The novel sustained 3-hydroxybutyrate donor poly-D-3-hydroxybutyric acid prevents inflammatory bowel disease through upregulation of regulatory T-cells.

Inflammatory bowel disease (IBD) is a chronic persistent intestinal disorder, with ulcerative colitis and Crohn's disease being the most common. However, the physio-pathological development of IBD is still unknown. Therefore, research on the etiology and treatment of IBD has been conducted using a variety of approaches. Short-chain fatty acids such as 3-hydroxybutyrate (3-HB) are known to have various physiological activities. In particular, the production of 3-HB by the intestinal microflora is associated with the suppression of various inflammatory diseases. In this study, we investigated whether poly-D-3-hydroxybutyric acid (PHB), a polyester of 3-HB, is degraded by intestinal microbiota and works as a slow-release agent of 3-HB. Further, we examined whether PHB suppresses the pathogenesis of IBD models. As long as a PHB diet increased 3-HB concentrations in the feces and blood, PHB suppressed weight loss and histological inflammation in a dextran sulfate sodium-induced IBD model. Furthermore, PHB increased the accumulation of regulatory T cells in the rectum without affecting T cells in the spleen. These results indicate that PHB has potential applications in treating diseases related to the intestinal microbiota as a sustained 3-HB donor. We show for the first time that biodegradable polyester exhibits intestinal bacteria-mediated bioactivity toward IBD. The use of bioplastics, which are essential materials for sustainable social development, represents a novel approach to diseases related to dysbiosis, including IBD.

Naphthoquinone Derivatives from Diospyros maritima.

From the chloroform extract of the fresh fruits of Diospyros maritima BLUME (Ebenaceae), five new naphthoquinone derivatives, 2,7'-dimethyl-2',3-bijuglone (27), 2,7'-dimethyl-3,3'-bijuglone (28), 2,7'-dimethyl-6,8'-bijuglone (29), 7,7'-dimethyl-3,3'-ethylidenebijuglone (30), and 2',7-dimethyl-3,6'-ethylidenebijuglone (31), were isolated, in addition to twenty-one known naphthoquinone derivatives: plumbagin (4), droserone (5), 2,3-epoxyplumbagin (8), 3,3'-biplumbagin (9), chitranone (10), 3,8'-biplumbagin (11), elliptinone (12), maritinone (13), isozeylanone (14), methylene-3,3'-biplumbagin (15), ethylidene-3,3'-biplumbagin (16), ethylidene-3,6'-biplumbagin (17), ethylidene-6,6'-biplumbagin (18), 7-methyl-ß-dihydrojuglone (19), 7-methyljuglone (20), 2,3-epoxy-7-methyljuglone (21), neodiospyrin (22), mamegakinone (23), ehretione (24), isoxylospyrin (25) and ß-dihydroplumbagin (26). The structures of the new compounds were established by spectral analysis. The quinones obtained from the chloroform extract of the fruits were compared with previously reported quinones obtained from ethanol extracts. The quinones in the fruits were categorized in three groups: quinones from ethanol extract only, quinones from chloroform extract only, and quinones from both extracts. The six naphthoquinones, 19-21, 25, 26, and 29, were examined for their ichthyotoxic activity and germination inhibitory activity. Quinones 19-21, 26, and 29 showed ichthyotoxic activity against Japanese killifish (Oryzias latipes var.) at 10 ppm; quinones 19 to 21 and 26 showed germination inhibitory activity toward lettuce seeds (Lactuca sativa L. var. Great Lakes) at 100 ppm.

Direct Production of (R)-3-Hydroxybutyric Acid of High Optical Purity by Halomonas sp. OITC1261 Under Aerobic conditions.

The chiral compound (R)-3-hydroxybutyric acid (R-3HB) has some important physiological functions in the human body and can also be applied as a functional material for industrial products. A novel Halomonas sp. OITC1261 isolated from a coastal sediment is selected for efficient production of R-3HB. This strain secreted R-3HB of high optical purity into the extracellular medium while maintaining poly(3-hydroxybutyric acid) (PHB) inside the microbial cell under aerobic conditions. There is a possibility that R-3HB is generated independently of PHB. Under aerobic cultivation, 58 g L-1 (0.65 g L-1 h-1 ) of R-3HB was produced simultaneously with 27 g L-1 (0.30 g L-1 h-1 ) of PHB. This direct production method of R-3HB contributes to the improvement of mass production technology.

Isolation of alkaliphilic bacteria for production of high optically pure L-(+)-lactic acid.

Lactic acid bacteria that grow under alkaline conditions (pH 10) were isolated from various sources in Okinawa (Japan). These alkali-tolerant and alkaliphilic bacteria were classified as follows: Microbacterium sp. (1 strain), Enterococcus spp. (9 strains), Alkalibacterium spp. (3 strains), Exiguobacterium spp. (5 strains), Oceanobacillus spp. (3 strains) and Bacillus spp. (7 strains) by 16S rRNA gene sequencing. By fermentation, many strains were able to convert glucose into mainly L-(+)-lactic acid of high optical purity in alkaline broth. This result indicated that valuable L-(+)-lactic acid-producing bacteria could be isolated efficiently by screening under alkaline conditions. Six strains were selected and their ability to produce lactic acid at different initial pH was compared. Enterococcus casseliflavus strain 79w3 gave the highest lactic acid concentration. Lactic acid concentration and productivity were 103 g L(-1) (optical purity of 99.5% as L-isomer) and 2.2 g L(-1) h(-1), respectively when 129 g L(-1) of glucose was used by batch fermentation.

Three new naphthoquinone derivatives from Diospyros maritima Blume.

Three new naphthoquinone derivatives, 6-(1-ethoxyethyl)plumbagin (16), ethylidene-3,3'-biplumbagin (17), and ethylidene-3,6'-biplumbagin (18), were isolated, in addition to six known naphthoquinones, isozeylanone (10), 3,3'-biplumbagin (11), chitranone (12), methylene-3,3'-biplumbagin (13), 2,3-epoxyplumbagin (14), and 3,8'-biplumbagin (15), from the fruits of Diospyros maritima Blume (Ebenaceae). The structures of the new compounds were established by spectroscopic methods. The eight naphthoquinones 11-18 were examined for ichthyotoxic activity and germination inhibitory activity. The quinones 11, 12, and 14-16 showed strong ichthyotoxic activity and the quinone 14 mild germination inhibitory activity.