Four New Flavonoid C-Glycosides Isolated from Achyranthes aspera and Their Nitric Oxide Production Inhibitory Activities

A chemical study of the methanol extract of the aerial parts of Achyranthes aspera led to the isolation of four new flavonoid C-glycosides ( 1 – 4 ) along with eight known analogs ( 5 – 12 ). Their structures were elucidated by a combination of spectroscopic data analysis, HR-ESI-MS, 1D and 2D NMR spectra. All the isolates were evaluated their NO production inhibitory activity in LPS-activated RAW264.7 cells. Compounds 2 , 4 , and 8 – 11 showed significant inhibition with IC₅₀ values ranging from 25.06 to 45.25 μM, compared to that of the positive control compound, L-NMMA, IC₅₀ value of 32.24 μM, whereas the remaining compounds were weak inhibitory activity with IC₅₀ values over 100 μM. This is the first report of 7 from Amaranthaceae family, and 11 from the genus Achyranthes.     

Side‐chain thioamides as fluorescence quenching probes

Thioamides, single atom oxygen‐to‐sulfur substitutions of canonical amide bonds, can be valuable probes for protein folding and protease studies. Here, we investigate the fluorescence quenching properties of thioamides incorporated into the side‐chains of amino acids. We synthesize and incorporate Fmoc‐protected, solid‐phase peptide synthesis building blocks for introducing N^ε‐thioacetyl‐lysine and γ‐thioasparagine. Using rigid model peptides, we demonstrate the distance‐dependent fluorescence quenching of these thioamides. Furthermore, we describe attempts to incorporate of N^ε‐thioacetyl‐lysine into proteins expressed in Escherichia coli using amber codon suppression.     

Anti-Alzheimer's Activity of Polyphenolic Stilbene-Rich Acetone Fraction of the Oil-Removed Seeds of Passiflora edulis: in Vivo and in Silico Studies

The stilbene-rich acetone fraction in high yield (6.6 %, PEAS) of Passiflora edulis Sims was prepared and evaluated for neuroprotective activity in murine Alzheimer's disease model induced by aluminum chloride and D-galactose. The phytochemical and HPLC-DAD-MS analysis of the polyphenolic stilbene-rich acetone fraction showed that it contained different stilbenes including trans-piceatannol, scirpusins A−B and cassigarol E. The total phenolic content (TPC) of PEAS was 413.87±1.71 mg GAE eqv/g. The neuroprotective activity of PEAS is typically presented in the Morris water maze-reference Spatial Memory test, where the Alzheimer's mice treated at 100 mg/kg (Alz-ED1) and 200 mg/kg (Alz-ED2) spent less than 47 % and 66 % of the time, respectively, than the Alzheimer's model mice (Alz). Two simple stilbenes, trans-piceatannol and trans-resveratrol, showed selectively inhibitory activity in silico against acetylcholinesterase (AChE). Two stilbene dimers, cassigarol E and scirpusin A, exhibited low nanomolar inhibitory potential against AChE and butyrylcholinesterase (BChE), significantly lower than those of the positive control, donepezil and tacrine. These findings suggest that the stilbenes from P. edulis seeds, particularly the stilbene dimers, warrant further investigation as potential neuroprotective candidates in the prevention of cognitive deficits associated with Alzheimer's disease.     

Aniridia,male pseudohermaphroditism,gonadoblastoma, mental retardation,and del 11p13

Summary A 20-month-old male patient was referred because of severe growth and mental retardation, bilateral glaucoma, hypospadias, and cryptorchidism. Karyotyping revealed a de novo complex three-chromosome rearrangement as well as deletion of band 11p13:46,XY,t(4;7;15)(q212;p14;q26),del(11) (p13p14). Trabeculectomia revealed bilateral aniridia. Surgery on the genitalia revealed male pseudohermaphroditism and bilateral gonadoblastoma. The kidneys were normal. A deficiency in catalase (CAT) activity allowed the regional assignment of the CAT gene to band 11p13.     

Comparative Study of the Effect of Snake Venoms on the Growth of Ciliates Tetrahymena pyriformis: Identification of Venoms with High Antiprotozoal Activity

Doklady Biochemistry and Biophysics - To search for compounds with antiprotozoal activity, effects of snake venoms on the ciliates Tetrahymena pyriformis was studied. T. pyriformis from subkingdom...     

Two different mechanisms of ampicillin resistance operating in strains of Vibrio cholerae O1 independent of resistance genes

Autoagglutinable strains of Vibrio cholerae O1 (seven nonfimbriate strains and one fimbriate strain) were transformed to obtain resistance to ampicillin. Two distinct mechanisms were found in these strains. One was operating in nonfimbriate strains by reducing OmpU protein production and the other was operating in a fimbriate strain (Bgd17) by newly overproducing cpxP protein. The twitching motility in the fimbriate Bgd17 strain disappeared depending on the production of cpxP protein, suggesting that fimbriation of V. cholerae O1 is controlled by a two-component signal transduction system.     

Protein phosphorylation in developing and regenerating rat kidney

Renal cytosolic extracts from rats of different ages and mononephrectomized rats were incubated with gamma-[32P]ATP and analysed by high resolution two-dimensional electrophoresis and autoradiography. Extracts from new-born and young rats showed a great number of phosphorylated proteins migrating between the origin and Mr 52,000. Among these proteins, the group co-migrating with phosphorylase b (Mr 97,000) was particularly evident in new-born and days-old rats. In extracts from mature rats, other proteins of lower molecular weight, particularly those migrating between Mr 60,000 and 44,000, became intensely phosphorylated. The number and intensity of phosphorylated proteins from extracts of normal and nephrectomized rats, however, did not vary. Activity of cAMP-dependent protein kinase and [3H]cAMP binding was also modified during neonatal development but not in compensatory renal growth. Since cAMP-PK and protein phosphorylation are known to be regulated in response to hormonal stimulations, these results may provide good indications for the understanding of hormonal involvement in kidney growth.