Inhibition of glucosylceramide synthase (GCS) is a major therapeutic strategy for Gaucher’s disease and has been suggested as a potential target for treating Parkinson’s disease. Herein, we report the discovery of novel brain-penetrant GCS inhibitors. Assessment of the structure–activity relationship revealed a unique pharmacophore in this series. The lipophilic ortho-substituent of aromatic ring A and the appropriate directionality of aromatic ring B were key for potency. Optimization of the absorption, distribution, metabolism, elimination, toxicity (ADMETox) profile resulted in the discovery of T-036, a potent GCS inhibitor in vivo. Pharmacophore-based scaffold hopping was performed to mitigate safety concerns associated with T-036. The ring opening of T-036 resulted in another potent GCS inhibitor with a lower toxicological risk, T-690, which reduced glucosylceramide in a dose-dependent manner in the plasma and cortex of mice. Finally, we discuss the structural aspects of the compounds that impart a unique inhibition mode and lower the cardiovascular risk.

Aiming to discover melanin-concentrating hormone receptor 1 (MCHR1) antagonists with improved safety profiles, we hypothesized that the aliphatic amine employed in most antagonists reported to date could be removed if the bicyclic motif of the compound scaffold interacted with Asp123 and/or Tyr272 of MCHR1. We excluded aliphatic amines from our compound designs, with a cutoff value of pK(a) < 8, and explored aliphatic amine-free MCHR1 antagonists in a CNS-oriented chemical space limited by four descriptors (TPSA, ClogP, MW, and HBD count). Screening of novel bicyclic motifs with high intrinsic binding affinity for MCHR1 identified the imidazo[1,2-a]pyridine ring (represented in compounds 6a and 6b), and subsequent cyclization of the central aliphatic amide linkage led to the discovery of a potent, orally bioavailable MCHR1 antagonist 4-[(4-chlorobenzyl)oxy]-1-(2-cyclopropyl-3-methylimidazo[1,2-a]pyridin-6-yl)pyridin-2(1H)-one 10a. It exhibited low potential for hERG inhibition and phospholipidosis induction as well as sufficient brain concentration to exert antiobesity effects in diet-induced obese rats.

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To discover a novel series of potent inhibitors of enteropeptidase, a membrane-bound serine protease localized to the duodenal brush border, 4-guanidinobenzoate derivatives were evaluated with minimal systemic exposure. The 1c docking model enabled the installation of an additional carboxylic acid moiety to obtain an extra interaction with enteropeptidase, yielding 2a . The oral administration of 2a significantly elevated the fecal protein output, a pharmacodynamic marker, in diet-induced obese (DIO) mice, whereas subcutaneous administration did not change this parameter. Thus, systemic exposure of 2a was not required for its pharmacological effects. Further optimization focusing on the in vitro IC 50 value and T 1/2 , an indicator of dissociation time, followed by enhanced in vivo pharmacological activity based on the ester stability of the compounds, revealed two series of potent enteropeptidase inhibitors, a dihydrobenzofuran analogue ( ( S )-5b , SCO-792) and phenylisoxazoline ( 6b ), which exhibited potent anti-obesity effects despite their low systemic exposure following their oral administration to DIO rats.

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Page 1122. In the body of Table 1, chemical structures for the R group are missing. The body of the table should be with chemical structures as follows:

Plants incorporate inorganic materials (biominerals), such as silica, into their various components. Plants belonging to the order Poales, like rice plants and turfgrasses, show comparatively high rates of silicon accumulation, mainly in the form of silica bodies. This work aims to determine the shapes and roles of these silica bodies by microscopic observation and optical simulation. We have previously found convex silica bodies on the leaves of rice plants and hot-season turfgrasses (adapted to hot-seasons). These silica bodies enabled light reflection and ensured reduction of the photonic density of states, which presumably prevented the leaves from overheating, as suggested by theoretical optical analyses. The silica bodies have been considered to have the functions of reinforcement of the plant body. The present work deals with cold-season turfgrasses, which were found to have markedly different silica bodies, cuboids with a concave top surface. They presumably acted as small windows for introducing light into the tissues, including the vascular bundles in the leaves. The area of the silica bodies was calculated to be about 5% of the total surface area of epidermis, which limits the thermal radiation of the silica bodies. We found that the light signal introduced through the silica bodies diffused in the organs even reaching the vascular bundles, the physiological functions of this phenomena remain as future problems. Light signal in this case is not related with energy which heat the plant but sensing outer circumstances to respond to them.