A biophysical elucidation for less toxicity of Agglutinin than Abrin-a from the Seeds of Abrus Precatorius in consequence of crystal structure

X-ray crystal structure determination of agglutinin from abrus precatorius in Taiwan is presented. The crystal structure of agglutinin, a type II ribosome-inactivating protein (RIP) from the seeds of Abrus precatorius in Taiwan, has been determined from a novel crystalline form by the molecular replacement method using the coordinates of abrin-a as the template. The structure has space group P41212 with Z = 8, and been refined at 2.6 Å to R-factor of 20.4%. The root-mean-square deviations of bond lengths and angles from the standard values are 0.009 Å and 1.3°. Primary, secondary, tertiary and quaternary structures of agglutinin have been described and compared with those of abrin-a to a certain extent. In subsequent docking research, we found that Asn200 of abrin-a may form a critical hydrogen bond with G4323 of 28SRNA, while corresponding Pro199 of agglutinin is a kink hydrophobic residue bound with the cleft in a more compact complementary relationship. This may explain the lower toxicity of agglutinin than abrin-a, despite of similarity in secondary structure and the activity cleft of two RIPs

A participação de PMEs portuguesas em alianças de I&D: programa CRAFT

A formação de alianças de base tecnológica conheceu um incremento notável nas décadas de 1980 e 1990, representando actualmente uma estratégia empresarial importante de acesso ao conhecimento tecnológico, fortemente incentivada pela generalidade dos países da OCDE. A literatura sobre alianças realça as enormes vantagens mútuas que podem resultar da cooperação tecnológica bem sucedida. Raramente, porém, são abordados empiricamente os problemas específicos da participação de PMEs em alianças de I&D, e menos ainda quando essas empresas pertencem a sectores tradicionais e têm limitações evidentes para participar em alianças de I&D. Este trabalho aborda esta problemática no quadro da participação de PMEs portuguesas no programa europeu CRAFT (1994-98). Os resultados indicam que o empenhamento dos parceiros, os aspectos culturais e a falta de recursos internos representam os aspectos mais negativos da cooperação. Isto é, em grande medida, consequência das condições iniciais que estiveram na génese das alianças mas a estrutura das alianças também é importante. As PMEs portuguesas ficaram, em geral, satisfeitas com os benefícios obtidos mas o sucesso técnico da aliança não garante que as empresas tenham condições para materializar os benefícios potenciais gerados no âmbito da aliança

Ecosystem-Driven Design of In-Home Terminals Based on Open Platform for the

Abstract—In-home healthcare services based on the Internet-of-Things (IoT) have great business potentials. To turn it into reality, a business ecosystem should be established first. Technical solutions should therefore aim for a cooperative ecosystem by meeting the interoperability, security, and system integration requirements. In this paper, we propose an ecosystem-driven design strategy and apply it in the design of an open-platform-based in-home healthcare terminal. A cooperative business ecosystem is formulated by merging the traditiona

<span style="font-size:12.0pt;font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";mso-ansi-language:EN-IN;mso-fareast-language: EN-IN;mso-bidi-language:AR-SA">Synthesis, characterisation and properties of manganese(II) complexes having pseudohalide coordination: X-ray crystal structure of an unusually distorted hexacoordinated [MnL(NCS)](ClO₄) species (L=pentadentate Schiff base ligand)</span>

329-332The synthesis, characterisation and properties of manganese(II) complexes from a pentadentate ligand (L) and pseudohalide anions having composition [MnL(X)](ClO4), where X = NCS (1), X = N3 (2) and X = NCO (3), is described. The structure of 1 has been determined by single crystal X-ray diffraction studies. The structure determination reveals that the manganese atom is hexacoordinated with an unusual distortion in the coordination sphere of this type of linear pentadentate ligand and thiocyanato anion acts as a terminal donor

Synthesis, structure and properties of [Co(L)(NO₃)]ClO₄.2H₂O (L = tetradentate Schiff bases): Example of chelating nitrate

1565-1570The synthesis and characterization of three mononuclear cobalt (II) complexes of the type [Co(L)(NO3 )]ClO4.2H2O [L = N,N'-(bis(pyridin -2-yl) formylidene)butane- 1 ,4-diamine (bpfd). 1 ; N,N'-(bis(pyridin -2-yl) me thylidene)butane- l, 4-diamine (bpmd). 2; and N,N' -(bis(pyridin -2-yl)benzylidene)butane-1 ,4-diamine (bpbd), 3] are described here. In IR, the presence of v(NO3) band at ~1380 cm-1 with distinct splittings is strongly suggestive of coordination of nitrate instead of its simple counter anionic view. X-ray diffraction studies of [Co(bpfd )(NO3)] ClO4.2H2O (1), has been made for the exact knowledge of its coordination sphere. Structural analysis reveals cobalt(II) centre in a distorted octahedral environment with a CoN4O2 chromophore ligated by four N atoms of the tetradentate Schiff base along with two O atoms of nitrate in a chelating fashion. The tetradenlate chelator is folded in the butylenic pan. The mononuclear units in 1 are engaged in intermulecular C-H. . O and O-H .. . O hydrogen bondings leading to a 2D sheet. Electrochemical electron transfer studies in MeCN solutions show an oxidative response presumably due to cobalt(III)-cobalt(II) couple. All the complexes display intraligand 1(π-π*) fluorescence and intraligand 3(π-π*) phosphorescence in glassy solutions (MeOH at 77 K)

Two new supramolecular malonato complexes of manganese(II): synthesis, crystal structure and magnetic property

A mononuclear [Mn(mal)(bipy)(H2O)2] (1) and a dinuclear [Mn2(mal)(phen)3(H2O)2(Cl)]Cl (2) (mal=malonate dianion; bipy=2,2′-bipyridine and phen=1,10-phenanthroline) have been synthesised and structurally characterized by X-ray crystallography. The structure of complex 1 shows that each Mn(II) is linked with one bipy, two water molecules and a malonate ligand forming distorted octahedral environment and each mononuclear fragment through H-bonding interactions form 2D supramolecular network. The structure of complex 2 comprises to an asymmetric dinuclear cation which is bridged by a single anti–anti malonate ligand and chloride anions. The two distorted Mn(II) centres are separated by large distance 6.256(3) Å due to the anti–anti bridging mode. The magnetic behavior of complex 2 studied in the temperature range 300–2 K corresponds to a weak antiferromagnetic coupling through the MnOCOMn anti–anti conformation. The magnetic data were fitted based on H=−2JS1·S2, yielding the intramolecular coupling constant J=−0.35 cm-1 with g=1.92 and R=1.255×10-4. A mononuclear [Mn(mal)(bipy)(H2O)2] (1) and a dinuclear [Mn2(mal)(phen)3(H2O)2(Cl)]Cl (2) (mal=malonate dianion; bipy=2,2′-bipyridine and phen=1,10-phenanthroline) have been synthesised and structurally characterized by X-ray crystallography. The structure of complex 1 shows that each mononuclear fragment through H-bonding interactions forms 2D supramolecular network. The structure of complex 2 comprises to an asymmetric dinuclear cation which is bridged by a single anti–anti malonate ligand and chloride anions. The magnetic behavior of complex 2 studied in the temperature range 300–2 K and it corresponds to a weak antiferromagnetic coupling through the MnOCOMn anti–anti conformation

Three new thiocyanato-bridged complexes of cadmium(II): syntheses, X-ray crystal structures and thermal properties

Three new thiocyanato-bridged polymers of cadmium(II), [Cd(me4dpt)(SCN)2] n (1) [me4dpt = 3,3′-iminobis(N,N-dimethylpropylamine], [Cd(me2tn)(SCN)2] n (2) (me2tn = N,N′-dimethyl-1,3-propanediamine) and [{amphyH} {Cd(SCN)3}] n (3) (ampyH = 4-aminopyridinium cation), have been synthesized and their molecular structures determined through X-ray crystallography. In Complex 1 each square pyramidal mononuclear fragment is H-bonded (N − H…S) to form a 1D supramolecular chain. Complex 2 is a 1D coordination polymer in which each distorted octahedral cadmium(II) ion is linked with the four bridging thiocyanates and one diamine. The structure of 3 reveals anionic [Cd(SCN)3]− zigzag chains arranged in an approximately hexagonal array with the 4-aminopyridinum cations occupying triangular channels. Each chain is H-bonded (N−H…N) to form a 2D supramolecular network. Upon heating, 1 and 2 melt and transform to transparent solid masses at ambient temperature over a few days. On scratching, these turn to a fine powder. This phenomenon is repeatable. Complex 3 upon heating loses a 4-aminopyridine molecule and transforms to [H][Cd(SCN)3] at ˜195°C

A three-dimensional honeycomb-like network constructed with novel “sinusoidal” one-dimensional chains via hydrogen bonding and π−π interactions

A one pot reaction of MnCl<SUB>2</SUB>, acetylene dicarboxylate (C<SUB>4</SUB>O<SUB>2</SUB><SUP>2-</SUP>), and 1,2-bis(4-pyridyl)ethane (bpe) leads to a compound formulated as [{Mn(bpe)(H<SUB>2</SUB>O)<SUB>4</SUB>}(C<SUB>4</SUB>O<SUB>4</SUB>)·<SUB>4</SUB>.5H<SUB>2</SUB>O] and has been shown by single crystal structure analysis to be a three-dimensional network with hexagonal and rhombohedral channels encapsulating C<SUB>4</SUB>O<SUB>4</SUB><SUP>2-</SUP> and water molecules, constructed by the one-dimensional “sinusoidal” [Mn(bpe)(H<SUB>2</SUB>O)<SUB>4</SUB>]<SUB>n</SUB><SUP>2+</SUP> cationic chains through extensive hydrogen-bonding and π−π interactions

Self-assembly of new three-dimensional molecular architectures of Cd(II) and Ag(I)–Na(I) using croconate as a building block

Two new coordination polymers [Cd(C5O5)(NH3)2]n (1) and [AgNa(C5O5)(H2O)2]n (2) (C5O52− = croconate dianion) have been synthesized and structurally characterized. Complex 1 is a one-dimensional coordination polymer of cadmium(II) bridging through the croconate dianion. In complex 1 each croconate chelates (O1 and O2) to a Cd centre, which is linked to another Cd centre by O1 through an oxo-bridge and the oxygen atom O5, neighbouring O1, binds to a third Cd centre and the remaining two oxygen atoms (O3 and O4) remain pendant. The 1D coordination polymer undergoes H-bonding interactions through N–H(NH3)⋯O (pendant of C5O5) resulting in a 3D supramolecular network. Compound 2 is a heterometallic (Ag,Na) 3D coordination polymer. Here the croconate dianions interweave the alternately aligned and layered –Na–(μ–H2O)2–Na–(μ–H2O)2− and –Ag–Ag–Ag– chains. Two croconates chelate one Ag atom and two such Ag atoms from two neighbouring layers are bridged through croconate (O1, O2) and one oxygen of each croconate remains pendant (O3). The oxygen atom (O2) from every croconate binds a Na atom via an oxo-bridge. These types of tridentate and tetradentate linkage of croconate in complexes 1 and 2 are unprecedented. The thermal studies of the complexes corroborate that the ammonia molecules in 1 and the water molecules in 2 are involved in coordination together with strong H- bonding interactions