CP-AFM Molecular Tunnel Junctions with Alkyl Backbones Anchored Using Alkynyl and Thiol Groups: Microscopically Different Despite Phenomenological Similarity.

In this paper, we report results on the electronic structure and transport properties of molecular junctions fabricated via conducting probe atomic force microscopy (CP-AFM) using self-assembled monolayers (SAMs) of n-alkyl chains anchored with acetylene groups (CnA; n = 8, 9, 10, and 12) on Ag, Au, and Pt electrodes. We found that the current-voltage (I-V) characteristics of CnA CP-AFM junctions can be very accurately reproduced by the same off-resonant single-level model (orSLM) successfully utilized previously for many other junctions. We demonstrate that important insight into the energy-level alignment can be gained from experimental data of transport (processed via the orSLM) and ultraviolet photoelectron spectroscopy combined with ab initio quantum chemical information based on the many-body outer valence Green's function method. Measured conductance GAg < GAu < GPt is found to follow the same ordering as the metal work function ΦAu < ΦAu < ΦPt, a fact that points toward a transport mediated by an occupied molecular orbital (MO). Still, careful data analysis surprisingly revealed that transport is not dominated by the ubiquitous HOMO but rather by the HOMO-1. This is an important difference from other molecular tunnel junctions with p-type HOMO-mediated conduction investigated in the past, including the alkyl thiols (CnT) to which we refer in view of some similarities. Furthermore, unlike in CnT and other junctions anchored with thiol groups investigated in the past, the AFM tip causes in CnA an additional MO shift, whose independence of size (n) rules out significant image charge effects. Along with the prevalence of the HOMO-1 over the HOMO, the impact of the "second" (tip) electrode on the energy level alignment is another important finding that makes the CnA and CnT junctions different. What ultimately makes CnA unique at the microscopic level is a salient difference never reported previously, namely, that CnA's alkyne functional group gives rise to two energetically close (HOMO and HOMO-1) orbitals. This distinguishes the present CnA from the CnT, whose HOMO stemming from its thiol group is well separated energetically from the other MOs.

Beneficial action of cinnamic acid against ovarian cancer via network pharmacology analysis and the pharmacological activity assessment.

Naturally occurring cinnamic acid (CA) shows the beneficial potential in the suppression of ovarian cancer (OC). Currently, the in-depth molecular mechanisms of CA to suppress OC are still undescribed entirely. Thus, our research used the preclinical methodology through network pharmacology approach and pharmacological evaluation in vitro to unshroud the anti-OC targets and mechanisms of CA. Our data primarily identified 202 CA targets and 495 OC targets, and additional 45 shared targets in CA and OC were screened as presented in interaction network map. All 11 core targets in CA against OC were identified completely. The enrichment analysis of core targets revealed the biological functions and molecular mechanisms of CA against OC in details, including metabolic recombination and immune microenvironment regulation. Additionally, pharmacological evaluation data in vitro suggested that CA inhibited human OC cell proliferation in the time- and dose-dependent manners. In conclusion, CA can exert antineoplastic effects against OC effectively, and the pharmacological functions may directly actualize through a multi-target and multi-pathway avenue for suppressing OC.

[Isolation of endophytic fungi from medicinal plant Brucea javanica and their microbial inhibition activity].

OBJECTIVE: To isolate and identify endophytic fungi from Brucea javanica, and to detect the antimicrobial activity of these strains. METHODS: Endophytic fungi were isolated by tissue inoculation culture and identified by conventional morphological characteristic method. Seven kinds of pathogenic fungi and three kinds of bacteria were used as targeting microbes to test microbial inhibition activities by agar plate antagonistic action and modified agar gel diffusion methods, respectively. RESULTS: A total of 83 endophytic fungi strains were isolated from the root, stem, leaf and fruit of Brucea javanica. 34 strains were obtained from the stem, 32 strains were obtained from the leaf, 15 strains were isolated from the root and 2 strains came from the fruit. These 73 strains which had been identified attribute to 5 orders, 6 families and 12 genera. For the isolated strains, 14 strains had antifungal activities against at least one pathogenic fungi, 9 strains showed antibacterial activities against one or more bacteria. Especially, the strain YJ-17 which belonged to Phomopsis genus showed the best inhibitory effect on the targeting microbes. CONCLUSION: The endophytic fungi from Brucea javanica show diversity and microbial inhibition activity, and are worthy for further study on plant disease controlling.

[Quality standard of zhuang medicine jasmini sambacis flos].

OBJECTIVE: To study the qualitative and quantitative determination of Zhuang medicine Jasmini Sambacis Flos and establish its quality control standard. METHODS: Macroscopic, microscopic and TLC identification were adopted to carry out the qualitative identification, the mensuration of inspection items and extractum were according to the Chinese Pharmacopoeia. The contents of quercetin and kaempferide in Jasmini Sambacis Flos were determined by HPLC. RESULTS: The qualitative identification methods had strong specificity. In HPLC quantitative determination, the linear range of quercetin and kaempferide was in the range of 0.4008 - 3.2064 microg and 0.0403 - 3.2256 microg, respectively. CONCLUSION: These methods are simple, accurate and reproducible, and can be used to control the quality of Jasmini Sambacis Flos effectively.

[Research on quality standards of zhuang medicine Lonicerae dasystylae flos].

OBJECTIVE: To establish quality standard of Zhuang medicine Lonicera dasystyla, and provide scientific basis for the quality control of L. dasystyla. METHOD: Characteristics of materia medica, microscopic features, TLC indentification, inspection, extractum and determination of chlorogenic acid, macranthoidin B, dipsacoside B were carried out through the experience, microscopic, physical and chemical methods, respectively. The standard of quality control was formulated thereafter. RESULT: The characteristics of materia medica, microscopic features, TLC indentification were specified, the average contents of water, total ash, acid-insoluble ash, alcohol-soluble extracts, chlorogenic acid were 11.6%, 6.6%, 0.2% , 24.4%, 1.16%, respectively, the total amount of macranthoidin B and dipsacoside B was 3.13%. Quality standard of L. dasystyla was proposed according to experimental results. CONCLUSION: The quality of L. dasystyla can be controlled effectively with the quality standard.

[Study on the pharmacognosy identification and UV identification of Basella rubra].

OBJECTIVE: To provide reference for identification and development of Basella rubra. METHODS: Microscopic identification and UV spectrometry methods were used. RESULTS: Obvious characteristics were found in the tissue structures of the roots, stems and leaves . And Basella rubra showed some UV spectrometry characteristics. CONCLUSION: The results can be used as the reference for analyzing the quality of the crude drug.