Volatile Constituents ofStachys obliqua L. (Lamiaceae) from Turkey

Composition and bioactivity of essential oil from Stachys macrostachya (Wend.) Briq

Stachys species belonging to Lamiaceae family have been used for medicinal purposes since ancient times. The aim of the present study was to investigate the chemical compositions and antibacterial, anti-tyrosinase activities of the essential oil of Stachys macrostachya. The essential oil was prepared by hydrodistillation method using a Clevenger-type apparatus and chemical composition was determined by gas chromatography (GC). The antibacterial activity of essential oil was performed by the disc diffusion and microdilution broth method against five Gram-positive and two Gram-negative bacteria. The tyrosinase inhibitory activity was evaluated by minor modifications of Masuda's method. According to the results of GC analyses, twenty-three compounds were identified representing 91.9% of the total volatile composition. The main compounds were germacrene D (12.2%), globulol (10.9%), α-pinene (9.7%), and valencene (7.6%). The present study showed that the tested essential oil of S. macrostachya exhibited antibacterial activity against Acinetobacter baumannii (MIC 62.50 μg/mL) and tyrosinase inhibition activity (IC50 22.86 ± 0.82 μg/mL). These results suggest that the essential oil could be exploited as a potential source of natural antimicrobial agents of this bacterium as well as tyrosinase inhibitors.

Taxonomical and Phytochemical Characterisation of 10 Stachys Taxa Recorded in the Balkan Peninsula Flora: A Review

The genus Stachys is one of the largest genera of the Lamiaceae, and it comprises about 300 species. Some species are highly polymorphic, with a number of infraspecific taxa. The aim of the present review is to summarise the available knowledge on 10 taxa belonging to the Balkan Peninsula flora (S. alpina L., S. germanica L., S. menthifolia Vis., S. obliqua Waldst. Et Kit., S. officinalis (L.) Trevis., S. palustris L., S. recta L. subsp. recta, S. recta L. subsp. subcrenata (Vis.) Briq., S. salviifolia Ten., and S. sylvatica L.) in order to enable insight into the identified biologically active substances and their possible application in intrageneric differentiation.

Phytochemical and biological studies of Stachys species in relation to chemotaxonomy: a review

The genus Stachys is comprised of about 300 species spread throughout the world, hence representing one of the largest genera of the Lamiaceae. Several Stachys species have been exploited in traditional medicine as astringent, wound-healing, anti-diarrhoeal, anti-nephritic and anti-inflammatory agents. Moreover, antimicrobial, antioxidant and cytotoxic activities of some Stachys species are documented. Iridoids, flavonoids, phenolic acids and diterpenoids are reported as secondary metabolites of different species of this genus. The aim of the present review is to summarize and to highlight the recent advances in current knowledge on Stachys species and to compile reports of chemical constituents isolated from the genus Stachys over the past decades, together with their structural features, biological activities, and structure-activity relationships. Diversity of chemical constituents is discussed in relationship with current Stachys infrageneric taxonomy, classification and relationships with systematically close genera.

Essential Oil Composition, Antimicrobial and Cytotoxic Activities of Two Endemic Stachys Cretica Subspecies (Lamiaceae) from Turkey

The chemical compositions of the water-distilled essential oil of Stachys cretica ssp. lesbiaca Rech. fil. and S. cretica ssp. trapezuntica Rech. fil. were determined by GC and GC–MS. Altogether 63 compounds were identified. The sesquiterpene hydrocarbon, germacrene D (20.3% and 12.9% respectively) was the main component identified in both oils. Furthermore, ethanol, light petroleum, dichloromethane, ethyl acetate and n-butanol extracts prepared from the aerial parts of the plants were tested for their antimicrobial activities against six bacterial strains and the yeast Candida albicans. The extracts exhibited no antibacterial activity, but the light petroleum and n-butanolic fractions showed low antifungal activities. Crude ethanolic extracts of the two subspecies were tested for their ability to inhibit the growth of HL-60 and Ishikawa human tumor cell lines. The IC50 values were 100 μg/mL for the HL-60 cell line and 200 μg/mL for the Ishikawa cell line.

GC-MS Analysis and Antimicrobial Activity of Essential Oil of Stachys Cretica Subsp. Smyrnaea

The essential oil from the aerial parts of Stachys cretica L. subsp. smyrnaea Rech. fil. (Lamiaceae), endemic to Turkey, was investigated by using GC and GC-MS. Thirty-four of 37 components, represented 99.7% of the total oil, were identified. The major components of the essential oil were trans-β-caryophyllene (51.0%), germacrene-D (32.8%), α-humulene (3.1%), δ-cadinene (2.1%) and δ-elemene (2.1%). The antimicrobial activity of the essential oil, trans-β-caryophyllene and five different extracts of the aerial parts of S. cretica L. subsp. smyrnaea were investigated by the standard disc diffusion method. The essential oil and trans-β-caryophyllene exhibited antibacterial and antifungal activities. The activity increased with increasing concentrations of the essential oil and the extracts. The essential oil showed antimicrobial activity, particularly against Pseudomonas aeruginosa and Bacillus subtilis. The extracts exhibited either moderate or no activity.

Chemical constituents of the essential oils of different stages of the growth of Stachys lavandulifolia Vahl. from Iran

The essential oil of the aerial parts of different stages of growth as pre-flowering, flowering and post flowering of Stachys lavandulifolia Vahl (Lamiaceae) were isolated by hydro distillation. The chemical composition of volatile oil was analyzed by capillary GC and GC/MS. The main components were found to be: alpha-pinene) 27.25, 25.66, 8.52%), myrcene (17.33, 9.33, 23.85%), beta-phellandrene (21.96, 37.49, 12.58%), beta-caryophylene (14.3, 8.38, 16.86%).

Identification of compounds from Etonia rosemary (Conradina etonia)

Mosquitoes transmit pathogens that result in diseases harmful to human, livestock, and wildlife hosts. Numerous measures can be used to reduce insect-borne disease risk to humans, and one approach is the use of topical repellents to prevent host-seeking arthropods from taking a blood meal. A current emphasis in the development of new repellents is that they be safe. Therefore, natural products sources are increasingly being explored. Compounds from plants of the mint family (Lamiaceae) have been demonstrated to be insect repellents. This study examines compounds from Etonia rosemary (Conradina etonia) to identify compounds for examination as insect repellents. Samples of Etonia rosemary were passively extracted with hexane, dichloromethane, and methanol and analyzed by GC/MS. This extraction method was chosen to eliminate thermal degradation of plant components that can occur during the distillation procedure. Additional headspace volatile compounds from this plant were identified using microscale purge-and-trap GC/MS. A variety of terpenes, terpenic alcohols, ketones, and aldehydes were identified in the extracts with terpenes and short-chained aldehydes detected in greatest abundance.

Essential oil analysis and antimicrobial activity of eight Stachys species from Greece

The volatile composition of eight Stachys species has been studied. The investigated taxa were St. alopecuros (L.) Bentham., St. scardica (Griseb.) Hayek, St. cretica L. ssp. cretica, St. germanica L. ssp. heldreichii (Boiss.) Hayek, St. recta L., St. spinulosa L., St. euboica Rech. and St. menthifolia Vis., growing wild in Greece. The essential oils were obtained by hydrodistillation in a modified Clevenger-type apparatus, and their analyses were performed by GC and GC-MS. Identification of the substances was made by comparison of mass spectra and retention indices with literature records. Sesquiterpene hydrocarbons were shown to be the main group of constituents of all taxa. Furthermore, the obtained essential oils were tested against the following six bacteria: Pseudomonas aeruginosa (ATCC 27853), Escherichia coli (ATCC 35210), Bacillus subtilis (ATCC 10907), Bacillus cereus (clinical isolates), Micrococcus flavus (ATCC 10240), Staphylococcus epidermidis (ATCC 2228), as well as against the following five fungi: Aspergillus niger (ATCC 6275), Penicillium ochrochloron (ATCC 9112), Epidermophyton floccosum (clinical isolates), Candida albicans (clinical isolates) and Trichophyton mentagrophytes (clinical isolates). The tested essential oils showed better activity against bacterial species than against fungi. Pseudomonas aeruginosa was the most resistant strain, as none of the essential oils was active against this strain. The essential oil of St. scardica has been proven most active against both bacteria and fungi.

A chemotaxonomic investigation of volatile constituents in Stachys subsect. Swainsonianeae (Labiatae)

The composition of the previously unknown essential oils of Stachys subsect. Swainsonianeae (Labiatae) are investigated by GC-MS analyses. The group includes the taxa Stachys ionica, St. spruneri, St. swainsonii ssp. swainsonii, St. swainsonii ssp. argolica, St. swainsonii ssp. melangavica and St. swainsonii ssp. scyronica, all endemic to Greece. Eighteen populations were analyzed, and more than two hundred components were identified. Statistical analyses of oil components separated St. ionica, due to its high amount of (E)-nerolidol, high amount of alpha-cadinol and low amount of (+)-(E)-caryophyllene. The rest of the taxa forms a coherent group where (+)-(E)-caryophyllene, delta-cadinene and partly beta-elemene, (+)-caryophyllene oxide and (+)-limonene predominate but each of them never exceeds 20% of the total. Essential oil composition reflects current taxonomy and phytogeography of the group with a somewhat isolated position for St. ionica. Similarities in morphology and essential oil composition of the St. swainsonii group and St. spruneri may be the result of extensive gene flow in the past. Evidence from volatile oil compounds that may attribute to St. swainsonii ssp. melangavica a hybrid origin from crosses between St. spruneri and St. swainsonii ssp. swainsonii/scyronica group is scarce.