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Ten sesquiterpene lactones, 8alpha-O-(3,4-dihydroxy-2-methylenebutanoyloxy)sonchucarpolide (4-epi-malacitanolide) (1), 8alpha-O-(4-acetoxy-2-hydroxymethylbuten-2-oyloxy)-4-epi-sonchucarpolide (2), malacitanolide (3), its 4'-acetyl derivative (4), 8alpha-O-(3,4-dihydroxy-2-methylenebutanoyloxy)dehydromelitensine (5), 8alpha-O-(3,4-dihydroxy-2-methylenebutanoyloxy)-15-oxo-5,7alphaH,6betaH-eleman-1,3,11(13)-trien-6,12-olide (6), the germacranolides 8alpha-O-(4-acetoxy-2-hydroxymethylbuten-2-oyloxy)salonitenolide (7), cnicin (8), and 4'-acetylcnicin (9), and the sesquiterpene methyl 8alpha-O-(3,4-dihydroxy-2-methylenebutanoyloxy)-6alpha,15-dihydroxyelema-1,3,11(13)-trien-12-oate (10), were isolated from the aerial parts of Centaurea spinosa. Nine known flavonoids were also isolated. The structures and the stereochemistry of the new compounds 1 and 2 were deduced by spectroscopic methods. The in vitro activity of 1-10 against three Gram-positive and three Gram-negative bacteria was evaluated using a microdilution method, and their in vitro cytotoxic activity was determined against a panel of human tumor cell lines.

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The volatile composition of two Eryngium species was studied. The essential oils were obtained by hydrodistillation in a modified Clevenger-type apparatus, and their analyses were performed by GC and GC-MS. A total of 58 different compounds were identified. Their main constituents were as follows: E. serbicum: germacrene D (19.7 %), E-elemene (10.0 %) and spathulenol (6.9 %); E. palmatum: sesquicineole (21.3 %), caryophyllene oxide (16.0 %), spathulenol (16.0 %) and sabinene (5.5 %). The main portion in both studied taxa consisted of sesquiterpenes.

Nine sesquiterpene lactones, anthemin A (1), 1alpha-hydroxydeacetylirinol-4alpha,5beta-epoxide (2), anthemin C (3), tatridin A (4), 1-epi-tatridin B (5), anthemin B (6), 6-deacetyl-beta-cyclopyrethrosin (7), elegalactone A (8), and 1beta,4alpha,6alpha-trihydroxyeudesm-11-en-8alpha-12-olide (9), were isolated from the aerial parts of A. melanolepis in addition to eight known flavonoids and three phenolic acids. Compounds 1, 3, and 6 are new natural products. The structures of the compounds were deduced by spectroscopic methods. The in vitro antimicrobial potential of the isolated sesquiterpene lactones against four Gram-positive and five Gram-negative bacteria and one fungus was evaluated using the microdilution method, and their in vitro cytotoxic activity was determined against a panel of human tumor cell lines. Furthermore, the pharmacokinetic profile of the sesquiterpene lactones was investigated using computational methods.

The chemical composition of the essential oil obtained from the leaves of Teucrium royleanum, growing in Pakistan, was investigated by GC-MS analyses. Kováts indices, mass spectra and standard compounds were used to identify a total of 46 individual compounds. Sesquiterpene hydrocarbons formed the main portion (42.2%) of the oil, among which β β β β β -santalene and cis-α α α α α-bisabolene were the predominant compounds. The potential antioxidant activity was also investigated and the sample tested was found to interact slightly with the stable free radical DPPH in a timedependent manner.

The formula that has been used for the calculation of the LC 50 values is 100 × (T − T 0 /T 0 ) = −50.The authors regret any inconvenience caused by the omission of this information at the time of publication.

A novel liposomal formulation was developed for the encapsulation of the oligopeptide leuprolide (GlpHisTrpSerTyr-D-LeuLeuArgProNHEt), a potent analogue of gonadotropin releasing hormone used in the treatment of advanced prostate cancer, endometriosis and precocious puberty. Leuprolide was synthesized using solid phase methodology on a {3-[(ethyl-Fmoc-amino)-methyl]-1-indol-1-yl}-acetyl AM resin and Fmoc/tBu chemistry. The new liposomal formulation, called 'liposomes in liposomes' is composed of egg phosphatidylcholine:dipalmitoylphosphatidylglycerol in a molar ratio of 98.91:1.09 (internal liposomes) and egg phosphatidylcholine:dipalmitoylphosphatidylglycerol:cholesterol in a molar ratio of 68.71:0.76:30.53 (external liposomes). It offers high encapsulation efficiency (73.8% for leuprolide); it can provide new delivery characteristics and it may have possible advantages in future applications regarding the encapsulation and delivery of bioactive peptides to target tissues. Furthermore, the physicochemical characteristics (size distribution and zeta-potential) of the liposomal formulations and the thermal effects on leuprolide in model lipidic bilayers composed of dipalmitoylphosphatidylcholine were studied using differential scanning calorimetry. Finally, the dynamic effects of leuprolide in an egg phosphatidylcholine/cholesterol system were examined using solid state 13C MAS NMR spectroscopy.