Records of Natural Products Articles

he MeOH extract of Dracaena viridiflora was found to display significant cytotoxicity against some cancer cell lines. Systematic phytochemical investigation of this extract led to the isolation and structure elucidation of ten secondary metabolites including five spirostane (1-5) and one furostane (6) steroidal saponins. Furthermore, some acetylated spirostane analogues and three previously unreported derivatives with the 22,26-epoxycholesta-5,22-diene skeleton (15-17) were prepared from trillin (1), prosapogenin A of dioscin (2) and dioscin (4) by reaction with ZnCl 2/Ac 2O. Among the isolated and semisynthetic compounds, dioscin showed the most potent cytotoxicity against A549, Jurkat and Skov-3 cells with IC 50 values of 0.42, 1.70 and 1.90 µg/mL, respectively. It was noteworthy that acetylation of the bioactive compounds led to semisynthetic derivatives which unfortunately did not present any activity. This is the first report on the phytochemical and pharmacological investigation of Dracaena viridiflora.

Two new 5-oxomilbemycins, 27-aldehyde -5-oxo milbemycin β 12 (1) and 2-hydroxymilbemycin K (2) , were isolated from a genetically engineered strain Streptomyces bingchenggensis BCJ60. Their structures were determined by comprehensive analyses of its 1H and 13C NMR, COSY, HMQC, and HMBC spectroscopic, HR - E S I - MS mass spectrometric and comparison with data from the literature . Preliminary studies showed that 27-aldehyde -5-oxo milbemycin β 12 (1) and 2-hydroxymilbemycin K (2) possessed strong acaricidal and nematocidal activities.

Six Origanum species, Origanum acutidens (Hand. -Mazz.) Ietsw. (OA), Origanum brevidens (Bornm.) Dinsm. (OB), Origanum haussknechtii Boiss. (OC), Origanum husnucan-baseri H.Duman, Aytaç & A.Duran (OHB), Origanum leptocladum Boiss. (OL), Origanum rotundifolium Boiss. (OR), belonging to sect. Brevifilamentum were analyzed for their essential oil and phenolic components. For the essential oil analyses, GC-MS and GC-FID were used. Phenolic contents of the aerial parts of the chloroform, acetone, and methanol extracts were analyzed using LC-MS/MS. Antioxidant activity of the species was investigated by three methods; DPPH free radical scavenging activity, β-carotene linoleic acid assays and CUPRAC assays. Also, acetyl and butyrylcholinesterase inhibition of the extracts were investigated. While the essential oil contents of the section Brevifilamentum showed difference in chemotype, the phenolic contents were found to be coumaric acids and derivatives. These groups were the most abundant components of the extracts. Especially rosmarinic acid was detected in high amounts in acetone and methanol extracts. OA had the best activity both in antioxidant and anticholinesterase assays.

The essential oil compositions and antimicrobial activities of two varieties of a new endemic Salvia species growing in Turkey were compared. The essential oils (EOs) were obtained from the aerial parts by hydrodistillation and were analysed by gas chromatography (GC), and gas chromatography-mass spectrometry (GC-MS). The major constituents of essential oils were sabinyl acetate (79.9 - 80.1 %) and α-pinene (3.2 - 3.8 %) in both varieties. Such high sabinyl acetate content of an essential oil of a Salvia species has not been reported hitherto. The essential oil of Salvia sericeo-tomentosa var. sericeo-tomentosa (ST) (having MIC/MBC values of 0.3/1.25 mg/mL) showed better activity than the essential oil of Salvia sericeo-tomentosa var. hatayica (SH) (having MIC/MBC values of 0.6/1.25 mg/mL) especially against Staphylococcus aureus and Bacillus subtilis. The ST and SH have exhibited significant antimicrobial activity against Escherichia coli and, methicillin-resistant S. aureus (MRSA).Whereas only modest antimicrobial activity has been observed against Pseudomonas aeruginosa, and any activity against Enterococcus faecalis,Proteus mirabilis and Klebsiella pneumoniae.

Five sesquiterpene coumarin ethers: umbelliprenin, umbelliprenin-10',11'-monoepoxide, conferone, mogoltacin and feselol were isolated from the fruits of Heptaptera cilicica. Their structures were identified by means of spectroscopic methods. AChE and BuChE inhibitory activities of the compounds were determined by molecular docking method which were confirmed by in vitro experiments. According to molecular docking results, total score of feselol and umbelliprenin were 5.69 and 3.23 kcal/mol against acetylcholinesterase, respectively. Total score for butyrylcholinesterase inhibitory effect of them were 2.76 and 4.99 kcal/mol, respectively. Feselol and umbelliprenin exhibited significantly high inhibitory potency against acetylcholinesterase (IC 50 = 1.26 ± 0.01 and 5.86 ± 0.03 μM, respectively) and butyrylcholinesterase (IC 50 = 9.98 ± 0.24 and 1.10 ± 0.19 μM, respectively). This is the first report of isolation of natural bioactives obtained from the chloroform extract of Heptaptera cilicica fruits with anticholinesterase activity.

Phytochemical studies of the aerial parts of Bidens cernua L. led to the isolation of six flavonoids: luteolin (1), flavanomarein (2), tilianin (3), maritimetin (4), cynaroside (5) and cosmosiin (6). The quantitative analysis of flavonoids exhibited 0.81% contents of flavonoids in flowers and 1.62% in the herb counted as a hyperoside equivalent. Total Tannins Content showed the occurrence of 7.87% in flowers and 5.83% in the herb. The chemical composition of the essential oil obtained from the herb of B. cernua was evaluated in 92.2%, which corresponds to 99 compounds. Antimicrobial activity of the essential oil was evaluated on Gram-positive, Gram-negative bacteria and fungi. The oil exhibited a strong antibacterial and antifungal activity, especially against Gram-positive bacterial strains. T his is the first time the aforementioned compound (3) has been isolated from B. cernua.

The chemical composition of the essential oil and the absolute of five populations of Acacia farnesiana, cultivated in Greece, have been investigated. The saturated hydrocarbons tricosane, nonadecane and heneicosane, along with methyl salicylate, characterized the chemical analysis of the essential oils and the absolutes, while hexadecanoic acid and α -amyrine were important constituents of some absolutes.

Trifolium L. species with a rich isoflavone content have been used as expectorant, analgesic, antiseptic, tonic, and wound-healer in folk medicine. The aim of the study is to evaluate pharmacological properties of the extracts and isolated compounds of T. tricocephalum. Phytochemical investigation of the aerial parts of T. trichocephalum led to the isolation of daidzein, genistein, quercetin, and daidzein 4'-O-β-glucoside for the first time from this species. Isolated compounds along with the methanol extract, water, ethyl acetate and chloroform subextracts were tested for their radical scavenging and cytotoxic activity which was evaluated by MTT assay. According to the results of activity tests, extracts showed a concentration-dependent radical scavenging activity as well as cytotoxic effect on HepG2 cells at 400 μg/mL, whereas the compounds did not exert any obvious cytotoxic effect at tested concentrations.

The essential oil was obtained by hydrodistillation from the aerial parts of Origanum rotundifolium Boiss. Its chemical content and composition were analyzed by using a gas chromatography (GC-FID) and gas chromatography-mass spectrometry (GC-MS). Total phenolic content of the essential oil was determined as 132.39 µg gallic acid equivalent by Folin–Ciocalteu’s method and the major component was identified as carvacrol (56.8 %) along with p-cymene (13.1 %), (Z)- b -ocimene (5.4 %), b -caryophyllene (3.9 %), borneol (3.4 %) and thymol (3.2 %). After chemical characterization, the essential oil was evaluated for its antioxidant activity by DPPH free radical, superoxide anion radical and hydrogen peroxide scavenging activities as well as ferrous ion-chelating power test, ABTS radical cation decolorization assay and ferric thiocyanate methods. Besides antioxidant activity, acetylcholinesterase and butyrylcholinesterase inhibitory activities of the essential oil were also evaluated by Ellman’s method. It demonstrated inhibitory activities on AChE and BuChE, key enzymes in the pathogenesis of Alzheimer’s disease (AD), in addition to significant antioxidant activity.

Sambucus nigra L. (Caprifoliaceae) known as ‘black elder’ is widely used as both food and medicinal plant in Europe. Elderflowers are consumed as herbal tea and its gargle has benefits in respiratory tract illnesses such as cough, influenza, inflammation in throat. In this study, we aimed to show the compositions of the volatile compounds-rich in extract and the essential oil of the elderflowers cultivated in Kütahya, Turkey. HS-SPME (Headspace-Solid Phase MicroExtraction) technique was employed to trap volatile compounds in the hexane extract of dried elderflowers. The volatile compounds in the essential oil from elderflowers isolated by hydrodistillation were analyzed GC and GC-MS systems, simultaneously. Results for the n-hexane extract: thirty volatile compounds were identified representing 84.4% of the sample. cis-Linalool oxide (27.3%) and 2-hexanone (10.5%) were found to be main compounds of the n-hexane extract. Results for the essential oil: fifteen volatile compounds were identified representing 90.4% of the oil. Heneicosane (18.8%), tricosane (17.3%), nonadecane (13%) and pentacosane (10.3%) were the major compounds of the oil.