerial parts and also the micromorphology and distribution of foliar trichomes of N. heliotropifolia from two different regions of Iran were studied. The extracted essential oils were significantly composed of caryophyllene oxide and phytol, which were quantified by GC and identified based on their GC/MS spectra. The essential oil compositions differed greatly with habitat as well as former investigations. Phytol was quantified between 0.75-10. 29% of the total essential oil, but caryophyllene oxide was quantified between 3.90-12.17% of the total essential oil. Trichomes investigations showed that leaves bear an indumentum of glandular and non-glandular hairs. Two main kinds of glandular trichomes were observed; peltate and capitate. The numbers of capitate and peltate trichomes varied between populations. Such great differences in the essential oil composition may be attributed to chemotype creation and also an adaptation of these populations to particular habitats.

Nepeta are widely distributed worldwide and in different parts of Iran where seventy-nine species were registered. The essential oil of these aromatic plants, which accumulates and secrets by trichomes, has been used in medicinal and industrial products. In addition, these epidermal structures can be used as taxonomic traits. We examined the morphology and density of leaves trichomes of twelve Nepeta species using the light and scanning electron microscopes. Three types of indumentum are found in these species, which composed of two main types of glandular: peltate and capitate, and nonglandular; branched and unbranched trichomes. The number of the observed hairs differed between the studied species and analyses of variant test (ANOVA) showed significant variations among some of them. CA-joined plot proved that trichomes could be used as distinguishing characteristic. Therefore, we suggested that the type of indumentum and the most abundant glandular and non-glandular trichomes have high taxonomic value in species identification within the genus.

The antioxidant activities of crude extract fractions using Hexane, Chloroform, Ethyl Acetate, Butanol and Water of Clematis orientalis and Clematis ispahanica were investigated. 1,1-diphenyl-2-picryl-hydrazyl (DPPH) assay and the ferric reducing/antioxidant potential (FRAP) were used to evaluate the antioxidant capacity. The total phenolics were found to be 4.37-9.38 and 1.32-11.37 mg gallic acid equivalents (GAE)/g in different fractions for C. orientalis and C. ispahanica, respectively. The ethyl acetate fraction of C. orientalis and chloroform fraction of C. ispahanica showed the highest DPPH and FRAP activities at a concentration of 300 μg/mL. The predominant phenolic compounds identified by HPLC in C. orientalis were Resorcinol (603.5 μg/g DW) in chloroform fraction and Ellagic acid (811.7 μg/g DW) in chloroform fraction of C. ispahanica.

In the current study, the trichome density and the chemical variation of the hydrodistillated essential oils were determined along the altitudinal gradient in Nepeta sessilifolia, N. heliotropifolia, and N. fissa. The capitate glandular trichomes were predominant in all populations studied. Denser leaves indumentum was observed in high altitude populations of N. heliotropifolia, and in low altitude populations of N. sessilifolia and N. fissa. Moreover, the inter-population chemical polymorphism was detected. In the lower population of N. sessilifolia, spathulenol (14.2%) was the major compound of essential oils. This oil had great amount of oxygenated sesquiterpene (35.3%), while the oil of high altitude population had great amount of diterpenes, namely phytol (32.8%). In N. fissa, the main compound in lower population was β-caryophyllene (33.1%), whereas in the higher population it was caryophyllene oxide (21.5%). In N. heliotropifolia, 1,8-cineole (20.1%) was as the principal oil compound in low altitude population and β-caryophyllene (18.8%) in the high altitude population. We suggested that the amount of different types of monoterpenes decreases along the altitudinal gradient and the amount of oxygenated compounds increases with the elevation.

Cardiac glycosides are used for treatment of irregular heartbeats, cardiac arrhythmia and congestive heart failures. In this research, digitoxin as a cardiac glycoside was identified and isolated for the first time in the world from Adonis aestivalis and investigated for its cytotoxic activity against cervical cancer cell (HeLa) lines and human lymphocytes by MTT test. Digitoxin extracted from the aerial parts of the plant collected from west of Iran and purified by column and thin layer chromatographic techniques. The structure of isolated cardiac glycoside was identified by IR, H NMR andC NMR methods and so the presence of digitoxin was established. The half maximal inhibitory concentration values for cervical cancer and lymphocyte cells were obtained to be 5.62 and 412.94 μg/mL. The results of this study introduced the new resource of digitoxin which has considerable cytotoxic effects against HeLa cancer cells but did not damage normal human lymphocyte cells.

Nepeta is one of the largest and important genera of Lamiaceae that is found in many parts of the world as wild plants. These aromatic plants produce essential oil for various pharmaceutical and industrial products. The essential oil composition in eight taxa of Nepeta was analyzed. One natural population from each taxon was selected, and their essential oils extracted using Clevenger apparatus. Moreover, GC and GC/MS analysis methods allowed to reveal the variability in essential oil composition and profile among the studied taxa. The oxygenated monoterpenes were dominant in the oils of N. meyeri, N. mirzayanii, N. racemosa, N. binaludensis, and N. glomerulosa. Phytol was the major compound in the essential oil of N. kotschyi var. persica and N. saccharata (11.56% and 27.04%, respectively). 4aα,7α,7aβ-nepetalactone (73.89%) and 4aα,7β,7aα-nepetalactone (83.92%) were the major constituents in essential oil of N. mirzayanii and N. meyeri, respectively. 1,8-cineol was the principal constituent in the oil of N. glomerulosa var. carmanica, N. binaludensis, N. pogonosperma and N. racemosa (23.34%, 43.49%, 53.94% and 70.89%, respectively). The studied taxa were classified into four distinct groups according to the UPGMA tree with high level of bootstrapping support. Each group was characterized by special trait(s) that could be used for identification of them. Therefore, four chemotypes were separated among the studied taxa: 1,8-cineol, 4aα,7α,7aβ-nepetalactone, 4aα,7β,7aα-nepetalactone, and carvacrol. It was also noticed that the composition of essential oil was highly varied compared to previous results.

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