Chemical composition of the essential oils ofStachys schtschegleevii Sosn. andStachys balansae Boiss & Kotschy from Iran

Stachys durandiana Coss., an endemic plant of Morocco: chemical composition of its aerial parts essential oil

The genus Stachys L. (Lamiaceae) comprises more than 300 species as annual or perennial herbs or small shrubs, spread in temperate regions of Mediterranean, Asia, America, and Southern Africa and several species have been used in the traditional medicine of many countries. Section Stachys, one of nineteen sections of genus Stachys, is divided in two subsections: Sylvaticae and Circinatae. In the present study the chemical composition of the essential oil from aerial parts of Stachys durandiana Coss., endemic of Morocco, and belonging to subsection Circinatae, was analysed by GC-MS. No report has been previously published on this species. The result showed the presence of large quantity of monoterpene hydrocarbons (73.3%), being α-pinene (38.0%) β-pinene (14.8%), and limonene (11.1%) the principal constituents. Furthermore, a complete review on the chemical composition and biological properties of all the other Stachys taxa, belonging to section Stachys, studied so far, was carried out.

Essential oils of Zingiber officinale: Chemical composition, in vivo alleviation effects on TPA induced ear swelling in mice and in vitro bioactivities

Zingiber officinale (ZO) is a traditional food condiment. The essential oils of Z. officinale (ZOEOs) are known to have multiple bioactivities. In this study, gas chromatography mass spectrometer (GC-MS) analytical method was used to identify active ingredient present in ZOEOs. A total of 41 compounds were identified in ZOEOs. Major components in ZOEOs were zingiberene (19.71%), (+)-β-cedrene (12.85%), farnesene (12.17%), α-curcumene (10.18%) and β-elemene (3.54%). Experimental results of 12-O-tetradecanoylphorbol-13 acetate (TPA) induced ear swelling validation mice model showed that ZOEOs treatment has better anti-inflammatory effect compared with ibuprofen (positive control) at high concentrations. Histological and immunohistochemical analysis showed that ZOEOs significantly decreased COX-2, IL-6 and NF-κB expression in a dose dependent manner. The mRNA levels of COX-2 and NF-κB were also down regulated by the application of ZOEOs. This indicated that ZOEOs exhibited positive effects in ear skin protection. Antibacterial experimental results showed that EOZOs had anti-bacterial effects on Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. DPPH radical scavenging, A549 cell line and LNCaP cell line inhibition results indicated that ZOEOs exhibited potential antioxidant and anti-tumor properties. The findings of these study provide scientific basis on therapeutic use of ZO in food, cosmetic and pharmaceutical industries.

Chemometric Analysis Based on GC-MS Chemical Profiles of Three Stachys Species from Uzbekistan and Their Biological Activity

The chemical composition of the essential oils (EOs) of Stachys byzantina, S. hissarica and S. betoniciflora growing in Uzbekistan were determined, and their antioxidant and enzyme inhibitory activity were assessed. A gas chromatography-mass spectrometry (GC-MS) analysis revealed the presence of 143 metabolites accounting for 70.34, 76.78 and 88.63% of the total identified components of S. byzantina, S. hissarica and S. betoniciflora, respectively. Octadecanal (9.37%) was the most predominant in S. betoniciflora. However, n-butyl octadecenoate (4.92%) was the major volatile in S. byzantina. Benzaldehyde (5.01%) was present at a higher percentage in S. hissarica. A chemometric analysis revealed the ability of volatile profiling to discriminate between the studied Stachys species. The principal component analysis plot displayed a clear diversity of Stachys species where the octadecanal and benzaldehyde were the main discriminating markers. The antioxidant activity was evaluated in vitro using 2,2-diphenyl-1-picryl-hydrazyl (DPPH), 2,2-azino bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), cupric reducing antioxidant capacity (CUPRAC), ferric reducing power (FRAP), chelating and phosphomolybdenum (PBD). Moreover, the ability of the essential oils to inhibit both acetyl/butyrylcholinesterases (AChE and BChE), α-amylase, α-glucosidase and tyrosinase was assessed. The volatiles from S. hissarica exhibited the highest activity in both the ABTS (226.48 ± 1.75 mg Trolox equivalent (TE)/g oil) and FRAP (109.55 ± 3.24 mg TE/g oil) assays. However, S. betoniciflora displayed the strongest activity in the other assays (174.94 ± 0.20 mg TE/g oil for CUPRAC, 60.11 ± 0.36 mg EDTA equivalent (EDTAE)/g oil for chelating and 28.24 ± 1.00 (mmol TE/g oil) for PBD. Regarding the enzyme inhibitory activity, S. byzantina demonstrated the strongest AChE (5.64 ± 0.04 mg galantamine equivalent (GALAE)/g oil) and tyrosinase inhibitory (101.07 ± 0.60 mg kojic acid equivalent (KAE)/g) activity. The highest activity for BChE (11.18 ± 0.19 mg GALAE/g oil), amylase inhibition (0.76 ± 0.02 mmol acarbose equivalent (ACAE)/g oil) and glucosidase inhibition (24.11 ± 0.06 mmol ACAE/g oil) was observed in S. betoniciflora. These results showed that EOs of Stachys species could be used as antioxidant, hypoglycemic and skincare agents.

Chemical Composition of Magonia pubescens Essential Oils and Gamma-Radiation Effects on Its Constituents and Cytotoxic Activity in Leukemia and Breast Cancer Model

Magonia pubescens A. St.-Hil. is a Brazilian species often used in ethnopharmacology for wound and pain healing and seborrhea treatment. For the first time, essential oils (EOs) obtained from M. pubescens inflorescences were studied. The plant materials (Montes Claros, Brazil, 2018) were submitted to different gamma-radiation doses and their chemical compositions were analyzed by GC/MS and GC-FID. The cytotoxic activity of the EOs was evaluated against K562 and MDA-MB-231 cancer cell lines. A total of 30 components were identified, being 24 compounds detected for the first time in M. pubescens. The main obtained components were hotrienol (35.9 %), cis-linalool oxide (17.0 %) and trans-linalool oxide (10.2 %). The chemical composition of the EO was slightly affected by the applied radiation doses. Irradiated and non-irradiated EOs showed cytotoxic activity against both cell lines and the non-irradiated EO sample was the most active against the K562 cell lines (IC₅₀ =22.10±1.98).

A comparative study: Influence of various drying methods on essential oil components and biological properties of Stachys lavandulifolia

The genus Stachys is a member of the Lamiaceae family. These are important medicinal plants which grow all over the world and are known for their flavoring and therapeutic effects and Stachys lavandulifolia is an endemic species of Iran. To acquire high-quality essential oil (EO), drying technique was implemented which is an essential part of this process. The present study designed to evaluate the influences of different drying techniques (fresh sample, shade, sunlight, freeze-drying, microwave, and oven-drying (40, 60, and 80°C) on EO yield and composition of S. lavandulifolia. The results indicated that the maximum EO yield was obtained by the shade-drying method. The main compounds found in the fresh samples were spathulenol, myrcene, β-pinene, δ-cadinene, and α-muurolol, while spathulenol, cyrene, δ-cadinene, p-cymene, decane, α-terpinene, β-pinene, and intermedeol were found to be the dominant compounds in the dry samples. Drying techniques were found to have a significant impact on the values of the main compositions, for example, monoterpene hydrocarbons such as α-pinene, β-pinene, myrcene, and β-phellandrene were significantly reduced by microwave drying, oven-drying (40, 60, and 80°C), and sunlight-drying methods. Drying techniques increased the antioxidant activity of S. lavandulifolia EOs especially those acquired by freeze-drying with the half-maximal inhibitory concentration (IC50) values 101.8 ± 0.8 mg/ml in DPPH assay and 315.2 ± 2.1 mg/ml in decreasing power assay. As a result, shade-, sun-, and oven-drying (40°C) were found to be the most important techniques for attaining maximum yields of EO.

α-Glucosidase Inhibition and Antibacterial Activity of Secondary Metabolites from the Ecuadorian Species Clinopodium taxifolium (Kunth) Govaerts

The phytochemical investigation of both volatile and fixed metabolites of Clinopodium taxifolium (Kunth) Govaerts (Lamiaceae) was performed for the first time. It allowed the isolation and characterization of the essential oil and six known compounds: carvacrol (1), squalane (2), uvaol (3), erythrodiol (4), ursolic acid (5), and salvigenin (6). Their structures were identified and characterized by Nuclear Magnetic Resonance (NMR) and Gas Chromatography coupled to Mass Spectroscopy (GC-MS), and corroborated by literature. The essential oil of the leaves was obtained by hydrodistillation in two different periods and analyzed by GC-MS and GC coupled to Flame Ionization Detector (GC-FID). A total of 54 compounds were detected, of which 42 were identified (including trace constituents). The major constituents were carvacrol methyl ether (18.9-23.2%), carvacrol (13.8-16.3%) and, carvacryl acetate (11.4-4.8%). The antibacterial activities were determined as Minimum Inhibition Concentration (MIC) against Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris, Pseudomonas aeruginosa and Micrococcus luteus. The hexane and methanol extracts exhibited activity only against Klebsiella pneumoniae (250 and 500 μg/mL respectively), while the ethyl acetate extract was inactive. The hypoglycemic activity was evaluated by the in vitro inhibition of α-glucosidase. The ethyl acetate (EtOAc) extract showed strong inhibitory activity with IC50 = 24.88 µg/mL, however methanolic and hexanic extracts showed weak activity. As a pure compound, only ursolic acid showed a strong inhibitory activity, with IC50 = 72.71 μM.

Chemical Compositions and Aroma Evaluation of Volatile Oil from the Industrial Cultivation Medium of Enterococcus faecalis

Enterococcus faecalis is one of the major lactic acid bacterium (LAB) species colonizing the intestines of animals and humans. The characteristic odor of the volatile oils obtained from both the liquid medium after incubation (MAI) and liquid medium before incubation (MBI) in the cultivation process of E. faecalis was investigated to determine the utility of the liquid medium. In total, fifty-six and thirty-two compounds were detected in the volatile oils from the MAI (MAI oil) and MBI (MBI oil), respectively. The principle components of MAI oil were 2,5-dimethylpyrazine (19.3%), phenylacetaldehyde (19.3%), and phenylethyl alcohol (9.3%). The aroma extract dilution analysis (AEDA) method was performed using gas chromatography-olfactometry (GC-O). The total number of aroma-active compounds identified in the volatile oil from MBI and MAI was thirteen compounds; in particular, 5-methyl-2-furanmethanol, phenylacetaldehyde, and phenylethyl alcohol were the most primary aroma-active compounds in MAI oil. These results imply that the industrial cultivation medium after incubation of E. faecalis may be utilized as a source of volatile oils.

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.

Composition of the Essential Oils and Antibacterial Activities of Hymenocrater yazdianus, Stachys obtusicrena and Nepeta asterotricha Three Labiatae Herbs Growing Wild in Iran

Water-distilled essential oils from leaves of Hymenocrater yazdianus Rech.f., flowers of Stachys obtusicrena Boiss., and stems and flowers of Nepeta asterotricha Rech.f, which are endemic to Iran, were analyzed by GC and GC/MS. Fifty-five components of the leaf oil of H. yazdianus were characterized, representing 95.1% of the total components detected. The major constituents were identified as 1,8-cineole (17.6%), β-caryophyllene (13.9%), α-pinene (10.6%) and caryophyllene oxide (10.4%). Germacrene-D (37.5%) and α-bisabolol (23.5%) were the main components among the twenty constituents characterized in the flower oil of S. obtusicrena, representing 90.8% of the total components detected. Thirty-five compounds representing 93.0% of the stem oil of N. asterotrica were identified among which terpinen-4-ol (22.8%) and γ-terpinene (14.1%) were the major ones. The flower oil of the species was characterized by higher amounts of terpinen-4-ol (24.8%), 4aα, 7aβ-nepetalactone (18.2%) and 1,8-cineole (11.6%) among the thirty-three components comprising 98.5% of the total oil detected.

The antibacterial activity of the stem, leaf and flower oils of Hymenocrater yazdianus, Stachys obtusicrena and Nepeta asterotricha against seven Gram-positive and Gram-negative bacteria were determined using the MIC method. The growth inhibitory zone (mm) was also measured.

Essential oil composition of leaves of Stachys yemenensis obtained by supercritical CO₂

This article reports the composition of the essential oil from the leaves of Stachys yemenensis. The essential oil was extracted by supercritical CO₂ (90 bar; 40 °C) and its chemical composition was determined by gas chromatography and gas chromatography-mass spectrometry. The major components of the sample were α-phellandrene (13.9%), β-phellandrene (11.7%), elemol (12.0%), spathulenol (6.7%), β-eudesmol (5.0%), α-eudesmol (4.75%) and squalene (4.8%). On the exhausted matrix, deprived of the volatiles, we carried out a high-pressure (250 bar) treatment for the extraction of squalene (49.7%). The antimicrobial activity of the essential oils has been assayed by using the broth dilution method on two American Type Culture Collection (ATCC) strains, Escherichia coli ATCC 35218 and Staphylococcus aureus ATCC 43300, and two clinical strains, Candida albicans and Candida glabrata.