[Clinical comprehensive evaluation of Ruyi Zhenbao Pills in treatment of osteoarthritis]

This study evaluated the clinical effectiveness of Ruyi Zhenbao Pills in the treatment of osteoarthritis, aiming to clarify its clinical advantages and promote rational drug use and related policy transformation. Following the relevant standards in Guidelines for the Comprehensive Evaluation of Drugs in Clinical Practice and Technical Specifications for the Clinical Comprehensive Evaluation of Chinese Patent Medicine, comprehensive research and related data on Ruyi Zhenbao Pills in the treatment of osteoarthritis were collected in the dimensions of safety, effectiveness, economy, innovation, suitability, accessibility, and traditional Chinese medicine(TCM) cha-racteristics(referred to as the "6+1" dimensions). Through evidence-based medicine, questionnaire surveys, health technology assessment, pharmacoeconomic evaluation, and other methods, a multi-criteria decision analysis(MCDA) model and CSC v2.0 software were used to comprehensively evaluate the clinical value of Ruyi Zhenbao Pills. Spontaneous reporting system data on adverse reactions and literature data indicate that the adverse reactions of Ruyi Zhenbao Pills are mostly general adverse reactions, with no reports of se-rious adverse reactions. The known risks are small, and its safety is rated as class A. It has been shown to effectively relieve joint pain and restore joint function in the treatment of osteoarthritis. However, more high-quality, large-sample randomized controlled trials are needed to further validate its effectiveness, which is rated as class B. There is evidence supporting its economic viability, and its economic is rated as class B. It demonstrates good clinical innovation, innovative enterprise service system, and industrial innovation, and innovation is rated as class A. Medical professionals and patients have a favorable perception of the suitability of Ruyi Zhenbao Pills, and further improvement can be made in terms of convenience of administration and promotion to facilitate rational drug use by healthcare professionals and patients. Suitability is rated as class B. The drug has a favorable price level, availability, and affordability, and accessibility is rated as class A. Ruyi Zhenbao Pills are a classic Tibetan medicinal prescription with excellent TCM theoretical characteristics. However, further research is needed on its use in human studies. TCM characteristics are rated as class B. Based on the evaluation results of the "6+1" dimensions, the comprehensive clinical evaluation is rated as grade B. Ruyi Zhenbao Pills have good clinical value in the treatment of osteoarthritis, and it is recommended to undergo the necessary procedures for conditional transformation into a policy for the management of essential clinical drugs.

[Report standards for clinical comprehensive evaluation of Chinese patent medicine]

The clinical comprehensive evaluation of drugs is an important basis for the return of clinical value, decision-making of medical and health authorities, and allocation of medical resources. In July 2021, the National Health Commission issued the Guidelines for the Management of Clinical Comprehensive Evaluation of Drugs(trial version 2021), which required the evaluation to be implemented from the six dimensions(safety, effectiveness, economy, innovation, suitability, and accessibility), and made detailed arrangements for the clinical comprehensive evaluation of drugs. As Chinese patent medicine differs from chemical medicines in terms of effective components and action modes, the clinical comprehensive evaluation of Chinese patent medicine should highlight the characteristics and advantages of traditional Chinese medicine(TCM) on the basis of general requirements of comprehensive clinical evaluation of drugs. At present, in the clinical comprehensive evaluation of Chinese patent medicine, unified report standards have not yet been generated, resulting in the uneven quality of existing reports. To standardize the clinical comprehensive evaluation report of Chinese patent medicine and improve its quality, the editorial team, based on the relevant policy documents of clinical comprehensive evaluation of drugs, formulated the clinical comprehensive evaluation report standards for Chinese patent medicine in combination with the previous practice and expert opinions. The report standards, containing seven sections with 15 items determined, focus on data source, evaluation content, evidence synthesis, quality control, and evaluation results supported with detailed interpretations to help researchers better understand and apply the report standards for clinical comprehensive evaluation of Chinese patent medicine, improve the report quality, and provide references for the decision-making by the national medical management authorities.

[General screening principles and inheritance paths of classic prescriptions in Tibetan medicine]

Due to the profound theoretical rationale, perfect diagnosis and treatment system, and characteristic medicinal resources, Tibetan medicine has been passed down to the present day as one of the four traditional medicine systems all over the world. With the development of modern society and the change in people's concept of seeking medical services, Tibetan medicine has gradually attracted wide attention by virtue of its natural, green and safe diagnosis and treatment characteristics, which enables it to be vigo-rously developed and inherited. There are numerous ancient books on Tibetan medicine, covering a large number of ancient prescriptions, which has laid a solid foundation for later scholars to thoroughly investigate the diagnosis and treatment rules in Tibetan medicine and apply them to modern clinical practice. Screening the classic prescriptions that meet modern clinical needs from those numerous ancient books is a new direction in the inheritance and development of Tibetan medicine. On the basis of historical origin and current application status of ancient prescriptions in Tibetan medicine, this paper preliminarily elaborated the definition of classic prescriptions of Tibetan medicine and their general screening principles and precautions, and also discussed the modern inheritance paths of classic prescriptions in Tibetan medicine from basic research, post-marketing evaluation, and the development of novel preparations. Considering the shortcomings in the present study, the key technical issues mentioned need to be more deeply explored and analyzed in future studies.

[Research advances in the mammalian target of rapamycin signaling pathway and its inhibitors in treatment of hepatocellular carcinoma]

Mammalian target of rapamycin (mTOR) is a serine/threonine protein kinase in the downstream of the phosphatidylinositol 3-kinases (PI3K) family. This kinase plays an important role in the development and progression of hepatocellular carcinoma (HCC). Preclinical data demonstrate that 40%-50% of HCC patients have dysregulated expression of the effectors of the mTOR signaling pathway, and the activation of the mTOR pathway is associated with poorly differentiated tumors, early tumor recurrence, and poor survival/prognosis. This article reviews the research advances in the potential role of the mTOR signaling pathway and its inhibitors in the treatment of HCC.

Characterizing and marker-assisting a novel chili pepper (Capsicum annuum L.) yellow bud mutant with cytoplasmic male sterility

Cytoplasmic male sterility (CMS) in pepper is a better way to produce hybrid seeds compared to manual production. We used the two sequence characterized amplified region (SCAR) markers (CRF-SCAR and CMS-SCAR₁₃₀) in CMS pepper, to identify the genotype. We assembled two CMS yellow bud mutants (YBM; YBM12-A and YBM12-B). This mutation in leaf color is controlled by a single dominant nuclear gene. The aim was to create a new hybrid seed production method that reduces the costs and increases F₁ hybrid seed purity. The results suggest that the CRF-SCAR and CMS-SCAR₁₃₀ markers can be used together in multiple generations to screen for restorer or maintainer genes. We found the marker linked to the restorer gene (Rf) in the C-line and F₁ hybrids, as well as partially in the F₂ generation, whereas it was not found in the sterile YBM12-A or the maintainer line YBM12-B. In the F₂ population, sterility and fertility segregated at a 3:1 ratio based on the CRF-SCAR marker. A 130 bp fragment was produced in the YBM12-A, F₁, and F₂ populations, suggesting that these lines contained sterile cytoplasm. A 140 bp fragment present in the YBM12-B and C-line indicated that these lines contained normal cytoplasm. In addition, we identified some morphological characters distinguishing sterile and fertile buds and flowers that may be linked to the sterility gene. If more restorer lines are identified, CMS expressing the YBM trait can be used in hybrid seed production.

Two Dimensional Antiferromagnetic Chern Insulator: NiRuCl6

Density functional theory (DFT) and Berry curvature calculations show that quantum anomalous Hall effect (QAHE) can be realized in two-dimensional(2D) antiferromagnetic (AFM) NiRuCl₆. The results indicate that NiRuCl₆ behaves as an AFM Chern insulator and its spin-polarized electronic structure and strong spin-orbit coupling (SOC) are responsible for the QAHE. By tuning SOC, we found that the topological property of NiRuCl₆ arises from its energy band inversion. Considering the compatibility between the AFM and insulators, AFM Chern insulator provides a new way to archive high temperature QAHE in experiments due to its different magnetic coupling mechanism from that of ferromagnetic (FM) Chern insulator.

Band gap engineering of early transition-metal-doped anatase TiO₂: first principles calculations

The thermal stability and electronic structures of anatase TiO2 doped with early transition metals (TM) (group III-B = Sc, Y and La; group IV-B = Zr and Hf; group V-B = V, Nb and Ta) have been studied using first principles calculations. It was found that all doped systems are thermodynamically stable, and their band gaps were reduced by 1-1.3 eV compared to pure TiO2. Doping with transition metals affects the strength of the hybrid orbital of TM-O bonding, and the band gap increases approximately linearly with the MP value of TM-O bonding.

Correlation between the band gap, elastic modulus, Raman shift and melting point of CdS, ZnS, and CdSe semiconductors and their size dependency

With structural miniaturization down to the nanoscale, the detectable quantities of solid materials no longer remain constant but become tunable. For the II-VI semiconductors example, the band gap expands, the elastic modulus increases, the melting point drops, and the Raman optical phonons experience red shift associated with creation of low frequency Raman acoustic modes that undergo blue shift with decreasing the dimensional scale. In order to understand the common origin of the size dependency of these seemingly irrelevant properties, we formulated these quantities for CdS, ZnS, and CdSe semiconductors from the perspectives of bond order-length-strength correlation and the local bond averaging approach. Consistency between the theory predictions and the measured size dependence of these quantities clarified that the undercoordination-induced local strain and quantum entrapment and the varied fraction of undercoordinated atoms of the entire solid correlate these quantities and dominate their size effect.

Size-suppressed dielectrics of Ge nanocrystals: skin-deep quantum entrapment

Although the dielectric behavior of nanostructured semiconductors has been intensively investigated, the physics behind observations remains disputed with possible mechanisms such as quantum confinement and dangling bond polarization. Here we show that theoretical reproduction of the measured dielectric suppression of Ge nanocrystals asserts that the dielectric suppression originates from the shorter and stronger bonds at the skin-deep surface, the associated local densification and quantum entrapment of energy. Coordination-imperfection induced local quantum entrapment perturbs the Hamiltonian that determines the band gap and hence, the process of electron polarization consequently.

Mechanically stiffened and thermally softened Raman modes of ZnO crystal

An analytical form connecting the energy shift of Raman modes directly to the bonding identities (order, nature, length, energy) of a specimen and the response of the bonding identities to the applied stimuli of temperature and pressure was presented for a deeper understanding of the atomistic origin of the ZnO Raman shift. Theoretical reproduction based on the BOLS correlation theory [Sun, C. Q. Prog. Solid State Chem. 2007, 35, 1] and the local bond average (LBA) approach [Sun, C. Q. Prog. Mater. Sci. 2009, 54, 179] of the measurements revealed that the thermally softened ZnO Raman modes arise from bond expansion and bond weakening due to vibration and that the pressure-stiffened Raman modes result from bond compression and bond strengthening due to mechanical work hardening. The developed approach could be useful in generalizing the lattice dynamics directly to the process of vibration and relaxation of a representative bond of the specimen under external stimuli.

Energy shifts of Si oxidation states in the system of Si nanocrystals embedded in SiO2 matrix

Energy shifts in the Si 2p levels of the five Si oxidation states Sin+ (n = 0, 1, 2, 3, 4) in the system of Si nanocrystals embedded in SiO2 matrix have been determined. The thermal annealing effect on the energy shifts has been studied. The result suggests that the Si nanocrystals and the SiO2 are thermally stable but the annealing can cause some structural deformations such as changes in the bond lengths and bond angles for the suboxides Si2O and SiO. The energy shifts generally show a linear dependence on the oxidation state n, suggesting that the energy shifts could be mainly determined by the nearest-neighbor oxygen atoms. It is shown that the chemical structures of the system are similar to those of the conventional SiO2/Si system in terms of the energy shifts.

Impedance labelless detection-based polypyrrole protein biosensor

A simple and sensitive electrochemical immunosensor with impedance labelless detection and novel data processing method was investigated. One-step copolymerization was used to electrochemically deposit an antibody impregnated polypyrrole film on a glassy carbon electrode surface for the immunosensor. Impedance measurements provided a labelless or reporterless method to detect antibody (Ab)-antigen (Ag) interactions. Dimensionless analysis was employed to successfully process the measured impedance data. Since the method derived unit impedance change to eliminate or reduce the variation of the bulk electronic properties of Ab/polypyrrole films, the signal to noise ratio (S/N) was significantly improved for high sensitivity and specificity. Nonspecific binding effect was studied by array electrode chips and was found out that the polypyrrole electrode without antibody attachment had much stronger nonspecific binding effect than the Ab/polypyrrole electrode; incubation followed by thoroughly washing significantly reduced the nonspecific interference. 10 pg/ml detection limit and superior specificity were achieved by the method, demonstrating a highly sensitive labelless immunosensor in comparison with the detection limit of ng -microgram/ml for the reported polypyrrole based immunosensors. The electrochemical immunosensors presented in this paper, due to its simplicity, low cost, high sensitivity and superior specificity, could be an invaluable tool for clinical diagnostics and could have potential applications in drug discovery, environmental and food analysis.

BMS-196085: a potent and selective full agonist of the human beta(3) adrenergic receptor

A series of 4-hydroxy-3-methylsulfonanilido-1,2-diarylethylamines were prepared and evaluated for their human beta(3) adrenergic receptor agonist activity. SAR studies led to the identification of BMS-196085 (25), a potent beta(3) full agonist (K(i)=21 nM, 95% activation) with partial agonist (45%) activity at the beta(1) receptor. Based on its desirable in vitro and in vivo properties, BMS-196085 was chosen for clinical evaluation.

Beta 3 agonists. Part 1: evolution from inception to BMS-194449

Screening of the BMS collection identified 4-hydroxy-3-methylsulfonanilidoethanolamines as full beta 3 agonists. Substitution of the ethanolamine nitrogen with a benzyl group bearing a para hydrogen bond acceptor promoted beta(3) selectivity. SAR elucidation established that highly selective beta(3) agonists were generated upon substitution of C(alpha) with either benzyl to form (R)-1,2-diarylethylamines or with aryl to generate 1,1-diarylmethylamines. This latter subset yielded a clinical candidate, BMS-194449 (35).(1)

Accumulation of mitochondrial DNA deletions in the malignant prostate of patients of different ages

It has been shown that mitochondrial DNA (mtDNA) deletion mutations accumulate with age in many tissues of the body. However, to date no one has shown that these deletions occur in the malignant prostate. Therefore, we hypothesize that such deletions do occur in the prostate and increasingly so with advanced age. To test this hypothesis, DNA was isolated from 34 radical prostatectomy specimens, and the entire mitochondrial genome (16.5kb) was amplified using long range PCR (LXPCR). The LXPCR products were visualized by gel electrophoresis, and the presence of low molecular weight (<16kb) bands was considered evidence of large mtDNA deletions. In order to show that these lower molecular weight LXPCR bands were not simply PCR artifact, we also digested mtDNA from a subset of the same patients and did Southern analysis with a mtDNA probe. Southern blots confirmed the existence of large deletions in every sample tested. Furthermore, several of the specific deletions identified by LXPCR were also seen in the Southern blots. From the LXPCR data, we found that as the age of the specimen increased, so did the average number of low molecular weight bands (i.e. deletions). In particular, one prominent band was seen at 1.2kb and became more consistent with advanced age.

[QTL analysis of anther length and ratio of stigma exsertion, two key traits of classification for cultivated rice (Oryza sativa L.) and common wild rice (O. rufipogon Griff.)]

A genetic map including 120 RFLP markers covering 1418.2 cM has been constructed using a BC1 population derived from a cross between common wild rice (Oryza rufipogon Griff.) from Dongxiang, Jiangxi Province, China, and an elite Indica variety Guichao 2. The linkage orders and genetic distances of markers in this map are consistent with the map constructed by Rice Genome Program of Japan except the markers of short arm of Chromosome 1. The QTLs analysis of anther length and ratio of stigma exsertion, two key traits of classification for cultivated rice and common wild rice indicated that there are two QTLs controlling anther length located at the region of C424-G39 of Chromosome 2, and C2807-C1263 of Chromosome 9 respectively. It was also found that there are two QTLs controlling ratio of stigma exsertion, and located at the region of C2289-R1553 of Chromosome 5 and G1149-R1963 of Chromosome 8 respectively. The detected QTLs affecting the key traits of classification for wild rice and cultivated rice will be useful for study of molecular evolution mechanism of cultivated rice.

[The comparison of genetic divergences and its relationships to heterosis revealed by SSR and RFLP markers in rice (Oryza sativa L.)]

Genetic divergences of 57 entries from 6 ecotypes of rice were surveyed by PCR analysis with 48 pairs of SSR and by Southern analysis by 50 RFLP probes. It was indicated that SSR markers detected polymorphism efficiently in comparison to RFLP markers, considering the allele numbers per locus and average gene diversity. Among all of 1,596 pairs, 1,452 pairs of genetic distances based on SSR data (GDSSR) were higher than the genetic distance based on RFLP data (GDRFLP) by average of 0.2492. The average GDSSR of entries within indica subspecies was 0.5483, but GDRFLP was only 0.2776. And the GDSSR and GDRFLP of entries with japonica subspecies were 0.577, 0.2405 respectively. The average GDSSR between varieties of interspecies was 0.8074, and the average GDRFLP was 0.7310. It is suggested that the GDSSR between varieties of introspecies or interspecies are higher than that of GDRFLP. The analysis of correlation between GDSSR and GDRFLP of any entry with other 56 entries indicated that the correlation coefficient for typical Indica or Japonica varieties were higher, but lower for Indica-like or Japonica-like materials. It was also found that the relationships between genetic distance based on these two kinds of markers and the yield of hybrid performance were not significant, but most of the correlation coefficient between heterosis and GDRFLP or GDSSR arrived at highly significant level.

Hydrogen peroxide mediates the cell growth and transformation caused by the mitogenic oxidase Nox1

Nox1, a homologue of gp91phox, the catalytic moiety of the superoxide (O(2)(-))-generating NADPH oxidase of phagocytes, causes increased O(2)(-) generation, increased mitotic rate, cell transformation, and tumorigenicity when expressed in NIH 3T3 fibroblasts. This study explores the role of reactive oxygen species (ROS) in regulating cell growth and transformation by Nox1. H(2)O(2) concentration increased approximately 10-fold in Nox1-expressing cells, compared with <2-fold increase in O(2)(-). When human catalase was expressed in Nox1-expressing cells, H(2)O(2) concentration decreased, and the cells reverted to a normal appearance, the growth rate normalized, and cells no longer produced tumors in athymic mice. A large number of genes, including many related to cell cycle, growth, and cancer (but unrelated to oxidative stress), were expressed in Nox1-expressing cells, and more than 60% of these returned to normal levels on coexpression of catalase. Thus, H(2)O(2) in low concentrations functions as an intracellular signal that triggers a genetic program related to cell growth.

A novel series of highly potent benzimidazole-based microsomal triglyceride transfer protein inhibitors

A series of benzimidazole-based analogues of the potent MTP inhibitor BMS-201038 were discovered. Incorporation of an unsubstituted benzimidazole moiety in place of a piperidine group afforded potent inhibitors of MTP in vitro which were weakly active in vivo. Appropriate substitution on the benzimidazole ring, especially with small alkyl groups, led to dramatic increases in potency, both in a cellular assay of apoB secretion and especially in animal models of cholesterol lowering. The most potent in this series, 3g (BMS-212122), was significantly more potent than BMS-201038 in reducing plasma lipids (cholesterol, VLDL/LDL, TG) in both hamsters and cynomolgus monkeys.

[A study of the genetic diversity of common wild rice (O. rufipogon Griff.) and cultivated rice (O. sativa L.) by RFLP analysis]

The genetic diversity of cultivated rice and common wild rice from 10 countries in Asia were evaluated by RFLP analysis using 44 probes of single copy. We used the parameters such as proportion of polymorphic loci (P), average number of alleles per locus (A), average number genotype per locus (Ng), degree of heterozygate per locus (Ho) and average gene diversity (Hs) showing genetic diversity. It is indicated that the common wild rice from China has the largest genetic diversity in the 10 countries, and the secondary is the common wild rice from India. The results also showed that the genetic diversity in Chinese common wild rice is larger than the genetic diversity in common wild rice of South and Southeast Asia. The average gene diversity (Hs) of South Asian wild rice is higher than Southeast Asian wild rice, while the parameters value of proportion of polymorphic loci (P), average number of alleles per locus (A) and average number genotype per locus (Ng), Southeast Asian wild rice is higher than South Asian wild rice. It is found that the genetic diversity in cultivated rice is obviously lower than in common wild rice. In the detected 44 loci, the number of polymorphic loci on O. sativa is as the same as 3/4 in O. rufipogon, the number of alleles in O. sativa is as the same as 60% in O. rufipogon, the number of genotype in O. sativa is as same as 1/2 in O. rufipogon. In O. sativa, the genetic diversity of indica is larger than that of japonica. O. rufipogon from China have highest value in degree of hetrozygate per locus (Ho), and Ho of wild rice is as two times as cultivated rice. It is showed that in the proceeding of wild rice evolved into cultivated rice, Ho and number of alleles was reduced, and the genetic diversity was decreased.

The effect of pH on the inhibition of bacterial growth by physiological concentrations of butyric acid: implications for neonates fed on suckled milk

Butyric acid is released from milk by pre-intestinal lipases during suckling. It is also known to inhibit bacterial growth. To investigate whether butyric acid may be a significant factor in controlling bacterial growth in the stomach of pre-weaned animals, the ability of butyric acid to inhibit growth of selected bacteria was tested over physiological ranges of pH and butyric acid concentrations. Six enteric and environmental strains of bacteria were used: two strains of Escherichia coli, Klebsiella pneumoniae, Enterococcus faecium, Enterococcus faecalis, and Enterococcus casseliflavus. At pH 4.5 and 5.0, the growth of all organisms was significantly inhibited in the presence of butyrate, and in some cases growth was completely arrested. At pH 6.0, butyric acid did not affect bacterial growth until the concentration reached 40 mM. The maximum concentration of butyric acid available in cow's milk after incubation with pre-gastric lipase is approximately 16 mM, which would be sufficient to prevent growth of the organisms tested at pH values occurring in the stomach. Therefore, butyric acid inhibition of bacterial growth may explain in part, the role of pre-intestinal lipases in young animals' natural defenses against bacteria in ingested food prior to weaning.

Differentiation and classification of parental lines and favorable genic interactions affecting F1 fertility in distant crosses of rice (Oryza sativa L.)

This study was intended to investigate the extent of genetic differentiation in parental lines of rice hybrids and to analyze the genetic basis underlying the fertility phenomenon in distant crosses. Two subsets of rice material (111 entries in total) were used, including 81 doubled-haploid (DH) lines and 30 Indica and Japonica rice varieties or lines (as a control). The DH lines was derived from a heterotic Indica/Japonica cross (Gui630/02428) by anther culture. The materials in the control represent a broad spectrum of the Asian cultivated rice gene pool including landraces, primitive cultivars, historically important cultivars, modern elite cultivars, super rice and parents of superior hybrids. In accordance with the NC II design, 57 out of the DH lines were test-crossed to two important wide compatibility lines: photoperiod-sensitive genetic male sterile (PGMS) line N422s and thermo-sensitive genetic male sterile (TGMS) line Peiai64s. The F1s and their parents, 182 entries in total, were examined for the performance of seven traits in a replicated field trial. All the rice materials was surveyed for polymorphisms using 92 RFLP markers selected from two published molecular marker linkage maps. Genotypes of the F1 hybrids at the molecular-marker loci were deduced from the parental genotypes. The analysis showed that there were two types of genetic differentiation in the two subsets of rice material; that is, qualitative differentiation in the control and quantitative differentiation in the DH lines. In addition, favorable genic interactions (both intra- or inter-locus) contributed to better increase the fertility in hybrids of distant crosses through incorporation of a wide-compatibility line as the female parent. Favorable genic interactions can be applied in hybrid rice breeding programs by selecting parents with an appropriate extent of genetic differentiation.

Dual metalloprotease inhibitors: mercaptoacetyl-based fused heterocyclic dipeptide mimetics as inhibitors of angiotensin-converting enzyme and neutral endopeptidase

A series of 7,6- and 7,5-fused bicyclic thiazepinones and oxazepinones were generated and incorporated as conformationally restricted dipeptide surrogates in mercaptoacyl dipeptides. These compounds are potent inhibitors of angiotensin-converting enzyme (ACE) and neutral endopeptidase (NEP) both in vitro and in vivo. Compound 1a, a 7,6-fused bicyclic thiazepinone, demonstrated excellent blood pressure lowering in a variety of animal models characterized by various levels of plasma renin activity and significantly potentiated urinary sodium, ANP, and cGMP excretion in a cynomolgus monkey assay. On the basis of its potency and duration of action, compound 1a (BMS-186716) was advanced into clinical development for the treatment of hypertension and congestive heart failure.

Aminodiol HIV protease inhibitors. Synthesis and structure-activity relationships of P1/P1' compounds: correlation between lipophilicity and cytotoxicity

A series of novel aminodiol inhibitors of HIV protease based on the lead compound 1 with structural modifications at P1' were synthesized in order to reduce the cytotoxicity of 1. We have observed a high degree of correlation between the lipophilicity and cytotoxicity of this series of inhibitors. It was found that appropriate substitution at the para position of the P1' phenyl group of 1 resulted in the identification of equipotent (both against the enzyme and in cell culture) compounds (10l, 10m, 10n, and 15c) which possess significantly decreased cytotoxicity.

New hydroxyethylamine HIV protease inhibitors that suppress viral replication

The synthesis of analogues of AcSerLeuAsn[Phe-HEA-Pro]IleValOMe (1, JG-365; where HEA stands for the hydroxyethylamine unit 2), a tight-binding inhibitor of HIVP, are reported. Systematic modification of the P3 and P3' regions of the inhibitors has led to smaller HIVP inhibitors that inhibit viral replication in HIV-infected and SIV-infected cell cultures. Six aliphatic and/or aromatic derivatives were prepared by replacing residues in the P3 regions of BocLeuAsn[Phe-HEA-Pro]IleValOMe. Aromatic side chains at P3 gave better inhibitors than aliphatic side chains. The better inhibitors in this series contained a beta-naphthylalanine or a biphenyl unit at P3. A second series of HIVP inhibitors were obtained by converting the P3 group into acyl groups. CbzAsn[Phe-HEA-Pro]IlePheOMe and Qua-Asn-[Phe-HEA-Pro]-Ile-Phe-OMe (where Qua = quinolin-2-ylcarbonyl) are potent HIVP inhibitors with Ki values equal to 1.0 and 0.1 nM, respectively. The inhibition constants were determined by using the continuous fluorometric assay developed by Toth and Marshall. The activities of the protease inhibitors for inhibition of SIV replication were determined in vitro using CEM x 174 cells. Inhibition of HIV infection was determined essentially as reported by Pauwels and co-workers. The anti-HIV assay was carried out in culture using CEM cells (a CD4+ lymphocyte line) infected with virus strain HTLV-IIIb with a multiplicity of infection of 0.1. Several analogues inhibited the cytopathic effect at concentrations of 0.1-0.8 microgram/mL. These results establish that good inhibitors of HIV protease that inhibit viral replication in infected lymphocytes in in vitro cell assays can be obtained from JG-365 when the AcSerLeu unit is replaced by aromatic acyl derivatives.

Convergence of somatosensory and baroreceptive inputs onto parabrachio-subfornical organ neurons in the rat: an electrophysiological study

Electrophysiological characteristics were described for neurons of the parabrachial nucleus (PBN) which receive baroreceptive and somatosensory inputs in the rat. Following focal electrical stimulation in the ipsilateral caudal nucleus of the tractus solitarii (NTS), the firing rates of these neurons were increased in 94 (55.6%), and decreased in 38 (22.5%). Fifty-three (54.5%) of 97 PBN neurons tested were excited, and 11 (11.3%) inhibited in response to contralateral common peroneal nerve (CPN) stimulation. Of these neurons, 52 were found to respond to both caudal NTS and CPN stimulation. Effects of subfornical organ (SFO) stimulation were also examined in 151 of 169 parabrachial neurons. 13 (7.7%) were activated antidromically and were located in the lateral division of the PBN, while 34 (22.5%) were affected orthodromically. Stimulation of the caudal NTS resulted in both a fall in the heart rate and changes of PBN neuronal firing rates. Similar effects were elicited by activating peripheral baroreceptors by the administration of phenylephrine, an alpha-adrenergic agonist. These results strongly indicate that: (1) the lateral PBN is involved in central cardiovascular control; (2) somatosensory and baroreceptive messages may converge onto some PBN neurons; and (3) some PBN neurons may relay baroreceptive information from the caudal NTS to the SFO.

Synthesis, conformation, and immunosuppressive activity of cyclosporines that contain epsilon-oxygen (4R)-4-[(E)-butenyl]-4,N-dimethyl-L-threonine analogues in the 1-position

A series of CsA analogues that contain novel epsilon-oxygen isosteres of (4R)-4-[(E)-butenyl]-4,N-dimethyl-L-threonine (MeBmt) in the 1-position were synthesized. The key steps for the syntheses of enantiomerically pure epsilon-oxygen MeBmt analogues 4-7 were based on the stereoselective epoxidation of cis-allylic alcohol derivative 12 with a peracid, followed by the application of a base-catalyzed intramolecular rearrangement of epoxyurethane 15, which was derived from the reaction of epoxy alcohol 14 and methyl isocyanate. All epsilon-oxygen MeBmt analogues have the same stereochemistry and the same functional groups as those on the alpha,beta,gamma-carbons of MeBmt except for the double bond of MeBmt, which is replaced by the -OCH2-group. The syntheses of the peptide portion of CsA analogues followed the strategy we reported previously. The immunosuppressive activities of CsA analogues 28a-e, determined by inhibition of concanavalin A stimulated thymocytes, showed that 28b, which has the closest structural resemblance to MeBmt, retains about 7-10% of activity of CsA, whereas the analogues 28a, 28c, and 28e retain about 2-5% activity. It is interesting to note that 28d, which has the larger benzyl group on the end of the side chain, is about 20-25% as active as CsA. Extensive conformational analyses by 1D and 2D NMR indicated that the conformation of the 33-membered peptide ring system for all CsA analogues was very similar to that of CsA. However, the NMR analyses revealed that the 1-position side chain of all these CsA analogues adopted a novel conformation in chloroform by forming a different intramolecular hydrogen bond between the beta-OH and the epsilon-oxygen of the same residue. The NMR data also suggest that the chloroform conformation of these CsA analogues is similar to the conformation observed in the crystal structure of CsA in that the 1-position side chain is folded across the cyclic peptide ring system.

Synthesis, conformation, and immunosuppressive activities of three analogues of cyclosporin A modified in the 1-position

The syntheses of three new cyclosporin A (CsA) analogues that contain novel MeBmt derivatives in the 1-position are described. The MeBmt analogue that contains an additional methyl group on C4, (2S,3R,6E)-4,4-dimethyl-3-hydroxy-2-(N-methylamino)-6-octenoic acid (MeBm2t), was synthesized in four steps beginning with the reaction of Pmz-Sar-OtBu with (4E)-2,2-dimethyl-4-hexenal. The C4 desmethyl analogue of MeBmt, (2S,3R,6E)-3-hydroxy-2-(N-methylamino)-6-octenoic acid (MeBth), was synthesized in nine steps by a route based on the Sharpless chiral epoxidation procedure. The alkynyl derivative of MeBmt, (2S,3R,4R)-4-methyl-3-hydroxy-2-(N-methylamino)-6-octynoic acid (MeByt), was synthesized by a modification of the procedure described by Tung et al. for the synthesis of MeBmt. Each MeBmt analogue was protected as the N,O-acetonide and coupled with the hexapeptide Abu-Sar-MeLeu-Val-MeLeu-Ala-OBzl. The resulting heptapeptide was deprotected and coupled with Fmoc-D-Ala-MeLeu-MeLeu-MeVal-OH. The resulting undecapeptides were deprotected and cyclized to give the corresponding CsA analogues. Conformational analysis by 1D and 2D NMR methods was carried out for each analogue in chloroform, and the results are compared with the corresponding solution conformations of CsA and dihydrocyclosporin. The immunosuppressive activities of each analogue, determined in concanavalin A stimulated thymocytes, are lower than obtained for CsA. The results establish the important effect the methyl group and the double bond in MeBmt have on the solution conformation of the 1-position residue in CsA and on immunosuppressive activity.

Glucosylsterols in extracts of Euryale ferox identified by high resolution NMR and mass spectrometry

The structures of three glucosylsterols in a glycolipid mixture from the product of the naturally dried medicinal plant Euryale ferox Salisb. have been elucidated by 500 MHz nuclear magnetic resonance and mass spectroscopic methods and characterized as follows: 24-methylcholest-5-enyl-3 beta-O-pyranoglucoside, 24-ethylcholest-5-enyl-3 beta-O-pyranoglucoside, and 24-ethylcholesta-5,22E-dienyl-3 beta-O-pyranoglucoside. These constituents may be the active substances of the medicinal plant.

Synthesis, biological activity, and conformational analysis of (2S,3R,4S)-MeBmt1-cyclosporin, a novel 1-position epimer of cyclosporin A

Cyclosporin A (CsA, 1), an immunosuppressive cyclic undecapeptide, contains a unique amino acid, (4R)-4-[(E)-butenyl]-4,N-dimethyl-L-threonine (MeBmt), that appears to be critically involved in the biological activity of CsA. In order to further explore the effect that structural elements in MeBmt have on the conformation and biological activity of CsA, the 4-epimer of MeBmt [(4S)-MeBmt, 2] and the corresponding CsA analogue [(4S)-MeBmt1-CsA, 3] have been synthesized. Biological assay using concanavalin A stimulated thymocytes indicated that (4S)-MeBmt1-CsA (3) has only 2-4% immunosuppressive activity relative to CsA. The NMR analysis by 1D and 2D NMR methods establishes the conformation of 3, of which the 33-membered cyclic peptide ring system in chloroform is very similar to that of CsA. However, the NMR analysis also reveals that the 1-position side chain orientation in (4S)-MeBmt1-CsA (3) is very different from that of CsA. Specifically, the (4S)-MeBmt alpha,beta-torsion angle (chi 1) has been rotated approximately 120 degrees relative to that of CsA, and the orientation of the butenyl side chain relative to the 33-membered peptide backbond is different. The orientation of the (4S)-MeBmt side chain is consistent with the possible conformations calculated for (4S)-MeBmt1-CsA (3) by using molecular mechanics (in vacuo) calculations. The conformational analysis suggests that the loss of biological activity for 3 results from an altered conformation of the 1-position side chain relative to the peptide backbond due to the changed chirality at C4 of MeBmt.