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Two novel cyclic tridecapeptides, tolybyssidins A (1) and B (2), were isolated from the culture medium of mass cultured cyanobacterium Tolypothrix byssoidea (EAWAG 195) by means of bioguided isolation. The gross structures of these peptides were determined by 1D and 2D NMR experiments and tandem mass spectrometry. Both peptides contain the nonnatural amino acid dehydrohomoalanine (Dhha) as well as proteinogenic amino acids albeit with D- or L-configuration. The compounds exhibit moderate antifungal activity against the yeast Candida albicans.

The effects of pregnancy or progesterone dominance on the beta-adrenergic responsiveness of the uterus were studied in myometrial membranes from mid- and late-pregnant rats (day 15 and on the 16th h of day 22 of pregnancy respectively) or 24 h after administration of progesterone. Levels of the high (RH)- and low (RL)-affinity states of the beta-adrenergic receptor were determined by competition experiments between 125I-labelled cyanopindolol binding and the selective beta-agonist isoproterenol. The ratio KL/KH (respective dissociation constants) was determined since it also reflects the degree of formation of the high-affinity state of the beta-adrenergic receptor. From day 15 to the 10th h of day 22 of pregnancy, two distinct affinity states were apparent: 80-55% RH (KH = 0.31-0.21 microM) and 45-20% RL (KL = 14-5 microM) with a ratio of KL/KH of 55-34. In the last 6 h before birth, beta-adrenergic receptors underwent uncoupling which was paralleled by decreased responsiveness of myometrial adenylate cyclase to isoproterenol (maximum velocity (Vmax) = 17 +/- 3 vs 44 +/- 3 fmol cyclic AMP/10 min per mg protein on day 15). At this stage of pregnancy, previous exposure to progesterone resulted in a 1.8-fold increase in 125I-labelled cyanopindolol-binding sites (Bmax) and the reappearance of the high-affinity state (67% RH, KH = 0.19 +/- 0.04 (S.E.M.) microM, ratio KL/KH = 81.1 +/- 16.9).(ABSTRACT TRUNCATED AT 250 WORDS)

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Euphorbia deflexa, an endemic spurge from Greece, was investigated for the occurrence of its diterpene constituents. Through continuous monitoring by 1H NMR, 22 diterpenoids were isolated, including 16 previously undescribed compounds (euphodeflexins A–P), which belong to the jatrophane, ingenane, segetane, and pepluane diterpene types. Their chemical structures were elucidated through a combination of HRESIMS, NMR spectroscopy, and X-ray data. The isolated diterpenoids were tested against a panel of human cancer cell lines, as well as against two bacterial strains. Compounds 1, 13, and 17 were active against the HeLa cell line with IC50 values 9.9, 9.8, and 5.8 μM, respectively.

Together with ten well known compounds, the quinic acid derivative chlorogenic acid, the nucleoside adenosine, two amino acids, tryptophan and phenylalanine, the anthraquinone derivatives, aloemodin, aloemodin acetate and chyrosphanol 1-O-gentiobioside, the flavon C-glycosides, isovitexin, isoorientin and isoorientin 4’-O-β -glucopyranoside, as well as two new acylated isoorientin derivatives, 6”-O-(malonyl)-isoorientin and 6”-O-[(S)-3-hydroxy-3-methylglutaroyl]-isoorientin, were isolated from the water soluble part of the methanolic extract of the fresh leaves of Asphodelus aestivus. All compounds were structurally identified by spectroscopic methods, including UV, MS, and NMR (1D and 2D) spectroscopy. Among the compounds isolated, chlorogenic acid and isoorientin were found to be the main compounds of the methanolic extract.

Carbohydrates U 0500Secondary Metabolites from Asphodelus aestivus -[isolation and structure determination of two new flavone C-glycosides (I) together with ten known compounds]. -(CALIS*, I.; BIRINCIOGLU, S. S.; KIRMIZIBEKMEZ, H.; PFEIFFER, B.; HEILMANN, J.; Z. Naturforsch., B: Chem. Sci. 61 (2006) 10, 1304-1310; Dep. Pharmacogn., Fac. Pharm., Hacettepe Univ., TR-06100 Ankara, Turk.; Eng.) -H. Toeppel 09-188