Volume 73, Issue 3-4

This study was designed to load different antibodies (Abs) and a fluorescent dye onto the red blood cell (RBC) surface. We have used fluorescein isothiocyanate (FITC)-conjugate anti-human Ab, CD22-PE (B-cell marker-phycoerythrin Ab), and 4′,6-diamidino-2-phenylindole (DAPI) for insertion over the RBC surface. In a first step, conjugation experiments were performed: in dimethyl sulfoxide (DMSO), RBCs were conserved and modified by succinic anhydride to create an additional -COOH group, and then activated with 3-(3-dimethylaminopropyl)carbodiimide- N -hydroxysuccinimide (EDC-NHS) in 2-( N -morpholino) ethanesulfonic acid hydrate buffer for insertion of labeled Abs or DAPI. In a second step, fluorescence signals were evaluated by microscopy and the mean fluorescence intensities of cell lysates were measured by spectrofluorometry. The results showed clear evidence for adsorption of FITC- and PE-labeled Abs to activated conserved RBCs. DAPI was adsorbed well also to DMSO-conserved RBCs without the need for an activation step. The DMSO conservation step was enough to create reactive RBCs for insertion of specific Abs and fluorescent dyes. The additional modification by succinic anhydride and activation with EDC-NHS resulted in two- to seven-fold increase in fluorescence signals, indicating a much higher RBC loading capacity. These Ab- and fluorescent dye-functionalized RBCs have potentially high application in developing new biomedical diagnostic and in vitro assay techniques.

Di-Wu-Yang-Gan Granules is a Traditional Chinese Medicine prescription used for the treatment of HBeAg-negative chronic hepatitis B patients in China. It consists of five commonly used Chinese herbs. However, the chemical constituents of the whole prescription had not been clarified yet. Hence, in this study, the chemical profiling of Di-Wu-Yang-Gan Granules was explored by ultra performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry, which can provide accurate molecular weight within 5-ppm error and sufficient MS/MS fragment ions without the need for precursor ion selection. As a result, 116 compounds were identified, including lignans, triterpenesaponins, flavonoids, coumarins, iridoids, nortriterpenoids, phenolic acids, and sesquiterpenes. All compounds were further assigned to the individual herbs. In conclusion, this established method was reliable and effective for the separation and identification of the constituents in Di-Wu-Yang-Gan Granules. The findings are beneficial for quality control of the prescription during production and provide helpful chemical information for exploring its efficacy and the mechanism of action. The fragmentation regularity summarized in this study also provided important information for the rapid identification of the chemical composition in herbal medicines or their prescription.

A series of novel 8-methoxyquinoline-2-carboxamide compounds containing 1,3,4-thiadiazole moiety was designed and synthesized by using an active substructure combination method. Then, the antibacterial activities of all the target compounds were evaluated in vitro against three Gram-positive bacteria and three Gram-negative bacteria. The antibacterial assay showed that some target compounds displayed moderate to good antibacterial efficacy in comparison with the reference drug Chloromycin. Some interesting results of structure-activity relationships were also discussed.

The objective of this study was to isolate and characterize antagonistic rhizobacteria from chili against a notorious phytopathogen Phytophthora capsici . Among the 48 bacteria isolated, BTLbbc-02, BTLbbc-03, and BTLbbc-05 were selected based on their inhibitory activity against P. capsici . They were tentatively identified as Burkholderia metallica BTLbbc-02 , Burkholderia cepacia BTLbbc-03, and Pseudomonas aeruginosa BTLbbc-05, respectively, based on their 16S rRNA gene sequencing. All inhibited the growth of P. capsici at varying levels by inducing characteristic morphological alterations of P. capsici hyphae. The cell-free culture supernatant of all three isolates impaired motility (up to 100%) and caused lysis (up to 50%) of the halted zoospores. Bioassays revealed that Pseudomonas sp. had higher antagonism and zoospore motility-inhibitory effects against P. capsici compared with two other isolates, Burkholderia spp. and B. metallica , which caused vacuolation in mycelium. All three bacteria suppressed sporangium formation and zoosporogenesis of P. capsici , and improved the seed germination and growth of cucumber. Our findings suggest that epiphytic bacteria, B. metallica , B. cepacia , and P. aeruginosa , could be used as potential biocontrol agents against P. capsici . A further study is required to ensure conformity with the existing regulations for soil, plant, and human health.

Breast cancer is the most endemic cause of cancer among women in both developed and developing countries. Benzimidazole derivatives exemplify one of the chemical classes that show strong cytotoxic activity especially against breast cancer cells (MCF-7). Aromatic amidine derivatives are known as a group of DNA interactive compounds that bind minor groove of the genome, especially A-T base pairs, and show significant in vitro and in vivo toxicity toward cancer cells. In light of these studies, some new mono/dicationic amidino benzimidazole derivatives were synthesized and evaluated for cytotoxic activity on cultured MCF-7 breast cancer cells. Some of these compounds have strongly inhibited MCF-7 cell viability in a dose-dependent manner compared with clinically used reference compounds, imatinib mesylate and docetaxel. Among them, 4-[(5(6)-bromo-1 H -benzimidazole-2-yl)amino]benzene-1-carboxamidine ( 30 ) showed the best inhibitory activity with IC 50 value of 4.6 nM.

Due to their numerous advantages, baculovirus expression vector systems (BEVS) have been widely used to express recombinant proteins for different purposes. Different strategies have been adopted to increase recombinant protein production. In this study, we transiently or stably expressed mouse c-Myc in High Five cells using a commercial pIB/V5 vector. Under the control of the OpIE2 promoter, this vector could enhance recombinant protein production. We found that transient expression of c-Myc in High Five cells improved recombinant protein production. Furthermore, we established two stable cell lines, High Five-c-Myc #1 and High Five-c-Myc #2, that stably expressed mouse c-Myc . We further found that the expression level of the recombinant protein was increased in these stable cell lines compared to control cell lines. These data indicate that overexpressing c-Myc in cells is a promising way to improve recombinant protein production in BEVS.

Two new limonoids, kostchyienones A ( 1 ) and B ( 2 ), along with 12 known compounds 3–14 were isolated from the roots of Pseudocedrela kostchyi . Compound ( 7 ) was isolated for the first time from a natural source. Their structures were elucidated on the basis of spectroscopic evidence. Compounds 1–6 and 13–14 gave IC 50 values ranging from 0.75 to 5.62 μg/mL for antiplasmodial activity against chloroquine-sensitive ( Pf3D7 ) and chloroquine-resistant ( PfINDO ) strains of Plasmodium falciparum . Compound 5 showed moderate potential cytotoxicity against the HEK239T cell line with an IC 50 value of 22.2±0.89 μg/mL. The antiplasmodial efficacy of the isolated compounds supports the medicinal value of this plant and its potential to provide novel antimalarial drugs.

Two compounds, compounds 1 and 2 , were isolated from Preussia sp. The molecular structures of both compounds were elucidated by analyzing one-dimensional (1D) and 2D nuclear magnetic resonance data along with high-resolution mass spectrometry data. Compound 1 was obtained as novel in structure, and compound 2 was recently reported elsewhere. Compound 1 did not show antioxidant and antimicrobial activities and brine shrimp toxicity, while compound 2 showed strong antioxidant activity (DPPH reduction capacity; IC 50 =3 μg/mL) and brine shrimp toxicity (LD 50 =50 μg/mL).