Determination of the volatile constituents and total phenolic contents of some endemic Stachys taxa from Turkey

The chemical composition of the aerial parts essential oil of Stachys ocymastrum L. Briq. (Lamiaceae) growing in Sicily (Italy)

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. Several species have been used in the traditional medicine to treat stress, skin inflammations, gastrointestinal disorders, asthma, and genital tumours. In the present study the chemical composition of the essential oil from aerial parts of Stachys ocymastrum L. Briq., belonging to section Olisia, endemic of the Western Mediterranean and Greece and collected in Sicily, was analysed by GC-MS. No one report has been previously published on any European accession of this species. The result showed the presence of large quantity of the diterpenoid phytol (23.80%). Other metabolites present in high quantity were β-caryophyllene (17.95%), geranyl-α-terpinene (13.26%) and trans-chrysanthenyl acetate (9.85%). Chemical considerations with respect all the other oils of Stachys taxa, belonging to section Olisia studied so far, were carried out.

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.

The influence of ripening stage and cultivation system on the total antioxidant activity and total phenolic compounds of yellow passion fruit pulp

BACKGROUND

This work aimed to investigate the influence of both ripening stage and cultivation system on the total phenolic compounds (TPC) and total antioxidant activity (TAA) of passion fruit pulp. TPC extraction was optimized using a 2³ central composed design. The variables were fruit pulp volume, methanol volume and extraction solution volume. TPC was determined using the Folin-Ciocalteu reaction, and TAA using the ABTS radical reaction.

RESULTS

The conditions to extract TPC were 2 mL passion fruit pulp and 9 mL extraction solution containing 40% methanol:water (v/v). TPC values increased in the passion fruit pulp during ripening for both cultivation systems, ranging from 281.8 to 361.9 mg gallic acid L⁻¹ (P ≤ 0.05) for the organic pulp and from 291.0 to 338.6 mg gallic acid L⁻¹ (P ≤ 0.05) for the conventional pulp.

CONCLUSION

TPC values increased during ripening for both organic and conventional passion fruit. The same was true for TAA values for conventional passion fruit. For organic passion fruit, however, TAA values were highest at the initial ripening stages. These results suggest that antioxidant compounds exert strong influence on the initial ripening stages for organic passion fruit, when TPC still did not reach its maximum level.

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.