Feasible structure-modification strategy for inhibiting aggregation-caused quenching effect and constructing exciton conversion channels in acridone-based emitters.

Acridone (ADO) is an anthracene-based derivative that plays an important role in the construction of organic light-emitting diode emitters. However, ADO suffers from an aggregation-caused quenching (ACQ) effect because of its strong intermolecular stacking and tendency to form excimers. In this work, we appended some electron-donating moieties with different rotors and substitution patterns on ADO to prepare six ADO-based derivatives. In addition, a benzonitrile group was introduced onto the nitrogen atom of the ADO unit to fabricate a high-energy charge-transfer (CT) state that formed a reverse intersystem crossing (RISC) channel. Systematic spectral measurements revealed that the rotors effectively suppressed the ACQ effect. In addition, aggregation-enhanced emission (AEE) was observed for the ADO derivatives modified with triphenylamine (TPA) because of the existence of multiple rotors and propeller-like conformation in TPA block. Theoretical calculations and the performance of electroluminescent devices containing the derivatives confirmed that the exciton conversion channel was constructed at the high-energy level and activated during device operation. Although the performance of these ADO-based derivatives was not ideal in terms of efficiency, the results confirmed the feasibility of this structure modification strategy to simultaneously inhibit the ACQ effect and construct excitons conversion channels.

[Identification of Curcuma herbs using XGBoost algorithm in electronic nose odor fingerprint].

This article aims to identify four commonly applied herbs from Curcuma genus of Zingiberaceae family,namely Curcumae Radix( Yujin),Curcumae Rhizoma( Ezhu),Curcumae Longae Rhizoma( Jianghuang) and Wenyujin Rhizoma Concisum( Pianjianghuang). The odor fingerprints of those four herbal medicines were collected by electronic nose,respectively. Meanwhile,XGBoost algorithm was introduced to data analysis and discriminant model establishment,with four indexes for performance evaluation,including accuracy,precision,recall,and F-measure. The discriminant model was established by XGBoost with positive rate of returning to 166 samples in the training set and 69 samples in the test set were 99. 39% and 95. 65%,respectively. The top four of the contribution to the discriminant model were LY2/g CT,P40/1,LY2/Gh and LY2/LG,the least contributing sensor was T70/2. Compared with support vector machine,random forest and artificial neural network,XGBoost algorithms shows better identification capacity with higher recognition efficiency. The accuracy,precision,recall and F-measure of the XGBoost discriminant model forecast set were 95. 65%,95. 25%,93. 07%,93. 75%,respectively. The superiority of XGBoost in the identification of Curcuma herbs was verified. Obviously,this new method could not only be suitable for digitization and objectification of traditional Chinese medicine( TCM) odor indicators,but also achieve the identification of different TCM based on their odor fingerprint in electronic nose system. The introduction of XGBoost algorithm and more excellent algorithms provide more ideas for the application of electronic nose in data mining for TCM studies.

A rapid discrimination of authentic and unauthentic Radix Angelicae Sinensis growth regions by electronic nose coupled with multivariate statistical analyses.

Radix Angelicae Sinensis, known as Danggui in China, is an effective and wide applied material in Traditional Chinese Medicine (TCM) and it is used in more than 80 composite formulae. Danggui from Minxian County, Gansu Province is the best in quality. To rapidly and nondestructively discriminate Danggui from the authentic region of origin from that from an unauthentic region, an electronic nose coupled with multivariate statistical analyses was developed. Two different feature extraction methods were used to ensure the authentic region and unauthentic region of Danggui origin could be discriminated. One feature extraction method is to capture the average value of the maximum response of the electronic nose sensors (feature extraction method 1). The other one is to combine the maximum response of the sensors with their inter-ratios (feature extraction method 2). Multivariate statistical analyses, including principal component analysis (PCA), soft independent modeling of class analogy (SIMCA), and hierarchical clustering analysis (HCA) were employed. Nineteen samples were analyzed by PCA, SIMCA and HCA. Then the remaining samples (GZM1, SH) were projected onto the SIMCA model to validate the models. The results indicated that, in the use of feature extraction method 2, Danggui from Yunnan Province and Danggui from Gansu Province could be successfully discriminated using the electronic nose coupled with PCA, SIMCA and HCA, which suggested that the electronic-nose system could be used as a simple and rapid technique for the discrimination of Danggui between authentic and unauthentic region of origin.

[Accurate identification of Psammosilene tunicoides and its confused species by systematic identification method].

OBJECTIVE: To develop an effective identification method for accurately discriminating Psammosilene tunicoides and its confused species by the combined method of microscopic identification and molecular identification, so-called systematic identification of Chinese materia medica (SICMM). METHOD: P. tunicoides and its confused species were accurately discriminated by SICMM method, which was established by comprehensively use of microscopic identification and DNA identification method. The DNA identification included the following analysis: the BLAST alignment, specific bases and N-J phylogenetic tree analysis. RESULT: The cluster crystals were not observed in P. tunicoides, but great deals of them were found in Silene viscidula. Further more, big differences of ITS sequence were observed and analyzed between P. tunicoides and its confused specie of S. viscidula. CONCLUSION: The system method is a scientific and accurate method for the identification of P. tunicoides and its counterfeit species.

Interventional effect of processing temperature on anti-angiogenesis of Coptis chinensis and screening of active components by UPLC-MS/MS on quail chick chorioallantoic membrane model.

ETHNOPHARMACOLOGICAL RELEVANCE: Coptis chinensis Franch. (CC), as a commonly used heat-clearing and toxin-resolving traditional Chinese herbal medicine, has gained increased attention for its anti-tumor activity. However, little is known about the anti-tumor angiogenesis effect of CC and its possible bioactive components. Also, it has been shown that temperature affects the quality of CC, albeit whether and how it affects the anti-angiogenic activity of CC is currently unknown. AIM OF THE STUDY: To determine the processing temperatures (40, 60, 80, 120, 140, 150, 160 and 200 °C) at which CC has the strongest anti-angiogenic effect and speculate the possible bioactive components. MATERIALS AND METHODS: The q-CAM model was constructed to explore the anti-angiogenesis agents of CC. The angiogenesis inhibition effects of CC samples at different processing temperatures and its seven alkaloids were determined based on morphological observation and vascular area proportion analysis. UPLC-MS/MS was employed to screen the potent active components of CC on anti-angiogenesis. RESULTS: All the intervention by CC at different processing temperatures and its seven alkaloids could inhibit angiogenesis on q-CAM vessels, as evidenced by a poor vasular development in morphological observation and a low vascular area proportion in vascular quantitative analysis, most evident in CC processed at 40 °C and palmatine. LC-MS revealed that palmatine displayed strongest inhibitory effect on q-CAM vessels with a high absorption due to its stable structure. And the maternal nucleus transformation phenomenon of CC alkaloids was found in the quail embryo metabolism. CONCLUSIONS: The q-CAM models in conjunction with the UPLC-MS/MS technique could be a useful tool for assessing tumor angiogenesis and screening tumor-targeted medicines. Processing temperature can affect the anti-angiogenesis effect of CC because of its function on the content of alkaloids, and palmatine can be considered as a prospective anti-angiogenic drug.

The commercial antibiotics with inherent AIE feature: In situ visualization of antibiotic metabolism and specifically differentiation of bacterial species and broad-spectrum therapy.

The research on pharmacology usually focuses on the structure-activity relationships of drugs, such as antibiotics, to enhance their activity, but often ignores their optical properties. However, investigating the photophysical properties of drugs is of great significance because they could be used to in situ visualize their positions and help us to understand their working metabolism. In this work, we identified a class of commercialized antibiotics, such as levofloxacin, norfloxacin, and moxifloxacin (MXF) hydrochloride, featuring the unique aggregation-induced emission (AIE) characteristics. By taking advantage of their AIE feature, antibiotic metabolism in cells could be in situ visualized, which clearly shows that the luminescent aggregates accumulate in the lysosomes. Moreover, after a structure-activity relationship study, we found an ideal site of MXF to be modified with a triphenylphosphonium and an antibiotic derivative MXF-P was prepared, which is able to specifically differentiate bacterial species after only 10 min of treatment. Moreover, MXF-P shows highly effective broad-spectrum antibacterial activity, excellent therapeutic effects and biosafety for S. aureus-infected wound recovery. Thus, this work not only discovers the multifunctionalities of the antibiotics but also provides a feasible strategy to make the commercialized drugs more powerful.

[Detection method and pattern recognition of ginseng and American ginseng pieces by electronic nose].

OBJECTIVE: To distinguish the ginseng and American ginseng pieces accurately and rapidly by electronic nose technology and principal component analysis (PCA) method. METHOD: The optimum conditions of electronic nose for ginseng and American ginseng pieces, such as sample size and volume, headspace volume, incubation time and temperature were determined by the orthogonal test, the data were processed by the normalization method and the preprocessed data were analyzed PCA. RESULT: The detection methods of ginseng and American ginseng pieces was established by electronic nose, and the odor fingerprint figures of ginseng and American ginseng pieces were obtained, and ginseng and American ginseng pieces were distinguished by PCA recognition pattern. CONCLUSION: A new accurate and rapid method to distinguish ginseng and American ginseng pieces was established by electronic nose detection.

Aggregation-induced emission luminogen with excellent triplet-triplet upconversion efficiency for highly efficient non-doped blue organic light-emitting diodes.

By combining aggregation-induced emission (AIE) effect and a triplet-triplet upconversion (TTU) process, a blue emitter with excellent photoluminescence quantum efficiency and high upconversion efficiency in the film state is developed, from which a highly efficient non-doped blue TTU organic light-emitting diode (TTU-OLED) was realized.

Simultaneously achieving high capacity storage and multilevel anti-counterfeiting using electrochromic and electrofluorochromic dual-functional AIE polymers.

With the advent of the big data era, information storage and security are becoming increasingly important. However, high capacity information storage and multilevel anti-counterfeiting are typically difficult to achieve simultaneously. To address this challenge, herein, two electrochromic and electrofluorochromic dual-functional polymers with aggregation-induced emission (AIE) characteristics were rationally designed and facilely prepared. Upon applying voltages, the absorption and fluorescence spectra of the AIE polymers can undergo reversible changes, accompanied by variation of their color and emission. By utilizing the controllable characteristics of the polymers, dual-mode display devices were fabricated via a simple spraying technique. More interestingly, a four-dimensional color code device was constructed by adding color change multiplexing to the two-dimensional space, thereby achieving high capacity information storage. Moreover, the color code device can also be applied in the multilevel anti-counterfeiting area. The encrypted information can be dynamically converted under different voltages. Thus, the AIE polymers show great promise for applications in multidimensional information storage and dynamic anti-counterfeiting, and the design strategy may provide a new avenue for advanced information storage and high security technology.

Cationic Tricyclic AIEgens for Concomitant Bacterial Discrimination and Inhibition.

New ionic compounds with aggregation-induced emission (AIE) feature has been widely studied. These AIE-based luminogens (AIEgens) not only effectively resolve aggregation-caused quenching (ACQ) problems that are encountered for most of conventional fluorescent dyes, but also exhibit promising applications in biological imaging, potentially for a wide variety of diseases. However, such an AIE system needs to be further developed. In this work, a series of novel cationic AIEgens that are comprised of tricyclic 2-aminopyridinium derivatives with seven-membered rings are designed and synthesized via a simple, multicomponent reaction. Notably, these AIEgens exhibit the ability to specifically stain gram-positive bacteria. Moreover, a specific AIEgen, BMTAP-7, possesses highly efficient bacteriostatic ability for Staphylococcus aureus (S. aureus) in both liquid medium and solid agar plates, which have a minimum inhibitory concentration (MIC) between 4 and 8 µg mL-1 . Using live-cell imaging and a wash-free process, it is observed that hydrophilic AIEgens are localized to mitochondria, whereas lipophilic AIEgens display specific staining of lysosomes. These AIEgens with bacteriostatic activity hold great promise for distinguishing between bacterial types and inhibiting bacterial infections in situ.

Theoretical study and experimental validation on the optical emission processes in "free" and "locked" pyrazine derivatives.

The excited-state properties of the "free" and "locked" pyrazine derivatives are investigated in solution. DCFP with "free" phenyls is theoretically calculated to be non-emissive due to the non-radiative energy dissipation through strong Duschinsky rotation effect, in agreement with the available experimental result. Surprisingly, DCBP with "bi-locked" phenyls is also calculated to be nonluminous. The emission of DCAP with "conjoined" architecture is predicted to be weaker than DCPP with "single-locked" phenyls, quite contrary to our intuition but further validated by the experimental measurement. The construction of four-, five- and six-membered ring respectively in DCBP, DCAP and DCPP is found to be the major structural origin for the descending relaxation energy in these "locked" systems, thus giving rise to the ascending luminescence order. Our work not only provides strategy for the molecular design of efficient organic light-emitting materials, but also offers valuable insight into the aggregation-induced emission phenomena.

White-light emission from a single heavy atom-free molecule with room temperature phosphorescence, mechanochromism and thermochromism.

Two heavy atom-free luminophores (SHB2t and SDB2t) with simple molecular structures have been synthesized via Suzuki coupling reactions in which both display white-light emission with prompt fluorescence and room temperature phosphorescence (RTP) in the solid state. The impressive RTP of the luminophores is produced by a synergistic effect of the strong intermolecular hydrogen bonding in addition to the spin-orbit coupling of the sulfonyl oxygen atoms and the moderate singlet-triplet energy gaps (ΔEST). These factors facilitate the intersystem crossing (ISC) process to generate triplet excitons in which the molecular conformations become immobilized to effectively suppress radiationless decay. Under the stimuli of mechanical force and solvent vapor, the RTP of SHB2t and SDB2t can be simply turned off and on by breaking and reforming the robust hydrogen bonding, which leads to remarkable and reversible mechanochromism between white and deep-blue emission. Moreover, two different thermochromic processes have been observed for the pristine and ground samples of SDB2t, in which a tricolor switching system between white, deep-blue and blue emission has been successfully achieved through the sequential control of grinding, heating and fuming. From detailed studies we have determined that the mechanism for the thermochromism of SDB2t is correlated with the rearrangement of the white-light emitting molecules to a new packing mode without RTP emission.

Achieving remarkable mechanochromism and white-light emission with thermally activated delayed fluorescence through the molecular heredity principle.

Achieving high contrast mechanochromism (Δλem,max > 100 nm) and white-light emission under mild conditions from a single compound with a simple structure is a great challenge. Herein, we report a novel dual-emissive compound, namely SCP, with an asymmetric molecular structure that fully inherits the photophysical properties of the parent molecules SC2 and SP2. SCP shows high contrast, linearly tunable mechanochromism and bright white-light emission arising from a combination of traditional fluorescence and thermally activated delayed fluorescence (TADF). The origin of the dual-emission for SCP was demonstrated based on the analysis of the white-emitting single crystals. In addition, a mechanism of luminochromism for SCP driven by the application of mechanical force is proposed. These observations present a rational design strategy for the development of high performance multi-functional materials for white-light emission.

Rapid discrimination of Apiaceae plants by electronic nose coupled with multivariate statistical analyses.

Since many Apiaceae plants, with antimicrobial activities, have similar characteristics, it is difficult to separate them from one another. The aim of this study is to distinguish different kinds of Apiaceae plants by an electronic nose (EN) and multivariate statistical analyses. The dynamic response of a metal oxide sensor array to Apiaceae plants showed that the response values and different kinds of Apiaceae plants were positively related. Atractylodis Macrocephalae Rhizoma (as the reference sample) and other nine different kinds of Apiaceae plants were measured. Multivariate statistical analyses, including linear discrimination analysis (LDA), principal component analysis (PCA), hierarchical clustering analysis (HCA) and artificial neural network (ANN), were employed. The result showed that these samples could be classified correctly by this method, which suggested that the EN system could be used as a simple and rapid technique for the discrimination of Apiaceae plants.

Rapid discrimination of Chinese red ginseng and Korean ginseng using an electronic nose coupled with chemometrics.

Red ginseng is a precious and widely used traditional Chinese medicine. At present, Chinese red ginseng and Korean ginseng are both commonly found on the market. To rapidly and nondestructively discriminate between Chinese red ginseng and Korean ginseng, an electronic nose coupled with chemometrics was developed. Different red ginseng samples, including Chinese red ginseng (n=30) and Korean ginseng (South Korean red ginseng and North Korean red ginseng n=26), were collected. The metal oxide sensors on an electronic nose were used to measure the red ginseng samples. Multivariate statistical analyses, including principal component analysis (PCA), discriminant factorial analysis (DFA) and soft independent modeling of class analogy (SIMCA), were employed. All of the samples were analyzed by PCA. Most of the samples were used to set up DFA and SIMCA models, and then the remaining samples (Nos. 9, 10, 17, 18, 29, 30, 34, 43, 44, 50, and 51) were projected onto the DFA and SIMCA models in the form of black dots to validate the models. The results indicated that Chinese red ginseng and Korean ginseng were successfully discriminated using the electronic nose coupled with PCA, DFA and SIMCA. The checking scores of the DFA and SIMCA models were 100. The samples projected onto the DFA and SIMCA models were all correctly discriminated. The DFA and SIMCA models were robust. Electronic nose technology is a rapid, accurate, sensitive and nondestructive method to discriminate between Chinese red ginseng and Korean ginseng.