Silylated Tag-Assisted Peptide Synthesis: Continuous One-Pot Elongation for the Production of Difficult Peptides under Environmentally Friendly Conditions.

Addition of the silylated tag (STag) enables peptides to be highly soluble in CPME, allowing them to be used at high concentrations in a coupling reaction to enhance reactivity and achieve effective synthesis of sterically hindered peptides. We described the development of a continuous one-pot STag-assisted peptide synthesis platform as a method that provides near-stoichiometric, speedy, environmentally friendly, and scalable peptide synthesis.

Analysis of sweating efficiency and its effects on the heat strain alleviation of clothed subjects.

Sweating efficiency (SE) is essential for evaluating heat strain. The dripping of sweat off the skin surface of a nude subject occurs locally at an area where the secreted sweat exceeds the local evaporative capacity. However, in clothed subjects, "dripping" sweat is absorbed by clothing. In the present paper, the cooling efficiency of the sweating of a clothed subject is analyzed in relation to SE. First, typical patterns for the regional distribution of the sweat rate (SR) and the capacity of evaporation (CE) of a nude subject were introduced, and the dripping sweat rate was derived as a surplus of the SR over the CE; an equation of SE was derived from combinations of the two typical SR patterns and the uniform CE pattern. Then, the values of SE were calculated numerically, and the results were found to be approximately equal to those obtained experimentally by Alber-Wallerström & Holmér and theoretically from the equation of 1 - 0.5wsw2 used in ISO7933. Based on these results, the SE was improved by arranging the distribution of the CE by controlling air velocities over the body surface. Further, the improved SE was found to contribute to the heat strain alleviation of clothed subjects.

Electroclinical features of epilepsy in patients with juvenile type dentatorubral-pallidoluysian atrophy.

PURPOSE: To clarify the electroclinical characteristics of epileptic seizures in patients with juvenile type dentatorubral-pallidoluysian atrophy (DRPLA). METHODS: Seventeen patients with juvenile type DRPLA confirmed by genetic analysis were studied retrospectively. The clinical records of all 17 patients and the ictal video electroencephalography (EEG) recordings from 12 of the 17 patients were reviewed. RESULTS: Electroclinical studies in 12 patients identified 11 habitual seizures in 6 patients as partial seizures on ictal video EEG recordings. Clinical manifestations composed mainly of versions of the head and loss of consciousness. These partial seizures were persistently recorded throughout the clinical course. Brief generalized seizures (atypical absence and myoclonic seizure) were observed in 6 of 12 patients at the early stage. In contrast, generalized tonic-clonic seizures (GTCS) were recorded in four advanced stage patients who were almost bedridden. Semiological studies in 17 patients showed that the prevalence of partial seizures was significantly higher in patients with younger epilepsy onset (below 10 years of age; chi(2) test, p < 0.05) and that the age of epilepsy onset was significantly lower in patients with partial seizures than in those without partial seizures (Mann-Whitney U test, p = 0.02). However, the number of CAG repeats and age at clinical onset were not significantly different between two groups. DISCUSSION: Partial seizure is one of the common epileptic features in juvenile type DRPLA, especially in patients with younger epilepsy onset. Seizure types may be affected in an age-dependent manner and change evolutionally during progression of the clinical stage.

Synthesis and structure-activity relationships of a series of substituted 2-(1H-furo[2,3-g]indazol-1-yl)ethylamine derivatives as 5-HT2C receptor agonists.

A series of novel indazole derivatives were synthesized, and their structure-activity relationships examined in order to identify potent and selective 5-HT2C receptor agonists. Among these compounds, (S)-2-(7-ethyl-1H-furo[2,3-g]indazol-1-yl)-1-methylethylamine (YM348) had a good in vitro profile, that is, high agonistic activity to the human 5-HT2C receptor subtype (EC50 = 1.0 nM) and high selectivity over 5-HT2A receptors. This compound was also effective in a rat penile erection model when administered p.o.

Infrared spectroscopic study of polytypic effects on the crystal-growth mechanism of n-hexatriacontane (n-C36H74).

The solution-crystallization mechanism was investigated for two polytypes in the M011 modification of n-hexatriacontane (n-C36H74), single-layered structure Mon, and double-layered one Orth II. The crystal growth under controlled supersaturation was followed with a micro- Fourier-transform-infrared spectrometer equipped with an optical system for oblique transmission measurements. Supersaturation dependence of growth behavior was significantly different between Mon and Orth II. Although the Mon crystal continued growing at a supersaturation of 0.27, the overgrowth of Orth II on the (001) face of the Mon crystal was confirmed at supersaturations below 0.21. Such a polytypic transformation was not observed for the Orth II crystal at any supersaturation below 0.30. The growth rate of Mon showed a quadratic dependence on supersaturation, while that of Orth II was approximately linear, suggesting spiral growth and two-dimensional-nucleation mechanisms for Mon and Orth II, respectively.

Study of thermodynamic stabilities of polytypes of n-C36H74 by solubility measurements and incoherent inelastic neutron scattering.

The thermodynamic properties of the two polytypes of n-hexatriacontane (n-C36H74), single-layered structure Mon and double-layered structure Orth II have been investigated by means of solubility measurements and incoherent inelastic neutron scattering. The solubility measurements reveal that Orth II is more stable than Mon by 1.2 kJ/mol because of the advantage of larger entropy. The neutron scattering measurements show that the vibrational modes of Orth II shift to the lower frequencies compared with those of Mon in the frequency region below 120 cm(-1). The advantage of Orth II in vibrational entropy due to the low-frequency shifts is estimated to be 9.6 J K(-1)/mol at 288 K under the harmonic approximation, which nearly agrees with the entropy difference of 6.8 J K(-1)/mol between Mon and Orth II determined by solubility measurements. These results suggest that the difference in vibrational entropy due to low-frequency modes mainly contributes to the relative thermodynamic stabilities of polytypic structures of long-chain compounds. From the frequency of methyl torsional mode, it is suggested that the cohesive force at the lamellar interface is stronger in Mon than in Orth II.

The influence of polytypic structures on the M011-->M101 solid-solid phase transition of n-C36H74: an application of the oblique infrared transmission method.

The molecular displacements on the M011-->M101 phase transition of n-hexatriacontane (n-C36H74) have been investigated with an IR microscope designed for the oblique infrared transmission method. It has been clarified that two polytypic structures of the M011 modification, single-layered structure (Mon) and double-layered one (Orth II), both transform to the M101 modification of single-layered structure with their respective mechanisms. On the M011(Mon)-->M101 transition, the inclination direction of molecular axis is changed by 90 degrees through an intermediate state in which the molecular chain is set perpendicular to the basal plane of the single crystal. On the other hand, a polymorphic-polytypic composite structural change on the M011(Orth II)-->M101 transition is accomplished through two kinds of molecular displacements occurring alternately along the stacking direction of molecular layers.

Synthesis and pharmacological evaluation of piperidinoalkanoyl-1,2,3,4-tetrahydroisoquinoline derivatives as novel specific bradycardic agents.

A series of piperidinoalkanoyl-1,2,3,4-tetrahydroisoquinoline derivatives were synthesized, and their bradycardic activities were investigated in the isolated right atria of guinea pigs and in conscious rats. These efforts identified the achiral compound 2f, which exhibited potent and long-lasting bradycardic activity with minimal effects on mean blood pressure in conscious rats.

Synthesis and pharmacological evaluation of N-acyl-1,2,3,4-tetrahydroisoquinoline derivatives as novel specific bradycardic agents.

A series of N-acyl-1,2,3,4-tetrahydroisoquinoline derivatives were synthesized and evaluated for their bradycardic activities in isolated guinea pig right atria and in urethane-anesthetized rats. These efforts resulted in identification of the compound 8a, which exhibits potent bradycardic activity with minimal influence on mean blood pressure in urethane-anesthetized rats. Oral administration of compound 8a to conscious rats revealed increased potency and prolonged duration of action when compared to Zatebradine.

Synthesis and pharmacological evaluation of 1-oxo-2-(3-piperidyl)-1,2,3,4- tetrahydroisoquinolines and related analogues as a new class of specific bradycardic agents possessing I(f) channel inhibitory activity.

A series of 1-oxo-2-(3-piperidyl)-1,2,3,4-tetrahydroisoquinolines and related analogues were prepared and evaluated for their bradycardic activities in isolated right atrium and in anesthetized rats. (+/-)-6,7-Dimethoxy-2-[1-[3-(3,4-methylenedioxyphenoxy)propyl]-3-piperidyl]-1,2,3,4-tetrahydroisoquinoline (4) was chosen as a lead, and structural modifications were performed on the tetrahydroisoquinoline ring and the terminal aromatic ring. The modifications on the tetrahydroisoquinoline ring revealed that the 1-oxo-1,2,3,4-tetrahydroisoquinoline ring system was optimum structure for both in vitro potency and in vivo efficacy. Furthermore, methoxy, ethoxy, and methoxycarbonyl groups were identified as preferable substituents on the terminal aromatic ring. One of the 1-oxo-1,2,3,4-tetrahydroisoquinoline derivatives, (R)-10a, was further evaluated for its bradycardic activity and inhibitory activity against I(f) currents. Compound (R)-10a demonstrated potent bradycardic activity in rats with minimal influence on blood pressure after oral administration. The compound also showed inhibition of I(f) currents (IC(50) = 0.32 muM) in guinea pig pacemaker cells.

(+/-)-2-(3-Piperidyl)-1,2,3,4-tetrahydroisoquinolines as a new class of specific bradycardic agents.

A series of (+/-)-2-(3-piperidyl)-1,2,3,4-tetrahydroisoquinolines were prepared and their bradycardic activities were examined in isolated guinea-pigs' right atria and in anesthetized rats. Modifications on the benzyl moiety of the parent compound, 1, led to the identification of compound 11e as a potent and specific bradycardic agent.

Pathway development and pilot library realization in diversity-oriented synthesis: exploring Ferrier and Pauson-Khand reactions on a glycal template.

Through a correlation of the ability of small molecules to bind biological macromolecules and their ability to modulate cellular and organismal processes, chemistry can inform biology and vice versa. Diversity-oriented organic synthesis (DOS), which aims to provide structurally complex and diverse small molecules efficiently, can play a key role in such chemical genetic studies. Here we illustrate the trial-and-error experimentation that can refine an initial pathway-planning exercise and result eventually in an effective diversity pathway. By exploring Ferrier and Pauson-Khand reactions on a glycal template, we have developed efficient and stereoselective syntheses of tricyclic compounds. In this pathway, diversity results from the substituents and their spatial relationships about the tricyclic rings. A pilot split-pool library synthesis of 2500 tricyclic compounds highlights the use of planning considerations in DOS and a "one-bead, one-stock solution" technology platform. Additionally, it illustrates a promising synthetic pathway for future chemical genetic studies.