Records of Natural Products Articles

 In our screening program for new agrochemicals from local wild plants, essential oil of Ostericum sieboldii flowering aerial parts was found to possess strong insecticidal activity against the red flour beetle, Tribolium castaneum and maize weevil, Sitophilus zeamais. The e ssential oil of O. sieboldii w as obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry (GC-MS). A total of 42 components of the essential oil were identified. The principal compounds in the essential oil O. sieboldii aerial parts were myristicin ( 30.31 %), α- terpineol (9. 9 2%), α- c adinol ( 7 . 2 9 % ) and β- farnesene ( 6.26 %) and l inalool (5.94%) . The essential oil possessed strong contact toxicity against S. zeamais and T. castaneum adults with LD 50 value s of 1 3.82 µg/adult and 8.47 µg/adult , respectively . The essential oil also showed fumigant toxicity against S . zeamais and T. castaneum adults with LC 50 value s of 27.39 mg/ L air and 20.92 mg/ L air , respectively .

 The essential oils from the fresh flower, leaf, and stem of Senecio pandurifolius (Asteraceae) were isolated by hydrodistillation in a Clevenger-type apparatus, and characterized by GC-FID and GC-MS. A total of forty-five, sixty, and forty-two compounds were identified, constituting over 90.1 %, 88.0%, and 89.0% of oil composition of the flower, leaf, and stem of S. pandurifolius , respectively. The chemical profile reveals the dominance of sesquiterpene hydrocarbons (flower: 42.4%, leaf: 43.4%, stem: 52.3%) . The main components of essential oils own to S. pandurifolius were α- cuprenene (30.7%) in flower, α­- zingiberene (16.1%) in leaf and γ -curcumene (14.9%) in stem. Terpene related compounds were in minor amounts in all parts (flower: 1.4%, leaf: 1.5%, stem: 1.9%) of the S. pandurifolius . Also there was no monoterpene hydrocarbons and oxygenated monoterpenes in the essential oil of the stem. In addition, antimicrobial activities of the essential oils of S. pandurifolius were investigated. The oils showed activity against Gram positive bacteria, mycobacterium and fungi, but not Gram negative bacteria. A high antimycobacterial activity was observed with leaf essential oil, which deserves further investigation to determine its active components.

The composition of supercritical CO 2 extracts and essential oils obtained by hydrodistillation of Bupleurum fruticosum L., growing spontaneously in Italy and Portugal, and its antifungal activity is reported. The collected extracts were analyzed by GC-FID and GC-MS methods. The minimal inhibitory concentration (MIC) and the minimal lethal concentration (MLC) were used to evaluate the antifungal activity of the oils against Candida albicans, C. tropicalis, C. krusei, C. guillermondii, C. parapsilosis, Cryptococcus neoformans, Trichophyton rubrum, T. mentagrophytes, Microsporum canis, M. gypseum, Epidermophyton floccosum, Aspergillus niger, A. fumigatus and A. flavus.

 It is well known that the excessive production of reactive oxygen species is hazardous for living organisms and damages major cellular constituents such as DNA, lipid and protein. To find new products reducing free radical damage is very important researches in recent pharmaceutical investigations. Considering this information, fourteen Veronica species are decided to research in the view point of their antioxidant capacity and the chemical content. Water extracts of the plants were tested for their radical scavenging activity against 2,2-diphenyl-1-picryl hydrazyl (DPPH), superoxide (SO) and nitric oxide (NO) radicals spectroscopically. Dose dependent radical scavenging activity was observed and the results were found to be comparable to that of ascorbic acid, quercetin and BHA which are known antioxidative compounds. In addition, gallic acid equivalent total phenolic contents of the plants were also determined using Folin-Ciocalteau reagent. The most significant scavenging activity was found for V. chamaedrys against SO radical (IC50 113.40 μg/ml) and V. officinalis against DPPH and NO radicals (IC50 40.93 μg/ml, 570.33 μg/ml, respectively) .

This study was designed to evaluate the chemical composition and antioxidant activity of the essential oils of Peucedanum longifolium and P. palimbioides. According to the GC-MS analysis, 35 compounds were accounted for 96.98% of the total oil of P. longifolia. Major components of the oil were 8-cedren-13-ol (33.74%), myristicin (8.03%), germacrene-D (7.73%) and D -3-carene (6.38%). In the case of P. palimbioides, 26 compounds were identified comprising the 98.96% of the total oil. The major compounds were described as a -pinene (35.45%), (E)-9-octadecenoic acid (23.57%) and b -pinene (20.19%). In general, P. palimbioides oil exhibited stronger than that of P. longifolia in all test systems. Especially in b -carotene/linoleic acid system, P. palimbioides showed strong activity against linoleic acid oxidation at 2.0 mg/mL concentration (90.58% ± 1.56). This value is too close to the synthetic antioxidants BHT and BHA at the same concentration (95.86% ± 0.23 and 93.05% ± 1.04, respectively). This plant also exhibited excellent chelating effect (90.39% ± 0.28) which is obviously greater than that of P. longifolium at 2.0 mg/mL concentration (24.12% ± 2.50). Chelating effect of the control agent EDTA was measured as 98.78% ± 0.78 (2.0 mg/mL).

The present study aimed to investigate the correlation between structure and spasmolytic activity of racemate and enantiomers of linalyl and citronellyl acetates, chemical constituents of several bioactive essential oils, such as Thymus leptophyllus essential oil, which contains linalyl acetate as major constituent. The monoterpene esters showed significant spasmolytic activity in guinea-pig isolated ileum. Therefore, these result confirm that linalyl acetate should be involved at spasmolytic activity of the Thymus leptophyllus essential oil. The (+)-, (-)-, and (±)-linalyl acetates exhibited a relaxant effect equipotent. (+)- and (-)-Citronellyl acetates also showed a similar effect, however, synergistic action was presented on constituents of citronellyl acetate racemate. The study showed that the racemate and enantiomers of linalyl and citronellyl acetates are bioactives and that the position of the functional group on the molecule structures influences the effect of relaxation of the ileum.

Centaurea is one of most important genera of Turkey flora. Some members of the genus have been used in Anatolian folk medicine. This study was undertaken in order to examine the in vitro antioxidant activities and fatty acid composition of Centaurea urvillei subsp. hayekiana. Antioxidative properties of the methanolic extract was assessed by different in vitro experiments including total phenolic and flavonoid content, phosphomolybdenum assay (total antioxidant capacity), free radical scavenging assay, β-caroten/linoleic acid bleaching test system, ferric and cupric ion reducing power. According to the results of antioxidant capacity assays, C. urvillei subsp. hayekiana showed moderately antioxidant activity in test methods. Fatty acid analysis was performed by GC and thirty-two fatty acids were identified. The oil of C. urvillei subsp. hayekiana was characterized by higher amounts of C 18:2 ω6 (linoleic acid) and C 18:1 ω9 (oleic acid). The results suggested that C. urvillei subsp. hayekiana may be utilized as a source of both natural antioxidant and linoleic acid in healthy medicine and food industry.

The leaf and bark extracts of Salix subserrata showed promising antibacterial, antifungal, and antialgal activities. The bio-guided study of the chemical constituents of the bark and leaves of Salixsubserrata (Salicaceae) has resulted in the isolation and characterization of eight compounds. These six compounds were identified as (+) catechin ( 1), 1,2-benzenedicarboxylic acid, bis (2-ethylhexyl) ester ( 2), saligenin (3), methyl 1-hydroxy-6-oxocyclohex-2-enecarboxylate (4), catechol (5), propyl acetate ( 6), β-sitosterol (7), and β-sitosterol glucopyranoside ( 8), were isolated for the first time from Salixsubserrata. The above compounds were individually identified by spectroscopic analyses and comparisons with reported data . Preliminary studies indicated that compound 1, mixture of compounds 3/4, and 7 showed good antibacterial, fungicidal, and algicidal properties.

During the screening of Nepalese ethnomedicinal plants for antiviral activities, Astilbe rivularis Buch.-Ham. , Saxifragaceae, was identified as a promising species. Bioassay-guided fractionation led to the isolation of arbutin, bergenin and a bergenin derivative. The structures were established by NMR studies. Except bergenin, the two compounds were found in this plant for the first time. A dimer of bergenin has not been described as a natural product before. The compounds showed in vitro antiviral activity against herpes simplex virus type-1 in non cytotoxic concentrations.

Polygonum barbatum (L.) Hara var. barbata (Polygonaceae), commonly known as ‘bekhanjabaj’, is a Bangladeshi perennial herb. A combination of the normal phase column chromatography and preparative thin layer chromatography on silica gel afforded sitosterone (1) from the petroleum ether fraction, and viscozulenic acid (2) and acetophenone (3) from the chloroform fraction of the methanol extract of the aerial parts of this plant . The free-radical-scavenging properties the isolated compounds 1-3 were evaluated by the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) assay.