Phytochemical Composition and Antioxidant Activity of Various Extracts of Fibre Hemp (Cannabis sativa L.) Cultivated in Lithuania.

The phytochemistry of fibre hemp (Cannabis sativa L., cv. Futura 75 and Felina 32) cultivated in Lithuania was investigated. The soil characteristics (conductivity, pH and major elements) of the cultivation field were determined. The chemical composition of hemp extracts and essential oils (EOs) from different plant parts was determined by the HPLC/DAD/TOF and GC/MS techniques. Among the major constituents, ß-caryophyllene (≤46.64%) and its oxide (≤14.53%), α-pinene (≤20.25%) or α-humulene (≤11.48) were determined in EOs. Cannabidiol (CBD) was a predominant compound (≤64.56%) among the volatile constituents of the methanolic extracts of hemp leaves and inflorescences. Appreciable quantities of 2-monolinolein (11.31%), methyl eicosatetraenoate (9.70%) and γ-sitosterol (8.99%) were detected in hemp seed extracts. The octadecenyl ester of hexadecenoic acid (≤31.27%), friedelan-3-one (≤21.49%), dihydrobenzofuran (≤17.07%) and γ-sitosterol (14.03%) were major constituents of the methanolic extracts of hemp roots, collected during various growth stages. The CBD quantity was the highest in hemp flower extracts in pentane (32.73%). The amounts of cannabidiolic acid (CBDA) were up to 24.21% in hemp leaf extracts. The total content of tetrahydrocannabinol (THC) isomers was the highest in hemp flower pentane extracts (≤22.43%). The total phenolic content (TPC) varied from 187.9 to 924.7 (average means, mg/L of gallic acid equivalent (GAE)) in aqueous unshelled hemp seed and flower extracts, respectively. The TPC was determined to be up to 321.0 (mg/L GAE) in root extracts. The antioxidant activity (AA) of hemp extracts and Eos was tested by the spectrophotometric DPPH● scavenging activity method. The highest AA was recorded for hemp leaf EOs (from 15.034 to 35.036 mmol/L, TROLOX equivalent). In the case of roots, the highest AA (1.556 mmol/L, TROLOX) was found in the extracts of roots collected at the seed maturation stage. The electrochemical (cyclic and square wave voltammetry) assays correlated with the TPC. The hydrogen-peroxide-scavenging activity of extracts was independent of the TPC.

Variations in Yield, Essential Oil, and Salicylates of Filipendula ulmaria Inflorescences at Different Blooming Stages.

Meadowsweet (Filipendula ulmaria) is an essential oil-bearing, pharmacologically valuable medicinal plant growing wild in floodlands that are either not usually used for agriculture or have low economic value. The aim of this work was to understand the relationship between the yield of F. ulmaria inflorescences and the qualitative and quantitative composition of the essential oil during flowering stages in different habitats. Five different habitats of F. ulmaria were investigated for evaluation of inflorescence characteristics (length and weight) and the quantitative and qualitative composition of essential oils in early and late blooming stages (growing stage BBCH 62−63 and BBCH 65−67/72−73, respectively). The results showed significant (p < 0.05) positive correlations between the length and weight of inflorescences both in early and in late blooming stages (r = 0.73 and r = 0.72, respectively). The early blooming stage was observed to have 1.2−2 times greater quantity of volatile oils in comparison with the late blooming stage. Salicylaldehyde and methylsalicylate were the main salicylates in both blooming stages. Spearman's correlation showed statistically significant relationship between percentages of salicylaldehyde and methylsalicylate (r = −0.94, p < 0.05). An increase in salicylaldehyde was accompanied by a decrease in methylsalicylate in essential oils. Statistically significant relations between the investigated parameters of plant and the parameters of habitat were not detected. The dried raw material yield of F. ulmaria in 1 ha in the late blooming stage was 18−56% higher than in the early blooming stage; however, the yield of essential oil in the early flowering stage was 1.5−1.6 times higher than in the late flowering stage. The obtained research data suggest that the low economic value of floodlands­the habitats of F. ulmaria­can be increased by using these areas as natural industrial plots.

In Vitro Antioxidant and Prooxidant Activities of Red Raspberry (Rubus idaeus L.) Stem Extracts.

Leaves and stems of red raspberry (Rubus idaeus) are used in Lithuanian folk medicine. Healing properties of raspberry are related to the content of bioactive compounds, mainly polyphenols. Extracts of raspberry leaves contained higher total phenolic content (TPC) (1290 mg/L, expressed in gallic acid equivalent) compared to that in extracts of stems or peeled bark (up to 420 mg/L and 598 mg/L, respectively). To find out whether the collection time of herbal material was critical for the properties of the extracts, the stems were collected at different times of the year. TPC in the extracts depended more on extraction conditions rather than on the sampling time. Antioxidant activity of raspberry stem and bark extracts tested by spectrophotometric (DPPH● scavenging) and electrochemical (cyclic and differential pulse voltammetry) assays correlated with TPC. DPPH radical scavenging activity values for stem, leaf, and bark extracts were as follows: ≤1.18 ± 0.07, 1.63 ± 0.10, and ≤1.90 ± 0.04 (mmol/L, TROLOX equivalent), respectively. Assessed electrochemically, hydrogen peroxide-scavenging activity of extracts was independent on TPC. The latter activity was related to the presence of some protein in the extract as revealed by gel electrophoresis. Prooxidant activity of raspberry stem extracts was dependent on solution pH and temperature.

Antioxidant and Toxic Activity of Helichrysum arenarium (L.) Moench and Helichrysum italicum (Roth) G. Don Essential Oils and Extracts.

Helichrysum arenarium (L.) Moench (sandy everlasting) is the only species from genus Helichrysum Mill that grows spontaneously in Lithuania. The chemical composition of the essential oils (EOs) from inflorescences and leaves of H. arenarium wild plants was analysed by GC-MS. Palmitic (≤23.8%), myristic (≤14.9%) and lauric (6.1%) acids, n-nonanal (10.4%), and trans-ß-caryophyllene (≤6.5%) were the major constituents in the EOs. For comparison, the main components in EO from flowers (commercial herb material) of H.italicum were γ-curcumene (21.5%), ß-selinene (13.6%), α-selinene (8.1%), ß-eudesmol (8.3%), and α-pinene (6.5%). Composition of H. arenarium methanolic extracts was investigated by HPLC-DAD-TOF. The main compounds were the following: luteolin-7-O-glucoside, naringenin and its glucoside, apigenin, chlorogenic acid, arenol, and arzanol. Antioxidant activity of EOs and extracts was tested by DPPH● and ABTS●+ assays. Sandy everlasting extracts exhibited significantly higher radical scavenging activities (for leaves 11.18 to 19.13 and for inflorescences 1.96 to 6.13 mmol/L TROLOX equivalent) compared to those of all tested EOs (0.25 to 0.46 mmol/L TROLOX equivalent). Antioxidant activity, assayed electrochemically by cyclic and square wave voltammetry correlated with total polyphenolic content in extracts and radical scavenging properties of EOs and extracts. The toxic activity of EOs of both Helichrysum species was evaluated using a brine shrimp (Artemia salina) bioassay. H. italicum inflorescence EO was found to be toxic (LC50 = 15.99 µg/mL) as well as that of H. arenarium (LC50 ≤ 23.42 µg/mL) oils.

Chemical Polymorphism of Essential Oils of Artemisia vulgaris Growing Wild in Lithuania.

Compositional variability of mugwort (Artemisia vulgaris L.) essential oils has been investigated in the study. Plant material (over ground parts at full flowering stage) was collected from forty-four wild populations in Lithuania. The oils from aerial parts were obtained by hydrodistillation and analyzed by GC(FID) and GC/MS. In total, up to 111 components were determined in the oils. As the major constituents were found: sabinene, 1,8-cineole, artemisia ketone, both thujone isomers, camphor, cis-chrysanthenyl acetate, davanone and davanone B. The compositional data were subjected to statistical analysis. The application of PCA (Principal Component Analysis) and AHC (Agglomerative Hierarchical Clustering) allowed grouping the oils into six clusters. AHC permitted to distinguish an artemisia ketone chemotype, which, to the best of our knowledge, is very scarce. Additionally, two rare cis-chrysanthenyl acetate and sabinene oil types were determined for the plants growing in Lithuania. Besides, davanone was found for the first time as a principal component in mugwort oils. The performed study revealed significant chemical polymorphism of essential oils in mugwort plants native to Lithuania; it has expanded our chemotaxonomic knowledge both of A. vulgaris species and Artemisia genus.

Variability, toxicity, and antioxidant activity of Eupatorium cannabinum (hemp agrimony) essential oils.

CONTENT: Eupatorium cannabinum L. (Asteraceae) is as a potential source of biologically active compounds. The plant is used in traditional medicine for the treatment of diarrhea and livers diseases. OBJECTIVE: The present study provides investigation on pharmacological properties (antioxidant and toxic activities) of essential oils of E. cannabinum, collected from 11 wild populations in Lithuania. MATERIALS AND METHODS: Twenty-two hemp agrimony essential oil samples were prepared by hydrodistillation according to the European Pharmacopoeia, and their chemical composition was determined by GC-FID and GC-MS. Compositional data were subjected to principal components analysis (PCA). Instead of conventional spectrophotometric methods, cyclic voltammetry (CV) and square wave voltammetry (SWV) techniques were applied to determine antioxidant activity of hemp agrimony essential oils. Meanwhile, toxicity of the oils was determined using brine shrimp (Artemia sp.) assay. RESULTS: Chemical profiles of E. cannabinum oils were described according to the first predominant components: germacrene D (≤22.0%), neryl acetate (≤20.0%), spathulenol (≤27.2%), and α-terpinene (11.5%). For the first time, α-zingiberene (≤7.8%) was found to be among three major constituents (as the second one) for hemp agrimony oils. SWV measurements revealed that oxidation potentials of compounds present in the oils are lower (below 0.1 V) compared with that of well-known antioxidant quercetin (0.15 V). Toxicity tests evaluated that hemp agrimony oils containing predominant amounts of germacrene D and neryl acetate were notably toxic (LC50 value 16.3-22.0 µg/mL). CONCLUSION: The study provided some new data concerning chemical composition and pharmaceutical properties of E. cannabinum essential oils.

Composition of seed essential oils of Rhododendron tomentosum.

For the first time, the chemical composition of the seed essential oil of Rhododendron tomentosum was determined. Forty-seven compounds were identified, comprising 91.7% of the total oil. Palustrol (38.3%) and ledol (27.0%) were the predominant constituents. Some constituents, such as beta-pinene oxide, iso-menthyl acetate, nerolidyl acetate, cadalene and guaiazulene were characteristic only for the seeds and were identified for the first time in Rh. tomentosum oils. For comparison purposes, the essential oil isolated from the shoots of the same plant were analyzed [GC(FID) in combination with RIs, GC-MS and 13C NMR]. More than a half of the oil was comprised of ledol (36.5%) and palustrol (21.0%). Quantitative analysis of ascaridol, a heat-sensitive compound, was carried out by 13C NMR spectroscopy. Indeed, ascaridol undergoes partial thermal isomerization to iso-ascaridol during GC analyses.

Caryophyllene oxide-rich essential oils of Lithuanian Artemisia campestris ssp. campestris and their toxicity.

The chemical composition of the essential oils of aerial parts of Artemisia campestris ssp. campestris, collected from ten different locations in Lithuania is detailed in this paper. The major component in all the oils was caryophyllene oxide (8.5-38.8%), whereas compounds with the caryophyllane skeleton ranged from 10.2 to 44.5%. Other representative constituents were germacrene D (< or = 15.0%), humulene epoxide II (< or = 8.1%), beta-ylangene (< or = 7.7%), spathulenol (< or = 6.8%), beta-elemene (< or = 6.8%), beta-caryophyllene (< or = 6.2%), junenol (< or = 6.1%) and alpha- or beta-pinene (< or = 5.5%). Eighty-seven compounds were identified, comprising 73.6-92.3% of the oils. The chemical composition was highly variable depending on the sample location. Toxicity of A. campestris oils was determined using the brine shrimp (Artemia sp.) assay. LC50 values ranging to 20 microg/mL were obtained for three of the oils after 24 hours of exposure. Data of this test revealed that A. campestris ssp. campestris essential oils with dominant caryophyllene oxide are notably toxic.