Recent advances in targeting myeloid-derived suppressor cells and their applications to radiotherapy.

Myeloid-derived suppressor cells (MDSCs) are a group of heterogenous immature myeloid cells with potent immune suppressive properties that not only constrain anti-tumor immune activation and functions, promote tumor progression, but also contribute to treatment resistance and tumor relapse. Targeting MDSCs may be a promising new cancer treatment method, but there is still a problem of low treatment efficiency. Combined application with radiotherapy may be a potential method to solve this problem. Drug delivery systems (DDSs) provide more efficient targeted drug delivery capability and can reduce the toxicity and side effects of drugs. Recent advance in DDSs targeting development, recruitment, differentiation, and elimination of MDSCs have shown promising effect in reversing immune inhibition and in overcoming radiotherapy resistance. In this review, we systematically summarized DDSs applied to target MDSCs for the first time, and classified and discussed it according to its different mechanisms of action. In addition, this paper also reviewed the biological characteristics of MDSCs and their role in the initiation, progression, and metastasis of cancer. Moreover, this review also summarizes the role of DDSs targeting MDSCs in radiosensitization. Finally, the future development of DDSs targeting MDSCs is also prospected.

Myeloid-derived suppressor cells in head and neck squamous cell carcinoma.

Myeloid-derived suppressor cells (MDSCs), which originated from hematopoietic stem cells, are heterogeneous population of cells that have different differentiation patterns and widely presented in tumor microenvironment. For tumor research, myeloid suppressor cells have received extensive attention since their discovery due to their specific immunosuppressive properties, and the mechanisms of immunosuppression and therapeutic approaches for MDSCs have been investigated in a variety of different types of malignancies. To improve the efficacy of treatment for head and neck squamous cell carcinoma (HNSCC), a disease with a high occurrence, immunotherapy has gradually emerged in after traditional surgery and subsequent radiotherapy and chemotherapy, and has made some progress. In this review, we introduced the mechanisms on the development, differentiation, and elimination of MDSCs and provided a detailed overview of the mechanisms behind the immunosuppressive properties of MDSCs. We summarized the recent researches on MDSCs in HNSCC, especially for targeting-MDSCs therapy and combination with other types of therapy such as immune checkpoint blockade (ICB). Furthermore, we looked at drug delivery patterns and collected the current diverse drug delivery systems for the improvement that contributed to therapy against MDSCs in HNSCC. Most importantly, we made possible outlooks for the future research priorities, which provide a basis for further study on the clinical significance and therapeutic value of MDSCs in HNSCC.

[Mechanism of miRNA-3679 Inhibiting Downstream ZADH2-Target Genes to Promote Hepatocellular Carcinoma Cell Proliferation].

Objective: To examine the relationship between miRNA-3679 and hepatocellular carcinoma (HCC) cell lines, and to verify the downstream target genes of miRNA-3679. Methods: PCR was used to determine the expression of miRNA-3679 in liver cancer cell lines, and databases, including ENCORI, miRDB and TargetScan, were used to predict the downstream target genes of miRNA-3679. qPCR of the normal control group (or NC group), miR-3679 inhibitor group and transfection negative control group (or inhibitor NC group) was done to determine the transfection efficiency of the target gene, thereby identifying zinc-binding alcohol dehydrogenase domain containing 2 (ZADH2) as the target gene. Western blot was used to determine the ZADH2 protein expression after miRNA-3679 inhibitor transfection. 5-Ethynyl-2'-deoxyuridine (EdU) staining was done to determine the effect of transfection of miRNA-3679 inhibitor and simultaneous transfection of miRNA-3679 and ZADH2 inhibitors on cell proliferation. Clone formation assay was done to determine the ability of cell clone formation. Flow cytometry was done to examine cell apoptosis. Results: The expression level of miRNA-3679 in HCC cell lines was higher than that in normal human liver cell lines (P<0.05). Through screening conducted with the databases, six genes, including GLUD1, B3GAT1, SLC46A3, MAP2K3, ATF5, and ZADH2, were found to be down-regulated in HCC. qPCR showed that ZADH2 expression increased significantly after transfection with miRNA-3679 inhibitor (P<0.01) and luciferase activity increased after transfection with miR-3679 inhibitor (P<0.01). Western blot results showed that ZADH2 protein expression of the miR-3679 inhibitor group was higher than that of the NC group (P<0.01). EdU analysis showed that the number of positive cells in the miRNA-3679 inhibitor group was lower than that in the NC group and the Inhibitor NC group (P<0.05). The clone count of the miR-3679 inhibitor+si-ZADH2 group was significantly higher than that of the miR-3679 inhibitor group (P<0.01). Flow cytometry showed that the number of apoptotic cells of the miR-3679 inhibitor+si-ZADH2 group was significantly lower than that of the miR-3679 inhibitor group (P<0.01). Conclusion: miRNA-3679 is significantly highly expressed in HCC cells and miRNA-3679 can directly interact with ZADH2 gene and affect its expression. Moreover, miRNA-3679 promotes the proliferation of HCC cells and inhibits their apoptosis by suppressing ZADH2.

Detection of an anti-angina therapeutic module in the effective population treated by a multi-target drug Danhong injection: a randomized trial.

It's a challenge for detecting the therapeutic targets of a polypharmacological drug from variations in the responsed networks in the differentiated populations with complex diseases, as stable coronary heart disease. Here, in an adaptive, 31-center, randomized, double-blind trial involving 920 patients with moderate symptomatic stable angina treated by 14-day Danhong injection(DHI), a kind of polypharmacological drug with high quality control, or placebo (0.9% saline), with 76-day following-up, we firstly confirmed that DHI could increase the proportion of patients with clinically significant changes on angina-frequency assessed by Seattle Angina Questionnaire (ΔSAQ-AF ≥ 20) (12.78% at Day 30, 95% confidence interval [CI] 5.86-19.71%, P = 0.0003, 13.82% at Day 60, 95% CI 6.82-20.82%, P = 0.0001 and 8.95% at Day 90, 95% CI 2.06-15.85%, P = 0.01). We also found that there were no significant differences in new-onset major vascular events (P = 0.8502) and serious adverse events (P = 0.9105) between DHI and placebo. After performing the RNA sequencing in 62 selected patients, we developed a systemic modular approach to identify differentially expressed modules (DEMs) of DHI with the Zsummary value less than 0 compared with the control group, calculated by weighted gene co-expression network analysis (WGCNA), and sketched out the basic framework on a modular map with 25 functional modules targeted by DHI. Furthermore, the effective therapeutic module (ETM), defined as the highest correlation value with the phenotype alteration (ΔSAQ-AF, the change in SAQ-AF at Day 30 from baseline) calculated by WGCNA, was identified in the population with the best effect (ΔSAQ-AF ≥ 40), which is related to anticoagulation and regulation of cholesterol metabolism. We assessed the modular flexibility of this ETM using the global topological D value based on Euclidean distance, which is correlated with phenotype alteration (r2: 0.8204, P = 0.019) by linear regression. Our study identified the anti-angina therapeutic module in the effective population treated by the multi-target drug. Modular methods facilitate the discovery of network pharmacological mechanisms and the advancement of precision medicine. (ClinicalTrials.gov identifier: NCT01681316).

6,12-Diphenyl-3, 9-diazatetraasterane-1, 5, 7, 11-tetracarboxylate Inhibits Proliferation, Migration and Promotes Apoptosis in Ovarian Cancer Cells.

6,12-Diphenyl-3,9-diazatetraasterane-1, 5, 7, 11-tetracarboxylate (DDTC) has been synthesized by the photodimerization of 4-phenyl-1,4-dihydropyridine-3,5-dicarboxylate. The potential of theercvantitumor activity and mechanism were investigated in vitro using MTT assay in human lung cancer cell line A549, ovarian cancer cell lines SKOV3 and A2780, breast cancer cell line MCF-7, gastric cancer cell line BGC-823, colon cancer cell line HT29, prostate cancer cell line DU145, and liver cancer cell line SMMC7721. The results show that DDTC can inhibit the growth of ovarian cancer SKOV3 and A2780 cells. The best IC50 value is approximately 5.29 ± 0.38 and 4.29 ± 0.39 µM, respectively. DDTC induced the cell cycle arrest in the G2 phase by flow cytometric analysis. The migration and invasion of ovarian cancer SKOV3 and A2780 cells were inhibited by DDTC. DDTC could increase the expression protein level of E-cadherin in A2780 cells and ascend the expression protein and mRNA levels of E-cadherin in SKOV3 cells. DDTC could also decrease the protein and mRNA expression of EMT (epithelial-to-mesenchymal transition) markers of N-cadherin and Vimentin. mRNA and protein expression level of checkpoint kinase 1 (Chk1) were significantly increased and expressions of cyclin-dependent kinase (CDK1) and cell division cycle 25a (Cdc25a) were decreased in the SKOV3 and A2780 cell lines. Moreover, DDTC induced apoptosis by the cleavage and activation of caspase 3 and caspase 9.

Codonopsis tangshen Oliv. Amelioration Effect on Diabetic Kidney Disease Rats Induced by High Fat Diet Feeding Combined with Streptozotocin.

Diabetic kidney disease (DKD) is the most serious microvascular complication during the development of diabetes with the characterizations of glomerular basement membrane thickening, mesangial expansion, and glomerular sclerosis, eventually leading to end-stage renal disease. This study aimed to investigate the melioration effect of Codonopisis tangshen Oliv. (COD) on the DKD model, which was established by unilateral nephrectomy (UN)-high fat diet feeding (HFD) combined with streptozotocin (STZ). After the DKD rats were oral treated with COD at a dose of 2.7 mg/kg for 4 consecutive weeks, the blood glucose, lipid metabolism, renal function, inflammatory mediators, and fibrosis-associated proteins were examined. In vivo, the COD administration obviously relieved the weight loss, water intake, and blood glucose; decreased the total cholesterol, triglyceride, and low-density lipoprotein cholesterol levels; and improved the renal function by reducing the expression of serum creatinine, uric acid, and urinary protein compared with the model group. The levels of pro-inflammatory cytokines of tumor necrosis factor-α, interleukin-1ß, and IL-6 were significantly inhibited by COD. Meanwhile, the deposition of collagen fiber was markedly increased, and the protein and mRNA expressions of transforming growth factor-ß1 and α-smooth muscle actin were markedly elevated in DKD rats, but they were decreased to some extent after the COD treatment. In conclusion, COD exhibited a protective effect on the UN-HFD feeding combined with STZ-induced DKD model by improving the blood glucose and lipid metabolism, relieving the inflammatory response, and mitigating the renal fibrosis, which provided scientific evidence for its applications in clinic.

Efficacy and Safety of Intravenous Urapidil for Older Hypertensive Patients with Acute Heart Failure: A Multicenter Randomized Controlled Trial.

PURPOSE: Urapidil is putatively effective for patients with hypertension and acute heart failure, although randomized controlled trials thereon are lacking. We investigated the efficacy and safety of intravenous urapidil relative to that of nitroglycerin in older patients with hypertension and heart failure in a randomized controlled trial. MATERIALS AND METHODS: Patients (>60 y) with hypertension and heart failure were randomly assigned to receive intravenous urapidil (n=89) or nitroglycerin (n=91) for 7 days. Hemodynamic parameters, cardiac function, and safety outcomes were compared. RESULTS: Patients in the urapidil group had significantly lower mean systolic blood pressure (110.1±6.5 mm Hg) than those given nitroglycerin (126.4±8.1 mm Hg, p=0.022), without changes in heart rate. Urapidil was associated with improved cardiac function as reflected by lower N terminal-pro B type natriuretic peptide after 7 days (3311.4±546.1 ng/mL vs. 4879.1±325.7 ng/mL, p=0.027) and improved left ventricular ejection fraction (62.2±3.4% vs. 51.0±2.4%, p=0.032). Patients given urapidil had fewer associated adverse events, specifically headache (p=0.025) and tachycardia (p=0.004). The one-month rehospitalization and all-cause mortality rates were similar. CONCLUSION: Intravenous administration of urapidil, compared with nitroglycerin, was associated with better control of blood pressure and preserved cardiac function, as well as fewer adverse events, for elderly patients with hypertension and acute heart failure.

Chemical Analysis of Dietary Constituents in Rosa roxburghii and Rosa sterilis Fruits.

Both Rosa roxburghii and R. sterilis, belonging to the Rosaceae, are endemic species in Guizhou Province, China. The fruits of these two species are mixed-used as functional food in the region. Aiming to elucidate the phytochemical characteristics of R. roxburghii and R. sterilis fruits, the essential oils and constituents in a methanol extract have been analyzed and compared by GC-MS and UFLC/Q-TOF-MS, respectively. As a result, a total of 135 volatile compounds were identified by GC-MS and 91 components were different between R. roxburghii and R. sterilis fruits; a total of 59 compounds in methanol extracts were identified by UFLC/Q-TOF-MS, including 13 organic acids, 12 flavonoids, 11 triterpenes, nine amino acids, five phenylpropanoid derivatives, four condensed tannins, two stilbenes, two benzaldehyde derivatives and one benzoic acid derivative; and nine characteristic compounds were found between R. roxburghii and R. sterilis fruits. This systematic study plays an important role for R. roxburghii and R. sterilis fruits in the product development.

Therapeutic effects of intravenous urapidil in elderly patients with hypertension and acute decompensated heart failure: A pilot clinical trial.

Urapidil has been proposed to be an effective vasodilator for the treatment of acute decompensated heart failure (ADHF); however, its effect on cardiac function, as compared with that of nitroglycerin, in elderly patients with hypertension and ADHF has yet to be determined. In the present study, a multicenter, open-label clinical trial was performed, in which 120 elderly patients with hypertension and ADHF were randomly assigned to the treatment (50-400 µg/min intravenous urapidil) or control group (5-40 µg/min intravenous nitroglycerin). The dosages of the medications were adjusted according to the blood pressure of the patients. The systolic and diastolic blood pressure, heart rate and serum level of N-terminal pro B-type natriuretic peptide (NT-proBNP) were evaluated at hospital admission and at days 1, 2, 3 and 7 after treatment. In addition, the left ventricular function was assessed by measuring the left ventricular ejection fraction (LVEF) and left ventricular end-diastolic volume at hospital admission and at days 2 and 7 after treatment. The results indicated that intravenous administration of urapidil and nitroglycerin were effective in lowering the blood pressure and heart rate within 7 days, with no significant differences observed between the two groups (P>0.05). By contrast, greater reduction in the serum NT-proBNP level (2,410.4±546.1 vs. 4,234.1±876.4 pg/ml; P<0.05) and greater improvement in the LVEF (55.3±3.4 vs. 45.2±2.4%; P<0.05) were observed in the urapidil-treated group, as compared with the nitroglycerin-treated group. No adverse events were reported during the treatment period in the two groups. The clinical outcomes at 6 months following discharge were evaluated and were not found to be significantly different between the two groups. In conclusion, the present results of the present study suggested that urapidil was as effective as nitroglycerin in controlling blood pressure and heart rate and was more effective in improving cardiac systolic function in elderly patients with hypertension and ADHF.

Chemical Profiles and Protective Effect of Hedyotis diffusa Willd in Lipopolysaccharide-Induced Renal Inflammation Mice.

Protective effect of Hedyotis diffusa (H. diffusa) Willd against lipopolysaccharide (LPS)-induced renal inflammation was evaluated by the productions of cytokines and chemokine, and the bioactive constituents of H. diffusa were detected by the ultra-fast liquid chromatography-diode array detector-quadrupole-time of flight mass spectrometry (UFLC-DAD-Q-TOF-MS/MS) method. As the results showed, water extract of H. diffusa (equal to 5.0 g/kg body weight) obviously protected renal tissues, significantly suppressed the productions of tumor necrosis factor-α (TNF-α), interleukin (IL)-1ß, IL-6, and monocyte chemoattractant protein (MCP)-1, as well as significantly promoted the production of IL-10 in serum and renal tissues. According the chemical profiles of H. diffusa, flavonoids, iridoid glycosides and anthraquinones were greatly detected in serum from H. diffusa extract treatment mice. Two main chemotypes, including eight flavonoids and four iridoid glycosides were found in renal tissues from H. diffusa extract treatment mice. The results demonstrated that water extract of H. diffusa had protective effect on renal inflammation, which possibly resulted from the bioactive constituents consisting of flavonoids, iridoids and anthraquinones.

A comparison of whole cell directed evolution approaches in breeding of industrial strain of Saccharomyces cerevisiae.

OBJECTIVE: To reduce the fermentation cost in very high gravity fermentations of ethanol using Saccharomyces cerevisiae, whole cell directed evolution approaches were carried out. RESULTS: The methods used included cell ploidy manipulation, global transcription machinery engineering and genome shuffling. Ethanol production by the four methods was improved compared with the control. Notably, the ethanol yield of a strain constructed by genome shuffling was enhanced by up to 11 % more than the control reaching 120 g ethanol/l in 35 h using a very high gravity fermentation with 300 g glucose/l. CONCLUSION: Genome shuffling can create strains with improved fermentation characteristics in very high gravity fermentations.

The genus Codonopsis (Campanulaceae): a review of phytochemistry, bioactivity and quality control.

Codonopsis, in the family Campanulaceae, is a genus containing 42 species of dicotyledonous herbaceous perennial plants, predominantly found in Central, East and South Asia. Several Codonopsis species are widely used in traditional medicine and are considered to have multiple medicinal properties. Among the Codonopsis species, Codonopsis pilosula (Franch.) Nannf. and C. lanceolata (Sieb. et Zucc.) Benth. & Hook. f. ex Trautv. are more popular than others according to the findings, especially phytochemical and bioactive studies. Phytochemical research shows that Codonopsis species contain mainly polyacetylenes, phenylpropanoids, alkaloids, triterpenoids and polysaccharides, which contribute to multiple bioactivities. However, the mechanisms of their bioactivities need to be further elucidated. The less popular Codonopsis species remain to be studied and exploited. In addition, although a series of methods for the quality evaluation of Codonopsis species have been developed, a feasible and reliable approach to the efficacious and safe use of various Codonopsis species is still needed, with considering botanical origin, chemical constituents and bioactive effects. This review aims to provide up-to-date and comprehensive information on the phytochemistry, bioactivity and quality control of medicinal plants in the genus Codonopsis and to highlight current gaps in knowledge, which is useful for the wider development of the Codonopsis genus.

Ultrasound-mediated synthesis of 4-substituted 1,4-dihydropyridine-3,5-dicarboxylates catalyzed by 1-carboxymethyl-3-methylimidazolium tetrafluoroborate under solvent free condition.

4-Substituted 1,4-dihydropyridine-3,5-dicarboxylates (4) have been synthesized by the solvent-free reaction of aldehyde, methyl propiolate and ammonium carbonate catalyzed by ionic liquid 1-carboxymethyl-3-methylimidazolium tetrafluoroborate under ultrasonic irradiation. The effects of changes in the ultrasonic power, temperature, catalysts and reactants on the synthesis of 4-substituted 1,4-dihydropyridine-3,5-dicarboxylates (4) are discussed. With the optimized reaction conditions, various aldehydes were used to synthesize 1,4-dihydropyridines (4) under the influence of ultrasound irradiation. Compared with the conventional thermal methods, the remarkable advantages of this method are the simple experimental procedure, shorter reaction time (2-10min) and high yield of product (76-95%). Furthermore, the green catalytic system can be recycled specific times without significantly decreasing the yields and reaction rates.

Hypericum japonicum Thunb. ex Murray: phytochemistry, pharmacology, quality control and pharmacokinetics of an important herbal medicine.

Hypericum japonicum Thunb. ex Murray is mainly distributed throughout Asia, Oceania and North America and is used as an important herbal medicine. H. japonicum contains many valuable secondary metabolites, such as flavonoids, phloroglucinols and xanthones and has hepatoprotective, anti-tumor, antibacterial, antiviral, and antioxidant activities and effects on the cardiovascular system and immunity. Coupled with phytochemical and pharmacological research, a series of analytical methods have been developed to evaluate the quality of H. japonicum based on its bioactive components. A pharmacokinetics study involved the absorption of two main flavonoids of H. japonicum in rats. This review aims to present an up-to-date and comprehensive overview of the phytochemistry, pharmacology, quality control and pharmacokinetics of H. japonicum, which should be useful for the greater development of H. japonicum, especially in the development of new drugs and therapeutics for various diseases.

HPLC/UV analysis of polyacetylenes, phenylpropanoid and pyrrolidine alkaloids in medicinally used Codonopsis species.

INTRODUCTION: Codonopsis Radix is commonly used as a tonic in traditional Chinese medicine. However, there is no suitable method to assess the quality of Codonopsis Radix based on multiple components having potential bioactivities. OBJECTIVE: To establish a HPLC/UV method for simultaneous quantitation of polyacetylenes (lobetyol, lobetyolin, lobetyolinin, cordifolioidyne B), phenylpropanoid (tangshenoside I) and pyrrolidine alkaloids (codonopyrrolidiums A, B) in Codonopsis Radix. METHODS: Large-scale methanol extraction of Codonopsis Radix, followed by chromatographic separation, provided the seven analytes for quantitation standards. Ultrasound-assisted methanol extracts of samples were analysed using reversed phase, gradient elution HPLC monitored at 215 nm. RESULTS: The method developed allowed efficient separation of the seven compounds and the detection and quantitation limits of the seven analytes were 0.10-0.32 µg/mL and 0.35-1.07 µg/mL, respectively. All calibration curves showed good linearities (r>0.9993) within the test ranges. Intraday and interday precisions were good with RSD<2.84%. The recoveries of all analytes ranged from 95.8 to 104.7%. CONCLUSION: HPLC/UV is an efficient and accurate method of analysis for simultaneous quantitation of seven components in Codonopsis Radix.

Genetic polymorphism of medicinally-used Codonopsis species in an internal transcribed spacer sequence of nuclear ribosomal DNA and its application to authenticate Codonopsis Radix.

Codonopsis Radix has been prescribed as the roots of Codonopsis pilosula, C. pilosula var. modesta and C. tangshen in Chinese Pharmacopoeia. In order to find out genetic markers for identifying the 3 taxa and to authenticate Codonopsis Radix, the molecular analysis of the internal transcribed spacer sequence of nuclear ribosomal DNA was conducted on Codonopsis plants collected widely from Gansu Prov. and Chongqing city of China, the main producing areas of Codonopsis Radix. Significant genetic polymorphism was observed, represented by 11 types of ITS sequences in C. pilosula, 5 types in C. pilosula var. modesta and 5 types in C. tangshen. Among the determined sequences, 1, 1 and 2 types were thought to be of pure lines of each taxon, respectively, designated as types P0, PM0, T1 and T3, and the rest might be derived from hybridization. Hybrid lines were inferred to be resulting from the combination of these pure lines. The informative sites for discriminating the 3 taxa were detected at the nucleotide positions 122nd, 226th, 441st and 489th from upstream of the ITS sequence. For discrimination of the types of C. tangshen, including one type T0 registered in GenBank, the nucleotides at positions 135th, 489th and 500th were informative. Botanical sources of the crude drugs produced in a wide range of the southeast Gansu Prov. were C. pilosula, just those from Wenxian of Gansu Prov. were C. pilosula var. modesta. The crude drugs produced in Chongqing were derived from C. tangshen.

Quality evaluation of medicinally-used Codonopsis species and Codonopsis Radix based on the contents of pyrrolidine alkaloids, phenylpropanoid and polyacetylenes.

A comparative study of 56 specimens of three medicinally-used Codonopsis taxa collected from China and 54 commercial samples of Codonopsis Radix available in Chinese, Japanese and Korean markets was carried out by quantitative analysis of seven major components: codonopyrrolidium B (1), codonopyrrolidium A (2), tangshenoside I (3), cordifolioidyne B (4), lobetyolinin (5), lobetyolin (6) and lobetyol (7). The quantitative results, based on a well-established HPLC-DAD method, indicated that the contents of these seven compounds varied considerably among the samples, not only inter-species but also intra-species. C. pilosula and C. pilosula var. modesta showed similar chemical compositions, while C. tangshen differed considerably from these two in chemical composition. The results of principal component analysis (PCA) indicated that two main groups were classified; one group mainly included C. pilosula, C. pilosula var. modesta and the commercial samples derived from these two taxa, while the other group was composed of C. tangshen and its derived commercial samples. Compound 1 was the main component in the roots of C. pilosula and C. pilosula var. modesta, while 3 and 2 had relatively high contents in the roots of C. tangshen. Therefore, 3, 2 and 1 could be chemical markers to differentiate C. tangshen from C. pilosula and C. pilosula var. modesta.

Convenient ultrasound-mediated synthesis of 1,4-diazabutadienes under solvent-free conditions.

An ultrasound-assisted preparation of 1,4-diazabutadienes via smooth condensation of diketones with amines under solvent-free conditions is described. The generality of this method was examined by the synthesized N,N'-diaryl- and N,N'-dialkyl-1,4-diazabutadiene derivatives. In addition to experimental simplicity, the main advantages of the procedure are mild conditions, short reaction time (2-15 min) and high yields (71-98%).

Tetra-kis(µ-4-methoxy-benzoato)bis-[(4-methoxy-benzoato)(1,10-phenan-throline)terbium(III)].

In the title dinuclear complex, [Tb(2)(C(8)H(7)O(3))(6)(C(12)H(8)N(2))(2)], each Tb(III) ion is eight-coordinated by two N atoms from a 1,10-phenanthroline ligand and six O atoms from the carboxyl-ate groups of five 4-methoxy-benzoate ligands in a distorted square-anti-prismatic geometry. All six 4-methoxy-benzoate ligands act in a bidentate mode, two coordinating to one Tb center each and the other four bridging two Tb centers [Tb⋯Tb separation = 4.3144 (6) Å]. In the crystal, inter-molecular π-π inter-actions between the aromatic rings of 1,10-phenanthroline and 4-methoxy-benzoate ligands [centroid-centroid distance = 3.742 (9) Å] link two mol-ecules into a centrosymmetric dimer. Weak inter-molecular C-H⋯O hydrogen bonds help to consolidate the crystal packing.

Diethyl 4-(4,5-dihydro-furan-2-yl)-3,5-di-methyl-1-phenyl-1,4-dihydro-pyrazine-2,6-dicarboxyl-ate.

In the title compound, C(22)H(26)N(2)O(5), the central 1,4-dihydro-pyrazine ring adopts a boat conformation, while the benzene ring and the two disordered components of the furan ring are inclined at angles of 77.9 (5) and 61.9 (7)°. Three of the C atoms of the furan ring are disordered over two positions with occupancies of 0.655 (18) and 0.345 (18). In the crystal structure, weak inter-molecular C-H⋯O hydrogen bonds link the mol-ecules into chains propagating in [010].