New peptide alkaloids from Hovenia dulcis and H. tomentella

From the root bark of Hovenia dulcis Thunb. and H. tommentella (Makino) Nakai (Rhamnaceae), three peptide alkaloids, frangulanine, hovenins-A and -B have been isolated. Hovenin-A has been shown to be des-N-methylfrangulanine (II).     

Reduction of severe acute respiratory syndrome coronavirus-2 infectivity by admissible concentration of ozone gas and water

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is causing the global coronavirus disease 2019 (COVID-19) pandemic. Because complete elimination of SARS-CoV-2 appears difficult, decreasing the risk of transmission is important. Treatment with 0.1 and 0.05 ppm ozone gas for 10 and 20 hr, respectively, decreased SARS-CoV-2 infectivity by about 95%. The magnitude of the effect was dependent on humidity. Treatment with 1 and 2 mg/L ozone water for 10 s reduced SARS-CoV-2 infectivity by about 2 and 3 logs, respectively. Our results suggest that low-dose ozone, in the form of gas and water, is effective against SARS-CoV-2.     

Cellular Auxin Homeostasis under High Temperature Is Regulated through a SORTING NEXIN1–Dependent Endosomal Trafficking Pathway

High-temperature-mediated adaptation in plant architecture is linked to the increased synthesis of the phytohormone auxin, which alters cellular auxin homeostasis. The auxin gradient, modulated by cellular auxin homeostasis, plays an important role in regulating the developmental fate of plant organs. Although the signaling mechanism that integrates auxin and high temperature is relatively well understood, the cellular auxin homeostasis mechanism under high temperature is largely unknown. Using the Arabidopsis thaliana root as a model, we demonstrate that under high temperature, roots counterbalance the elevated level of intracellular auxin by promoting shootward auxin efflux in a PIN-FORMED2 (PIN2)-dependent manner. Further analyses revealed that high temperature selectively promotes the retrieval of PIN2 from late endosomes and sorts them to the plasma membrane through an endosomal trafficking pathway dependent on SORTING NEXIN1. Our results demonstrate that recycling endosomal pathway plays an important role in facilitating plants adaptation to increased temperature.     

2-Bromoadenosine-Substituted 2′,5′-Oligoadenylates Modulate Binding and Activation Abilities of Human Recombinant RNase L

Abstract

2-Bromoadenosine-substituted analogues of 2–5A, p5′A2′p-5′A2′p5′(br²A), p5′(br²A)2′p5′A2′p5′A, and p5′(br²A)2′p5′(br²A)2′p-S′(br²A), were prepared via a modification of a lead ion-catalyzed ligation reaction and were subsequently converted into the corresponding 5′-triphosphates. Both binding and activation of human recombinant RNase L by various 2-bromoadenosine-substituted 2–5A analogues were examined. Among the 2-bromoadenosine-substituted 2–5A analogues, the analogue with 2-bromoadenosine residing in the 2′-terminal position, p5′A2′p5′A2′p-5′(br²A), showed the strongest binding affinity and was as effective as 2–5A itself as an activator of RNase L. The CD spectrum of p5′A2′p-5′A2′p5′(br²A) was superimposable on that of p5′A2′p5′A2′p5′A, indicative of an anti orientation about the base-glycoside bonds as in naturally occurring 2–5A.     

Facile Method for the Preparation of 7-Methyl-8-oxoguanosines as an Immunomodulator¶

Abstract

Reaction of 9-(2,3,5-tri-O-acetyl-β-D-ribofuranosyl)-7-methylguaninium iodide (2a) with hydrogen peroxide in acetic acid gave the corresponding 7-methyl-8-oxoguanosine derivative (3a) in good yield. Deprotection of 3a easily gave 7-methyl-8-oxoguanosine (1), which is well-known as an immunomodulator. Substitution of acetyl group at the N-position of guanine ring accelerated the oxidation reaction of the 7-methylguaninium iodide.

     

Autologous Bone-Marrow Mesenchymal Stem Cell Implantation and Endothelial Function in a Rabbit Ischemic Limb Model

Background

The purpose of this study was to determine whether autologous mesenchymal stem cells (MSCs) implantation improves endothelial dysfunction in a rabbit ischemic limb model.

Methods

We evaluated the effect of MSC implantation on limb blood flow (LBF) responses to acetylcholine (ACh), an endothelium-dependent vasodilator, and sodium nitroprusside (SNP), an endothelium-independent vasodilator, in rabbits with limb ischemia in which cultured MSCs were implanted (n = 20) or saline was injected as a control group (n = 20). LBF was measured using an electromagnetic flowmeter. A total of 10⁶ MSCs were implanted into each ischemic limb.

Results

Histological sections of ischemic muscle showed that capillary index (capillary/muscle fiber) was greater in the MSC implantation group than in the control group. Laser Doppler blood perfusion index was significantly increased in the MSC implantation group compared with that in the control group. LBF response to ACh was greater in the MSC group than in the control group. After administration of N^G-nitro-L-arginine, a nitric oxide synthase inhibitor, LBF response to ACh was similar in the MSC implantation group and control group. Vasodilatory effects of SNP in the two groups were similar.

Conclusions

These findings suggest that MSC implantation induces angiogenesis and augments endothelium-dependent vasodilation in a rabbit ischemic model through an increase in nitric oxide production.     

Homostachydrine is a Xenobiotic Substrate of OCTN1/SLC22A4 and Potentially Sensitizes Pentylenetetrazole-Induced Seizures in Mice

Neurochemical Research - Understanding of the underlying mechanism of epilepsy is desired since some patients fail to control their seizures. The carnitine/organic cation transporter OCTN1/SLC22A4...     

Novel molecular identification methods for the larger black flour beetle,Cynaeus angustus (Coleoptera: Tenebrionidae)

Two new methods were developed for identifying Cynaeus angustus (LeConte) (Coleoptera: Tenebrionidae) by DNA amplification using simplex and real-time PCR targeting the cytochrome c oxidase subunit I (COI) sequence reported previously. The specificities of the PCR primers and probe were also confirmed by the two PCR methods using the 22 main stored-product insect species, including DNA samples from nine tenebrionid beetle species. The results showed that the newly developed simplex and real-time PCR-based methods have sufficient specificity for analysis. The limits of detection for C. angustus total DNA by the simplex and multiplex PCR were 320 fg and 20 pg, respectively.