Lenzimycins A and B, metabolites with antibacterial properties from Brevibacillus sp. associated with the dung beetle Onthophagus lenzii

Symbiotic microorganisms associated with insects can produce a wide array of metabolic products, which provide an opportunity for the discovery of useful natural products. Selective isolation of bacterial strains associated with the dung beetle, Onthophagus lenzii, identified two strains, of which the antibiotic-producing Brevibacillus sp. PTH23 inhibited the growth of Bacillus sp. CCARM 9248, which is most closely related to the well-known entomopathogen, Bacillus thuringiensis. A comprehensive chemical investigation based on antibiotic activity discovered two new antibiotics, named lenzimycins A and B (1-2), which inhibited growth of Bacillus sp. CCARM 9248. The 1H and 13C NMR, MS, MS/MS, and IR analyses elucidated the structures of 1 and 2, which comprised a novel combination of fatty acid (12-methyltetradecanoic acid), glycerol, sulfate, and N-methyl ethanolamine. Furthermore, the acid hydrolysis of 1 revealed the absolute configuration of 12-methyltetradecanoic acid as 12S by comparing its optical rotation value with authentic (R)- and (S)-12-methyltetradecanoic acid. In addition to inhibition of Bacillus sp. CCARM 9248, lenzimycins A and B were found to inhibit the growth of some human pathogenic bacteria, including Enterococcus faecium and certain strains of Enterococcus faecalis. Furthermore, the present study elucidated that lenzimycins A and B activated a reporter system designed to detect the bacterial cell envelope stress, thereby indicating an activity against the integrity of the bacterial cell wall

Randomized Controlled Trial Comparing the Efficacy of Sustained-Release Formula of Mosapride-Plus-Esomeprazole Combination Therapy to Esomeprazole Monotherapy in Patients with Gastroesophageal Reflux Disease

We aimed to evaluate whether adding a sustained-release (SR) formula of mosapride to proton-pump inhibitors (PPIs) would be more effective in controlling symptoms than PPI alone in patients with gastroesophageal reflux disease (GERD). Sixty patients with heartburn and/or regurgitation were randomly assigned to two groups: mosapride SR 15 mg combined with esomeprazole 20 mg once daily (ME group) and esomeprazole 20 mg once daily alone (E group). The primary endpoint was the complete-resolution rate of GERD symptoms after eight-week medication, and the secondary endpoints were the complete-resolution rate of GERD symptoms after four-week medication, symptom-improvement rates ≥ 50% after four- and eight-week medication, and change in reflux-disease-questionnaire (RDQ) and GERD-health-related quality-of-life (GERD-HRQL) scores from baseline at four- and eight-week medication. No significant differences in complete-symptom-resolution rates at eight weeks and four weeks or in the changes in RDQ and GERD-HRQL scores from baseline at four- and eight-week medication were observed between the ME and E groups. The symptom-improvement rate of ≥50% after four and eight weeks was comparable between both groups. Adding mosapride SR to esomeprazole in patients with GERD provides no additional benefits in controlling GERD symptoms

Randomized Controlled Trial Comparing the Efficacy of Sustained-Release Formula of Mosapride-Plus-Esomeprazole Combination Therapy to Esomeprazole Monotherapy in Patients with Gastroesophageal Reflux Disease

We aimed to evaluate whether adding a sustained-release (SR) formula of mosapride to proton-pump inhibitors (PPIs) would be more effective in controlling symptoms than PPI alone in patients with gastroesophageal reflux disease (GERD). Sixty patients with heartburn and/or regurgitation were randomly assigned to two groups: mosapride SR 15 mg combined with esomeprazole 20 mg once daily (ME group) and esomeprazole 20 mg once daily alone (E group). The primary endpoint was the complete-resolution rate of GERD symptoms after eight-week medication, and the secondary endpoints were the complete-resolution rate of GERD symptoms after four-week medication, symptom-improvement rates ≥ 50% after four- and eight-week medication, and change in reflux-disease-questionnaire (RDQ) and GERD-health-related quality-of-life (GERD-HRQL) scores from baseline at four- and eight-week medication. No significant differences in complete-symptom-resolution rates at eight weeks and four weeks or in the changes in RDQ and GERD-HRQL scores from baseline at four- and eight-week medication were observed between the ME and E groups. The symptom-improvement rate of ≥50% after four and eight weeks was comparable between both groups. Adding mosapride SR to esomeprazole in patients with GERD provides no additional benefits in controlling GERD symptoms

Synergistic Effect of Cold Treatment Combined with Ethyl Formate Fumigation against <i>Drosophila suzukii</i> (Diptera: Drosophilidae)

Drosophila suzukii is a quarantine pest that is rapidly spreading in berries. This study evaluated the synergistic effect of combination treatment with ethyl formate (EF) and cold temperature for D. suzukii control on imported grapes. A higher insecticidal effect was observed at 1 °C than at 5 °C at all developmental stages, and the pupal stage showed the strongest tolerance to cold temperature. After EF fumigation alone, eggs showed the highest tolerance at 216.67 mg·h/L (LCT99 value), and adults showed the highest susceptibility at D. suzukii control in the 12 L desiccator was shorter in the combination treatment group at the LCT80 value than at the LCT50 value of the egg stage. EF showed a very high sorption rate (24%) after 4 h of exposure at a grape loading ratio of 15% in a 0.65 m3 fumigation chamber. As the grape loading ratio for combination treatment decreased, D. suzukii mortality increased, but when EF was administered at the LCT80 value, there was little difference in the mortalities of the eggs and larvae but not the pupae. All D. suzukii developmental stages were completely controlled within 7 days after combination treatment, and phytotoxicity was not observed in grapes. These results suggest that the combination of cold-temperature treatment and EF fumigation could be used for D. suzukii control

New Cyclic Cystine Bridged Peptides from the Sponge Suberites waedoensis

Two new peptides, chujamides A (1) and B (2), were isolated from the marine sponge Suberites waedoensis, which was collected from Korean waters. Based upon the results of the combined spectroscopic analyses, the structures of these compounds were determined to be proline-riched and cyclic cystine bridged dodeca- and undecapeptides. The absolute configurations of all amino acid residues were determined to be l by advanced Marfey’s analysis. The new compounds exhibited weak cytotoxicities against A549 and K562 cell-lines, and compound 2 also demonstrated moderate inhibitory activity against Na+/K+-ATPase

Investigation of a Nosocomial Outbreak of Imipenem-Resistant Acinetobacter baumannii Producing the OXA-23 β-Lactamase in Korea

We investigated an outbreak of Acinetobacter baumannii in an intensive care unit and in the surgery, medicine, neurology, and urology wards of the Kosin University Gospel Hospital in Busan, Korea. The outbreak involved 36 cases of infection by A. baumannii producing the OXA-23 β-lactamase over an 8-month period and was caused by a single pulsed-field gel electrophoresis clone. The epidemic isolates were characterized by a modified cloverleaf synergy test. Isoelectric focusing of crude bacterial extracts detected one nitrocefin-positive band with a pI value of 6.65. PCR amplification and characterization of the amplicons by direct sequencing indicated that the epidemic isolates carried a bla(OXA-23) determinant. The epidemic isolates were characterized by a multidrug resistance phenotype that remained unchanged over the outbreak, including penicillins, cephamycins, extended-spectrum cephalosporins, carbapenems, monobactams, and aminoglycosides. This study shows that the bla(OXA-23) resistance determinant may become an emerging therapeutic problem

Zeolite Synthesis from a Charge Density Perspective: The Charge Density Mismatch Synthesis of UZM‑5 and UZM‑9

A charge density model of aluminosilicate zeolite synthesis is presented. This model has been applied to the charge density mismatch (CDM) synthesis of UZM-5 and UZM-9 zeolites at 150 and 100 °C, respectively, using the same synthesis mixture that includes tetraethylammonium (TEA⁺), tetramethylammonium (TMA⁺), and Na⁺ ions as structure-directing agents (SDAs). It allows a seamless description of the contributions of both the hydroxide and SDA components of the CDM barrier to zeolite synthesis. The syntheses are described as temperature-driven confrontations with the CDM barrier, resulting in disproportionation to solution and solid products with diverging charge densities. The presence of the CDM barrier and this tunable disproportionation in charge density, along with the suitable choice of SDA concentrations, allows a flexible and cooperative participation of SDAs, as the synthesis medium initially forms aluminosilicate networks that maximize Coulombic stabilization under the conditions at hand. The UZM-5 synthesis at 150 °C is characterized by much higher fractional Si and Al yields (0.85 Si and 0.94 Al vs 0.30 Si and 0.70 Al) and a higher Si/Al ratio (ca. 7 vs 3) compared to UZM-9 synthesis at 100 °C. Unlike the latter case, TEA⁺ plays an important role in the nucleation of UZM-5. However, TMA⁺ was found to be essential for the nucleation of both zeolites. While Na⁺ is required to crystallize UZM-9, the nucleation rate of UZM-5 is about twice as fast in the absence of Na⁺. On the other hand, the crystal growth rate of this small-pore zeolite is over 10 times faster with Na⁺ present, giving a considerably larger crystallite size

Cytotoxic Diterpenoid Pseudodimers from the Korean Sponge <i>Phorbas gukhulensis</i>

Four new cytotoxic diterpenoid pseudodimers (<b>2</b>–<b>5</b>), along with a previously reported one, gukulenin A (<b>1</b>), were isolated from the marine sponge <i>Phorbas gukhulensis</i> collected off the coast of Gagu-do, Korea. These novel compounds, designated gukulenins C–F (<b>2</b>–<b>5</b>), were determined by extensive spectroscopic analyses to be pseudodimers of the gagunins, like gukulenin A. The termini of the tropolone-containing side chains in gukulenins C–E (<b>2</b>–<b>4</b>) were found to have diverse modifications involving acetamides or taurine, whereas gukulenin F (<b>5</b>) was formed from <b>1</b> by the ring-opening of a cyclic hemiketal. The relative and absolute configurations were assigned by Murata’s and modified Snatzke’s methods using a HETLOC experiment and a CD measurement of a dimolybdenum complex, respectively. All of these compounds exhibited significant cytotoxicity against the K562 and A549 cell lines