Role of the Ring Methyl Groups in Abscisic Acid Activity in Erucic Acid Accumulation in Oilseed Rape (Brassica napus L.)

Modification of the structure of abscisic acid (ABA) has been reported to result in modification of its physiologic activity. In this study we tested the effect of removing methyl groups from the ring and of chirality of ABA on activity in microspore-derived embryos of oilseed rape (Brassica napus L.). The natural (+)-ABA molecule induced growth inhibition and an increase in the amount of erucic acid accumulated in the oil at medium concentrations less than 1 μm. (−)-ABA showed similar effects. Removing the 7′-methyl group resulted in a dramatic decrease in activity: (+)-7′-demethyl-ABA retained some activity as a growth inhibitor; a 10–100 μm concentration of this compound was needed for a response, and (−)-7′-demethyl-ABA was almost completely inactive. Similar effects were observed with regard to elongase activity, which catalyzes erucic acid biosynthesis from oleic acid. Removal of the 8′- and 9′-methyl groups resulted in a more complex response. These compounds all showed intermediate activity; for growth inhibition, the presence of the 9′-methyl was the more important determinant, whereas chirality dominated the response on erucic acid accumulation, with the (+)-enantiomers being more active. Received July 25, 1997; accepted October 31, 1997     

Chemical Composition and Biological Activity of Centaurea baseri: New Species from Turkey

The genus Centaurea L. is one of the largest and important genera of Asteraceae family. Centaurea species have been widely used as herbal remedies in folk medicine for their antidandruff, antidiarrheic, antirheumatic, anti‐inflammatory, choleretic, diuretic, digestive, stomachic, astringent, antipyretic, cytotoxic, and antibacterial properties. Centaurea baseri Kose & Alan is a recently described local endemic species in Turkey and this is the first study on the chemical composition and bioactivity of its hydrodistilled essential oil and the crude extract. According to chromatospectral analysis, hexadecanoic acid (42.3%), nonacosane (8.2%), and heptacosane (8.0%) were the main compounds of the essential oil, while 16 compounds were determined in the MeOH extract using LC/MS. Furthermore, antimicrobial, antioxidant, and cytotoxic effects of the essential oil and the extract were evaluated in comparison with the standard agents. The extract showed strong antifungal effect against Candida utilis at the concentration of 60 μg/ml (MIC) where the EO showed growth inhibition at the concentration of 47.00 μg/ml (MIC) against pathogen Bacillus cereus. Both the essential oil and the extract did not show any selective antioxidant properties. The extract showed remarkably selective cytotoxic properties against MCF‐7, PANC‐1, A549, and C6 glioma cells.     

Longer lifespan in male mice treated with a weakly estrogenic agonist,an antioxidant,an α‐glucosidase inhibitor or a Nrf2‐inducer

The National Institute on Aging Interventions Testing Program (ITP) evaluates agents hypothesized to increase healthy lifespan in genetically heterogeneous mice. Each compound is tested in parallel at three sites, and all results are published. We report the effects of lifelong treatment of mice with four agents not previously tested: Protandim, fish oil, ursodeoxycholic acid (UDCA) and metformin – the latter with and without rapamycin, and two drugs previously examined: 17‐α‐estradiol and nordihydroguaiaretic acid (NDGA), at doses greater and less than used previously. 17‐α‐estradiol at a threefold higher dose robustly extended both median and maximal lifespan, but still only in males. The male‐specific extension of median lifespan by NDGA was replicated at the original dose, and using doses threefold lower and higher. The effects of NDGA were dose dependent and male specific but without an effect on maximal lifespan. Protandim, a mixture of botanical extracts that activate Nrf2, extended median lifespan in males only. Metformin alone, at a dose of 0.1% in the diet, did not significantly extend lifespan. Metformin (0.1%) combined with rapamycin (14 ppm) robustly extended lifespan, suggestive of an added benefit, based on historical comparison with earlier studies of rapamycin given alone. The α‐glucosidase inhibitor, acarbose, at a concentration previously tested (1000 ppm), significantly increased median longevity in males and 90th percentile lifespan in both sexes, even when treatment was started at 16 months. Neither fish oil nor UDCA extended lifespan. These results underscore the reproducibility of ITP longevity studies and illustrate the importance of identifying optimal doses in lifespan studies.     

Leaf age and larval performance of the leaf beetle Paropsis atomaria

ABSTRACT.

• 1 Larval performance of the leaf beetle Paropsis atomaria Oliver was determined for larvae raised on both new and mature leaves of Eucalyptus blakelyi Maiden. Larvae were transferred to mature leaves at different ages; control larvae stayed on new leaves through all instars.
• 2 Only larvae reared on new leaves through the third instar survived to pupate on mature leaves; developmental time was prolonged by 20% and pupal weight was reduced by 50% in these larvae compared with larvae reared entirely on new leaves. Almost all larvae died when transferred to mature leaves as first, second or third instars.
• 3 Low survival and slow development on mature leaves was mainly due to failure by larvae to feed. Larvae palpated leaves and could discriminate among leaf ages immediately, without biting into the leaf tissue.
• 4 New leaves had higher concentrations of oil and tannins than old leaves, while there were no significant differences in nitrogen concentrations in the two types of leaves. Mature leaves were more than 3 times tougher than new leaves, in terms of g mm^?2 of penetrometer force.
• 5 In drought years E. blakelyi may not produce sufficient new leaves to supply specialist herbivores with their preferred food resource. We infer that drought years reduce P. atomaria larval performance significantly, and influence the population dynamics of the insect.

     

Rosmarinus officinalis essential oil modulates renal toxicity and oxidative stress induced by potassium dichromate in rats

BACKGROUNDChromium hexavalent (CrVI) is known as a toxic contaminant that induced oxidative stress and nephrotoxicity in humans and animals. Rosmarinus officinalis is a perennial herb rich in biologically active constituents that have powerful antioxidant properties. So, the current work evaluated the effectiveness of Rosmarinus officinalis essential oil (REO) against alterations induced by potassium dichromate in the kidney of male rats.METHODSGC-MS analysis, in vitro total phenol contents, and DPPH scavenging activity of REO were estimated. Thirty-five Wistar male rats were categorized into 5 groups. The first group was the control, the second one was orally administered rosemary essential oil (REO; 0.5 mL/kg BW), the third group was injected intraperitoneally with hexavalent chromium (CrVI; 2 mg/kg BW) for 14 days, the fourth group used as the protective group (REO was administrated 30 min before i.p. injection of CrVI) and the fifth group applied as the therapeutic group (rats injected with CrVI 30 min followed by oral administration of REO), respectively.RESULTSTwenty-nine components were detected with high total phenolic contents and high DPPH scavenging activity. Results revealed that CrVI- intoxicated rats showed a valuable increase in oxidative stress profile (TBARS and H₂O₂) and a notable decline in glutathione (GSH), total protein content, and enzymatic antioxidants (SOD, CAT, GPx, and GST). Furthermore, serum kidney functions biomarkers (urea, creatinine, and uric acid) were increased significantly. Also, the administration of CrVI showed histological and immunohistochemical (PCNA-ir) changes in rat kidney tissue. Otherwise, administration of REO pre or post-treatment with CrVI significantly restored most of the biochemical parameters in addition to improvement in kidney tissue architecture. Moreover, individual intake with REO exhibited an amendment in oxidative stress markers.CONCLUSIONConclusively, REO had a potential antioxidant capacity in ameliorating K₂Cr₂O₇-induced nephrotoxicity, especially in the protection group.     

Oleaginous yeasts: Biodiversity and cultivation

Microbial lipids produced by oleaginous microorganisms, also called microbial oils and single cell oils (SCOs), are very promising sources for several oil industries. The exploration of efficient oleaginous yeast strains, meant to produce both high-quantity and high-quality lipids for the production of biodiesel, oleochemicals, and the other high value lipid products, have gained much attention. At present, the number of oleaginous yeast species that have been discovered is 8.2% of the total number of known yeast species, most of which have been isolated from their natural habitats. To explore high lipid producing yeasts, different methods, including high-throughput screening methods using colorimetric or fluorometric measures, have been developed. Understanding of the fatty acid composition profiles of lipids produced by oleaginous yeasts would help to define target lipid-related products. For lipid production, the employment of low-cost substrates suitable for yeast growth and lipid accumulation, and efficient cultivation processes are key factors for successfully increasing the amount of the accumulated lipid yield while decreasing the cost of production.     

9-Hydroxydodecanoic acid,an acid from Blepharis sindica seed oil

A hitherto unknown hydroxy acid has been isolated from Blepharis sindica seed oil has been characterized as 9-hydroxydodecanoic acid by IR, NMR and mass spectral studies. The structure of this acid was further supported by its chemical transformations.     

Roots volatiles and fatty acids of coriander (<Emphasis Type="Italic">Coriandrum sativum</Emphasis> L.) grown in saline medium

An hydroponic culture was conducted to investigate the effect of saline stress on the essential oil and fatty acid composition of Tunisian coriander (Coriandrum sativum L.) roots. Ten days old coriander seedlings were treated during 3 weeks with different NaCl concentrations (0, 25, 50 and 75 mM). Roots volatile components and fatty acids were analyzed. The essential oil yield was 0.06% in the control, on the basis of dry matter weight, and did not changed at low concentration (25 mM), while it increased significantly with increasing NaCl concentrations to reach 0.12 and 0.21% at 50 and 75 mM NaCl, respectively. The major volatile component was (E)-2-dodecenal with 52% of total essential oil constituents, followed by decanal, dodecanal, (E)-2-tridecenal and (E)-2-dodecenal. Further, the amount of these compounds was affected differently by the NaCl level. Total fatty acid amount of coriander roots increased significantly only with 50 and 75 mM NaCl. Three major fatty acids: linoleic (43%), oleic (25.5%) and palmitic (21.6%) were identified. Linoleic acid amount remains unchanged at 25 mM, while it increased with raising NaCl concentrations. However, oleic acid amount decreased only at 25 mM and no effect was observed at 50 and 75 mM. Fatty acid percentages were differently affected by salt. The oleic/linoleic ratio was reduced with raising NaCl concentrations.