X-ray Crystallographic Structures of Two Lamotrigine Analogues: (I) 3,5-Diamino-6-(2-chlorophenyl)-1,2,4-triazine Water Solvate and (II) 3,5-Diamino-6-(3,6-dichlorophenyl)-1,2,4-triazine Methanol Solvate

Abstract The X-ray crystal structures of two lamotrigine derivatives (I) 3,5-diamino-6-(2-chlorophenyl)-1,2,4-triazine, C₉H₈ClN₅, (465BL) as a hydrate, and (II) 3,5-diamino-6-(3,6-dichlorophenyl)-1,2,4-triazine, C₉H₇Cl₂N₅, (469BR) as a methanol solvate, have been carried out at liquid nitrogen temperature and room temperature, respectively. A detailed comparison of the two structures is given. Both are centrosymmetric with (I) in the orthorhombic space group Pbca, a = 12.2507(3), b = 15.7160(6), c = 21.71496(9) ?, Z = 16, and (II) in the monoclinic space group C2/c, a = 38.553(3), b = 4.9586(2), c = 14.546(2) ?, β = 111.59(1)°, Z = 8. Final R indices [I > 2sigma(I)] for (I) are R1 = 0.0670, wR2 = 0.1515 and for (II) R1 = 0.0434, wR2 = 0.1185. Structure (I) has water of crystallization in the lattice and (II) includes a solvated CH₃OH. Structure (I) is characterized by having two crystallographically independent molecules, A and B, of 465BL, per asymmetric unit. Molecule B has a very unusual feature in that the 2-chlorophenyl ring is statistically disordered, occupying site (1) in 87.5% of the structure and site (2) in 12.5% of the structure. Sites (1) and (2) are related by an exact 180° pivot of the phenyl ring about the ring linkage bond. The presence of two independent molecules per asymmetric unit provides an ideal opportunity for the conformational flexibility of the molecule 465BL to be studied. Structure (I) also includes a further unusual feature in that the lattice contains one fully occupied water molecule and an additional solvated water which is only 33% occupied. Index Abstract Rex A. Palmer, Brian S. Potter, Michael J Leach and Babur Z. Chowdhry The crystal structures of two lamotrigine analogues: (I) 3, 5-diamino-6-(2-chlorophenyl)-1, 2, 4-triazine, water solvate and (II) 3, 5-diamino-6-(3,6-dichlorophenyl)-1, 2, 4-triazine methanol solvate are presented. Structure (I) includes two molecules per asymmetric unit labeled A and B where molecule B is unusually disordered having Cl in either position 2 (87.5% occupied) or position 6 of the phenyl ring (12.5% occupied), the two sites being related by 180deg rotation about the ring linkage bond. Molecule I(A) on the other hand shows no disorder. The relative orientations of the two rings in I(A and B) and in II is shown to be different. Lamotrigine and analogues have been investigated for some time for their effects on the central nervous system. For example both lamotrigine and 5-(2,3,5-trichlorophenyl)-2,4-diaminopyrimidine (code name BW 1003C87) are voltage-gated sodium channel blockers as well as blocking the release of the neurotransmitter glutamate. BW 1003C87 has also been shown to reduce the release of glutamate evoked by veratrine in brain tissue, providing a therapeutic approach in both cerebral ischemia and epilepsy [B. S. Meldrum, J. H. Swan, M. J. Leach, M. H. Millan, R. Gwinn, K. Kadota, S. H Graham, J. Chen, R. P. Simon , Brain Res., 1992, 593, 1.]. This is one of a series of papers on the structures of lamotrigine analogues.      

Low Temperature X-ray Structures of Two Crystalline Forms (I) and (II) of the Pyrimidine Derivative and Sodium Channel Blocker BW1003C87: 5-(2,3,5-Trichlorophenyl)-2,4-diaminopyrimidine

Abstract The X-ray crystal structures of two crystalline forms of 5-(2,3,5-trichlorophenyl)-2,4-diaminopyrimidine, C₁₀H₇Cl₃N₄ (code name BW1003C87) (I) and (II), have been carried out at liquid nitrogen temperature. A detailed comparison of the two structures is given. Both are centrosymmetric, with structure (I) in the triclinic space group P unit cell a = 6.4870(10), b = 9.216(2), c = 12.016(2) ?, α = 75.78(3)°, β = 89.95(3)°, γ = 83.45(3)°, V = 691.5(2) ?³, Z = 2 and density (calculated) = 1.544 Mg/m3; and (II) in the monoclinic space group P2₁/c, unit cell a = 12.000(2), b = 7.518(2), c = 13.450(3) ?, β = 97.87(3)°, V = 1202.0(5) ?³, Z = 4, Density (calculated) = 1.600 Mg/m3. Structure (I) includes a solvated CH₃OH in the lattice. Final R indices [I > 2sigma(I)] are R1 = 0.0427, wR2 = 0.1075 for (I) and R1 = 0.0487, wR2 = 0.1222 for (II). R indices (all data) are R1 = 0.0470, wR2 = 0.1118 for (I) and R1 = 0.0623, wR2 = 0.1299 for (II). 5-Phenyl-2,4 diaminopyrimidine and 6-phenyl-1,2,4 triazine derivatives, which include lamotrigine (3,5-diamino-6-(2,3-dichlorophenyl)-1,2,4-triazine), have been investigated for some time for their effects on the central nervous system. Both lamotrigine and 5-(2,3,5-trichlorophenyl)-2,4-diaminopyrimidine (code name BW1003C87), the subject of the present study, are anticonvulsant as well as neuroprotective in models of brain ischaemia and in a model of white matter ischaemia. BW1003C87 is a sodium channel blocker which also reduces the release of the neurotransmitter glutamate. The three dimensional structures reported here form part of a newly developed data base for the detailed investigation of members of this drug family and their biological activities. Index Abstract Rex A. Palmer, Brian S. Potter, Michael J Leach and Babur Z. Chowdhry 5-(2,3,5-trichlorophenyl)-2,4-diaminopyrimidine occurs in two crystalline forms whose X-ray structures are described here. The molecular conformations in (I) and (II) are quite distinct as illustrated, the ring linkage torsion angle differing by 23.5 deg. (I) has a methanol solvate molecule in the lattice.      

Low Temperature X-ray Crystallographic Structures of Two Lamotrigine Analogues: (I) 2-Methyl,3-amino, 5-imino-6-(2,3-dichlorophenyl)-1,2,4-triazine Water Solvate and (II) 2-Methyl,3,5-diamino-6-(2,3-dichlorophenyl)-1,2,4-triazine Isethionate,Hemi-hydrate

Abstract The X-ray crystal structures of two lamotrigine derivatives (I) 2-methyl, 3-amino, 5-imino-6-(2, 3-dichlorophenyl)-1,2,4-triazine, C₁₀H₉Cl₂N₅, as the hemi hydrate and (II) 2-methyl,3,5-diamino-6-(2,3-dichlorophenyl)-1,2,4-triazine, C₁₀H₁₀Cl₂N₅, as the isethionate-water solvate, have been carried out at liquid nitrogen temperature. A detailed comparison of the two structures is given. Both are monoclinic and centrosymmetric, with (I) in space group C2/c, and (II) in space group P2₁/n. For (I) the unit cell dimensions are a = 19.5466(10), b = 7.5483(4), c = 15.7861(8) ?, β = 91.458(3)°, volume = 2328.4(2) ?³, Z = 8, density = 1.590 Mg/m³; for (II). For (II) the unit cell dimensions are a = 6.0566(2), b = 11.0084(4) c = 23.9973(9) ?, β = 92.587(3)°, volume = 1598.35(10) ?³, Z = 4, density = 1.597 Mg/m³. For (I) final R indices [I > 2sigma(I)] are R1 = 0.0356, wR2 = 0.0782 and R indices (all data) are R1 = 0.0424, wR2 = 0.0817. For (II) final R indices [I > 2sigma(I)] are R1 = 0.0380, wR2 = 0.0871 and R indices (all data) R1 = 0.0558, wR2 = 0.0949. Both structures have a molecule of water of crystallization and (II) also includes a solvated CH₃SO₃. Comparisons are made between the two structures. Structure (I) is very unusual in having a = NH group at position C5′ on the triazine ring. No other examples of this particular substitution, which is usually −NH₂, have been reported. Index Abstract Rex A. Palmer, Brian S. Potter, Michael J Leach and Babur Z. Chowdhry The crystal structures of (I) 2-methyl,3-amino, 5-imino-6-(2, 3-dichlorophenyl)-1, 2, 4-triazine, water solvate and (II) 2-methyl,3, 5-diamino-6-(2, 3-dichlorophenyl)-1, 2, 4-triazine isethionate water solvate are presented. The relative orientation of the two rings is shown to vary. Lamotrigine and analogues have been investigated for some time for their effects on the central nervous system. For example both lamotrigine and 5-(2,3,5-trichlorophenyl)-2,4-diaminopyrimidine (code name BW 1003C87) are voltage-gated sodium channel blockers as well as blocking the release of the neurotransmitter glutamate [D. R. Riddall, M. J. Leach, J. Garthwaite, Mol. Pharmacol. 2006, 69 (1), 278.3], BW10003C87 (like lamotrigine) has been shown to exhibit excitatory amino acid antagonist activity similar to that of three conventional antiepileptic drugs phenytoin, carbamazepine and phenobarbital [R. Lingamaneni, H. C. Hemmings Jr., Epilepsy Res. 1993, 15, 101.]. BW 1003C87 has also been shown [B. S. Meldrum, J. H. Swan, M. J. Leach, M. H. Millan, R. Gwinn, K. Kadota, S. H Graham, J. Chen, R. P. Simon , Brain Res., 1992, 593, 1.] to reduce the release of glutamate evoked by veratrine in brain tissue, providing a therapeutic approach in both cerebral ischemia and epilepsy. This is one of a series of papers on the structures of lamotrigine analogues.      

Central Nervous System Drugs: Low Temperature X-ray Structures of (I) the Base 5-(2,3-Dichlorophenyl)-2,4-diamino-6-fluoromethyl-pyrimidine (4030W92) and (II) 5-(2,6-Dichlorophenyl)-1-H-2,4-diamino-6-methyl-pyrimidine methanesulphonic acid salt (227C89)

Abstract  The X-ray crystal structures of (I), the base 4030W92, 5-(2,3-dichlorophenyl)-2,4-diamino-6-fluoromethyl-pyrimidine, C₁₁H₉Cl₂FN₄, and (II) 227C89, the methanesulphonic acid salt of 5-(2,6-dichlorophenyl)-1-H-2,4-diamino-6-methyl-pyrimidine, C₁₁H₁₁Cl₂N₄ · CH₃O₃S, have been carried out at low temperature. A detailed comparison of the two structures is given. Structure (I) is non-centrosymmetric, crystallizing in space group P2₁ with unit cell a = 10.821(3), b = 8.290(3), c = 13.819(4) ?, β = 105.980(6)°, V = 1191.8(6) ?³, Z = 4 (two molecules per asymmetric unit) and density (calculated) = 1.600 mg/m³. Structure (II) crystallizes in the triclinic space group with unit cell a = 7.686(2), b = 8.233(2), c = 12.234(2) ?, α = 78.379(4), β = 87.195(4), γ = 86.811(4)°, V = 756.6(2) ?³, Z = 2, density (calculated) = 1.603 mg/m³. Final R indices [I > 2sigma(I)] are R1 = 0.0572, wR2 = 0.1003 for (I) and R1 = 0.0558, wR2 = 0.0982 for (II). R indices (all data) are R1 = 0.0983, wR2 = 0.1116 for (I) and R1 = 0.1009, wR2 = 0.1117 for (II). 5-Phenyl-2,4 diaminopyrimidine and 6-phenyl-1,2,4 triazine derivatives, which include lamotrigine (3,5-diamino-6-(2,3-dichlorophenyl)-1,2,4-triazine), have been investigated for some time for their effects on the central nervous system. The three dimensional structures reported here form part of a newly developed data base for the detailed investigation of members of this structural series and their biological activities. Index Abstract  Low temperature X-ray structures of (I): the base 5-(2,3-dichlorophenyl)-2,4-diamino-6-fluoromethyl-pyrimidine (4030W92); and (II): 5-(2,6-dichlorophenyl)-1-H-2,4-diamino-6-methyl-pyrimidine methanesulphonic acid salt (227C89) are presented. Both drugs act on the central nervous system. (I) crystallizes in non-centrosymmetric space group P2₁ with two molecules A and B per asymmetric unit cell and (II) is triclinic in space group . The absolute configuration of (I) is determined.      

Monitoring the Evolution of Asynchrony between Mean Arterial Pressure and Mean Cerebral Blood Flow via Cross-Entropy Methods

Cerebrovascular control is carried out by multiple nonlinear mechanisms imposing a certain degree of coupling between mean arterial pressure (MAP) and mean cerebral blood flow (MCBF). We explored the ability of two nonlinear tools in the information domain, namely cross-approximate entropy (CApEn) and cross-sample entropy (CSampEn), to assess the degree of asynchrony between the spontaneous fluctuations of MAP and MCBF. CApEn and CSampEn were computed as a function of the translation time. The analysis was carried out in 23 subjects undergoing recordings at rest in supine position (REST) and during active standing (STAND), before and after surgical aortic valve replacement (SAVR). We found that at REST the degree of asynchrony raised, and the rate of increase in asynchrony with the translation time decreased after SAVR. These results are likely the consequence of the limited variability of MAP observed after surgery at REST, more than the consequence of a modified cerebrovascular control, given that the observed differences disappeared during STAND. CApEn and CSampEn can be utilized fruitfully in the context of the evaluation of cerebrovascular control via the noninvasive acquisition of the spontaneous MAP and MCBF variability.     

Chemical Diversity and Potential Target Network of Woody Peony Flower Essential Oil from Eleven Representative Cultivars (Paeonia × suffruticosa Andr.)

Woody peony (Paeonia × suffruticosa Andr.) has many cultivars with genetic variances. The flower essential oil is valued in cosmetics and fragrances. This study was to investigate the chemical diversity of essential oils of eleven representative cultivars and their potential target network. Hydro-distillation afforded yields of 0.11–0.25%. Essential oils were analyzed by GC-MS and GC-FID which identified 105 compounds. Three clusters emerged from multivariate analysis, representative of phloroglucinol trimethyl ether (‘Caihui’), citronellol (‘Jingyu’, ‘Zhaofen’ and ‘Baiyuan Zhenghui’) and mixed (the rest of the cultivars) chemotypes. ‘Zhaofen’ and ‘Jingyu’ also exhibited low levels of other rose-related compounds. The main components were subjected to a target network approach. Drug-likeness screening gave 20 compounds with predictive blood–brain barrier permeation. Compound target network identified six key compounds, namely nerol, citronellol, geraniol, geranic acid, cis-3-hexen-1-ol and 1-hexanol. Top enriched terms in GO, KEGG and DisGeNET were mostly related to the central nervous system (CNS). Protein—protein interactions revealed a core network of 14 targets, 11 of which were CNS-related (targets for antidepressants, analgesics, antipsychotics, anti-Alzheimer’s and anti-Parkinson’s agents). This work provides useful information on the production of woody peony essential oils with specific chemotypes and reveals their potential importance in aromatherapy for alternative treatment of CNS disorders.     

微量元素锰污染对人体的危害

介绍了微量元素锰污染的来源、毒性机理以及对人体的危害。慢性锰中毒主要表现为神经毒性、生殖毒性,锰也能引起肝脏、肺等脏器的损害。由于锰不能被生物降解,在环境中只能发生各种形态之间的转化,所以锰造成的污染消除很困难,对人体引起的影响和危害成为人们更为关注的问题。     

Conductive Biomaterials as Substrates for Neural Stem Cells Differentiation towards Neuronal Lineage Cells

The injuries and defects in the central nervous system are the causes of disability and death of an affected person. As of now, there are no clinically available methods to enhance neural structural regeneration and functional recovery of nerve injuries. Recently, some experimental studies claimed that the injuries in brain can be repaired by progenitor or neural stem cells located in the neurogenic sites of adult mammalian brain. Various attempts have been made to construct biomimetic physiological microenvironment for neural stem cells to control their ultimate fate. Conductive materials have been considered as one the best choices for nerve regeneration due to the capacity to mimic the microenvironment of stem cells and regulate the alignment, growth, and differentiation of neural stem cells. The review highlights the use of conductive biomaterials, e.g., polypyrrole, polyaniline, poly(3,4‐ethylenedioxythiophene), multi‐walled carbon nanotubes, single‐wall carbon nanotubes, graphene, and graphite oxide, for controlling the neural stem cells activities in terms of proliferation and neuronal differentiation. The effects of conductive biomaterials in axon elongation and synapse formation for optimal repair of central nervous system injuries are also discussed.     

Antimycobacterial and anticancer activity of newly designed cinnamic acid hydrazides with favorable toxicity profile

A series of twelve novel hybrids of cinnamic acid and thiocarbohydrazones were designed, synthesized in high yield using a simple coupling strategy via acid chlorides, and evaluated for their impact against Mycobacterium tuberculosis (Mtb) and cancer cells survival. Among them, compound 3 demonstrated strong anti-Mtb activity by reducing bacilli survival for>90 % in all three treated Mtb isolates, whereas isoniazid and rifampicin did not. Moreover, compound 3 didn’t affect vitality of HepG-2 cells, implying on advantageous hepatotoxicity profile compared to current therapeutic options for tuberculosis. Compounds 2a and 3b displayed as strong inducers of apoptosis in A549 cells, both activating intrinsic caspase pathway and cell cycle arrest at the G0/G1 phase. Subsequent analyses disclosed differences in their activities, where 3b has ability to induce production of mitochondrial superoxide anions, while 2a significantly inhibited cellular mobility. More importantly, 3b considerably affected viability of HepG-2 and HaCaT cells, whereas 2a had moderate impact only on the later. Molecular modeling studies indicated high permeability and good absorption through the human intestine, and moderate aqueous solubility with poor blood–brain barrier permeability. In summary, our results reveal that novel compounds 3 and 2a represent promising agents for tuberculosis and cancer treatment, respectively, indicating that further investigation needs to be performed to clarify the mechanisms of their anti-Mtb and anticancer activity.