Enzymatic transformation of esculetin as a potent class of α-glucosidase inhibitors.

A rapid and simple enzymatic transformation of the representative coumarin esculetin (1) with polyphenol oxidase originating from Agaricus bisporus afforded five new oxidized metabolites, esculetinins A (2), B (3), C (4), D (5), and E (6), together with the known compound isoeuphorbetin (7). The structures of the oligomerized transformation products were established on the basis of spectroscopic interpretations. The esculetin oligomers 2 and 3 revealed highly enhanced inhibitory activities against α-glucosidase, with IC50 values of 0.7 ± 0.1 and 2.3 ± 0.3 µM, respectively, as compared to the original esculetin. Kinetic analysis also exhibited that the two new potent metabolites 2 and 3 have competitive modes of action.

Gamma irradiation-assisted degradation of rosmarinic acid and evaluation of structures and anti-adipogenic properties.

Radiation is a promising technique for improving the safety and shelf-life of processed foods. In the present investigation, the degradation mechanism and bioactivity improvement of rosmarinic acid (RA) were studied in response to various gamma irradiation doses (10, 20, and 50 kGy). RA exposed to gamma irradiation at 50 kGy was completely degraded and showed an increased inhibitory effect against 3 T3-L1 preadipocyte compare to the parent compound. Structures of the newly generated compounds 2-4 from irradiated RA at 50 kGy were elucidated based on spectroscopic methods, including 1H nuclear magnetic resonance (NMR) and mass spectrometry (MS). Interestingly, compounds 2 and 5 exhibited significantly enhanced anti-adipogenic properties in 3 T3-L1 cells compared to the original compound. These results provide evidence that structural changes in RA induced by gamma irradiation might enhance biological efficacy.

Multidetector-row computed tomography of a Valsalva sinus aneurysm in a patient with Behçet disease.

Behçet disease is a multisystem disease, which can cause cardiovascular manifestations such as arterial occlusion or aneurysm. This report describes multidetector-row computed tomography findings of an unruptured aneurysm of the left Valsalva sinus which was associated with Behçet disease. A 45-year-old woman with Behçet disease had an aneurysm of the left Valsalva sinus which constricted the left anterior descending artery. The multidetector-row computed tomography was useful in detecting the aneurysm and complications, and was beneficial in the evaluation of patency in the coronary arteries after surgery.

Effects of lysophosphatidic acid on sodium currents in rat dorsal root ganglion neurons.

Lysophosphatidic acid (LPA), a simple phospholipid, induces pain. To elucidate an involvement of ion channel mechanism in the LPA-induced pain, its effects on sodium currents in rat dorsal root ganglion (DRG) neurons were investigated. LPA suppressed tetrodotoxin-sensitive (TTX-S) sodium current, but increased tetrodotoxin-resistant (TTX-R) sodium current, when currents were evoked by step depolarizations to 0 mV from a holding potential of -80 mV. In both types of currents, LPA produced a hyperpolarizing shift of both activation and inactivation voltages. LPA had a negligible effect on the maximal conductance of TTX-S current, but increased that of TTX-R current. The results suggest that the enhancement of TTX-R current may contribute to the LPA-induced pain.