Design and Synthesis of Novel Diphenyl Ether Carboxamide Derivatives To Control the Phytopathogenic Fungus Sclerotinia sclerotiorum

Sclerotinia stem rot (SSR) caused by the phytopathogenic fungus Sclerotinia sclerotiorum has led to serious losses in the yields of oilseed rape and other crops every year. Here, we designed and synthesized a series of carboxamide derivatives containing a diphenyl ether skeleton by adopting the scaffold splicing strategy. From the results of the mycelium growth inhibition experiment, inhibition rates of compounds 4j and 4i showed more than 80% to control S. sclerotiorum at a dose of 50 μg/mL, which is close to that of the positive control (flubeneteram, 95%). Then, the results of a structure-activity relationship study showed that the benzyl scaffold was very important for antifungal activity and that introducing a halogen atom on the benzyl ring would improve antifungal activity. Furthermore, the results of an in vitro activity test suggested that these novel compounds can inhibit the activity of succinate dehydrogenase (SDH), and the binding mode of 4j with SDH was basically similar to that of the flutolanil derivative. Morphological observation of mycelium revealed that compound 4j could cause a damage on the mycelial morphology and cell structure of S. sclerotiorum, resulting in inhibition of the growth of mycelia. Furthermore, in vivo antifungal activity assessment of 4j displayed a good control of S. sclerotiorum (>97%) with a result similar to that of the positive control at a concentration of 200 mg/L. Thus, the diphenyl ether carboxamide skeleton is a new starting point for the discovery of new SDH inhibitors and is worthy of further development.

[Endovascular repair of ruptured abdominal aortic aneurysms assisted by double balloon occlusion technique combined with intra-aneurysm fibrin binder injection technique]

Objective: To investigate the long-term efficacy and safety of alternating double balloon occlusion combined with intra-aneurysm injection of human fibrin binder in the endovascular repair of ruptured abdominal aortic aneurysm (rAAA). Methods: The clinical data of 28 patients with rAAA admitted to Department of Vascular Surgery, the Fourth Affiliated Hospital of Guangxi Medical University from January 2015 to December 2019 were retrospectively analyzed. There were 23 males and 5 females, aged (62±5) years (range: 46 to 88 years).The maximum diameter of the tumors was (65.2±10.5) mm (range: 47.3 to 100.5 mm), all of which were subrenal rAAA. The intraoperative EVAR for abdominal aortic aneurysm was successfully performed under the emergency green channel procedure, and this surgery was assisted used the double balloon occlusion technique in aorta of inferior renal and superior renalcombined with intraoperative human fibrin binder injection technique. Observation indexes included: patients with preoperative preparation, operation time, hospitalization days, surgical treatment success rate and the incidence of postoperative complications, and aortic stent form during the follow-up period, the incidence of leakage, branch stents patency rate and infection rates. Results: The preoperative preparation time of 28 patients was (45.5±8.5) minutes (range:20 to 100 minutes). The operation time was (100.0±15.5) minutes (range:85 to 210 minutes), the ICU stay time was (7±2) days(range:1 to 17 days). The length of hospitalization was (13.5±2.5) days(range:5 to 43 days). The success rate of surgical treatment was 92.9% (26/28). Two patients died, 1 case died of postoperative multifocal lacunar cerebral infarction and massive gastrointestinal hemorrhage, and another elderly patient (84 years old) died of massive abdominal fluid due to preoperative abdominal aortic aneurysm rupture, postoperative complicated with significant abdominal compartment syndrome, and secondary multiple organ failure. Balloon occlusion of the upper renal aorta took (13±2)minutes (range:12 to 30 minutes). The intraoperative injection of fibrin adhesive was (14±2) ml(range:6 to 28 ml) in 22 cases. The incidence of major postoperative complications was 57.1% (16/28). Among the 26 patients who survived the surgery, 69.2% (18/26) completed the 3-year follow-up, and the follow-up time was (30±3) months(range:13 to 36 months). During the follow-up, the aortic stent was in good shape without obvious displacement. The incidence of leakage within 6 months after the operation was 10.7% (3/28), and there was no internal leakage in the patients who were followed up for 36 months after the operation. The patency rate of renal artery and iliac artery branch stents was 16/18. The incidence of stent infection was 7.7% (2/26), 1 case occurred at 1 month and another case at 6 months, respectively. All patients recovered after prolonged intensive anti-infection therapy. Conclusions: Under the standard emergency treatment process, the double balloon alternating occlusion technique combined with the intra-aneurysm injection of human fibrin adhesive technique can assist the successful completion of the endovascular repair of rAAA, effectively improve the success rate of treatment for patients, and reduce the incidence of postoperative leakage and serious complications. The mid-term and long-term results of EVAR for rAAA are good, safe and reliable.

Design, synthesis, and antifungal activity of carboxamide derivatives possessing 1,2,3-triazole as potential succinate dehydrogenase inhibitors

Succinate dehydrogenase (SDH) is demonstrably one of the most important molecular targets in development of new fungicide. In our continuous efforts to discover novel SDH inhibitors, forty-two carboxamide derivatives containing 1,2,3-triazole ring were designed and synthesized, which were precisely characterized by ¹H NMR, ESI-MS, elemental analysis and X-ray single-crystal diffraction. The compounds were screened for antifungal activities against phytopathogenic fungi by mycelia growth inhibition assay in vitro. Compound A3-3 exhibited significant antifungal activity against Sclerotinia sclerotiorum, Botrytis cinerea, Rhizoctonia cerealis and Gaeumannomyces graminsis with EC₅₀ values of 1.08, 8.75, 1.67 and 5.30 μg/mL, respectively, comparable to those of commercial SDHI boscalid. In vivo testing demonstrated that A3-3 was effective for suppressing rape sclerotinia rot, cucumber grey mould and wheat powdery mildew caused by S. sclerotiorum， B. cinerea and Blumeria graminis at a dosage of 200 μg/mL. Inhibition activities against SDH test proved the designed analogues were effective in the enzyme level. The molecular docking simulation revealed that A3-3 interacted with ARG43，TYR58 and TRP173 of the SDH through hydrogen bond and pi-pi interaction, which could explain the probable mechanism of action between the inhibitor and target protein.

[Magnetic-activated cell sorting (MACS) versus density gradient centrifugation (DGC) for the selection of human sperm in assisted reproductive techniques]

Objective: To investigate whether the assisted reproductive techniques (ART) outcomes can be improved by using magnetic-activated cell sorting combined isolate density gradient centrifugation (MACS-DGC), and to compare the results with the conventional isolate density gradient centrifugation (DGC) method. Methods: In the period from January to December 2014, patients who attended the andrology laboratory for sperm DNA fragmentation analysis and underwent the in vitro fertilization and embryo transfer (IVF-ET) treatment were divided into 3 groups, and each group has two subgroups according to the way of fertilization : in vitro fertilization (IVF) as subgroup 1 and intracytoplasmic sperm injection (ICSI) as subgroup 2. Group A (A1, A2 ): DNA fragmentation index(DFI)≥20 and using MACs; Group B (B1, B2): DFI≥20 and using isolate method; Group C (C1, C2): DFI<20 and using isolate method. The fertilization rate, good-quality embryos, implantation rate, pregnancy rate and live-birth rate of each group were analyzed. Results: Similar results were obtained among groups for all the parameters compared: On IVF cycles no significant difference was observed in fertilization rate, percentage of good-quality embryos on day 3, implantation rate, positive beta-hCG tests, and live-birth rate among the three subgroups (A1 vs B1 vs C1). Between the subgroups of ICSI cycles (A2 vs B2 vs C2) the percentage of high-quality embryos, pregnancy rate, implantation rate and live-birth rate were all significantly higher in the MACS-DGC (A2) group compared to DGC alone (B2). Conclusion: Based on the results, MACS as a part of sperm preparation technique will not improve sperm fertilizing potential, embryos quality, implantation rate, pregnancy rate or live-birth rate of IVF, but it may help select the most fertile sperm and to improve clinical outcomes of ICSI.

[Application of lower abdominal aorta balloon occlusion technique by ultrasound guiding during caesarean section in patients with pernicious placenta previa]

Objective: To discuss the feasibility, effect and safety of lower abdominal aorta balloon occlusion technique by ultrasound guiding during caesarean section in patients with pernicious placenta previa. Methods: The clinical data of 40 patients with pernicious placenta previa complicated with placenta accreta from January 2015 to August 2017 in Liuzhou workers hospital were analyzed retrospectively. The study group included 20 cases, which were operated in the way of cesarean section combined lower abdominal aorta balloon occlusion technique by ultrasound guiding, while the control group also included 20 cases, which were operated in the way of the conventional cesarean section without balloon occlusion technique. The bleeding amount, blood transfusion volume, operative total time, hysterectomy and complications of the two groups were compared. Results: The bleeding amount and blood transfusion volume in study group were(850±100)ml and (400±50)ml, which were lower than that of the control group[(2 500±230)ml and (1 500±100)ml], the difference was statistically significant(t=35.624, 16.523, all P<0.05). In addition, the hysterectomy rate in study group was 5%, which was lower than that in the control group(30%), the difference was statistically significant(χ²=8.672, P<0.05). And the total time of operation was (2.0±0.5)h in the study group, which was shorter than that in the control group[(3.5±0.4)h]. The difference was statistically significant(t=11.362, P<0.05). No postoperative complications took place in the study group.The blood pressure, heart rate and blood oxygen fluctuated significantly, and the postoperative renal function was significantly reduced in the control group. Conclusions: The lower abdominal aorta balloon occlusion technique by ultrasound guiding during a caesarean section in patients with pernicious placenta previa can effectively control the bleeding during operation, and preserve reproductive function to the utmost degree.Therefore, the technique is safe, feasible, convenient and cheaper, and worthy of being widely applied in clinic.

[Effect of resection of adenoids and tonsillectomy on immune function in children with obstructive sleep apnea hypopnea syndrome]

Objective:To remove the immune function of children with obstructive sleep apnea hypopnea syndrome by resection of adenoids and tonsillar. Method: The fasting peripheral venous blood of children with OSAHS and healthy children were collected. The lymphocyte subsets, NK cells and immunoglobulin levels were compared between the two groups. The fasting blood samples of OSAHS children were collected again after 2d, 30d, 60d and 90d after operation. The changes of lymphocyte subsets, NK cells and immunoglobulin levels were observed after operation. Result: Before operation, at the 0.05 test level, it was not yet clear that the levels of IgG, IgM, IgA, NK, CD3+, CD4+ and CD8+ in OSAHS children were significantly different from those in the control group. The levels of IgA, CD3+ and CD4+ decreased significantly in children at 2d and OSAHS after operation, and IgG, IgM, IgA, NK, CD3+ and IgA continued to rise after 60d until ninetieth day after operation. Conclusion: There is no statistical disorder of immune level in children with OSAHS compared with healthy children. The implementation of adenoidectomy and tonsillectomy in children with OSAHS, the level of immunity in 90 days can be restored to the preoperative level.

Nigrosporanenes C and D, two new cyclohexene derivatives from the enphytic fungus Nigrospora oryzae S4

Two new cyclohexene derivatives, nigrosporanenes C and D (1 and 2), together with three known compounds (3-5), were isolated from the culture of an endophyte Nigrospora oryzae S4. Their structures were characterized by a combination of detailed spectroscopic analysis and comparison of their NMR data with those reported in the literature. All compounds were tested for anti-phytopathogenic activity, however, none of them showed activity at a concentration of 20 μM.

Chaetomium globosum CDW7, a potential biological control strain and its antifungal metabolites

Screening for endophytic fungi with antifungal activity is an effective strategy for the discovery of novel biopesticides. Our previous work indicated that Chaetomium globosum CDW7, an endophyte from Ginkgo biloba, exhibited strong inhibitory activity against plant pathogenic fungi in vitro. In this study, we evaluated the CDW7 strain for its antifungal activities against nine phytopathogenic fungi and its biocontrol potential against rape sclerotinia rot caused by Sclerotinia sclerotiorum. The fermentation broth of CDW7 could successfully inhibit disease development in S. sclerotiorum-infected rape in vivo with 57.8% protective efficiency, which is comparable to that of carbendazim (59.8%) at 250 μg mL-1. The fermentation broth also expressed significant activity stability when exposed to 60°C and UV illumination, or when stored at 4°C. Furthermore, we found that 10% fermentation broth can promote the germination and growth of rape seedlings. Followed by the bioassay-guided approach, seven known metabolites were isolated and identified by spectroscopic analyses. Among them, chaetoglobosin A and D exhibited inhibitory activity against S. sclerotiorum with IC50 values of 0.35 and 0.62 μg mL-1, respectively, compared with carbendazim (0.17 μg mL-1). Therefore, our study demonstrated that CDW7 is a promising biocontrol fungus against S. sclerotiorum in agriculture.

[Effect of tympanostomy tube insertion with adenoidectomy for children with recurrent otitis media with effusion]

Objective:To observe the clinical effect of tympanostomy tube insertion with adenoidectomy for children with recurrent otitis media with effusion. Method:One hundred and twenty-six cases of children with recurrent otitis media were randomly divided into observation group and control group(63 in each group), subsequently compared the therapeutic effect of the two groups which observation group had tympanostomy tube insertion with adenoidectomy and the other group had only tympanostomy tube insertion. Result:In terms of the total effective rate,observation group and control group were 96.82% and 76.19% respectively, the difference had statistical significant(P<0.05);compared to control group, the recurrent rate of observation group after treatment was extremely lower, the same as middle ear cavity effusion time, which both had statistical significance (P<0.05); the complete healing time of two groups had no statistical significance(P>0.05). Conclusion:Tympanostomy tube insertion with adenoidectomy has significant treatment effect for children with recurrent otitis media with effusion, it could reduce the recurrent rate after surgery and shorten the time of middle ear cavity effusion.

Synthesis and Biological Evaluation of Benzimidazole Phenylhydrazone Derivatives as Antifungal Agents against Phytopathogenic Fungi

A series of benzimidazole phenylhydrazone derivatives (6a–6ai) were synthesized and characterized by ¹H-NMR, ESI-MS, and elemental analysis. The structure of 6b was further confirmed by single crystal X-ray diffraction as (E)-configuration. All the compounds were screened for antifungal activity against Rhizoctonia solani and Magnaporthe oryzae employing a mycelium growth rate method. Compound 6f exhibited significant inhibitory activity against R. solani and M. oryzae with the EC₅₀ values of 1.20 and 1.85 μg/mL, respectively. In vivo testing demonstrated that 6f could effectively control the development of rice sheath blight (RSB) and rice blast (RB) caused by the above two phytopathogens. This work indicated that the compound 6f with a benzimidazole phenylhydrazone scaffold could be considered as a leading structure for the development of novel fungicides.

Anti-phytopathogenic activity of sporothriolide, a metabolite from endophyte Nodulisporium sp. A21 in Ginkgo biloba

Phytopathogenic fungi such as Rhizoctonia solani and Sclerotinia sclerotiorum caused multiple plant diseases resulting in severe loss of crop production. Increasing documents endorsed that endophytes are a striking resource pool for numerous metabolites with various bioactivities such as anti-fungal. Here we reported the characterization and anti-phytopathogenic activity of sporothriolide, a metabolite produced by Nodulisporium sp. A21-an endophytic fungus in the leaves of Ginkgo biloba. Among the total twenty-five endophytic fungi isolated from the healthy leaves of G. biloba, the fermentation broth (FB) of the strain A21 was found potently inhibitory activity against R. solani and S. sclerotiorum using mycelia growth inhibition method. A21 was then identified as Nodulisporium sp., the asexual stage of Hypoxylon sp., by microscopic examination and ITS rDNA sequence data comparison. Under the bioassay-guided fractionation, sporothriolide was isolated from the petroleum ether extract of the FB of A21, whose structure was established by integrated interpretation of HR-ESI-MS and (1)H- and (13)C-NMR. Furthermore, the crystal structure of sporothriolide was first reported. In addition, sporothriolide was validated to be potently antifungal against R. solani, S. sclerotiorum and inhibit conidium germination of Magnaporthe oryzae in vitro and in vivo, indicating that it could be used as a lead compound for new fungicide development.

Construction of an immobilised acetylcholinesterase column and its application in screening insecticidal constituents from Magnolia officinalis

BACKGROUND

Application of a matrix-immobilised target enzyme for screening inhibitors is widely used in drug development, but there are few studies in insecticide discovery. In this paper, an economical and effective immobilised acetylcholinesterase (AChE) column was prepared using the sol-gel embedment method, which was further combined with high-performance liquid chromatography for screening the AChE inhibitors and insecticidal compounds from complex natural products.

RESULTS

AChE inhibitory constituents magnolol and honokiol were isolated from the ethanol extract of Magnolia officinalis, with IC50 values of 0.069 and 0.057 mM respectively. In an in vivo bioassay, magnolol and honokiol showed insecticidal activity against Nilaparvata lugens, with LC50 values of 0.324 and 0.137 mM, which are comparable with that of commonly used insecticide chlorpyrifos (0.233 mM). Moreover, molecular docking was carried out against a homology model of N. lugens AChE. The complexes showed that magnolol and honokiol placed themselves nicely into the active site of the enzyme and exhibited an interaction energy that was in accordance with our activity profile data.

CONCLUSION

These results demonstrate that magnolol and honokiol have great applied potential to be developed as natural insecticides, and an immobilised AChE column is very useful as a rapid screening tool for target enzymes towards potent inhibitors.

Synthesis and antifungal activity of 1,2,3-triazole phenylhydrazone derivatives

A series of 1,2,3-triazole phenylhydrazone derivatives were designed and synthesized as antifungal agents. Their structures were determined based on (1)H-NMR spectroscopy, MS, elemental analysis and X-ray single-crystal diffraction. The antifungal activities were evaluated against four phytopathogenic fungi including Rhizoctonia solani, Sclerotinia sclerotiorum, Fusarium graminearum and Phytophthora capsici, by the mycelium growth inhibition method in vitro. Compound 5p exhibited significant anti-phytopathogenic activity, with the EC50 values of 0.18, 2.28, 1.01, and 1.85 μg mL(-1), respectively. In vivo testing demonstrated that 5p was effective in the control of rice sheath blight, rape sclerotinia rot and fusarium head blight. A 3D-QSAR model was built for a systematic SAR profile to explore more potent 1,2,3-triazole phenylhydrazone analogs as novel fungicides.

Design, synthesis, antifungal, and antioxidant activities of (E)-6-((2-phenylhydrazono)methyl)quinoxaline derivatives

Different substituted phenylhydrazone groups were linked to the quinoxaline scaffold to provide 26 compounds (6a-6z). Their structures were confirmed by (1)H and (13)C NMR, MS, elemental analysis, and X-ray single-crystal diffraction. The antifungal activities of these compounds against Rhizoctonia solani were evaluated in vitro. Compound 6p is the most promising one among all the tested compounds with an EC50 of 0.16 μg·mL(-1), more potent than the coassayed positive control fungicide carbendazim (EC50: 1.42 μg·mL(-1)). In addition, these compounds were subjected to antioxidant assay by employing diphenylpicrylhydrazyl (DPPH) and mice microsome lipid peroxidation (LPO) methods. Most of these compounds are potent antioxidants. The strongest compounds are 6e (EC50: 7.60 μg·mL(-1), DPPH) and 6a (EC50: 0.96 μg·mL(-1), LPO), comparative to or more potent than the positive control Trolox [EC50: 5.90 μg·mL(-1) (DPPH) and 18.23 μg·mL(-1) (LPO)]. The structure and activity relationships were also discussed.

Maternal plasma levels of cell-free β-HCG mRNA as a prenatal diagnostic indicator of placenta accrete

OBJECTIVE

Several biomarkers, including maternal serum creatinine kinase and α-fetoprotein, have been described as potential tools for the diagnosis of placental abnormalities. This study aimed to determine whether maternal plasma mRNA levels of the β subunit of human chorionic gonadotropin (β-HCG) could predict placenta accreta prenatally.

METHODS

Sixty-eight singleton pregnant women with prior cesarean deliveries (CDs) were classified into three groups: normal placentation (35 women, control group); placenta previa alone (21 women, placenta previa group); and both placenta previa and placenta accreta (12 women, placenta previa/accreta group). Maternal plasma concentrations of cell-free β-HCG mRNA were measured by real-time reverse-transcription polymerase chain reaction and were expressed as multiples of the median (MoM).

RESULTS

Cell-free β-HCG mRNA concentrations (MoM, range) were significantly higher in women with placenta accreta (3.65, 2.78-7.19) than in women with placenta previa (0.94, 0.00-2.97) or normal placentation (1.00, 0.00-2.69) (Steel-Dwass test, P < 0.01 and P < 0.01, respectively). In the placenta previa/accreta group, the concentration of cell-free β-HCG mRNA was significantly higher among women who underwent CDs with hysterectomy (4.41, 3.49-7.19) than among women whose CDs did not result in hysterectomy (3.20, 2.78-3.70) (Mann-Whitney U test, P = 0.012).

DISCUSSION

An increased level of cell-free β-HCG mRNA in the maternal plasma of women with placenta accreta may arise from direct uteroplacental transfer of cell-free placental mRNA molecules.

CONCLUSIONS

The concentration of cell-free β-HCG mRNA in maternal plasma may be applicable to the prenatal diagnosis of placenta accreta, especially to identify women with placenta accreta likely to require hysterectomy.

Synthesis and antifungal activity of nicotinamide derivatives as succinate dehydrogenase inhibitors

Thirty-eight nicotinamide derivatives were designed and synthesized as potential succinate dehydrogenase inhibitors (SDHI) and precisely characterized by (1)H NMR, ESI-MS, and elemental analysis. The compounds were evaluated against two phytopathogenic fungi, Rhizoctonia solani and Sclerotinia sclerotiorum, by mycelia growth inhibition assay in vitro. Most of the compounds displayed moderate activity, in which, 3a-17 exhibited the most potent antifungal activity against R. solani and S. sclerotiorum with IC50 values of 15.8 and 20.3 μM, respectively, comparable to those of the commonly used fungicides boscalid and carbendazim. The structure-activity relationship (SAR) of nicotinamide derivatives demonstrated that the meta-position of aniline was a key position contributing to the antifungal activity. Inhibition activities against two fungal SDHs were tested and achieved the same tendency with the data acquired from in vitro antifungal assay. Significantly, 3a-17 was demonstrated to successfully suppress disease development in S. sclerotiorum infected cole in vivo. In the molecular docking simulation, sulfur and chlorine of 3a-17 were bound with PHE291 and PRO150 of the SDH homology model, respectively, which could explain the probable mechanism of action between the inhibitory and target protein.

Cerebroside C increases tolerance to chilling injury and alters lipid composition in wheat roots

Chilling tolerance was increased in seed germination and root growth of wheat seedlings grown in media containing 20 µg/mL cerebroside C (CC), isolated from the endophytic Phyllosticta sp. TG78. Seeds treated with 20 µg/mL CC at 4 °C expressed the higher germination rate (77.78%), potential (23.46%), index (3.44) and the shorter germination time (6.19 d); root growth was also significantly improved by 13.76% in length, 13.44% in fresh weight and 6.88% in dry mass compared to controls. During the cultivation process at 4 °C for three days and the followed 24 h at 25 °C, lipid peroxidation, expressed by malondialdehyde (MDA) content and relative membrane permeability (RMP) was significantly reduced in CC-treated roots; activities of lipoxygenase (LOX), phospholipid C (PLC) and phospholipid D (PLD) were inhibited by 13.62-62.26%, 13.54-63.93% and 13.90-61.17%, respectively; unsaturation degree of fatty acids was enhanced through detecting the contents of CC-induced linoleic acid, linolenic acid, palmitic acid and stearic acid using GC-MS; capacities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) were individually increased by 7.69-46.06%, 3.37-37.96%, and -7.00-178.07%. These results suggest that increased chilling tolerance may be due, in part, to the reduction of lipid peroxidation and alternation of lipid composition of roots in the presence of CC.

Synthesis and antioxidant activity of novel Mannich base of 1,3,4-oxadiazole derivatives possessing 1,4-benzodioxan

A new series of Mannich base of 1,3,4-oxadiazole derivatives possessing 1,4-benzodioxan (6a-6ae) were synthesized and characterized by (1)H NMR, ESI-MS and elemental analysis. The structure of 6b was further confirmed by single crystal X-ray diffraction. All these novel compounds were screened for their in vitro antioxidant activity employing 2,2'-diphenyl-1-picrylhydrazyl radical (DPPH), 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonate) cationic radical (ABTS(+)) and ferric reducing antioxidant power (FRAP) scavenging assays. Due to the combination of 1,4-benzodioxan, 1,3,4-oxadiazoles and substituted phenyl ring, most of them exhibited nice antioxidant activities. In all of these three assays mentioned above, compounds 6f and 6e showed significant radical scavenging ability comparable to the commonly used antioxidants, BHT and Trolox. Seven compounds with representative substituents or activities were selected for further assays in chemical simulation biological systems-inhibition of microsomal lipid peroxidation (LPO) and protection against 2,2'-azobis (2-amidinopropane hydrochloride) (AAPH) induced DNA strand breakage, in which, 6f and 6e were demonstrated to be of the most potent antioxidant activities.

The presence and expression of the hepatitis B virus in human oocytes and embryos

BACKGROUND

The objective of this study was to explore the potential for vertical transmission of hepatitis B virus (HBV) from parents to offspring via human germ cells.

METHODS

For study samples, 250 oocytes from hepatitis B surface antigen (HBsAg) seropositive women and 578 embryos from couples with at least one HBsAg seropositive partner were collected. HBV DNA in the nuclei of oocytes and embryos was detected by fluorescence in situ hybridization; HBsAg expression was analysed using immunofluorescence; and serum HBV DNA levels were measured by real-time PCR. The HBV infection duration of the women and the serum HBsAg status of their mothers were also examined.

RESULTS

HBV DNA was present in 9.6% (24/250) of oocytes and 14.4% (83/578) of embryos. Rates of HBV DNA positive embryos were similar among couples in which the woman, man or both partners were HBsAg seropositive, 13.1% (57/436), 21.3% (16/75) and 14.9% (10/67), respectively. Rates of positivity in oocytes and embryos were significantly higher in a group with high serum levels HBV DNA than in a group with lower serum levels (P= 0.004 and P= 0.002, respectively). Higher rates of oocyte positivity were found for women whose mothers were HBV infected compared with those with uninfected mothers. Expression of HBsAg was observed in 8.7% (2/28) oocytes and 14.1% (10/71) embryos (P= 0.34).

CONCLUSIONS

The presence of HBV DNA in human oocytes or embryos was related to the women's serum levels of HBV DNA and the infection status of their mothers. The HBV positive embryos were either maternally or paternally dependent. HBV infection may result in vertical transmission to the offspring via germ cells.

[Study on chemical constituents isolated from Juncus effuses]

OBJECTIVE

To study the constituents isolated from Juncus effuses Linn..

METHODS

The compounds were isolated through chromatographic approaches, such as Silica gel. CC, Sephadex LH-20 and were identified by a combination of spectroscopic methods (UV, MS, 1H-NMR, 13C-NMR and NOE).

RESULTS

8 kinds of compounds were identified which included four flavonoids, luteolin (I), eriodictyol (II), 2', 5', 5, 7-tetrahydroxyflavone (III), glucoluteolin (IV); two aromatic compounds, methyl p-hydroxybenzoate (V), vanillic acid (VI); a fatty acid, hexadecanoic acid (I) and an alkane, n-Tetradecane (VIII).

CONCLUSION

Compound II, III, V, VI, VII, VIII were firstly isolated from this plant.

6,6′-Oxydichroman

The title compound, C₁₈H₁₈O₃, was synthesized from dichroman in concentrated sulfuric acid. The mol­ecule has a twofold axis passing through the central O atom. The dihedral angle between the two symmetry-related benzene rings is 63.6 (3)°. Weak C—H⋯π inter­actions are present in the structure.

Antifungal and new metabolites of Myrothecium sp. Z16, a fungus associated with white croaker Argyrosomus argentatus

AIMS

Fungal infection is still a life-threatening risk for the immunocompromised population such as AIDS patients and those who receive treatments with immunosuppressors and/or frequent administrations of wide-spectrum antibiotics, which inevitably lead to the drug resistance and unbalanced microflora populations. The present work was accordingly performed to characterize more potent antifungal metabolites from various cultures of marine fungi residing in white croaker Argyrosomus argentatus.

METHODS AND RESULTS

The three most common opportunistic human pathogens Candida albicans (CCCCM ID 00148), Aspergillus niger (CCCCM ACCC 30005) and Trichophyton rubrum (CCCCM ID 00001) were selected as test fungi. A total of 16 cultivable fungal strains were isolated from the variant tissues of Ar. argentatus collected from the Yellow Sea, followed by preliminary antifungal screenings of the EtOAc extracts of the corresponding cultures. As a result, the inhibition of the three target fungi, plus being allergic to isolators' skin, were discerned with the EtOAc extract of the fungus under the isolation number Z16 that was identified subsequently as Myrothecium sp. by a combination of morphological and 18S rDNA finger-typing characteristics. A follow-up bioassay fractionation of the EtOAc extract, in conjunction with spectral analyses [MS, (1)H-NMR, (13)C-NMR, distortionless enhancement by polarization transfer (DEPT), heteronuclear multiple quantum coherence (HMQC) and heteronuclear multiple bond resonance (HMBC)] wherever required, afforded eventually the characterization of a new acid (compound 1: 4,5-ditridecyl-octanedioic acid), three macrocyclic trichothecenes including roridin A (compound 2), verrucarin A (compound 3) and 8beta-acetoxy-roridin H (compound 4), (22E,24R)-cerevisterol (compound 5) and N-phenyl-beta-amino-naphthalene (compound 6). In vitro antifungal tests showed that the three trichothecenes were active against A. niger, T. rubrum and C. albicans with MICs of 31.25, 62.5 and 125 microg ml(-1) for compound 2, 250, 125 and 31.25 microg ml(-1) for compound 3 as well as 125, 62.5 and 125 microg ml(-1) for compound 4 respectively. The MICs of ketoconazole (co-assayed herewith as a positive reference) against A. niger, T. rubrum and C. albicans were 31.25, 250, 31.25 microg ml(-1) respectively. A preliminary structure-activity relationship of the antifungal trichothecenes was highlighted in brief.

CONCLUSIONS

The present investigation demonstrated that marine fungus Myrothecium sp. Z16 associated with white croaker (Ar. argentatus), was an efficient producer of a new acid and antifungal trichothecenes, the latter presumably being also the allergic substances in the culture.

SIGNIFICANCE AND IMPACT OF THE STUDY

The title marine fungus was investigated to be a resource of new aliphatic acid, and trichothecenes with potent antifungal and dermal toxic actions.

Structure and Total Synthesis of Aspernigerin: A Novel Cytotoxic Endophyte Metabolite

Aspernigerin (1), a novel cytotoxic alkaloid consisting of an unprecedented structural framework has been isolated from the extract of a culture of Aspergillus niger IFB-E003, an endophyte in Cyndon dactylon. Its structure was elucidated on the basis of comprehensive NMR spectral analysis and confirmed by single-crystal X-ray analysis. Aspernigerin (1) has been shown to be cytotoxic to the tumor cell lines nasopharynyeal epidermoid KB, cervical carcinoma Hela, and colorectal carcinoma SW1116 with corresponding IC(50) values of 22, 46, and 35 microM, respectively. A feasible total synthetic route for aspernigerin (1) has been established for further pharmacological research.

Regioselective sonochemical synthesis of genistein derivatives

Differential functionalization of the phenolic groups in genistein was carried out in excellent yields under ultrasonic irradiation. The isoflavone ring had proved to be unstable under stirring at 60 degrees C and phenyl benzyl ketone was unexpectedly isolated instead of the genistein derivative.

New and cytotoxic anthraquinones from Pleospora sp. IFB-E006, an endophytic fungus in Imperata cylindrical

In addition to 7-methoxy-2-methyl-3,4,5-trihydroxyanthraquinone (1), physcion (2), macrosporin (3), deoxybostrycin (4), altersolanol B (5) and dactylariol (6), a new hexahydroanthraquinone named pleospdione (7) was isolated from the culture of Pleospora sp . IFB-E006, an endophytic fungus residing in the normal stem of Imperata cylindrical (Gramineae). Structure determination of pleospdione was accomplished using IR, HR-ESI-MS, 1D and 2D NMR spectral analysis. Compounds 4 - 6 exhibited significant cytotoxic activity against human colon cancer (SW1116) and leukemia (K562) cell lines while compounds 1, 2 and 7 were only weakly or moderately active.

Endophytic naphthopyrone metabolites are co-inhibitors of xanthine oxidase, SW1116 cell and some microbial growths

Fractionation of the extract of Aspergillus niger. IFB-E003, an endophyte in Cyndon dactylon, gave four known compounds naphtho-gamma-pyrones rubrofusarin B, fonsecinone A, asperpyrone B and aurasperone A, which were further investigated biologically. Rubrofusarin B was shown to be cytotoxic to the colon cancer cell line SW1116 (IC50: 4.5 microgml-1), and aurasperone A inhibitory on XO (xanthine oxidase) (IC50: 10.9 micromoll-1). Moreover, the four naphtho-gamma-pyrones exhibited growth inhibitions against the five test microbes with MICs ranging in between 1.9 and 31.2 microgml(-1). The present recognition of rubrofusarin B and aurasperone A as strong co-inhibitors on XO, colon cancer cell and some microbial pathogens is of significance for the imperative discovery of new relevant therapeutic agents.

The solution structure of rat Aβ-(1–28) and its interaction with zinc ion: insights into the scarcity of amyloid deposition in aged rat brain

The amyloid beta-peptide (Abeta) is a major component of insoluble amyloid deposits in Alzheimer's disease, and the ability of the beta-peptide to exist in different conformations is dependent on residues 1-28 [beta-(1-28)]. However, different from humans, no Abeta amyloid deposition has been found in aged rats' brains. Studying the three-dimensional solution structure of rat Abeta-(1-28) and the binding circumstance of Zn(2+) is beneficial to a clear understanding of the potential role of Zn(2+) in Alzheimer-associated neuropathogenesis and to suggest why there is no amyloid deposition in aged rats' brains. Here we used nuclear magnetic resonance (NMR) spectroscopy to determine the solution structure of rat Abeta-(1-28) and the binding constant of Zn(2+) to rat Abeta-(1-28). Our results suggest that (1) the three-dimensional solution structure of rat Abeta-(1-28) is more stable than that of human Abeta-(1-28) in DMSO- d(6) and that a helical region from Glu16 to Val24 exists in the rat Abeta-(1-28); (2) the affinity of Zn(2+) for rat Abeta-(1-28) is lower than that for human Abeta-(1-28) and the NMR data suggest that Arg13, His6, and His14 residues provide the primary binding sites for Zn(2+); and (3) the proper binding of Zn(2+) to rat Abeta-(1-28) can induce the peptide to change to a more stable conformation.

[Study of distribution and metabolism of methamphetamine in hair of guinea pig]

OBJECTIVE

To study the distribution and metabolism of methamphetamine in the hair of guinea pig.

METHODS

Determination of methamphetamine and its metabolite amphetamine in hair was performed by GC/MS and GC/NPD. Concentration-time course of methamphetamine and amphetamine in hair of guinea were recorded. Relationship between hair color, administrated dose and drug concentration in hair were also discussed.

RESULTS

The concentration of amphetamine is higher than the concentration of methamphetamine in the hair of guinea administrated a single dose or seven doses of methamphetamine. The concentration of methamphetamine and amphetamine were significantly related with administration dose and the incorporation rate into white and brown hair is much poorer than that of black hair.

CONCLUSION

Administration methods, dose and the color of hair affect the concentration of methamphetamine and amphetamine.

3-(Diethoxyphosphoryloxy)-1,2,3-benzotriazin-4(3H)-one (DEPBT): a new coupling reagent with remarkable resistance to racemization

[formula: see text] The new crystalline phosphate reagent 3-(diethoxyphosphoryloxy)-1,2,3-benzotriazin-4(3H)-one (DEPBT) mediates amide bond formation with a remarkable resistance to racemization. Comparative racemization studies were carried out and DEPBT proved to be superior to typical phosphonium and uronium coupling reagents. DEPBT is easily prepared and is exceedingly stable with a shelf life of months at room temperature. The advantageous properties of DEPBT render it a useful and unique addition to the arsenal of coupling reagents.

Influence of reaction conditions on syntheses of sweetener precursors catalyzed by thermolysin in tert-amyl alcohol

The activity of enzymes to form a peptide bond in organic solvent was greatly influenced by observed pH and water content. The precursors of two sweeteners, P-Asp-Xaa-OR (P=Z or For, Xaa-OR=Phe-OMe or Ala-OcHex), were synthesized by enzyme, and the reaction conditions were studied systematically. Z-Asp-OH was coupled with H-Phe-OMe or H-Ala-OcHex by thermolysin in tert-amyl alcohol. The best coupling results were obtained when the optimized observed pH was 8 or 9, and the water content was about 6% (V/V). The protecting group Z is better than For under the reaction conditions and H-Phe-OMe is a better nucleophile than H-Ala-OcHex. The expected optically pure peptides were obtained when the racemic amino acids were used as amino components in the starting materials. The physical constants of P-Asp-Xaa-OR synthesized by thermolysin are identical with those of peptides synthesized by chemical method.

Isolation and characterization of a group of oligopeptides related to oxidized glutathione from the root of Panax ginseng

Six gamma-glutamyl oligopeptides were isolated for the first time from aqueous methanol extracts of Panax ginseng root by using column chromatography on ion-exchange resin, gel filtration and reverse-phase high-performance liquid chromatography. Their structures had been established with the methods of amino acid analysis, N-terminal, C-terminal determination and double-coupling sequence analysis. They were: P-I (N-gamma-glutamylcystinyl-bis-glycine), P-ll (gamma-glutamylcysteinylglycine disulfide, oxidized glutathione), P-III (N,N'-bis-gamma-glutamylcystinylglycine), P-IV (gamma-glutamylcysteinylglycinamide disulfide), P-V (N-gamma-glutamylglycylcysteine disulfide), P-VI(gammaglutamylarginine); five of them are related to oxidized glutathione. The structures were further confirmed by the chemical synthesis. As far as we know, P-V (N-gamma-glutamylglycylcysteine disulfide) is a new biologically active peptide which exhibits somnogenic effect and is more potent than that of P-II.

Studies on the neuroexcitotoxin beta-N-oxalo-L-alpha,beta-diaminopropionic acid and its isomer alpha-N-oxalo-L-alpha,beta-diaminopropionic acid from the root of Panax species

The neuroexcitotoxic nonprotein amino acid, beta-N-oxalo-L-alpha,beta-diaminopropionic acid (beta-N-ODAP) was found in Panax species such as Panax ginseng 'C.A. Meyer' (cultivated in Northeastern China), Panax quinquefolius (L), Panax notoginseng 'F.H. Chen' (cultivated in Southwestern China), Korean red ginseng and Jilin (China) red ginseng. beta-N-ODAP was verified to be a natural substance, and its isomer alpha-N-oxalo-L-alpha,beta-diaminopropionic acid (alpha-N-ODAP) is very likely an artifact generated during the separation process. The interconversion between beta-N-ODAP and alpha-N-ODAP was observed. Results showed that both beta-N-ODAP and alpha-N-ODAP can easily be converted into their isomers at higher temperature or in acidic and basic solution. Their interconversion equilibrium constant and rate constants were obtained. Upon extensive study and a good understanding of the interconversion, accurate physical constants and spectroscopic data such as MS, 1H NMR, 13C NMR and UV were obtained.

Synthesis of new amino acid and peptide derivatives of estradiol and their binding affinities for the estrogen receptor

A series of amino acid and peptide derivatives of estradiol have been synthesized by coupling 17 beta-aminoestra-1,3,5(10)-trien-3-ol, 17-hydrazonoestra-1,3,5(10)-trien-3-ol with amino acids or peptides, using tetrahydrothiazole-2-thione, N-hydroxy-1,4-epoxycyclohex-5-ene-2,3-dicarbonylimide, benzotriazolyloxy-tris(dimethylamino)phosphonium hexafluorophosphate, and p-nitrophenol as reagents. N-protected peptidyl steroids were deprotected by traditional methods. The relative binding affinities of the deprotected derivatives to the estrogen receptor were determined by competitive radioligand binding assay.

Epidemiologic survey of vibration syndrome among riveters, chippers and grinders in the railroad system of the People's Republic of China

Vibration syndrome caused by hand-held vibrating tools in 14 locomotive and rolling stock plants in four regions of the People's Republic of China (south, north, middlewest, and northeast) and the influence of climatic factors on its prevalence rate were studied. For 1,028 male workers (705 riveters, 284 chippers, and 39 grinders), the prevalence rate of the syndrome was 13.4% and for a reference group of 256 workers it was 1.6%. The prevalence rate of white finger in the four regions differed and was higher in northeast and north China than in south and middlewest China. This finding suggests that cold climate and humidity may be causative factors of the vibration syndrome.

Synthesis of delta sleep-inducing peptide (DSIP) and its physiological activity

Protected nonapeptide--Delta Sleep-Inducing Peptide (DSIP) formula: see text has been synthesized by classical method. The product has been treated with TFA and purified on DEAE-Sephadex-A25 column, pure free nonapeptide obtained and alpha to beta transposition of Asp-residue found to be absent. It has been assayed by electrophoresis at pH 3.8, microcrystallinecellulose TLC and HPLC. The physiological activities of synthetic DSIP are performed on rabbits by using intravenous administration or mesodiencephalic ventricular infusion. Its function of intensifying delta and sigma waves on rabbit's electroencephalogram (EEG) is evident. There is no concomitant increase of delta- and sigma-enhancing effect following mesodiencephalic ventricular infusion of 10 or 20 times higher than 5 microgram/rabbit doses. Results of 6-day consecutive intravenous administration (50 microgram/kg) indicate that there is no obvious sign of adaptation to DSIP. Results suggest that the physiological function of endogenous sleep-inducing peptide is different from that of general sleeping draught.