A Novel Short-Step Synthesis of New Xanthenedione Derivatives from the Cyclization of 3-Cinnamoyl-2-styrylchromones

Novel (E)-3-aryl-4-benzylidene-8-hydroxy-3,4-dihydro-1 H-xanthene-1,9(2H)-diones are prepared by the cyclization of (E,E)-3-cinnamoyl-5-hydroxy-2-styrylchromones efficiently catalyzed with boron tribromide. The (E,E)-3-cinnamoyl-5-hydroxy-2-styrylchromones are obtained from the Baker–Venkataraman rearrangement of (E,E)-2-acetyl-1,3-phenylene bis(3-phenylacrylate), which is greatly improved under microwave irradiation.

A new natural spiro heterocyclic compound and the cytotoxic activity of the secondary metabolites from Juniperus brevifolia leaves

Copyright © 2010 Elsevier B.V. All rights reserved.

A new strategy for the synthesis of 3-cinnamoyl-2-styrylchromones and their transformation into new xanthenodiones derivatives

23rd ISHC Congress will be held in Glasgow, Scotland from July 31 August 4, 2011.

Synthesis of new 1,8-dihydroxy-9h-xanthen-9-ones

XXVth European Colloquium on Heterocyclic Chemistry, Reading, UK, 13 – 17 Agosto de 2012.

Synthesis and antioxidant activity of new xanthone-type compounds

3rd Portuguese Meeting on Medicinal Chemistry and 1st Portuguese-Spanish-Brazilian Meeting on Medicinal Chemistry, Aveiro, 28-30 Novembro 2012.

New xanthenodione: synthesis and antioxidant activity evaluation

6th Spanish-Portuguese-Japanese Organic Chemistry Symposium, Lisboa, de 18 a 20 de Julho de 2012 (Poster Communication).

New syntheses of potential biologically active xanthones and benzoxanthones

10º Encontro Nacional de Química Orgânica e 1º Simpósio Luso-Brasileiro de Química Orgânica, Lisboa, 4-6 Setembro de 2013.

A new frontier in biodiversity inventory: a proposal for estimators of phylogenetic and functional diversity

Copyright © 2014 The Authors. Methods in Ecology and Evolution © 2014 British Ecological Society.

New mitochondrial and nuclear evidences support recent demographic expansion and an atypical phylogeographic pattern in the Spittlebug Philaenus spumarius (Hemiptera, Aphrophoridae)

Copyright: © 2014 Rodrigues et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Xanthenedione derivatives, new promising antioxidant and acetylcholinesterase inhibitor agents

Natural and synthetic xanthone derivatives are well-known for their ability to act as antioxidants and/or enzyme inhibitors. This paper aims to present a successful synthetic methodology towards xanthenedione derivatives and the study of their aromatization to xanthones. Additionally their ability to reduce Fe(III), to scavenge DPPH radicals and to inhibit AChE was evaluated. The results demonstrated that xanthenedione derivative 5e, bearing a catechol unit, showed higher reduction capacity than BHT and similar to quercetin, strong DPPH scavenging activity (EC50 = 3.79 ± 0.06 μM) and it was also showed to be a potent AChEI (IC50 = 31.0 ± 0.09 μM) when compared to galantamine (IC50 = 211.8 ± 9.5 μM).

The Yellow-­crowned Night Heron Nyctanassa violacea (Aves: Pelecaniformes: Ardeidae) in the Azores and Madeira Archipelagos: a new species for the Western Palearctic

This paper presents and describes the first confirmed occurrence of the Yellow-crowned Night Heron Nyctanassa violacea in the Azores, which also represents the first record for Europe and the Western Palearctic. We also present and discuss subsequent reports of the species in Macaronesia. Several hypotheses may help to explain the occurrence of this species in this part of the Atlantic, including disorientation caused by strong winds and increasing observation pressure. However, further studies are necessary to assess the part played by the different factors in the occurrence of new vagrant individuals/species in Macaronesia.

A new species of Malacoctenus from the Cape Verde Islands, eastern Atlantic (Pisces Teleostei, Labrisomidae)

Malacoctenus carrowi is described on the basis of three specimens from the Cape Verde Islands. The species is most similar to the only other eastern Atlantic species of the same genus, Malacoctenus africanus Cadenat, 1951. M. carrowi differs in colouration, a more elongated body, longer snout length, lower lateral line scale count and the absence of scales on the breast and is probably endemic to the Cape Verde Islands. A key to the Atlantic species of Malacoctenus is provided.

Seven invertebrates new for the marine fauna of Madeira Archipelago

Ocaña and den Hartog (2002) recorded 18 species of sea anemones from Madeira archipelago. During SCUBA dives along the coasts of Madeira and Porto Santo, the present author encountered a further three sea anemone species and several other marine invertebrates not yet recorded for the marine fauna of Madeira Island. Similar to previous publications (e.g. Wirtz 1998, Wirtz 2007, Ocaña & Wirtz 2009), these findings are reported here.

New data on hoverflies (Diptera: Syrphidae) from the Azorean island Pico (Portugal)

The hoverfly fauna of the Azores currently comprises 23 species (Smit 2010), but the current state of knowledge concerning these species differs for each island. In the year 1938, R. Frey and R. Storå recorded the first seven hoverfly species on Pico Island (Frey 1945), and these very same ones were still mentioned by Rojo et al. (1997). Smit (2010) added one more species to this list (Table 1). In the summer of 2014, the author of this article sampled hoverflies on Pico Island in several habitats. In this paper, the results will be presented.

A sea urchin (Diadema africanum Rodriguez et al., 2013) and a pipe fish (Syngnathus phlegon Risso, 1827) : two new records for the Azores

Maciel & Costa (2010) reported the presence of 17 species of costal sea urchins (Echinoidea) in the Azores, while Porteiro et al. (2010) reported six species of pipefishes (Syngnathidae) for the area. During SCUBA diving at Santa Maria Island, the first author detected a sea urchin and a pipe fish which are new to the marine fauna of the Azores.