Air-dried Aerial Parts Research Articles

A Comparison between Bulgarian Tanacetum parthenium Essential Oil from Two Different Locations.

Tanacetum parthenium L. (Asteraceae) is a perennial herbaceous plant with a long-standing historical use in traditional medicine. Recently Tanacetum parthenium L. essential oil has been associated with a promising potential for future applications in the pharmaceutical industry, in the cosmetics industry, and in agriculture. Investigations on the essential oil (EO) have indicated antimicrobial, antioxidant, and repellent activity. The present study aimed to evaluate the chemical composition of Bulgarian T. parthenium essential oil from two different regions, to compare the results to those reported previously in the literature, and to point out some of its future applications. The essential oils of the air-dried flowering aerial parts were obtained by hydrodistillation using a Clevenger-type apparatus. The chemical composition was evaluated using gas chromatography with mass spectrometry (GC-MS). It was established that the oxygenated monoterpenes were the predominant terpene class, followed by the monoterpene hydrocarbons. Significant qualitative and quantitative differences between both samples were revealed. Camphor (50.90%), camphene (16.12%), and bornyl acetate (6.05%) were the major constituents in the feverfew EO from the western Rhodope Mountains, while in the EO from the central Balkan mountains camphor (45.54%), trans-chrysanthenyl acetate (13.87%), and camphene (13.03%) were the most abundant components.

Chemical Composition and Antimicrobial Activity against the Listeria monocytogenes of Essential Oils from Seven Salvia Species.

In recent years, essential oils (EOs) have received interest due to their antibacterial properties. Accordingly, the present study aimed to investigate the effectiveness of the EOs obtained from seven species of Salvia on three strains of Listeria monocytogenes (two serotyped wild strains and one ATCC strain), a bacterium able to contaminate food products and cause foodborne disease in humans. The Salvia species analysed in the present study were cultivated at the Botanic Garden and Museum of the University of Pisa, and their air-dried aerial parts were subjected to hydrodistillation using a Clevenger apparatus. The obtained EOs were analysed via gas chromatography coupled with mass spectrometry for the evaluation of their chemical composition, and they were tested for their inhibitory and bactericidal activities by means of MIC and MBC. The tested Eos showed promising results, and the best outcomes were reached by S. chamaedryoides EO, showing an MIC of 1:256 and an MBC of 1:64. The predominant compounds of this EO were the sesquiterpenes caryophyllene oxide and β-caryophyllene, together with the monoterpenes bornyl acetate and borneol. These results suggest that these EOs may possibly be used in the food industry as preservatives of natural origins.

Antidepressant polyprenylated acylphloroglucinols from Hypericum ascyron.

Phytochemical investigation on the 90% EtOH extract of the air-dried aerial parts of Hypericum ascyron resulted in the isolation of three new polycyclic polyprenylated derivatives ascyronines A-C (1-3). Structural elucidation of all the compounds was performed by spectral methods such as 1D and 2D (1H-1H COSY, HMQC, and HMBC) NMR spectroscopy. All the polycyclic polyprenylated acylphloroglucinols were evaluated for their antidepressant activity by inhibiting the reuptake of tritiated serotonin ([3H]-5-HT) and noradrenalinet ([3H]-NE) in rat brain synaptosomes. Compounds 2 and 3 exhibited weak antidepressant activities in the [3H]-5-HT mode.

Phytochemical Analysis of the Aerial Part of Golden Dock (<i>Rumex Maritimus</i> L.)

Introduction. Golden dock (Rumex maritimus L., Polygonaceae) is used as a medicinal and food plant in Asian countries. The plant contains phytochemicals of various classes: flavonoids, tannins, anthraquinones etc. Plant extracts exhibit antibacterial, antioxidant, anti-inflammatory, astringent activity, and have antidiabetic potential. The plant is annual, and most of the biologically active substances accumulate in its aboveground organs. An important problem is the standardization of Rumex maritimus and the development of regulatory documentation for its the introduction to medical practice.Aim. To conduct phytochemical analysis of the aerial part of golden dock.Materials and methods. Air-dried aerial part of Rumex maritimus collected at flowering and beginning of fruiting stage, as well as individual above-ground organs (leaves, flowers, fruits, stems), were used for obtaining the extracts. Qualitative analysis of the extracts was carried out using reverse phase HPLC. The relative content of the components in the mixture was calculated by the method of simple normalization. Total content of free anthraquinones and anthraglycosides in terms of chrysophanic acid was determined using spectrophotometric method after acid hydrolysis. Total tannin content was calculated by titrimetric method.Results and discussion. Flavonoids isoquercetin and avicularin were first discovered in the aerial part of Rumex maritimus. The dominant component of the plant is rutin. Chrysophanol predominates among anthraquinones. The highest concentration of anthraquinones (2.80 ± 0.04 %) was found in flowers. Tannins accumulate mainly in leaves (9.97 ± 0.02 %). A significant amount of tannins (6.60 ± 0.03 %) and anthracene derivatives (1.96 ± 0.03 %) is contained in the whole aerial part.Conclusion. Phytochemical analysis of the aerial part of Rumex maritimus showed the presence of a significant amount of anthraquinones. As a plant raw material it is proposed to use the herb of Rumex maritimus. Standardization is recommended for anthraquinones in terms of chrysophanic acid (at least 1.5 %).

Exploring Echinops polyceras Boiss. from Jordan: Essential Oil Composition, COX, Protein Denaturation Inhibitory Power and Antimicrobial Activity of the Alcoholic Extract.

In this article, we present the first detailed analysis of the hydro-distilled essential oil (HDEO) of the inflorescence heads of Echinops polyceras Boiss. (Asteraceae) from the flora of Jordan, offering observations at different growth (pre-flowering, full-flowering and post-flowering) stages. Additionally, we investigated the methanolic extract obtained from the aerial parts of the plant material at the full flowering stage in order to determine its inhibitory activity in terms of COX and protein denaturation and evaluate its antimicrobial effects against S. aureus (Gram-positive) and E. coli (Gram-negative) bacteria. Performing GC/MS analysis of HDEO, obtained from the fresh inflorescence heads at the different growth stages, resulted in the identification of 192 constituents. The main class of compounds detected in these three stages comprised aliphatic hydrocarbons and their derivatives, which amounted to 50.04% (pre-flower), 40.28% (full-flower) and 41.34% (post-flower) of the total composition. The oils also contained appreciable amounts of oxygenated terpenoids, primarily sesquiterpenoids and diterpenoids. The pre-flowering stage was dominated by (2E)-hexenal (8.03%) in addition to the oxygenated diterpene (6E,10E)-pseudo phytol (7.54%). The full-flowering stage primarily contained (6E,10E)-pseudo phytol (7.84%), β-bisabolene (7.53%, SH) and the diterpene hydrocarbon dolabradiene (5.50%). The major constituents detected in the HDEO obtained at the post-flowering stage included the oxygenated sesquiterpenoid intermedeol (5.53%), the sesquiterpene hydrocarbon (E)-caryophyllene (5.01%) and (6E,10E)-pseudo phytol (4.47%). The methanolic extract obtained from air-dried aerial parts of E. polyceras displayed more COX-2 inhibition than COX-1 inhibition at a concentration level of 200 µg/mL. The extract exhibited a capacity to inhibit protein denaturation that was comparable with respect to the activity of diclofenac sodium and displayed moderate levels of antimicrobial activity against both bacterial species. The current results demonstrate the need to perform further detailed phytochemical investigations to isolate and characterize active constituents.

Cytotoxic ent-Kaurane Diterpenoids from Rabdosia Rubescens.

One new (1) and 11 reported ent-kaurane diterpenoids (2-12) were received from the ethanol extract of the air-dried aerial parts of Rabdosia rubescens collected in Jiyuan. Their structures were determined in accordance with high resolution electrospray ionization mass spectroscopy, one dimensional (1D) and two-dimensional (2D) NMR spectroscopy and the data published in the literature. The cytotoxic activity of these isolated compounds was assessed against SMMC-7721, A-549, H-1299 and SW-480 cancer cell lines. Compounds 2-6 revealed significant cytotoxic activity on lung cancer cell lines A549 with IC50 values from 6.2 to 28.1 μM. Analysis of structure-activity relationship of these tested compounds indicated the carbonyl at C-15 and hydroxy at C-1 together could be crucial groups for inhibiting lung cancer cell lines A549 proliferation.

The hypothesis of tautomeric equilibrium between epimers in ciquitins A and B

Recently, ciquitins A and B isolated from the powdered and defatted airdried aerial parts of Leucophyllum ambiguum were reported as a mixture of conformers in a solution at room temperature. Considering the existence of a hemiacetal hydroxyl fragment in the ciquitins A and B, they are more likely to exist in the form of epimer rather than the mixture of conformers. To confirm this hypothesis, the NMR calculations of two epimers at C-9 (1-a and 1-b) were performed and the results matched well with experimental NMR data of mixtures (1). Moreover, a brief discussion on the reason for this hypothesis was also presented.

Evaluating the in vitro Cytotoxicity of Thymus vulgaris Essential Oil on MCF-7 and HeLa Cancer Cell Lines

Thyme essential oil (TEO) was extracted from dried leaves of Thymus vulgaris. The air-dried aerial parts of the plant produced 1.0% yield of TEO. The detection of this essential oil’s compounds was performed by GC-MASS. The cytotoxic activity of TEO was evaluated against two human cancer cell lines, namely HeLa (human epithelial cervical cancer) and MCF-7 (human breast carcinoma). Cells grown in 96 multi-well plates were treated with six concentrations of EO (6.25, 12.5, 25, 50, 100, 200 ppm) and incubated at 37 °C for 72 hrs. Cancer cell lines elicited various degrees of sensitivity to the cytotoxic effect of essential oil. The TEO exhibited significant differences (p≤ 0.01) between the effects of all concentrations against these two human cell lines. The results showed the highest toxicity of TEO on HeLa cell line (78.67%) and MCF-7 cell line (83.60%) at 200 ppm concentration. Also the values of half-maximal inhibitory concentration (IC50) of TEO against HeLa and MCF-7 cell lines were 34.63 and 27.66 ppm, respectively. Cells treated with the IC50 of TEO showed a significant difference (p ≤ 0.01) in p53 fold expression between HeLa cell line (4.33±0.41 folds) and MCF-7 cell line (5.10±0.32 folds). In general, a dose-dependent decrease the survival of the two cell lines was observed. In addition, MCF-7 cell line revealed higher sensitivity against TEO than HeLa cell line.

Hyperacmosin N, new acylphloroglucinol derivative with complicated caged core from Hypericum acmosepalum

Three new polycyclic polyprenylated acylphloroglucinol derivatives, hyperacmosins N–P (1–3), were isolated from the air-dried aerial parts of Hypericum asmosepalum. Especially, compound1possessed a rare hexacyclic core, which was formed via oxidation and radical cyclization. Their structures were established by NMR, HRMS (ESI), and experimental electronic circular dichroism (ECD) spectra. The plausible biogenetic pathways of1-3were proposed, which gave an insight for future biomimetic synthesis of the novel compounds.

Lavandula angustifolia ve L. intermedia Türlerinin Hasat Sonrası Kuruma Sürelerinin Uçucu Yağlarının Kimyasal Bileşenleri Üzerindeki Etkileri

This study reported the chemical composition of essential oils of Lavender (L. angustifolia subs. angustifolia) and Lavandin (Lavandula x intermedia var. Super A). GC and GC/MS analyses were used for the identification of essential oils. The essential oils from fresh and air-dried aerial parts of Lavender and Lavandin were obtained by hydrodistillation method. In total, 49, 51, 50 and 40 constituents were identified and quantified in the essential oils of L. angustifolia (fresh and air-dried aerial parts) and L. intermedia (fresh and air-dried aerial parts) respectively. The major components of essential oils of L. angustifolia (fresh), L. angustifolia (air-dried aerial parts), L. intermedia (fresh) and L. intermedia (air-dried aerial parts) were 1,8-cineole (12.65%, 10.15%, 12.74%, 2,28%), linalool (38.31%, 37.94%, 38.10%, 47.47%), camphor (13.74%, 12.52%, 7.61%, 6.67%), borneol (6.82%, 7.16%, 6.84%, 4.64%). While the 1,8 cineole (12.65%, 10.15%) concentration decreased with the post-harvest drying process, the linaly acetate (1.02%, 2.80%) concentration increased in the essential oils of fresh and air-dried aerial parts of L. angustifolia. This study provides evidence that there is a change in essential oil components with post-harvest drying. Thus, it was concluded that the essential oil of the plant can be obtained by distillation of fresh and air-dried aerial plants after the harvest, considering the desired compound ratio.

Hyperacmosins K-M, three new polycyclic polyprenylated acylphloroglucinols from Hypericum acmosepalum.

Hyperacmosins K–M (1–3), three new polycyclic polyprenylated acylphloroglucinol (PPAPs) derivatives, were isolated from the air-dried aerial parts of Hypericum asmosepalum. Compounds 1 and 2 both possessed a rare 5,5-spiroketal subunit with the loss of C-2′ carbonyl in the phloroglucinal ring, while compound 3 featured an unusual 1,2-seco-bicyclo[3.3.1] PPAP skeleton. Their structures were confirmed by NMR, HRESIMS, and CD spectra. The plausible biogenetic pathways of 1–3 were proposed, which gave an insight for future biomimetic synthesis of the novel compounds.

Mugwort (Artemisia vulgaris L.) essential oils rich in germacrene D, and their toxic activity

ABSTRACT The chemical composition of essential oils of Artemisia vulgaris L. plants collected in Lithuanian has been reported. The oils were obtained by hydro-distillation from air-dried aerial parts. Up to 75 compounds (an average 88.7– 99.3% of the total oil content) were identified by GC−MS and GC (FID). Germacrene D (10.6 ± 2.5 – 30.5 ± 2.0%) was revealed as the first principal constituent in the investigated oils. To the best of our knowledge, mugwort essential oils rich in germacrene D are quite rare. 1,8-Cineole (6.9 ± 1.9 − 9.8 ± 1.1%, in 4 oils), β-pinene (6.7 ± 1.2 and 8.4 ± 2.3%), sabinene (8.5 ± 1.8%), cis-thujone (12.9 ± 2.5%), β-caryophyllene (5.5 ± 1.3 − 16.7 ± 4.2%, in 5 samples), caryophyllene oxide (6.4 ± 1.1 − 9.3 ± 1.3%, in 4 oils), α-humulene (5.5 ± 1.5%) and davanone (6.5 ± 2.5%) were found to be the second or third major compounds. The toxic activity of five mugwort essential oil samples was evaluated using a brine shrimp (Artemia sp.) bioassay. LC50 mean values (10.25–19.11 µg/mL) revealed that the oils containing appreciable amounts of germacrene D were notably toxic.

Unusual derivatives from Hypericum scabrum

Three new compounds (1–3) with unusual skeletons were isolated from the n-hexane extract of the air-dried aerial parts of Hypericum scabrum. Compound 1 represents the first example of an esterified polycyclic polyprenylated acylphloroglucinol that features a unique tricyclo-[4.3.1.11,4]-undecane skeleton. Compound 2 is a fairly simple MPAP, but with an unexpected cycloheptane ring decorated with prenyl substituents, and compound 3 has an unusual 5,5-spiroketal lactone core. Their structures were determined by extensive spectroscopic and spectrometric techniques (1D and 2D NMR, HRESI-TOFMS). Absolute configurations were established by ECD calculations, and the absolute structure of 2 was confirmed by a single crystal determination. Plausible biogenetic pathways of compounds 1–3 were also proposed. The in vitro antiprotozoal activity of the compounds against Trypanosoma brucei rhodesiense and Plasmodium falciparum and cytotoxicity against rat myoblast (L6) cells were determined. Compound 1 showed a moderate activity against T. brucei and P. falciparum, with IC50 values of 3.07 and 2.25 μM, respectively.

Efficacy of Essential Oil and Hydrosol Extract of Marrubium vulgare on Fungi Responsible for Apples Rot

Background: The microorganisms such as Penicillium expansum and Botrytis cinerea are wellknown pathogens in apples during postharvest. So, to protect apples from these pathogens, chemical control methods were exercised. Introduction: The main objective of this work was to study the chemical composition and the in-vitro and in-vivo antifungal properties of essential oil and hydrosol extract of Marrubium vulgare. Methods: In this work, the air-dried aerial parts of Marrubium vulgare were hydrodistilled in a Clevengertype apparatus. The essential oil and hydrosol extract isolated were analyzed using Gas Chromatography (GC) and Mass Spectrometry (GC/MS). The in-vitro antifungal activity of the both extracts was investigated against Botrytis cinerea, Penicillium expansum and Alternaria alternata fungi using radial growth technique. The effect of the essential oil and hydrosol extract on disease development of apple caused by Penicillium expansum in the in-vivo conditions was assessed. Results: The essential oil of Marrubium vulgare was characterized principally by E-β-caryophyllene (23.5%), E-β-farnesene (21%), α-humulene (14.8%), β-bisabolene (11.1%), caryophyllene oxide (6.8%) and phytol (3.1%). While, the methyl-eugenol (65.5%), α-Bisabolol (12.5%), linalool (6.5%) and caryophyllene oxide (6.2%) were the major compounds of hydrosol extract. The result of in-vitro antifungal activity of hydrosol extract showed an interesting antifungal inhibition against Botrytis cinerea, Penicillium expansum and Alternaria alternata with percentage inhibition ranging from 77% to 89% at low concentration of 0.15 mL/L. The essential oil was found to inhibit the growth of Penicillium expansum in a dose-dependent manner, with a percentage inhibition of 100% at 30 mL/L. Furthermore, essential oil and hydrosol extract have demonstrated promising in-vivo antifungal activity to control infection of apples by Penicillium expansum up to 25th day of storage, compared with the control. Conclusion: The preventive and protective effects of essential oil and hydrosol extract could be exploited as an ideal alternative to synthetic fungicides for using the protection of stored apples from fungal phytopathogens.

Eucalyptus camaldulensis, Citrus aurantium, and Citrus sinensis Essential Oils as Antifungal Activity against Aspergillus flavus, Aspergillus niger, Aspergillus terreus, and Fusarium culmorum

Several molds are able to colonize wood and many building products or solid wood causing losses for their valuable uses. Essential oils (EOs) from aromatic plants can be used as an ecofriendly biofungicide against the growth of several molds. EOs from Eucalyptus camaldulensis, Citrus aurantium, and C. sinensis have a broad-spectrum antimicrobial activity. EOs from of E. camaldulensis air-dried aerial parts, C. aurantium leaf and C. sinensis peel, and their combinations (1:1 v/v) were evaluated for their antifungal activity against the growth of four common mold fungi (Aspergillus flavus, A. niger, A. terreus, and Fusarium culmorum). The chemical compositions of the EOs were analyzed with GC/MS. The main compounds in EO from E. camaldulensis were spathulenol (20.84%), eucalyptol (12.01%), and sabinene (9.73%); in C. aurantium were linalyl acetate (42.29%), and linalool (29.76%); and in C. sinensis were D-limonene (73.4%) and γ-terpinene (22.6%). At 50 µL/mL, C. sinensis EO showed the highest fungal mycilial growth inhibition (FMGI) percentage (86.66%) against A. flavus. C. sinensis, E. camaldulensis, and E. camaldulensis/C. sinensis showed FMGI values of 96%, 91.66%, and 75.66% respectively, against A. niger. EOs from C. aurantium and C. sinensis showed potent activity against A. terreus (100% FMGI), while C. aurantium/E. camaldulensis and E. camaldulensis/C. sinensis showed FMGI values of 74.33% and 70.66%, respectively. Potent activity against F. culmorum with 100% was observed as the application of E. camaldulensis and C. sinensis EOs at 50 µL/mL, while E. camaldulensis/C. sinensis (50 µL/mL) showed FMGI value of 65.66%. The results suggest using the EOs and their combinations from E.camaldulensis, C. aurantium, and C. sinensis as a biofungicide against molds. The potent properties of EOs offer the possibility of using them as eco-friendly, safe, and cost-effective antimicrobials for molds that could cause discoloration of the wood packaging or food spoilage.

Chemical Constituents of Eremostachys macrophylla Montbr. & Auch. Aerial Parts

Background: Eremostachys macrophylla Montbr. & Auch. is one of the wild growing species of herbs found in East Azerbaijan province of Iran. These species are used in folk medicine for the healing of wound, treatment of snake bites, rheumatism and joint pains. The primary aim of this study was to obtain natural pure compounds and this was done by subjecting the aerial parts of Eremostachys macrophylla Montbr. & Auch. to phytochemical analysis. Methods: The air-dried and crushed aerial parts were respectively extracted with n-hexane, dichloromethane (DCM) and methanol (MeOH) solvents using a soxhlet apparatus. The 10%, 20% and 40% of MeOH in water Sep-Pak fractions of the MeOH extract were subjected to a preparative reversed- phase high performance liquid chromatography (RP-HPLC). Also, the isolated pure compounds were identified by one-dimensional nuclear magnetic resonance (1D-NMR) spectroscopic technique. Results: The results obtained in this study showed the presence of seven pure components; (1) Lamalbide, (2) Sesamoside, (3) Phlomiol, (4) Verbascoside, (5) Luteolin-7-O- glucoside, (6) Apigenin-7-O- rutinoside and (7) Kaempferol-3-O- glucoside with iridoid, phenylethanoid and flavonoid structures. Conclusion: The results from the study demonstrated that the aerial parts of E. macrophylla could be a good source of iridoids, phenylethanoids and flavonoids.

ESSENTIAL OIL AND VOLATILE COMPONENTS DRACOCEPHALUM DIVERSIFOLIUM

Plants of the genus Dracocephalum belong to the subfamily Nepetoideae of the family Lamiaceae of the order Lamiales and include about 70 species worldwide. In Uzbekistan grows 16 species of this genus. The purpose of this study was to study the chemical composition of the essential oil and gasoline extract of Dracocephalum diversifolium.
 To obtain the essential oil and gasoline extract were used the aerial parts of the plant (stems, flowers and leaves). Essential oil was isolated by hydrodistillation method. The gasoline extract was obtained by treating the air-dried aerial part of the plant with extraction gasoline. The composition of the isolated essential oil and gasoline extract was studied by GC-MS. It was revealed that the predominant components of essential oil content of D. diversifolium was sabinene (20.7%), β-pinene (10.6%), DL-limonene (7.5%), trans-valerenil acetate (7.5%), m-cymene (6.2%), 1,8-cineole (5.0%), T-cadinol acetate (4.4%), δ-cadinene (3.9%), caryophyllene (2.4%). Among the volatiles of the gasoline extract of D. diversifolium was dominated 1,8-cineole (17.0%), 3,5,5,9-tetramethyl-2,4a,5,6,9,9a-hexahydro-1H-benzo[a]cycloheptene (11.2%), δ-cadinene (8.7%), myrtenyl acetate (4.3%), β-pinene (3.9%), 4-terpinenyl acetate (3.2%), δ-cadinol (3.1%), δ-elemene (2.8%), eremophila-1(10),8,11-triene (2.8%), sabina ketone (2.5%), m-cymol (2.2%), 10,12-octadecadiynoic acid (2.0%). For the first time, by hydrodistillation method isolated essential oil from the aerial part of D. diversifolium, growing in Uzbekistan, in which 29 compounds were identified by GC-MS analysis. For the first time the chemical composition of the gasoline extract of the aerial part of D. diversifolium was studied by GC-MS. It was identified 28 components. A comparative analysis of the component composition of the essential oil and gasoline extract of D. diversifolium was carried out, in which established the dominant components for each sample.

Metabolic profiling, antioxidant, and antibacterial activity of some Iranian Verbascum L. species

The first step in introducing a medicinal plant into farming systems and industrial pharmacology is the realization of its metabolic profile and biological features. In the present study, ten Verbascum species including V. cheirantifolium, V. erianthum, V. macrocarpum, V. punalense, V. sinuatum, V. songaricum, V. speciosum, V. stachidiforme, V. thapsus, and V. densiflorum were collected from Iran and their phytochemical characteristics and biological activities were studied. The powdered air-dried aerial flowering parts of the plants were extracted with methanol by maceration. The crude methanolic extracts were further fractionated by solvent-solvent partitioning to obtain various fractions using n-hexane and ethyl acetate. The total phenol and flavonoid, phenolics and iridoids contents and metabolic profiling of the obtained extracts and enriched-fractions were assessed using UV, HPLC–PDA, LC–MS and in silico methods, respectively. Antioxidant activity using DPPH and FRAP methods, and antibacterial activity against Gram-positive and -negative bacteria were also studied. The highest contents of total phenol (51.94 ± 2.30 mg GAE/g DW) and total flavonoid (22.57 ± 1.73 mg QE/g DW) were found in V. sinuatum. The range of the highest content (mg/g DW) among the other compounds were found to be rutin (0.11–21.0), rosmarinic acid (0.33–12.16), p-coumaric acid (0.10–10.22), ferulic acid (0.11–7.82), gentisic acid (0.09–5.73), protocatechuic acid (0.09–4.74), salicylic acid (2.45–4.36), quercetin (0.13–3.21), and harpagoside (0.001−0.320) in the studied species. In addition, twenty-eight compounds were qualitatively identified in the plant extracts. The highest content of metabolites supported the observed highest antioxidant activity in V. speciosum and V. songaricum. Phenolic-enriched fraction of V. songaricum showed the highest antibacterial activity (MIC 0.12 mg/mL) against Staphylococcus aureus. Association analysis showed a significant positive correlation between biological properties and phenolic compounds. In conclusion, V. songaricum and V. sinuatum could be selected as adequate species for further exploitation in agricultural systems and pharmaceutical industry.

Toxic, Radical Scavenging, and Antifungal Activity of Rhododendron tomentosum H. Essential Oils.

The chemical composition of eight (seven shoot and one inflorescence) essential oils (EOs) of Rh. tomentosum H. plants growing in Eastern Lithuania is reported. The plant material was collected during different phases of vegetation (from April to October). The oils were obtained by hydrodistillation from air-dried aerial parts (leaves and inflorescences). In total, up to 70 compounds were identified by GC−MS and GC (flame-ionization detector, FID); they comprised 91.0 ± 4.7%–96.2 ± 3.1% of the oil content. Sesquiterpene hydrocarbons (54.1 ± 1.5%–76.1 ± 4.5%) were found to be the main fraction. The major compounds were palustrol (24.6 ± 2.6%–33.5 ± 4.4%) and ledol (18.0 ± 2.9%–29.0 ± 5.0%). Ascaridol isomers (7.0 ± 2.4%–14.0 ± 2.4% in three oils), myrcene (7.2 ± 0.3% and 10.1 ± 1.3%), lepalol (3.3 ± 0.3% and 7.9 ± 3.0%), and cyclocolorenone isomers (4.1 ± 2.5%) were determined as the third main constituents. The toxic activity of marsh rosemary inflorescence and shoot oils samples was evaluated using a brine shrimp (Artemia sp.) bioassay. LC50 average values (11.23–20.50 µg/mL) obtained after 24 h of exposure revealed that the oils were notably toxic. The oil obtained from shoots gathered in September during the seed-ripening stage and containing appreciable amounts of palustrol (26.0 ± 2.5%), ledol (21.5 ± 4.0%), and ascaridol (7.0 ± 2.4%) showed the highest toxic activity. Radical scavenging activity of Rh. tomentosum EOs depended on the plant vegetation stage. The highest activities were obtained for EOs isolated from young shoots collected in June (48.19 ± 0.1 and 19.89 ± 0.3 mmol/L TROLOX (6-hydroxy-2,5,7,8-tetra-methylchromane-2-carboxylic acid) equivalent obtained by, respectively, ABTS•+ (2,2′-amino-bis(ethylbenzothiazoline-6-sulfonic acid) diammonium salt) and DPPH•(2,2-diphenyl-1-picrylhydrazyl) assays). Agar disc diffusion assay against pathogenic yeast Candida parapsilosis revealed the potential antifungal activity of EOs. An alternative investigation of antifungal activity employed mediated amperometry at yeast Saccharomyces cerevisiae-modified electrodes. The subjection of yeast cells to vapors of EO resulted in a three to four-fold increase of electrode responses due to the disruption of yeast cell membranes.

Furofuranone Lignans from Leucophyllum ambiguum.

Eight furofuranone lignans with an endo,endo relationship between the oxygen atoms, an exo,exo relationship between the aryl groups, and a chair,chair conformation (1-4 and 6-9), in addition to the α-amino acid (3S)-hydroxy-3',4'-dimethoxy-L-phenylalanine (5), veratric acid (10), and β-sitosterol (11), were isolated from the powdered and defatted air-dried aerial parts of Leucophyllum ambiguum. Four of these lignans, ciquitins A-D, 1-4, were isolated for the first time as natural products. The structures of these compounds were established based on their spectrometric/spectroscopic data. Additionally, single-crystal X-ray crystallography confirmed the structure of ciquitin A (1), and derivatization with (9S)-naproxen and X-ray diffraction crystallography data established its absolute configuration. Ciquitins A (1) and B (2) possess a 9-hydroxy group; this chemical characteristic grants these species conformational isomerism not seen in the other six lignans. The conformers of 1 and 2 are distinguishable via their 1H and 13C NMR spectroscopic data. This is the first report of this phenomenon, and hence, a complete assignment of the signals in both spectra of each conformer for each compound is presented. Compounds 1-9 were found to exhibit potent inhibitory activity in the 1.0 × 10-3 to 2.2 μM range against acetylcholinesterase, an enzyme directly involved in the etiology of Alzheimer's disease and senile dementia. Thus, these natural products are promising agents that are potentially useful for the treatment of neurological degeneration.