101,992 research outputs found
Radiospongilla inesi Nicacio, Severi & Pinheiro, 2011, sp. nov.
No full textRadiospongilla inesi sp. nov. Nicacio & Pinheiro (Figs 1–4) Holotype. UFPEPOR 935. Recife, Parque Estadual Dois Irmãos, Riacho do Prata, Pernambuco State, Brazil, 8 ° 1 ' 9.40 "S, 34 ° 56 ' 39.93 "W, coll. Nicacio, G. 29 /X/ 2009. Type locality. Brazil, Northeast Region, Eastern North Atlantic Basin, Pernambuco. Paratypes. Recife, Parque Estadual Dois Irmãos, Riacho do Prata, Pernambuco State, Brazil, 8 ° 1 ' 9.40 "S, 34 ° 56 ' 39.93 "W. 20 /V/ 2007 coll. Severi, W. UFPEPOR 674; 11 /XII/ 2009 coll. Pinheiro, U.S. UFPEPOR 940; 16 / XII/ 2009 coll. Nicacio, G. UFPEPOR 944; 16 /XII/ 2009 coll. Nicacio G., MNRJ 14746; 11 /I/ 2010 coll. Nicacio, G., UFPEPOR 948; 11 /I/ 2010 coll. Nicacio, G., UFPEPOR 949; 11 /I/ 2010 coll. Nicacio, G., UFPEPOR 950; 06/IV/ 2010 coll. Nicacio, G., UFPEPOR 1091; 06/IV/ 2010 coll. Nicacio, G., UFPEPOR 1092; 06/IV/ 2010 coll. Nicacio, G., UFPEPOR 1093. Additional material. Recife, Parque Estadual Dois Irmãos, Riacho do Prata, Pernambuco State, Brazil, 8 ° 1 ' 9.40 "S, 34 ° 56 ' 39.93 "W. 23 /X/ 2009 coll. Pinheiro, U.S. UFPEPOR 932; 23 /X/ 2009 coll. Pinheiro, U.S. UFPEPOR 934; 11 /XII/ 2009 coll. Pinheiro, U.S. UFPEPOR 936; 11 /XII/ 2009 coll. Pinheiro, U.S. UFPEPOR 937; 11 /XII/ 2009 coll. Pinheiro, U.S. UFPEPOR 938; 11 /XII/ 2009 coll. Pinheiro, U.S. UFPEPOR 939; 16 /XII/ 2009 coll. Nicacio, G. UFPEPOR 942; 16 /XII/ 2009 coll. Nicacio, G. UFPEPOR 946; 16 /XII/ 2009 coll. Nicacio, G. UFPEPOR 947; 11 /I/ 2010 coll. Nicacio, G., UFPEPOR 952; 11 /I/ 2010 coll. Nicacio, G., UFPEPOR 953; 11 /I/ 2010 coll. Nicacio, G., UFPEPOR 954; 11 /I/ 2010 coll. Nicacio, G., UFPEPOR 955; 11 /I/ 2010 coll. Nicacio, G., UFPEPOR 956; 11 /I/ 2010 coll. Nicacio, G., UFPEPOR 957; 11 /I/ 2010 coll. Nicacio, G., UFPEPOR 958; 11 /I/ 2010 coll. Nicacio, G., UFPEPOR 959; 06/IV/ 2010 coll. Nicacio, G., UFPEPOR 1094. FIGURE 1. Map of the geographic distribution and of the type locality of Radiospongilla inesi sp. nov. from Recife, Pernambuco State (in detail), Brazil (8 ° 1 ' 9.40 "S, 34 ° 56 ' 39.93 "W) FIGURE 2. Radiospongilla inesi sp. nov. in situ from Recife, Pernambuco State, Brazil (8 ° 1 ' 9.40 "S, 34 ° 56 ' 39.93 "W). FIGURE 3. Radiospongilla inesi sp. nov. from Recife, Pernambuco State, Brazil (8 ° 1 ' 9.40 "S, 34 ° 56 ' 39.93 "W) Holotype UFPEPOR 935 (Coleção de Porifera da Universidade Federal de Pernambuco) SEM illustration of spicules and gemmule: a) Megasclere oxea b) Detail of the center of megasclere oxea c–d) Gemmosclere acanthostrongyle e) Gemmule f) Detail of the surface of the gemmule g) Detail of the gemmoscleres radially embedded. Other material examined. Holotype of Radiospongilla amazonensis Volkmer-Ribeiro & Maciel, 1983 (MNRJ 0088). Diagnosis. Radiospongilla with megascleres oxeas microspined at middle of the axis or rarely smooth (15 %), microscleres absent, gemmoscleres acanthostrongyles strongly spined (n= 47–55 – 68), with straight and sharply pointed spines uniformly distributed along the axis, terminal spines with curved tips toward to the middle of axis, without formation of pseudorotules. Description of holotype. UFPEPOR 935 is encrusting, about 7 cm in diameter and 2 cm thickness, with one large and conspicuous osculum. Color is yellowish in vivo and light-brown after fixed in ethanol. Surface hispid. Megascleres oxeas slightly curved, microspined at the middle of the axis or rarely smooth (240–271.68 – 312 / 9– 11.1 – 15 µm), microscleres absent, gemmoscleres acanthostrongyles (66–70.74 – 78 / 3–3.68 – 4 µm). Description. Sponge ranging from volcano-shaped, encrusting or massive, with a large conspicuous osculum and/or scattered small oscula (Fig. 2 a–c). It has a maximum thickness of 3 cm and 40 cm of diameter. Color yellowish in vivo and light-brown after fixed in ethanol. Body is soft to very fragile. Surface hispid. Anisotropic skeleton with multispicular bundles connected by abundant spongin. Megascleres oxeas (228–260 – 288 / 9–12 µm) fusiform, straight or slightly curved, microspined at the middle of axis or rarely (15 %) smooth (Fig. 3 a; Fig. 4 a–d). Microscleres absent. Gemmules abundant, yellowish, spherical, free, scattered or clustered at the base of sponge (300–338 – 384 µm). Foramen tubular single and without a collar. Gemmular theca tri-layered with gemmoscleres radially embedded. Outer layer with protruding distal apices of the gemmoscleres. Pneumatic layer well developed network of irregular spongin fibers. Inner layer of sublayered compact spongin (Fig. 3 e–g). Gemmoscleres acanthostrongyles (51–69 – 78 / 3–3.2 – 4 µm) straight, strongly spined (n= 47–55 – 68), radially embedded in gemmules (Fig. 3 c–g; Fig. 4 e–g). The spines of gemmoscleres along the axis are straight and sharp, uniformly distributed, however the terminal spines have curved tips toward the middle of axis. The spines along the axis are larger than the spines of the extremities and do not form pseudorotules. Free gemmoscleres can also be found in the symplasm, identical to those embedded in gemmules. FIGURE 4. Radiospongilla inesi sp. nov. from Recife, Pernambuco State, Brazil (8 ° 1 ' 9.40 "S, 34 ° 56 ' 39.93 "W) Light microscopy illustration of megascleres and gemmoscleres: a–b) Smooth oxea megascrele (UFPEPOR 944 and UFPEPOR 1091, respectively) c–d) Spiny oxea megasclere (UFPEPOR 959) e–g) Gemmosclere acanthostrongyle (UFPEPOR 944, UFPEPOR 959 and UFPEPOR 1091, respectvely). Ecology. The specimens were collected on the concrete substrate in perennial shallow waters environments, ponds and streams, depth ranging from 5 cm to 2 m, located at Parque Estadual Dois Irmãos, an urban remnant of Atlantic Forest. The area has approximately 387.4 ha, with undulating topography and altitudes ranging from 10 to 100 m. The climate is Tropical wet and dry (As), following The Köppen Climate Classification for coastal regions of Northeastern Brazil. This region is hot and humid, with annual medium precipitation 2,460 mm and monthly average temperatures above 23 ° C (Machado et al., 1998). Within the specimens were found Chironomids associated to sponges. Etymology. The species is dedicated to Dr. Inês Ezcurra de Drago, for her great contribution to the knowledge of freshwater sponges from South America. Remarks. Radiospongilla inesi sp. nov. is allocated to Radiospongilla on the basis of its anisotropic multispicular choanosomal skeleton, gemmoscleres as acanthostrongyles radially embedded on the gemmules and the lack of microscleres. The specimens studied here exhibit morphological differences from the other South American species that justify the proposal of a new species. Compared with Radiospongilla amazonensis, which has megascleres as thicker oxeas and strongyles, this new species has only one category of megasclere which is on average also thinner than those of R. amazonensis (Table 1). The ends of oxea megascleres of R. amazonesis are slightly rounded and abruptly pointed (and hence listed as strongyles in Table 1), in contrast to those of R. inesi sp. nov. which are fusiform, sharply pointed oxeas (Fig. 3 a; Fig. 4 a–d). Moreover, R. amazonensis has gemmoscleres strongly spined at the extremities while in R. inesi sp. nov. the spines are uniformly distributed along the axis and also more abundant (Table 1). Radiospongilla crateriformis is the most similar species of Radiospongilla to the new species. Although that species possesses microspined oxea megascleres, it does not present smooth megascleres like R. inesi sp. nov. The main difference between these two species is the morphology of gemmoscleres. Radiospongilla. crateriformis displays curved spines and which are more concentrated at the extremities, giving appearance of pseudorotules, these gemmoscleres do not show a developed rotule but a group of curved hooks radiating from the apices of the shaft (Potts, 1887, Plate X, Fig.V; Bass & Volkmer-Ribeiro, 1998, Fig. 2–3). However, R. inesi sp. nov. has spined extremities curved only at the tips and the spines along the axis are uniformly distributed and in greater number, as well the middle spines are larger than the extremities spines (Fig. 3 c–e, 4 e–g).Published as part of Nicacio, Gilberto, Severi, William & Pinheiro, Ulisses, 2011, New species of Radiospongilla (Porifera: Spongillidae) from Brazilian inland waters, pp. 56-63 in Zootaxa 3132 on pages 58-62, DOI: 10.5281/zenodo.20738
The Knoevenagel reaction in electrochemically activated solvents
No full textThe electrochemical activation of organic solvents HS (CH3CN, CH3CH,CN, DMF, DMSO) containing Et4NPF6 as supporting electrolyte (i.e. their electrolysis under galvanostatic control) allows to induce in these solutions, in the absence of any catalyst, the Knoevenagel condensation between CH-acid CH2(CN)(2) (1) and carbonylic substrates 2a-e. Reaction products 3a-e were isolated in good yields 97-48%. The progress of the Knoevenagel condensation is affected by Q (number of Faradays per mol of 1 supplied to the electrodes) and, moderately, by the nature of the solvents. The rates of the single steps were compared by elementary voltammetric analysis
Electrochemically induced N-acryloylation of chiral oxazolidin-2-ones
No full textA new method for N-acryloylation of Evans' chiral auxiliaries (oxazolidin-2-ones) with alpha,alpha ' -dichloro ketones in the presence of the electrogenerated base 2-pyrrolidone anion is described. N-Enoyloxazolidin-2-ones are obtained, under mild reaction conditions, in good to high yields
Condensazione di Knoevenagel indotta elettrochimicamente in assenza di solvente e di elettrolita di supporto
No full textAn electrochemical alternative strategy to the synthesis of beta-lactams. Part 2 [1] C3-C4 Bond formation.
No full textElectrochemically induced synthesis of -lactams, by cyclization (via C3 C4 bond formation) of haloamides XCHR1 CONR2 CHR3 R4 (X: Br,
Cl), has been achieved in suitable solvent-supporting electrolyte solutions previously electrolyzed under galvanostatic control. The yields and
the stereochemistry of the process are affected by the nature of substituents R1 –R4 and of solvent-supporting electrolyte solutions and by the
electrolysis conditions
Electrochemical methods for the synthesis and the N-acryloylation of oxazolidin-2-ones chiral auxiliaries
No full textSimple electrochemical methodologies for
the synthesis (without the use of toxic and
dangerous reagents) of chiral oxazolidin-2-ones
by reaction of activated CO2 with chiral amino
alcohols and for the N-acryloylation of
oxazolidin-2-ones with activated α,α’-
polychloroketones, have been reported. The
activation of carbon dioxide was achieved
either by electrochemical reduction of CO2 or
by reduction of a gaseous mixture of O2/CO2 or
by deprotonation of the substrates (via
electrogenerated bases). The activation of
polychloroketones was carried out by their
electrochemical reduction in solutions
containing oxazolidin-2-ones as well as
ketones. Chiral oxazolidin-2-ones and N-enoyl
oxazolidin-2-ones were isolated in good to high
yields
The reaction of 1,2-amino alcohols with carbon dioxide in the presence of 2-pyrrolidone electrogenerated base. New synthesis of chiral oxazolidin-2-ones
No full textElectrochemically induced aza-Henry reaction: A new, mild, and clean synthesis of alpha-nitroamines
No full textThe addition reaction of nitro compounds to azomethine functions, known as the aza-Henry (or nitro-Mannich) reaction was performed electrochemically under solvent and supporting electrolyte-free conditions. Reaction yields are very good and the method is very clean, avoiding the use of any classical solvent or catalyst
Stereoselective electrochemical carboxilation: 2-phenylsuccinates from chiral cinnamic acid derivatives
No full textChiral 2-phenyl succinic ester derivatives have been obtained under mild conditions, in short times and with
satisfactory yields by electrochemical reduction of chiral cinnamic acid derivatives under a CO2 atmosphere. When
4R-(diphenylmethyl)-oxazolidin-2-one was used as a chiral auxiliary the two diastereoisomers could be easily
separated by flash chromatography and the R-isomer was obtained as major product
Reactivity of electrogenerated N-heterocyclic carbene in room-temperature ionic liquids. Cyclization to 2-azetidinone ring via C3-C4 bond formation
No full textThe intrinsic chemistry of imidazolium-
based room-temperature ionic liquids, related to the
acidity of the C-2 imidazolium cation, can be modi-
fied via cathodic cleavage of the C-2/hydrogen bond.
N-Heterocyclic carbenes, electrogenerated by elec-
trolysis of imidazolium-based room-temperature
ionic liquids, are stable bases that are strong enough
to deprotonate bromoamides 1a–k yielding the azeti- din-2-one ring via C-3/C
4 bond formation. The
electrosynthesis of b-lactams 2a–k has been achieved
under mild conditions, elevated yields and avoiding
the use of toxic, volatile, molecular solvents
- …
