Analysis of quality evaluation and optimal harvest period of Aurantii Fructus from different sources using UHPLC-Q-TOF-MS/MS.

INTRODUCTION: The active constituents in Aurantii Fructus sourced from different regions within Hunan Province exhibit variations, with certain samples demonstrating substandard quality. OBJECTIVES: The aim of this study is to conduct a comparative analysis of the chemical composition and quality of Aurantii Fructus from various sources, establish a robust methodology for quality evaluation, and determine the optimal harvesting period. MATERIALS AND METHODS: The components of Aurantii Fructus were qualitatively analyzed using a non-targeted metabolomics approach. Multivariate statistical analyses were conducted to identify potential markers, enabling qualitative and quantitative evaluation of the quality and optimal harvest period of Aurantii Fructus. RESULTS: Overall, 155 compounds were identified in Aurantii Fructus, with Huangpi exhibiting the highest number of components. Eleven potential markers were selected to assess the quality of Aurantii Fructus. The average content of Huangpi was the highest, indicating a high level of similarity. The samples' overall scores were ordered as follows: Huangpi > Xiangcheng > Choucheng > Daidai. Anren and Changde's Huangpi exhibited high contents, being rich in chemical components, resulting in favorable scores. Similarly, Changde's Xiangcheng displayed significant medicinal value. As the harvest time was delayed, there was an increase in fruit size, accompanied by thinner peels and a continuous decrease in the contents of potential markers. The best harvest period of Aurantii Fructus was within 1 week before and after the Lesser Heat. CONCLUSION: The present study establishes a precise and efficient method for evaluating the quality of Aurantii Fructus, thereby providing more comprehensive insights into its composition. This research lays the foundation for subsequent development and utilization of Aurantii Fructus.

[Transcriptional regulation mechanism of differential accumulation of flavonoids in different varieties of Lonicera macranthoides based on metabonomics and transcriptomics].

This study aims to explore the molecular regulatory mechanism of the differential accumulation of flavonoids between 'Xianglei' and the wild type of Lonicera macranthoides. The flowers, stems, and leaves of the two varieties of L. macranthoides were collected. Ultra-performance liquid chromatography-mass spectrometry(UPLC-MS) and high-throughput sequencing(RNA-seq) were employed to screen out the differential flavonoids, key differentially expressed genes(DEGs) and transcription factors(TFs). Fourteen DEGs were randomly selected for verification by qRT-PCR. The results showed that a total of 17 differential flavonoids were obtained, including naringin chalcone, apigenin, and quercetin. The transcriptomic analysis predicted 19 DEGs associated with flavonoids, including 2 genes encoding chitin synthase(CHS) and 3 genes encoding chalcone isomerase(CHI). The regulatory network analysis and weighted gene co-expression network analysis(WGCNA) screen out the key enzyme genes CHS1, FLS1, and HCT regulating the accumulation of flavonoids. MYB12 and LBD4 may be involved in the biosynthesis of flavonoids by regulating the expression of key enzyme genes CHS1, FLS1, and HCT. The qRT-PCR and RNA-seq results were similar regarding the expression patterns of the 14 randomly selected DEGs. This study preliminarily analyzed the transcriptional regulatory mechanism for the differential accumulation of flavonoids in the two varieties of L. macranthoides and laid a foundation for further elucidating the regulatory effects of key enzyme genes and TFs on the accumulation of flavonoids.

[Three-dimensional multi-component analysis of Aurantii Fructus quality and research on influencing factors].

The present study explored the consistency of the content proportions of active components of Aurantii Fructus and analyzed the influencing factors based on three-dimensional multi-component analysis. A total of 839 Aurantii Fructus samples in 65 research articles were analyzed using the three-dimensional multi-component analysis mode. The content data of flavonoid components(naringin, hesperidin, neohesperidin, narirutin, and nobiletin), coumarin components(meranzin and gluconolactone), and alkaloid(synephrine) in 386 samples which met the criteria of 2020 edition of the Chinese Pharmacopoeia were extracted and adjusted to percentages, and the content ratios between components were calculated. The influencing factors of Aurantii Fructus quality were analyzed. The results showed content ratios of components as follows: neohesperidin∶naringin in the range of 0.4-1.2; narirutin∶naringin in the range of 0.02-0.16; hesperidin∶naringin in the range of 0.01-0.3; nobiletin∶naringin in the range of 0.000 588 3-0.069 68; synephrine∶naringin in the range of 0.02-0.042; gluconolactone∶naringin in the range of 0.001-0.01; meranzin∶naringin in the range of 0.000 4-0.035. The quality of Aurantii Fructus was closely related to the origin, variety, harvesting time, and processing method of medicinal materials. Harvesting time had a greater impact on the quality of Aurantii Fructus, and the origin and variety had a certain impact on the quality of Aurantii Fructus. The findings of this study indicated that the ratios between flavonoid components, flavonoids and coumarin components, and flavonoids and alkaloids fluctuated. The production base should optimize the varieties, harvesting period, and processing methods of Aurantii Fructus to provide a scientific basis for the production of high-quality Aurantii Fructus.

[Mining and identification of members of MYB transcription factor family in Lonicera macranthoides].

As a large family of transcription factors, the MYB family plays a vital role in regulating flower development. We studied the MYB family members in Lonicera macranthoides for the first time and identified three sequences of 1R-MYB, 47 sequences of R2R3-MYB, two sequences of 3R-MYB, and one sequence of 4R-MYB from the transcriptome data. Further, their physicochemical properties, conserved domains, phylogenetic relationship, protein structure, functional information, and expression were analyzed. The results show that the 53 MYB transcription factors had different conserved motifs, physicochemical properties, structures, and functions in wild type and 'Xianglei' cultivar of L. macranthoides, indicating their conservation and diversity in evolution. The transcript level of LmMYB was significantly different between the wild type and 'Xianglei' cultivar as well as between flowers and leaves, and some genes were specifically expressed. Forty-three out of 53 LmMYB sequences were expressed in both flowers and leaves, and 9 of the LmMYB members showed significantly different transcript levels between the wild type and 'Xianglei' cultivar, which were up-regulated in the wild type. The results provide a theoretical basis for further studying the specific functional mechanism of the MYB family.

[Research progress on Rhododendron molle in treatment of rheumatoid arthritis].

Rheumatoid arthritis(RA), as a chronic autoimmune disease, has a high incidence and disability rate, causing significant suffering to patients. Due to its complex pathogenesis, it has not been fully elucidated to date, and its treatment remains a challenging problem in the medical field. Although western medicine treatment options have certain efficacy, they require prolonged use and are expensive. Additionally, they carry risks of multiple infections and adverse reactions like malignancies. The Chinese herbal medicine Rhododendron molle is commonly used in folk medicine for its properties of dispelling wind, removing dampness, calming nerves, and alleviating pain in the treatment of diseases like rheumatic bone diseases. In recent years, modern clinical and pharmacological studies have shown that the diterpenoids in R. molle are effective components, exhibiting immune-regulatory, anti-inflammatory, and analgesic effects. This makes it a promising candidate for treating RA with a broad range of potential applications. However, R. molle has certain toxic properties that hinder its clinical application and lead to the wastage of its resources. This study reviewed recent research progress on the mechanism of R. molle in preventing and treating RA, focusing on its chemical components, anti-inflammatory and analgesic properties and summarized the adverse reactions associated with R. molle, aiming to offer new ideas for finding natural remedies for RA and methods to reduce toxicity while enhancing the effectiveness of R. molle. The study seeks to clarify the safety and efficacy of R. molle and its extracts, providing a theoretical basis for its application prospects and further promoting the development and utilization of R. molle resources.

Highly Efficient Red/NIR-Emissive Fluorescent Probe with Polarity-Sensitive Character for Visualizing Cellular Lipid Droplets and Determining Their Polarity.

Lipid droplets (LDs), which are ubiquitous organelles existing in almost all eukaryotic cells, have attracted a lot of attention in the field of cell biology over the last decade. For the biological study of LDs via fluorescence imaging, the superior LD fluorescent probes with environmental polarity-sensitive character are highly desired and powerful but are very scarce. Herein, we have newly developed such a kind of fluorescent probe named LDs-Red which enables us to visualize LDs and to further reveal their polarity information. This fluorescent probe displays the advantages of intense red/near-infrared emission, high LD staining specificity, and good photostability; thus, it would be very useful for LD fluorescence imaging application. As a result, the three-dimensional confocal imaging to visualize spatial distribution of LDs and the multicolor confocal imaging to simultaneously observe LDs and other cellular organelles have been realized using this new LD fluorescent probe. Furthermore, the polarity-sensitive emission character of this probe enables us to quantitatively determine the LD polarity via spectral scan imaging. Consequently, the cancer cells (HepG2, HeLa, and Panc02) displaying lower polarity of LDs than the normal cells (L929, U251, and HT22) have been systematically demonstrated. In addition, this polarity-sensitive probe displaying shorter fluorescence wavelengths in cancer cells than in normal cells has an important and potential ability to distinguish them.

Embedding Proteins within Spatially Controlled Hierarchical Nanoarchitectures for Ultrasensitive Immunoassay.

Modulating the precise self-assembly of functional biomacromolecules is a critical challenge in biotechnology. Herein, functional biomacromolecule-assembled hierarchical hybrid nanoarchitectures in a spatially controlled fashion are synthesized, achieving the biorecognition behavior and signal amplification in the immunoassay simultaneously. Biomacromolecules with sequential assembly on the scaffold through the biomineralization process show significantly enhanced stability, bioactivity, and utilization efficiency, allowing tuning of their functions by modifying their size and composition. The hierarchically hybrid nanoarchitectures show great potential in construction of ultrasensitive immunoassay platforms, achieving a three order-of-magnitude increase in sensitivity. Notably, the well-designed HRP@Ab2 nanoarchitectures allow for optical immunoassays with a detection range from picogram mL-1 to microgram mL-1 on demand, providing great promise for quantitative analysis of both low-abundance and high-residue targets for biomedical applications.

Anti-diabetic drug canagliflozin hinders skeletal muscle regeneration in mice.

Canagliflozin is an antidiabetic medicine that inhibits sodium-glucose cotransporter 2 (SGLT2) in proximal tubules. Recently, it was reported to have several noncanonical effects other than SGLT2 inhibiting. However, the effects of canagliflozin on skeletal muscle regeneration remain largely unexplored. Thus, in vivo muscle contractile properties recovery in mice ischemic lower limbs following gliflozins treatment was evaluated. The C2C12 myoblast differentiation after gliflozins treatment was also assessed in vitro. As a result, both in vivo and in vitro data indicate that canagliflozin impairs intrinsic myogenic regeneration, thus hindering ischemic limb muscle contractile properties, fatigue resistance recovery, and tissue regeneration. Mitochondrial structure and activity are both disrupted by canagliflozin in myoblasts. Single-cell RNA sequencing of ischemic tibialis anterior reveals a decrease in leucyl-tRNA synthetase 2 (LARS2) in muscle stem cells attributable to canagliflozin. Further investigation explicates the noncanonical function of LARS2, which plays pivotal roles in regulating myoblast differentiation and muscle regeneration by affecting mitochondrial structure and activity. Enhanced expression of LARS2 restores the differentiation of canagliflozin-treated myoblasts, and accelerates ischemic skeletal muscle regeneration in canagliflozin-treated mice. Our data suggest that canagliflozin directly impairs ischemic skeletal muscle recovery in mice by downregulating LARS2 expression in muscle stem cells, and that LARS2 may be a promising therapeutic target for injured skeletal muscle regeneration.

[Cloning and function analysis of chalcone isomerase gene and chalcone synthase gene in Lonicera macranthoides].

In order to explore the functions of genes of key rate-limiting enzymes chalcone isomerase(CHI) and chalcone synthase(CHS) in the biosynthesis of flavonoids in Lonicera macranthoides, this study screened and cloned the cDNA sequences of CHI and CHS genes from the transcriptome data of conventional variety and 'Xianglei' of L. macranthoides. Online bioinformatics analysis software was used to analyze the characteristics of the encoded proteins, and quantitative reverse-transcription polymerase chain reaction(qRT-PCR) to detect the expression of CHI and CHS in different parts of the varieties at different flowering stages. The content of luteo-loside was determined by high performance liquid chromatography(HPLC) and the correlation with the expression of the two genes was analyzed. The results showed that the CHI and CHS of the two varieties contained a 627 bp and 1170 bp open reading frame(ORF), respectively, and the CHI protein and CHS protein were stable, hydrophilic, and non-secretory. qRT-PCR results demonstrated that CHI and CHS of the two varieties were differentially expressed in stems and leaves at different flowering stages, particularly the key stages. Based on HPLC data, luteoloside content was in negative correlation with the relative expression of the genes. Thus, CHI and CHS might regulate the accumulation of flavonoids in L. macranthoides, and the specific functions should be further studied. This study cloned CHI and CHS in L. macranthoides and analyzed their expression for the first time, which laid a basis for investigating the molecular mechanism of the differences in flavonoids such as luteoloside in L. macranthoides and variety breeding.

STED Nanoscopy Imaging of Cellular Lipid Droplets Employing a Superior Organic Fluorescent Probe.

Lipid droplets (LDs) are spherical organelles that participate in numerous biological processes. In order to visualize LDs on the nanoscale, nanoscopy fluorescence imaging is considered as the most attractive technique but is substantially limited by the characteristics of fluorescent probes. Thus, the development of a superior fluorescent probe that is capable of nanoscopy fluorescence imaging has attracted enormous attention. Herein, a benzodithiophene-tetraoxide-based molecule Lipi-BDTO has been developed that can easily undergo the stimulated emission depletion (STED) process and displays high photostability. These two characteristics of fluorescent probes finely satisfy the requirements of STED nanoscopy imaging. Indeed, applying the probe for STED imaging achieves a high resolution of 65 nm, belonging to one of the leading results of LDs fluorescence imaging. Furthermore, the high photostability of this fluorescent probe enables it to monitor the dynamics of LDs by time-lapse STED imaging as well as to visualize the three-dimensional (3D) spatial distribution of LDs by 3D STED imaging. Notably, the resolution of the 3D STED image represents one of the best LDs fluorescence imaging results so far. Besides STED nanoscopy imaging, the superior utility of this fluorescent probe has been also demonstrated in two-color 3D confocal imaging and four-color confocal imaging.

Anatomical knee variables result in worse outcomes of lateral meniscal allograft transplantation with discoid lateral menisci than with nondiscoid lateral menisci.

PURPOSE: To compare the clinical results of meniscal allograft transplantation (MAT) between patients with discoid lateral meniscus (DLM) and non-DLM (NDLM) and to analyse whether anatomical deformities cause worse clinical results in DLM patients. METHODS: Patients who underwent unilateral MAT from 2005 to 2017, including 115 patients with DLMs or NDLMs, were included in this study. Clinical outcomes [International Knee Documentation Committee (IKDC) scores, Lysholm scores, Tegner scores, and visual analogue scale (VAS) scores] and radiographic and MRI data were assessed. Clinical outcomes and anatomical knee variables were analysed by multivariate stepwise regression. RESULTS: After more than 2 years of follow-up, 9 patients were lost to follow-up, and 59 patients with DLM and 47 patients with NDLM were included. The mean postoperative results were significantly better than the preoperative data (P < 0.05) in both the DLM and NDLM groups. In addition, postoperative IKDC, Lysholm, and VAS scores but not Tegner scores were better in the NDLM group than in the DLM group. Several anatomical knee variables differed significantly between the NDLM and DLM groups and were associated with MAT outcomes. The condylar prominence ratio of the lateral and medial femoral condyles adjacent to the intercondylar notch and squaring of the lateral femoral condyle (the distance of the straight articular condylar surface) were independent factors significantly correlated with the Lysholm scores for MAT at last follow-up. CONCLUSION: MAT improved knee function in both patients with DLM and patients with NDLM, but patients NDLM had better clinical outcomes than patients with DLM. The condylar prominence ratio and squaring of the lateral femoral condyle may underlie this result. LEVEL OF EVIDENCE: III.

Determination of risk factors for predicting the onset of symptoms in asymptomatic COVID-19 infected patients.

Background: The number of asymptomatic infected patients with coronavirus disease 2019 (COVID-2019) is rampaging around the world but limited information aimed on risk factors of asymptomatic infections. The purpose of this study is to investigate the risk factors of symptoms onset and clinical features in asymptomatic COVID-19 infected patients. Methods: A retrospective study was performed in 70 asymptomatic COVID-2019 infected patients confirmed by nucleic acid tests in Hunan province, China between 28 January 2020 and 18 February, 2020. The epidemiological, clinical features and laboratory data were reviewed and analyzed. Presence or absence at the onset of symptoms was taken as the outcome. A Cox regression model was performed to evaluate the potential predictors of the onset of symptoms. Results: The study included 36 males and 34 females with a mean age of 33.24±20.40 years (range, 0.5-84 years). There were 22 asymptomatic carriers developed symptoms during hospitalization isolated observation, and diagnosed as confirmed cases, while 48 cases remained asymptomatic throughout the course of disease. Of 70 asymptomatic patients, 14 (14/70, 20%) had underlying diseases, 3 (3/70, 4.3%) had drinking history, and 11 (11/70, 15.7%) had smoking history. 22 patients developed symptoms onset of fever (4/22, 18.2%), cough (13/22, 59.1%), chest discomfort (2/22, 9.1%), fatigue (1/22, 4.5%), pharyngalgia (1/22, 4.5%) during hospitalization; only one (1/22, 4.5%) patient developed signs of both cough and pharyngalgia. Abnormalities on chest CT were detected among 35 of the 69 patients (50.7%) after admission, except for one pregnant woman had not been examined. 4 (4/70, 5.7%) and 8 (8/70, 11.4%) cases showed leucopenia and lymphopenia. With the effective antiviral treatment, all the 70 asymptomatic infections had been discharged, none cases developed severe pneumonia, admission to intensive care unit, or died. The mean time from nucleic acid positive to negative was 13.2±6.84 days. Cox regression analysis showed that smoking history (P=0.028, hazard ratio=4.49, 95% CI 1.18-17.08) and existence of pulmonary disease (P=0.038, hazard ratio=7.09, 95% CI 1.12-44.90) were risk factors of the onset of symptoms in asymptomatic carries. Conclusion: The initially asymptomatic patients can develop mild symptoms and have a good prognosis. History of smoking and pulmonary disease was prone to illness onset in asymptomatic patients, and it is necessary to be highly vigilant to those patients.

Arthroscopic subscapularis augmentation combined with capsulolabral reconstruction is safe and reliable.

PURPOSE: The study aimed to compare modified arthroscopic subscapularis augmentation (MASA) with tenodesis of the upper third of the subscapularis tendon using a tendon combined with capsulolabral reconstruction (Group A) or Bankart repair (Group B) for recurrent anterior shoulder instability (RASI). METHODS: A retrospective series of 49 patients underwent primary surgery for RASI with glenoid bone loss (GBL) < 25%. Outcomes included the Oxford Shoulder Instability Score (OSIS), Visual Analogue Scale (VAS) score, Rowe score, and American Shoulder and Elbow Surgeons (ASES) functional outcome scale score. Recurrent instability, sports activity level, and range of motion (ROM) were also analysed. RESULTS: No significant differences were observed at baseline. Forty-six patients were available for more than 2 years of follow-up. At the last follow-up after surgery, the patients in both groups had experienced significant improvements in all outcome scores (P < 0.05 for all), and obvious decreases in forward flexion and external rotation were noted in both groups (P < 0.05 for all). Group A had superior ASES scores, VAS scores, and OSISs (P < 0.05) but did not experience significant differences in either the Rowe score or ROM compared to Group B. Group A had lower rates of recurrent instability and superior outcomes for the return to sports activities. One patient in Group A had subluxation, and 4 patients in Group B had dislocation or subluxation. No patients in either group experienced neurovascular injury, joint stiffness, or surgical wound infection. CONCLUSION: For RASI with GBL < 25%, MASA with tenodesis of the upper third of the subscapularis tendon using a tendon combined with capsulolabral reconstruction was a safe technique that produced better outcomes in terms of ASES scores, VAS scores, OSISs, the return to sports, and postoperative recurrent instability and did not decrease the ROM compared to that achieved by arthroscopic Bankart repair. LEVEL OF EVIDENCE: III.

Semi-synthesis of Twelve Known 20Z/E Pseudo-Ginsenosides and Their Comparative Study of Antioxidative Activity in Free Radical Induced Hemolysis of Rabbit Erythrocytes.

Twelve pseudo-ginsenosides were synthesized under a mild condition, via a simple three-step called acetylation, elimination-addition and saponification. The inhibitory effects of these twelve pseudo-ginsenosides were screened on the hemolysis of rabbit erythrocytes caused by 2,2'-azobis (2-amidinopropane hydrochloride) (AAPH). It was found that the IC50 values followed the sequence of (20Z) pseudo-protopanaxatriol (pseudo-PPT)<(20Z) pseudo-protopanaxadiol (pseudo-PPD)<(20Z) pseudo-Rh2<(20E) pseudo-PPT<(20E) pseudo-PPD<(20E) pseudo-Rh2<(20Z) pseudo-Rg2<(20E) pseudo-Rg2

Tetramer as efficient structural mode for organizing antioxidative carboxylic acids: The case in inhibiting DNA oxidation.

To overcome the problem on the relationship of antioxidative effect with the branch number in a tetramer, we herein designed a series of antioxidants with pentaerythritol, glycerol, and ethylene glycol as the cores, and gallic, ferulic, caffeic, and p-hydroxybenzoic acids as the antioxidative moieties. In the case of DNA oxidation mediated by 2,2'-azobis(2-amidinopropane hydrochloride, AAPH), it was found that the stoichiometric factor (n) of a carboxylic acid increased rapidly when the acid was esterified with ethylene glycol, glycerol, and pentaerythritol to form a dimer, trimer, and tetramer, respectively. Interestingly, the coefficient in the equation of n∼{branch} ({branch} referred to the number of branches) was higher than one, indicating that the antioxidative effect was enhanced more promptly than the increase of the number of branches. Meanwhile, tetramer exhibited high intercalation effect with DNA strand. Therefore, additionally antioxidative effect was ascribed to the tethering effect resulting from tetrameric structure and strong intercalation with DNA strand generated by tetramer.

Transcriptional regulation of the daptomycin gene cluster in Streptomyces roseosporus by an autoregulator, AtrA.

Daptomycin is a cyclic lipopeptide antibiotic produced by Streptomyces roseosporus. To reveal the transcriptional regulatory mechanism of daptomycin biosynthesis, we used the biotinylated dptE promoter (dptEp) as a probe to affinity isolate the dptEp-interactive protein AtrA, a TetR family transcriptional regulator, from the proteome of mycelia. AtrA bound directly to dptEp to positively regulate gene cluster expression and daptomycin production. Meanwhile, both ΔatrA and ΔadpA mutants showed bald phenotype and null production of daptomycin. AdpA positively regulated atrA expression by direct interaction with atrA promoter (atrAp), and removal of ArpA in S. roseosporus, a homolog of the A-factor receptor, resulted in accelerated morphological development and increased daptomycin production, suggesting that atrA was the target of AdpA to mediate the A-factor signaling pathway. Furthermore, AtrA was positively autoregulated by binding to its own promoter atrAp. Thus, for the first time at the transcriptional level, we have identified an autoregulator, AtrA, that directly mediates the A-factor signaling pathway to regulate the proper production of daptomycin.

ILK-PI3K/AKT pathway participates in cutaneous wound contraction by regulating fibroblast migration and differentiation to myofibroblast.

The interactions between fibroblasts and the extracellular matrix in wound contraction are mainly mediated via integrin signaling. Integrin-linked kinase (ILK) is a key mediator in integrin signal transduction. We investigated the role of ILK in cutaneous wound contraction. We found that ILK was involved in cutaneous wound healing in rats, and ILK and PI3K/AKT inhibitors inhibited wound contraction and re-epithelialization, consequently delaying wound healing in vivo. Further, using in vitro studies, we demonstrated that ILK and PI3K/AKT inhibitors suppressed the contraction of fibroblast-populated collagen lattices, inhibited fibroblast migration, and interrupted the effect of TGF-ß1 on promoting alpha smooth muscle actin (α-SMA) expression in fibroblasts. When ILK expression was directly blocked by ILK small interfering RNA transfection, the migration and α-SMA expression of normal dermal fibroblasts were significantly suppressed as well. The data suggest that the ILK-PI3K/AKT signaling pathway mediates cutaneous wound contraction by regulating fibroblast migration and differentiation to myofibroblasts.

DepR1, a TetR Family Transcriptional Regulator, Positively Regulates Daptomycin Production in an Industrial Producer, Streptomyces roseosporus SW0702.

Daptomycin is a potent cyclic lipopeptide antibiotic. It is widely used against various Gram-positive bacterial pathogens. Historically, a poor understanding of the transcriptional regulation of daptomycin biosynthesis has limited the options for targeted genetic engineering toward titer improvement. Here, we isolated a TetR family transcriptional regulator, DepR1, from the industrial producer Streptomyces roseosporus SW0702 using a biotinylated dptE promoter (dptEp) as a probe. The direct interaction between DepR1 and dptEp then was confirmed by electrophoretic mobility shift assays and DNase I footprinting assays. The deletion of depR1 led to a reduction in dptEp activity and the cessation of daptomycin production. The ΔdepR1 mutant produced less red pigment and failed to sporulate on R5 medium. This suggests that DepR1 plays a positive role in the control of morphological differentiation. Moreover, DepR1 was positively autoregulated by directly binding to its own promoter. This might account for the positive feedback regulation of daptomycin production. Based on these positive effects, genetic engineering by overexpression of depR1 raised daptomycin production and shortened the fermentation period both in flask and in fermentor.

[Pharmacokinetics of loganin, ferulic acid and stilbene glucoside in Bushen Tongluo formula in vivo].

To study the pharmacokinetics characteristic of loganin, ferulic acid and stilbene glucoside in rat plasma after oral administration of Bushen Tongluo formula. The plasma samples were treated by using liquid-liquid extraction technique, the concentrations were determined by HPLC-UV. Johnson spherigel C18 column (4.6 mm x 250 mm, 5 µm) was adopted and eluted with the of mobile phase of methanol-water containing 0.01% glacial acetic acid in a gradient mode, with the flow rate at 1.0 mL x min(-1), column temperature at 30 degrees C and injection volume of 10 µL. According to the findings, loganin was determined at 235 nm, ferulic acid and stilbene glucoside were determined at 320 nm, with the sample size of 10 µL. The pharmacokinetic parameters of loganin, ferulic acid and stilbene glucoside were calculated by DAS 2. 0 software as follows: C(max) was (0.369 ± 0.042), (0.387 ± 0.071), (0.233 ± 0.044) mg x L(-1); t(max) was (0.226 ± 0.022), (0.282 ± 0.031), (0.233 ± 0.044) h; t(½ß) was (6.89 ± 0.20), (10.73 ± 0.11), (6.93 ± 0.09) h; AUC(0-∞) was (1.91 ± 0.36), (3.22 ± 0.52), (1.52 ± 0.33) mg x h x L(-1); AUCO(0-t) was (1.62 ± 0.33), (2.58 ± 0.43), (1.30 ± 0.30) mg x h x L(-1); CL was (20.2 ± 4.0), (1.39 ± 0.23), (31.7 ± 6.9) L x h(-1) x kg(-1), respectively. The results showed that after the oral administration with Bushen Tongluo formula, loganin, ferulic acid and stilbene glucoside showed concentration-time curves in conformity with the two compartment model, with a rapid absorption, loganin and stilbene glucoside was excreted at a moderate speed, and ferulic acid was excreted slowly (but with the highest bioavailability). Bushen Tongluo formula can main maintain plasma concentration with three administrations everyday and so is suitable to be made into common oral preparation.