ABSTRACT
A new crinine-type alkaloid crijaponine A (1), a new galanthamine-type alkaloid crijaponine B (2), and 11 known alkaloids-ungeremine (3), lycorine (4), 2-O-acetyllycorine (5), 1, 2-O-diacetyllycorine (6), (-)-crinine (7), 11-hydroxyvittatine (8), hamayne (9), (+)-epibuphanisine (10), crinamine (11), yemenine A (12), and epinorgalanthamine (13)-were isolated from the rhizome and fruits of Crinum asiaticum var. japonicum. The structural elucidation of the isolated compounds was performed by spectroscopic methods including 2D NMR. The isolated compounds were evaluated for cytotoxicity against HeLa and HL-60 cells lines and were tested for acetylcholinesterase inhibition activity.
Subject(s)
Alkaloids/chemistry , Crinum/chemistry , Fruit/chemistry , Plant Extracts/chemistry , Rhizome/chemistry , Humans , Molecular StructureABSTRACT
Fragile X mental retardation protein (FMRP), a causative gene (FMR1) product of Fragile X syndrome (FXS), is an RNA-binding protein to regulate local protein synthesis in dendrites for postsynaptic functions. However, involvement of FMRP in local protein synthesis in axons for presynaptic functions remains unclear. Here we investigated role of FMRP in local translation of the active zone protein Munc18-1 during presynapse formation. We found that leucine-rich repeat transmembrane neuronal 2 (LRRTM2)-conjugated beads, which promotes synchronized presynapse formation, induced simultaneous accumulation of FMRP and Munc18-1 in presynapses of axons of mouse cortical neurons in neuronal cell aggregate culture. The LRRTM2-induced accumulation of Munc18-1 in presynapses was observed in axons protein-synthesis-dependently, even physically separated from cell bodies. The accumulation of Munc18-1 was enhanced in Fmr1-knockout (KO) axons as compared to wild type (WT), suggesting FMRP-regulated suppression for local translation of Munc18-1 in axons during presynapse formation. Using naturally formed synapses of dissociated culture, structured illumination microscope revealed that accumulation of Munc18-1 puncta in Fmr1-KO neurons increased significantly at 19 days in vitro, as compared to WT. Our findings lead the possibility that excessive accumulation of Munc18-1 in presynapses at early stage of synaptic development in Fmr1-KO neurons may have a critical role in impaired presynaptic functions in FXS.
Subject(s)
Fragile X Mental Retardation Protein/physiology , Membrane Proteins/metabolism , Munc18 Proteins/metabolism , Nerve Tissue Proteins/metabolism , Neurogenesis/physiology , Synapses/metabolism , Animals , Axons/metabolism , Cerebral Cortex , Dendrites/metabolism , Fragile X Syndrome , Mice , Mice, Inbred C57BL , Mice, KnockoutABSTRACT
The thermal properties and crystallization of biodegradable and optically active poly[(S)-2-hydroxybutyrate] [P(S-2HB)], poly(l-lactide) (PLLA), poly(d-lactide) (PDLA) and their blends were investigated. The results of differential scanning calorimetry, wide-angle X-ray scattering (WAXS), and polarized optical microscopy first indicated heterostereocomplexation between biodegradable and optically active polyesters having different chemical structures and opposite configurations, that is, P(S-2HB) and PDLA. The melting temperature of the heterostereocomplex was higher than those of pure polymers. Such cocrystallization was not observed for P(S-2HB)/PLLA blends having identical configurations. The WAXS profile of P(S-2HB)/PDLA heterostereocomplex was very similar to those of the PLLA/PDLA and P(S-2HB)/P(R-2HB) homostereocomplexes and each crystalline diffraction peak of the heterostereocomplex was located between those of the homostereocomplexes. The present study strongly suggests that heterostereocomplexation will provide a novel versatile method for preparing biodegradable polyester materials with a wide range of physical properties and biodegradability.
