7. On the priority of "Genistion purgantis" Tüxen in Tüxen & Oberdorfer 1958 and "Senecioni-Genistetum purgantis" Tüxen & Oberdorfer 1958

In a recent review of which we were co-authors (Rivas-Martínez, Belmonte, Cantó, Fernández-González, Fuente, Moreno, Sánchez-Mata & Sancho, Lazaroa 7: 93-124. 1987), rejection of names Genistion purgantis Túxen in Túxen & Oberdorfer 1958 [Veróff. Geobot. Inst. Rúbel Zúrich 32: 228] and Senecio tournefortii-Genistapurgans Ass. Túxen & Oberdorfer 1958 [op. cit.: 229-230] versus Pino-Cytision purgantis Rivas-Martínez 1964 [Anales lnst. Bot. Cavanilles 22: 358] and Junipero nanae-Sarothamnetum purgantis Rivas-Martínez 1963 [Anales Inst. Bot. Cavanilles 21(1): 172-186] respectively, was proposed and adopted.

New records of interesting xenophytes in the Iberian Peninsula. V

As a continuation of previous research on the naturalization of non-native vascular plants in the Iberian Peninsula new chorological data are presented for 16 xenophytes recorded between 2010 and 2014, mostly in the provinces of Huelva and Barcelona (Spain) and in the Algarve and Estremadura (Portugal). For each taxon details about distribution, habitats occupied, previous records, degree of naturalization, etc. are provided. Lachenalia bulbifera and Cyperus albostriatus are probably reported for the first time in the wild in Europe, as are Gamochaeta filaginea, and Dysphania anthelmintica and Oenothera lindheimeri for Portugal and Spain respectively. Cosmos bipinnatus is cited as a novelty for the Algarve (Portugal). Newly reported or confirmed for the province of Huelva are: Amaranthus hypochondriacus, Epilobium brachycarpum, Nephrolepis cordifolia, Ficus microcarpa, Tamarix parviflora and Tamarix ramosissima, while Atriplex semibaccata, Chloris truncata, and Elymus elongatus subsp. ponticus are new for Barcelona. Finally, Passiflora caerulea is a novelty for both Barcelona and Huelva provinces.

N-terminal His(7)-modification of glucagon-like peptide-1(7-36) amide generates dipeptidyl peptidase IV-stable analogues with potent antihyperglycaemic activity

Glucagon-like peptide-1(7-36)amide (GLP-1) possesses several unique and beneficial effects for the potential treatment of type 2 diabetes. However, the rapid in-activation of GLP-1 by dipeptidyl peptidase IV (DPP IV) results in a short half-life in vivo (less than 2 min) hindering therapeutic development. In the present study, a novel His(7)-modified analogue of GLP-1, N-pyroglutamyl-GLP-1, as well as N-acetyl-GLP-1 were synthesised and tested for DPP IV stability and biological activity. Incubation of GLP-1 with either DPP IV or human plasma resulted in rapid degradation of native GLP-1 to GLP-1 (9-36),amide, while N-acetyl-GLP-1 and N-pyroglutamyl-GLP-1 were completely resistant to degradation. N-acetyl-GLP-1 and N-pyroglutamyl-GLP-1 bound to the GLP-1 receptor but had reduced affinities (IC50 values 32(.)9 and 6(.)7 nM, respectively) compared with native GLP-1 (IC50 0(.)37 nM). Similarly, both analogues stimulated cAMP production with EC50 values of 16(.)3 and 27 nM respectively compared with GLP-1 (EC50 4(.)7 nM). However, N-acetyl-GLP-1 and N-pyroglutamyl-GLP-1 exhibited potent insulinotropic activity in vitro at 5(.)6 mM glucose (P

Novel dipeptidyl peptidase IV resistant analogues of glucagon-like peptide-1(7-36)amide have preserved biological activities in vitro conferring improved glucose-lowering action in vivo

Although the incretin hormone glucagon-like peptide-1 (GLP-1) is a potent stimulator of insulin release, its rapid degradation in vivo by the enzyme dipeptidyl peptidase IV (DPP IV) greatly limits its potential for treatment of type 2 diabetes. Here, we report two novel Ala(8)-substituted analogues of GLP-1, (Abu(8))GLP-1 and (Val(8) GLP-1 which were completely resistant to inactivation by DPP IV or human plasma. (Abu(8))GLP-1 and (Val(8))GLP-1 exhibited moderate affinities (IC50: 4.76 and 81.1 nM, respectively) for the human GLP-1 receptor compared with native GLP-1 (IC50: 0.37 nM). (Abu(8))GLP-1 and (Val(8))GLP-1 dose-dependently stimulated cAMP in insulin-secreting BRIN BD11 cells with reduced potency compared with native GLP-1 (1.5- and 3.5-fold, respectively). Consistent with other mechanisms of action, the analogues showed similar, or in the case of (Val(8))GLP-1 slightly impaired insulin releasing activity in BRIN BD11 cells. Using adult obese (ob/ob) mice, (Abu(8))GLP-1 had similar glucose-lowering potency to native GLP-1 whereas the action of (Val(8))GLP-1 was enhanced by 37%. The in vivo insulin-releasing activities were similar. These data indicate that substitution of Ala(8) in GLP-1 with Abu or Val confers resistance to DPP IV inactivation and that (Val(8))GLP-1 is a particularly potent N-terminally modified GLP-1 analogue of possible use in type 2 diabetes.