Triterpenes from Periandra dulcis roots

Three oleanane triterpenes were isolated from the roots of Periandra dulcis,and identified as 3β-hydroxy-25-al-olean-18-en-30-oic acid (periandric acid I), 3β-hydroxy-25-al-olean-12-en-30-oic acid (periandric acid II) and 3-oxo-25-hydroxy-olean-12-en-30-oic acid. The former two compounds (periandric acids I and II) were identical with the aglycones obtained by hydrolysis of periandrin I and II, respectively and the latter one was a new triterpene.     

Circadian rhythms of testosterone-dependent behaviors,crowing and locomotor activity,in male Japanese quail

Summary An apparatus was devised to record crowing (mate calling by males) together with locomotor activity and recorded data was analyzed by several methods for rhythm analysis. Crowing and locomotor activity of Japanese quail held on long days were recorded during sexual development as estimated from circulating gonadotropins and testosterone. Both behaviors were testosterone-dependent but commencement of crowing preceded the increase in locomotor activity. When the two behaviors attained their maximum levels, crowing showed consistent daily rhythms in which two peaks were apparent, a major one at the onset of light and a broader one 8 hours later. Locomotor activity also showed a clear daily rhythm with a peak between the two peaks of crowing rhythm suggesting a fixed phase relationship between the two rhythms.Both rhythms free-ran under constant dim light with periods shorter than 24 h. They persisted in birds which had been castrated and then supplied with exogenous testosterone via implanted Silastic capsules. The durations of both rhythms were quite comparable to each other and they maintained a fixed phase relationship similar to that found under LD cycles.The results indicate that testosterone is essential for the induction of crowing and for the enhancement of locomotor activity but the formation of the rhythms in behavior was strictly dependent on a circadian oscillatory mechanism.Abbreviations LH luteinizing hormone - FHS follicle-stimulating hormone - LD light-dark - LDim light-dim light     

Flavonoids in the leaves of twenty-eight polygonaceous plants

Flavonoids in the leaves of twenty-eight species belonging to the Polygonaceae were studied. Thirty-three kinds of flavonoids were isolated, and eighteen kinds were obtained as crystals. Quercetin glycosides were commonly found in the family. In the quercetin glycosides, 3-O-rhamnoside was most frequently found: 3-O-glucuronide is also distributed widely. Myricetin glycosides were rare. Methylated flavonols were found in some species of the sectionsEchinocaulon andPersicaria. Eleven kinds ofC-glycosylflavones were found in the present survey, andC-glycosylflavones were distributed in all species of the genusRheum and in almost all species of the section Tiniaria.Rumex Acetosella andPolygonum suffultum are exceptional, the former contains flavone glycoside and the latterC-glycosylflavones only, as main components.     

Evidence that cyclic AMP may regulate Ca2+-mobilization and phospholipases in thrombin-stimulated human platelets

The regulation of human platelet responses by cyclic AMP (cAMP) has been investigated by measuring thrombin-stimulated serotonin release, Ca²⁺ uptake and phospholipase activity. Thrombin-induced 1,2-diacylglycerol (DG) formation as a result of phospholipase C activation was inhibited by pretreatment with dibutyryl cAMP (dbcAMP) in a dose-dependent manner. Subsequent failure to produce phosphatidic acid (PA), which is converted from 1,2-DG by phosphorylation and would serve as intracellular Ca²⁺ ionophore, appeared to parallel the decrease in Ca²⁺ uptake activity. Phospholipase A₂ activity, monitored by the production of [³H]lysophosphatidylcholine and [³H]lysophosphatidylethanolamine, was also suppressed by dbcAMP. These data indicate that the intracellular cAMP level may be closely associated with Ca²⁺ uptake and phospholipases activation. In addition, it is suggested that alteration of intracellular cAMP regulates phospholipase activation and consequently platelet responses, perhaps by controlling available Ca²⁺ content.     

Significance of 12S Toxin of Clostridium botulinum Type E

The pathogenesis of type E botulism is discussed as an aspect of the physicochemical and biological properties of 12S toxins (prototoxin and trypsin-activated 12S toxin) and the Ealpha and Ebeta components of each 12S toxin. A molecular weight of 350,000 was determined for each 12S toxin and 150,000 for Ealpha and Ebeta. Owing to the structure comprising the subunits Ealpha and Ebeta, 12S toxins are much more stable than Ealpha at low pH values and high temperatures. Such was also the case with type A 19S toxin and its alpha component. The Ealpha component alone accounts for the total toxicity of type E toxin. The toxic substance detected in the blood of the animals administered 12S toxins orally or parenterally was identified as Ealpha from the molecular size and the chromatographic pattern. Prototoxin escaping from detoxification in the stomach owing to the subunit structure may undergo dissociation in the intestine to release the Ealpha component. After absorption, the activated Ealpha appeared in the circulating blood without any further signs of dissociation or enzymatic digestion.     

Three extra copies of a C4-related gene in H-2 w7 mice are C4/Slp hybrid genes generated by multiple recombinational events

Mice bearing the H-2 _w7 haplotype have five C4-related genes and constitutively express the Slp antigen. To understand the structure and evolution of the five C4-related genes of the C3H.W7 mouse, we have determined nucleotide sequences of the 5 end region of these genes. A C4/Slp hybrid nature was confirmed for three of five C4-related genes as predicted previously by restriction enzyme analysis. The nucleotide sequences of the 5 flanking regions of these three hybrid genes showed close similarity to that of the C4 gene, while the 3 side of the ninth exon of the three hybrid genes showed close similarity to that of the Slp gene. In contrast, the regions between the first exon and the middle of the ninth exon of the three hybrid genes showed a mosaic structure of C4-like and Slp-like sequences. Moreover, the boundaries of the C4-like and Slp-like sequences were quite different among the three hybrid genes. The pattern of nucleotide sequence diversity in this region among the five C4-related sequences could be mainly explained not by point mutations but by gene conversions or unequal crossovers. These results suggest that multiple genetic recombinational events between two homologous sequences played an important role in the generation and diversification of the extra copies of the C4/Slp gene in the H-2 ^w7 mouse.The nucleotide sequence data reported in this paper have been submitted to the DDBJ, EMBL, and GenBank nucleotide sequence databases and have been assigned the accession numbers D90167-71.     

Purification and characteristics of cytosolic chitinase from Piromyces communis OTS1

Abstract A chitinase was purified from the cytosolic fraction of the anaerobic rumen fungus Piromyces communis OTS1 by affinity chromatography using regenerated chitin, gel filtration and chromatofocusing. The chitinase was most active at pH 6.2 and at 60 °C in a 20-min assay. The molecular mass of the purified protein was estimated by SDS-PAGE to be 42 kDa and its pI was 4.9. The enzyme activity, which was of the 'endo' type, was inhibited by A⁺, Hg²⁺ and allosamidin. N -Acetyl- β -glucosaminidase and 'exo' type chitinase activity were absent from the purified preparation.     

A novel gene family defined by human dihydropyrimidinase and three related proteins with differential tissue distribution

We have isolated cDNA clones encoding dihydropyrimidinase (DHPase) from human liver and its three homologues from human fetal brain. The deduced amino acid (aa) sequence of human DHPase showed 90% identity with that of rat DHPase, and the three homologues showed 57–59% aa identity with human DHPase, and 74–77% aa identity with each other. We tentatively termed these homologues human DHPase related protein (DRP)-1, DRP-2 and DRP-3. Human DRP-2 showed 98% aa identity with chicken CRMP-62 (collapsin response mediator protein of relative molecular mass of 62 kDa) which is involved in neuronal growth cone collapse. Human DRP-3 showed 94–100% aa identity with two partial peptide sequences of rat TOAD-64 (turned on after division, 64 kDa) which is specifically expressed in postmitotic neurons. Human DHPase and DRPs showed a lower degree of aa sequence identity with Bacillus stearothermophilus hydantoinase (39–42%) and Caenorhabditis elegans unc-33 (32–34%). Thus we describe a novel gene family which displays differential tissue distribution: i.e., human DHPase, in liver and kidney; human DRP-1, in brain; human DRP-2, ubiquitously expressed except for liver; human DRP-3, mainly in heart and skeletal muscle.     

Detection of Y-bearing porcine spermatozoa by in situ hybridization using digoxigenin-labeled,porcine male-specific DNA probe produced by polymerase chain reaction

This study was carried out to determine whether Y-bearing porcine spermatozoa could be detected by in situ hybridization using a digoxigenin (Dig)-labelled DNA probe specific to the Y chromosome produced by polymerase chain reaction (PCR). A conventional PCR (with Dig-dUTP) was performed using a set of oligonucleotide primers (5′-AAGTGGTCAGCGTGTCCATA-3′ and 5′-TTTCTCCTGTATCCTCCTGC-3′) for 236 bp fragment of porcine male-specific DNA sequence and 1.25 × 10⁴ template white blood cells obtained from a boar. When fluorescence in situ hybridization with the Dig-labelled DNA probe was applied to the metaphase chromosome spreads prepared from both boar and gilts, the fluorescein signal was only detected on the long arm of the Y chromosome. In addition, immunocytochemical detection with the Dig-labelled DNA probe and alkaline phosphatase-labeled anti-Dig was applied to both sperm nuclei pretreated with dithiothreitol and white blood cells; 51% of sperm nuclei and 96% of white blood cells obtained from boar were labelled, whereas none of white blood cells obtained from gilts were labelled with the Dig-labelled DNA probe. The results indicated that in situ hybridization with porcine male-specific DNA probe produced by PCR made possible the direct visualization of Y-bearing porcine spermatozoa by in situ hybridization. © 1995 Wiley-Liss, Inc.