Proton-Pump Inhibitors and Risk of Bloodstream Infection without an Identifiable Source: a Hospital-Based Case-Control Study.

The association between proton-pump inhibitor (PPI) use and systemic infections caused by bacterial translocation is unclear. This study aimed to investigate whether patients receiving PPI therapy have a higher risk of bloodstream infections (BSI) without an identifiable source of infection. We conducted a hospital-based case-control study which enrolled all patients aged 20 years and older who were hospitalized in Ichinomiya Nishi Hospital with BSI confirmed by two sets of positive blood cultures in 2019. Patient data were collected from medical records, and the bacterial translocation-type (BT-type) BSI group was defined as patients with BSI without an identifiable source of infection, whereas those with a BSI from an identifiable source were assigned to the control group based on the diagnostic criteria for each infectious disease. Data from 309 patients, including 66 cases and 243 controls, were analyzed. Compared with PPI non-users, PPI users had a 2.4-fold higher risk of developing BT-type BSI after controlling for potential confounders (adjusted odds ratio: 2.41, 95% confidence interval: 1.29-4.51, P = 0.006). In conclusion, PPI use is associated with a higher risk of BSI without an identifiable source; therefore, PPI use might increase the risk of BSI secondary to bacterial translocation.

Extremely Long Lived Localized Singlet Diradicals in a Macrocyclic Structure: A Case Study on the Stretch Effect.

Localized singlet diradicals have attracted much attention, not only in the field of bond-homolysis chemistry, but also in nonlinear optical materials. In this study, an extremely long lived localized singlet diradical was obtained by using a new molecular design strategy in which it is kinetically stabilized by means of a macrocycle that increases the molecular strain of the corresponding σ-bonded compound. Notably, the lifetime of this diradical (14 µs) is two orders of magnitude longer than that of a standard singlet diradical without a macrocyclic structure (≈0.2 µs) at 293 K. The species is persistent below a temperature of 100 K. In addition to the kinetic stabilization of the singlet diradical, the spontaneous oxidation of its corresponding ring-closed compound at 298 K produced oxygenated products under atmospheric conditions. Apparently, the "stretch effect" induced by the macrocyclic structure plays a crucial role in extending the lifetime of localized singlet diradicals and increasing the reactivity of their corresponding σ-bonded compounds.

Lactomycins A-C, Dephosphorylated Phoslactomycin Derivatives that Inhibit Cathepsin B, from the Marine-derived Streptomyces sp. ACT232.

Three new polyketides, lactomycins A (1)-C (3), were isolated from the culture broth of a marine-derived Streptomyces sp. ACT232 as cathepsin B inhibitors. Their structures were determined by a combination of NMR and MS data analyses to be the dephosphorylated derivatives of a phoslactomycin class of metabolites. Lactomycins exhibited cathepsin B inhibitory activity (IC50 0.8 to 4.5 µg/mL). Even though the biosynthetic gene clusters found in the genome of the current strain have high similarity to those of phoslactomycin, neither phoslactomycins nor leustroducsins were detected by LC-MS analyses of the crude extract.

7-Oxoorobanchyl acetate and 7-Oxoorobanchol as germination stimulants for root parasitic plants from flax (Linum usitatissimum).

Germination stimulants for root parasitic plants produced by flax (Linum usitatissimum L.) were purified and characterized. The root exudate of flax contained at least 8 active fractions, and liquid chromatography-tandem mass spectrometry (LC-MS/MS) and gas chromatography mass spectrometry (GC-MS) analyses suggested that there were 6 strigolactones. Two of them were identified as orobanchol and orobanchyl acetate by comparing NMR and GC-MS and LC-MS/MS data with those of synthetic standards. One of the two novel strigolactones was purified and determined as 7-oxoorobanchyl acetate [((3aS,4S,8bS,E)-8,8-dimethyl-3-(((R)-4-methyl-5-oxo-2,5-dihydrofuran-2-yloxy)methylene)-2,7-dioxo-3,3a,4,5,6,7,8,8b-octahydro-2H-indeno[1,2-b]furan-4-yl acetate) by 1D and 2D NMR spectroscopic, and ESI- and EI-MS spectrometric analyses. The other one was also purified and identified as 7-oxoorobanchol. The remaining two compounds could not been characterized due to their scarcity.

Fabacyl acetate, a germination stimulant for root parasitic plants from Pisum sativum.

A germination stimulant, fabacyl acetate, was purified from root exudates of pea (Pisum sativum L.) and its structure was determined as ent-2'-epi-4a,8a-epoxyorobanchyl acetate [(3aR,4R,4aR,8bS,E)-4a,8a-epoxy-8,8-dimethyl-3-(((R)-4-methyl-5-oxo-2,5-dihydrofuran-2-yloxy)methylene)-2-oxo-3,3a,4,5,6,7,8,8b-decahydro-2H-indeno[1,2-b]furan-4-yl acetate], by 1D and 2D NMR spectroscopic, ESI- and EI-MS spectrometric, X-ray crystallographic analyses, and by comparing the (1)H NMR spectroscopic data and relative retention times (RR(t)) in LC-MS and GC-MS with those of synthetic standards prepared from (+)-orobanchol and (+)-2'-epiorobanchol. The (1)H NMR spectroscopic data and RR(t) of fabacyl acetate were identical with those of an isomer prepared from (+)-2'-epiorobanchol except for the opposite sign in CD spectra. This is the first natural ent-strigolactone containing an epoxide group. Fabacyl acetate was previously detected in root exudates of other Fabaceae plants including faba bean (Vicia faba L.) and alfalfa (Medicago sativa L.).