Microbial transformation of artemisinin and its derivatives / 中国中药杂志

Microbial transformation is an efficient enzymatic approach for the structural modification of exogenous compounds to obtain derivatives. Compared with traditional chemical synthesis, the microbial transformation has in fact the undoubtable advantages of strong region-and stereo-selectivity, and a low environmental and economic impact on the production process, which can achieve the reactions challenging to chemical synthesis. Because microbes are equipped with a broad-spectrum of enzymes and therefore can metabolize various substrates, they are not only a significant route for obtaining novel active derivatives, but also an effective tool for mimicking mammal metabolism in vitro. Artemisinin, a sesquiterpene with a peroxy-bridged structure serving as the main active functional group, is a famous antimalarial agent discovered from Artemisia annua L. Some sesquiterpenoids, such as dihydroartemisinin, artemether, and arteether, have been developed on the basis of artemisinin, which have been successfully marketed and become the first-line antimalarial drugs recommended by WHO. As revealed by pharmacological studies, artemisinin and its derivatives have exhibited extensive biological activities, including antimalarial, antitumor, antiviral, anti-inflammatory, and immunomodulatory. As an efficient approach for structural modification, microbial transformation of artemisinin and its derivatives is an increasingly popular strategy that attracts considerable attention recently, and numerous novel derivatives have been discovered. Herein, this paper reviewed the microbial transformation of artemisinin and its artemisinin, including microbial strains, culture conditions, product isolation and yield, and biological activities, and summarized the advances in microbial transformation in obtaining active derivatives of artemisinin and the simulation of in vivo metabolism of drugs.

Preparation of Rehmanniae Radix Juice for Baihe Dihuangtang Based on UPLC-Q-TOF-MS / 中国实验方剂学杂志

ObjectiveTo compare the four preparation methods of Rehmanniae Radix juice described in ancient literature and find the method that is most suitable for the preparation of Rehmanniae Radix juice used in Baihe Dihuangtang. MethodThe ancient medical books record four methods for preparing Rehmanniae Radix juice： crushing fresh Rehmanniae Radix for juice， steaming fresh Rehmanniae Radix for juice， boiling fresh Rehmanniae Radix for juice， and boiling dry Rehmanniae Radix for juice. Ultra performance liquid chromatography-quadrupole time-of-flight mass spectrometry （UPLC-Q-TOF-MS） was employed to detect the compounds in the four juice samples， followed by principal component analysis （PCA）. Result① Totally 27 compounds were identified in the juice samples， including 10 iridoid glycosides， 14 phenylethanoid glycosides， 2 phenolic acids， and 1 irisone. Among them， 15 common compounds were shared by the four juice samples， including 7 iridoid glycosides， 7 phenylethanoid glycosides， and 1 phenolic acid. ② Five common compounds in the four juice samples can be matched with the reference standards， which were catalpol， aucubin， rehmannioside D， ajugol， and purpureaside C. ③ Verbascoside and isoacteoside were not detected in the juice prepared by crushing fresh Rehmanniae Radix， while it was detected in the other three juice samples， which indicated that the two components were produced after heating rather than being the original components in fresh Rehmanniae Radix. ④ The comparison of the ion fragments demonstrated that verbascoside was produced from purpureaside C after the cleavage of the glycosidic bond and removal of a molecule of mannose. ⑤ Isoacteoside could be isomerized from verbascoside， and its relative content increased with the extension of heating time. However， the relative content of verbascoside and purpureaside C did not decrease significantly. Therefore， it was hypothesized that purpureaside C was produced from its upstream component. ConclusionThe juice prepared by crushing fresh Rehmanniae Radix has the chemical composition significantly different from the juice samples prepared with the other 3 methods， while the latter 3 juice samples had similar chemical composition. Although all the four methods can be used， it is more suitable to prepare Rehmanniae Radix juice by steaming fresh Rehmanniae Radix， boiling fresh Rehmanniae Radix， and boiling dry Rehmanniae Radix.

The Risk Factors of Thrombosis in Patients with Philadelphia Chromosome-negative Myeloproliferative Neoplasms / 中国实验血液学杂志

OBJECTIVE@#To investigate the overview of thrombosis in myeloproliferative neoplasms(MPN) patients, and to explore the risk factors of thrombosis at diagnosis and during follow-up.@*METHODS@#The clinical data of 388 MPN patients treated in our hospital were collected. The patients were followed up by outpatient and phone. The risk factors of thrombosis were analyzed by statistical methods.@*RESULTS@#Among 388 MPN patients, 161 patients (41.49%) showed thromboses at diagnosis or during follow-up. Among them, 92.55% were arterial thromboses, 146 cases (96.27%) were complicated with thromboses at diagnosis, and 36 cases (11.46%) showed newly thromboses or progression of previous thromboses among the 314 received full follow-up patients. Age (P＜0.001, HR:1.033, 95%CI:1.016-1.051), JAK2V617F mutation (P=0.037, HR:1.72, 95%CI: 1.033-2.862), hypertension (P＜0.001, HR:2.639, 95%CI:1.659-4.197) and hyperlipidemia (P＜0.001, HR:2.659, 95%CI:1.626-4.347) were the independent risk factors affecting thrombosis at diagnosis of the patients. During the follow-up, age (P=0.016, HR:1.032, 95%CI: 1.006-1.059) and previous thrombosis history (P=0.019, HR:2.194, 95%CI: 1.135-4.242) were the independent risk factors affecting the progression of thrombosis at different sites or on the basis of the previous thrombosis in the patients.@*CONCLUSION@#Patients with advanced age, JAK2V617F mutation or complicated with hypertension and hyperlipidemia shows a higher risk of thrombosis at diagnosis, while the patients with advanced age or previous thrombosis history shows a higher risk of progression of thrombosis during the follow-up.

A novel flavanone from Thymus przewalskii / 中国中药杂志

This study was to investigate the chemical constituents from the aerial parts of Thymus przewalskii. The chemical consti-tuents were separated and purified by column chromatography on silica gel, ODS, Sephadex LH-20 and semi-prepared HPLC, and their structures were determined by physicochemical properties and spectroscopic data. Four flavanones were isolated from the ethanol extract of the aerial parts of T. przewalskii, and identified as(2S)-5,6-dihydroxy-7,8,4'-trimethoxyflavanone(1), 5,4'-dihydroxy-6,7-dimethoxyflavanone(2),(2S)-5,4'-dihydroxy-7,8-dimethoxyflavanone(3), sakuranetin(4), respectively. Compound 1 was a new compound and its configuration was determined by CD spectrum, compound 3 was natural product which was isolated for the first time and their configurations were determined by CD spectra. Compound 2 was isolated from the genus Thymus for the first time and compound 4 was isolated from T. przewalskii for the first time. Furthermore, cytotoxicity test was assayed for the four flavanones. They exhibited weak cytotoxicity against human lung cancer cells(A549), with the IC_(50) from 74.5 to 135.6 μmol·L~(-1).

Application of DESI-MSI in Quality Control of Banxia Xiexintang / 中国实验方剂学杂志

Objective::To prepare 15 batches of Banxia Xiexintang substance benchmark and lyophilized powder from different places, and the lyophilized powder was analyzed by ultra-high performance liquid chromatography with diode array detection (UHPLC-DAD) and desorption electrospray ionization-mass spectrometry imaging (DESI-MSI) in order to investigate the advantages of DESI-MSI in quality control of famous classical formulas. Method::Taking Banxia Xiexintang as the research model, fingerprints of the substance benchmark and lyophilized powder were established by UHPLC-DAD, and the content of index components and the yield of dry extract were also investigated. Meanwhile, as the research carrier, the lyophilized powder corresponding to Banxia Xiexintang was dissolved in methanol and dotted on qualitative filter paper with 5 μL quantitative capillary, and fixed it on the slide to make samples. The samples were analyzed on a DESI-MSI system in positive and negative ion mode with methanol-formic acid (1 000∶1, flow rate of 3 μL·min-1) as spray solvent, N2 as spray gas (pressure of 0.5 MPa). The scanning range was 100-1 200 Da, the spatial resolution was 300 μm, the spray voltage was 3 kV, the sampling cone voltage was ±40 V, incidence angle of sprayer was 60 degree, its collection angle was 10 degree, the ion source temperature was 120 ℃. Result::DESI-MSI could not only detect the index components of liquiritin, baicalin and wogonoside, as well as the common peaks of liquiritin apioside, berberine and glycyrrhizic acid, but also analyzed them semi-quantitatively, the analysis results were basically consistent with UHPLC-DAD. At the same time, DESI-MSI could detect 16 other components from Glycyrrhizae Radix et Rhizoma, Coptidis Rhizoma, Scutellariae Radix, Jujubae Fructus and Ginseng Radix et Rhizoma, such as licoricesaponin G2, palmatine, coptisine, rutin and ginsenoside Rg1, and present their relative content visually. The qualitative analysis ability of DESI-MSI was much better than UHPLC-DAD. Conclusion::DESI-MSI can be used as the quality control method for substance benchmark and lyophilized powder and dispensing granules of famous classical formulas with advantages of high sensitivity, strong analytical ability, no complex sample processing, qualitative and relative content analysis of complex samples without reference substance.

Determination of impurity diketo aldehyde in bulk drug and preparations of dihydroartemisinin / 中国中药杂志

Diketo aldehyde (DKA),one of the most important impurities in dihydroartemisinin,was synthesized through reaction between dihydroartemisinin and anhydrous ferrous bromide under a N₂ atmosphere, and an HPLC method was established for the determination of DKA in bulk drug and in DHA tablet. DKA was prepared from dihydroartemisinin in the presence of FeBr₂.The chromatographic separation was achieved through an Agilent Eclise XDB-C₁₈ column (4.6 mm×250 mm,5 μm), and the optimal mobile phase consisted of acetonitrile and water in the ratio of 37:63 at flow rate of 1.0 mL·min⁻¹.The detection was carried out at 216 nm, and column temperature was 15 °C.The injection volume was 40 μL.The method featured a good linearity (=0.999 9),precision (1.0%),repeatability (1.3%),stability (DKA standards RSD=1.0% and in tablet form instability),recovery (92.88%),limits of detection (0.20 mg·L⁻¹) ,and limits of quantification (0.78 mg·L⁻¹). The result show that the content of DKA in bulk drug was 0.086 7%-2.622 9%, and the content of DKA in tablet was 0.068 3%-0.615 1%.

Remifentanil preconditioning lowers cardiac troponin I levels in patients undergoing off-pump coronary artery bypass graft surgery / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the value of cardiac troponin I (cTnI) levels in assessing myocardial protection by remifentanil precondition against myocardial injury induced by off-pump coronary artery bypass (OPCAB).</p><p><b>METHODS</b>Twenty-four patients undergoing OPCAB were randomized into control and remifentanil preconditioning group (n=12). All the patients received pretreatment with oral diazepam (10 mg), intramuscular morphine (10 mg) and hyosine (0.3 mg). General anesthesia was induced with midazolam (0.08 mg/kg), etomidate (0.1-0.3 mg/kg), fentanyl (5-10 microg/kg), and rocuronium (1 mg/kg), and maintained with isoflurane inhalation and propofol infusion. Intermittent fentanyl and pipecuronium were given intravenously. In remifentanil preconditioning group, remifentanil (5 microg/kg in 50 ml normal saline) was infused in 10 min after anesthesia induction, and only NS was administered in the control group. Blood samples were obtained before and at 0, 2, 6, 24, and 48 h after the operation to determine serum cTnI levels.</p><p><b>RESULTS</b>In both of the two groups, the cTnI levels increased significantly at the postoperative time points (0, 2, 6, 24, and 48 h) as compared with those before the operation (P<0.05). The cTnI levels of remifentanil preconditioning group were markedly decreased after the operation in comparison with those of the control group (P<0.05).</p><p><b>CONCLUSION</b>Remifentanil preconditioning decreases the cTnI levels and reduces myocardial injury induced by OPCAB.</p>

Effect of levosimendan on B-type natriuretic peptide levels in patients with advanced heart failure: a meta-analysis / 南方医科大学学报

<p><b>OBJECTIVE</b>To conduct a meta-analysis of the effect of levosimendan on B-type natriuretic peptide (BNP) levels and evaluate the therapeutic effect of levosimendan on advanced heart failure.</p><p><b>METHODS</b>A meta-analysis was performed on the selected data to analyze the effect of levosimendan on BNP levels.</p><p><b>RESULTS</b>Levosimendan decreased BNP by a mean of 337.66 [95%CI (-296.30, -379.02)] pg/ml 24 h after the administration, and by 259.92 [95%CI (-195.76, -324.08)] pg/ml at 48 h, and by 123.09 [95%CI(-53.32,-195.86)] pg/ml at 1 week. Levosimendan resulted in improvements of the cardiac function by about 29%, 22%, and 10% at 24 h, 48 h and 1 week after the administration.</p><p><b>CONCLUSION</b>Levosimendan produces favorable effects on the cardiac functions and BNP levels.</p>