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41.
Steroidal saponins from the aerial parts of Tribulus pentandrus Forssk   总被引:1,自引:0,他引:1  
Seven new steroidal glycosides named pentandrosides A(1)-G(7) were isolated from the EtOH extract of the aerial parts of Tribulus pentandrus. Pentandrosides A(1)-E(5) possess cholestane aglycones, pentandroside F(6) a furostan-type aglycone and pentandroside G(7) an unusual acyloxypregnane aglycone probably derived from the degradation of a furostan skeleton. Structure elucidation of 1-7 was accomplished through the extensive use of 1D- and 2D NMR experiments including 1H-1H (DQF-COSY, 1D-TOCSY) and 1H-13C (HSQC, HMBC) spectroscopy along with ESIMS and HRESIMS.  相似文献   
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Yucca schidigera (Agavaceae) is one of the major commercial source of steroidal saponins. Two products of yucca are available on the market. These include dried and finely powdered logs (yucca powder) or mechanically pressed and thermally condensed juice (yucca extract). These products possess the GRAS label which allows their use as foaming agent in soft drink (root beer), pharmaceutical, cosmetic, food, and feeding-stuffs industries. The main application of yucca products is in animal nutrition, in particular as a feed additive to reduce ammonia and fecal odors in animal excreta. The positive effects of dietary supplementation with yucca products on the growth rates, feed efficiency, and health of livestock seem to be due not only to the saponin constituents but also to other constituents. These observations prompted us to investigate the phenolic constituents of Y. schidigera. This study led to the isolation of resveratrol, trans-3,3′,5,5′-tetrahydroxy-4′-methoxystilbene, the sprirobiflavonoid larixinol along with novel phenolic derivatives with very unusual spirostructures, named yuccaols A–E and yuccaone A. Taking into account the multifunctional activities of resveratrol and the novelty of yuccaols A–E, structurally related to resveratrol, a program aimed to evaluate for yucca phenolics some of the activities exerted by resveratrol has been carried out. This review describes the chemistry of yucca saponins and phenolics, summarizes the biological activities of yucca products and constituents and gives an account on the actual and potential applications of yucca products.  相似文献   
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The effect of propylthiouracil-induced neonatal hypothyroidism on some aspects of the biogenesis of free (non-synaptosomal) mitochondria in the cerebral hemispheres and in the cerebellum of developing rat has been studied. The results obtained show that in hypothyroid rats mitochondrial DNA synthesis is delayed, mitochondrial RNA synthesis is not affected and cytochrome aa3 content of mitochondria is lower than in controls. Furthermore ultrathin sections of 14-and 21-day old hypothyroid rat cerebella show mitochondria with an altered ultrastructural organization and large intracristal spaces.  相似文献   
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Grain protein content (GPC) in durum wheat (Triticum turgidum var. durum) is negatively correlated with grain yield. To evaluate possible genetic interrelationships between GPC and grain yield per spike, thousand-kernel weight and kernel number per spike, quantitative trait loci (QTL) for GPC were mapped using GPC-adjusted data in a covariance analysis on yield components. Phenotypic data were evaluated in a segregating population of 120 recombinant inbred lines derived from crossing the elite cultivars Svevo and Ciccio. The material was tested at five environments in southern Italy. QTL were determined by composite interval mapping based on the Svevo?×?Ciccio linkage map described in Gadaleta et al. (2009) and integrated with DArT markers. The close relationship between GPC and yield components was reflected in the negative correlation between the traits and in the reduction of variance when GPC values were adjusted to yield components. Ten independent genomic regions involved in the expression of GPC were detected, six of which were associated with QTL for one or more grain yield components. QTL alleles with increased GPC effects were associated with QTL alleles with decreased effects on one or more yield component traits, or vice versa (i.e. the allelic effects were in opposite direction). Four QTL for GPC showed always significant effects, and these QTL should represent genes that influence GPC independently from variation in the yield components. Such genes are of special interest in wheat breeding since they would allow an increase in GPC without a concomitant decrease in grain yield.  相似文献   
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BackgroundManual measurement of 4-meter gait speed by a stopwatch is the gold standard test for functional assessment in older adults. However, the accuracy of this technique may be biased by several factors, including intra- and inter-operator variability. Instrumental techniques of measurement using accelerometers may have a higher accuracy. Studies addressing the concordance between these two techniques are missing. The aim of the present community-based observational study was to compare manual and instrumental measurements of 4-meter gait speed in older individuals and to assess their relationship with other indicators of physical performance.MethodsOne-hundred seventy-two (69 men, 103 women) non-disabled community-dwellers aged ≥65 years were enrolled. They underwent a comprehensive geriatric assessment including physical function by Short Physical Performance Battery (SPPB), hand grip strength, and 6-minute walking test (6MWT). Timed usual walking speed on a 4-meter course was assessed by using both a stopwatch (4-meter manual measurement, 4-MM) and a tri-axial accelerometer (4-meter automatic measurement, 4-MA). Correlations between these performance measures were evaluated separately in men and women by partial correlation coefficients.ResultsIn both genders, 4-MA was associated with 4-MM (men r = 0.62, p<0.001; women r = 0.73, p<0.001), handgrip strength (men r = 0.40, p = 0.005; women r = 0.29, p = 0.001) and 6MWT (men r = 0.50, p = 0.0004; women r = 0.22, p = 0.048). 4-MM was associated with handgrip strength and 6MWT in both men and women. Considering gait speed <0.6 m/s as diagnostic of dismobility syndrome, the two methods of assessment disagreed, with a different categorization of subjects, in 19% of men and 23% of women. The use of accelerometer resulted in 29 (13 M, 16 F) additional diagnoses of dismobility, compared with the 4-MM.ConclusionsIn an older population, the concordance of gait speeds manually or instrumentally assessed is not optimal. The results suggest that manual measures might lead to misclassification of a substantial number of subjects. However, longitudinal studies using standardized and validated procedures aimed at the comparison of different techniques are needed before recommending the use of accelerometers in comprehensive geriatric assessment.  相似文献   
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Gonadal hormones have been shown to exert modulatory effects on nociception and analgesia. To investigate the role of gonadal hormones in the response by female rats to both phasic and persistent nociceptive stimulation, we evaluated the effects of long-term ovariectomy (OVX, 6 months) on the thermal pain threshold and on formalin-induced responses. The thermal pain threshold was evaluated with the plantar test apparatus, while persistent pain was induced by a subcutaneous injection of dilute formalin (50 microliter, 10%) in the dorsal hind paw. The formalin test was carried out in an open field apparatus where the animal's spontaneous behavior and formalin-induced responses (licking duration, flinching frequency and flexing duration of the injected paw) were recorded for 60 min. Estradiol and corticosterone plasma levels were determined in blood collected from the anesthetized animals at the end of the test. In OVX females, the duration of formalin-induced licking was longer than in Intact females during both the first and the second phase; flinching and flexing did not differ from Intact. The thermal pain threshold was only slightly affected by OVX. Estradiol and corticosterone were lower in OVX females than Intact ones. These data indicate that long-term depletion of gonadal hormones in female rats modulates the pain-induced behavioral responses related to supraspinal neural circuits (licking of the injected paw) rather than more spinally mediated responses such as formalin-induced flinching and withdrawal latency in the plantar test.  相似文献   
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