The genus Anthemis L. of Asteraceae (Compositae) is represented in the Flora of Turkey by 81 taxa belonging to 51 species, 29 of which are endemic to Turkey. One of the endemic species is A. dipsacea Bornm. A. pectinata Boiss.& Reuter var. pectinata and A. dipsacea are distributed in western regions of Turkey. A. pseudocotula Boiss. grows wild in the western, eastern, and southern regions of Turkey. A detailed botanical description of the studied three species is presented in Flora of Turkey [1].

All of these Anthemis species are called as “Papatya” in Turkey, and infusions of A. pseudocotula are used in Turkish traditional medicine especially for hemorrhoid [2]. Papatya is a common name given to plants whose flowers resemble those of Roman and German chamomile. Many Anthemis spp. are used as herbal tea and for food flavoring, as well as cosmetics and in the pharmaceutical industry [35]. Their extracts, tinctures, salves, and tisanes are widely used as antispasmodic, anti-inflammatory, and antibacterial in Europe. The occurrence of sesquiterpene lactones, flavonoids, and essential oils in various Anthemis species has been reported in previous works [612].

To the best of our knowledge, there is no published report on the phytochemical composition and antimicrobial activity of A. dipsacea, A. pectinata var. pectinata, and A. pseudocotula essential oils. Therefore, we focused our study on the composition of the oils using GC and GC-MS analysis; antimicrobial activity was determined using the agar disc diffusion method.

The results of GC/MS analysis of essential oils of A. dipsacea, A. pectinata var. pectinata and A. pseudocotula obtained by hydrodistillation are shown in Table 1. Eighty-four components representing 88.8% A. pseudocotula essential oil, 75 compounds representing 85.3% A. pectinata var. pectinata essential oil, and 71 compounds representing 84.1% A. pseudocotula essential oil were characterized.

Table 1 Essential Oil Compositions of A. dipsacea, A. pectinata var. pectinata, and A. pseudocotula, %

Although the Anthemideae is one of the chemically most investigated tribes of Asteraceae, according to literature only the essential oils of A. montana L. ssp. carpatica [6], A. carpatica Willd. [13], A. nobilis L.[14], A. tinctoria L. [15], A. melampodina auct. Non Delili [16], A. xylopoda O. Schwarz [17], A. ruthenica M.B. and A. arvensis L. [18, 22], A. cretica L. ssp. leucanthemoides (Boiss.) Grierson [19], A. altissima L. var. altissima [20], A. altissima L. [21] A. arvensis L. [22], A. aciphylla Boiss. var. discoidea Boiss. [23], A. chia L., A. tomentosa L., A. auriculata Boiss., A. weneri L. ssp. weneri Stoj.&Acht., A. altissima L., A. melanolepis Boiss., A. tinctoria L. var. parnassica and A. cotula L. [24], A. triumfetti (L.) DC. [25], A. hyalina DC. [26], and A. wiedemaniana Fish. Et. Mey. [27] have been studied so far.

To the best of our knowledge, no report exists on the essential oil compositions of A. dipsacea, A. pectinata var. pectinata, and A. pseudocotula. According to our results, the common main constituents of the essential oil from aerial parts of A. dipsacea were characterized by a high percentage of fatty acid [hexadecanoic acid (13.5%)], followed by sesquiterpene hydrocarbons [germacrene D (10.2%) and β-caryophyllene (5.6%)]. Fatty acid [hexadecanoic acid (9.5%)] and oxygenated monoterpenes [linalool (8.9%) and 1,8-cineole (7.5%)] were found to be the main components in the essential oil from the aerial parts A. pseudocotula. Fatty acids (hexadecanoic or palmitic) were also observed to be the major constituents in previously studied essential oils originating from A. altissima, A. ruthenica, and A. arvensis [21, 22].

The essential oil from the aerial parts of A. pectinata var. pectinata was characterized by a high percentage of santolinatriene (49.5%). With such a high percentage, this oil could be a good source of santolinatriene, since this compound is rarely encountered in essential oils. The monoterpene hydrocarbon (santolinatriene) was also found to be the major constituent in previously studied essential oil of A. melampodina [16]. It was first isolated from Santolina chamaecyparissus L. [28].

Results from the antimicrobial screening tests are shown in Table 2. As is clearly seen in Table 2, the essential oils of A. dipsacea, A. pectinata var. pectinata, and A. pseudocotula inhibited the growth of four out of eight microorganisms but had no effect on the growth of Enterobacter cloacae ATCC 13047, Enterococcus faecalis ATCC 29212, Staphylococcus epidermidis ATCC 12228, and Salmonella thyphimurium CCM 5445. Staphylococus aureus ATCC 6538P, Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 11230, and Escherichia coli ATCC 22998 were inhibited by the essential oils of A. dipsacea, A. pectinata, and A. pseudocotula at a concentration of 20 μL/disc when compared with standard antibiotics such as ceftazidime (CF20), sulbactam/ampicilin (SAM20), and nystatin (NS20) used as positive controls. A comparison of these findings with the control antibiotics CF20 and SAM20 showed that these essential oils have strong antibacterial activity against Staphylococus aureus ATCC 6538P, Escherichia coli ATCC 11230, Pseudomonas aeruginosa ATCC 27853, and Escherichia coli ATCC 29998. The oil showed activity similar to that of SAM20 against Escherichia coli ATCC 11230 and Escherichia coli ATCC 22998. However, its antibacterial effects were moderate against the remaining four bacteria. The essential oils of A. dipsacee, A. pectinata var. pectinata, and A. pseudocotula were ineffective against Candida albicans ATCC 10239.

Table 2 Antimicrobial Activity of Essential Oils of A. dipsacea, A. pectinata var. pectinata, and A. pseudocotula

Hexadecanoic acid (palmitic acid) is known to be a potential antibacterial agent [29]. Previous studies showed that linalool and 1,8-cineole are well-known antimicrobial compounds isolated from different plant species [3034]. The essential oil of A. pseudocotula showed stronger antibacterial activity than the other oils.This activity may be attributed to the presence of higher concentrations of linalool (8.9%) and 1,8-cineole (7.5%) in this oil than in the other oils.