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La ingeniería bioquímica juega un papel importante en el desarrollo tecnológico de los procesos de obtención ya sea de cuerpos fructíferos de setas con potencial medicinal para el consumo directo, o en la fabricación de nutracéuticos y/o suplementos dietarios. Esta investigación implementó una metodología en biorreactor para el cultivo del hongo macromiceto Lentinula edodes, conocido comúnmente como Shiitake, con el objetivo de evaluar el efecto que tienen la velocidad de agitación y el flujo de aire en la producción de biomasa y de metabolitos de mediana y baja polaridad. Se determinó que el rendimiento y la productividad más altos de producción de biomasa se logra a unas condiciones de 80 rpm y 0,50 vvm obteniendo 0,0260 g/g y 0,00433 g/L*h respectivamente. Igualmente, en cuanto a la composición de esta biomasa, se concluyó que se genera un máximo contenido de proteína (33,4% del micelio liofilizado) a unas condiciones de 140 rpm y 0,75 vvm, los esteroles alcanzaron un porcentaje de 89,32% del extracto en DCM a 80 rpm y 0,5 vvm. Los resultados del análisis por GC-MS confirman la amplia variedad de compuestos que se pueden obtener a partir de un cultivo en biorreactor del hongo Lentinula edodes.

The lipid compositions of the seed oils of some Nigella species were investigated. The total oil content of the seeds ranged from 28.0 to 36.4%. GC-MS fatty acid compositional analysis of the Nigella seed oils revealed the content of linoleic acid to be the highest (40.3-58.9%). Other prominent fatty acids were as follows: oleic (18.7-28.1%), palmitic (10.1-12.5%), 22:1 D11 (3.2-3.8%) and stearic (2.6-3.1%) acids. All the Nigella seed oils analysed exhibited differences in their tocopherol contents. The oils extracted from the seeds contained between 1.70-4.12 mg/100 g alpha-T, 0.97-4.51 mg/100 g gamma-T, and 4.90-17.91 mg/100 g beta-T3. The total tocopherol content in seeds varied between 9.15 mg/100 g to 24.65 mg/100 g. The compositions of the sterol fractions were determined by gas liquid chromatography. The total amounts of sterols ranged between 1,993.07 mg/kg to 2,182.17 mg/kg. The main component was beta-sitosterol (48.35-51.92%), followed by 5-avenasterol, campesterol, and stigmasterol.

Background. Dietary plant sterols, especially sitostanol, reduce serum cholesterol by inhibiting cholesterol absorption. Soluble sitostanol may be more effective than a less soluble preparation. We tested the tolerability and cholesterol-lowering effect of margarine containing sitostanol ester in a population with mild hypercholesterolemia. Methods. We conducted a one-year, randomized, double-blind study in 153 randomly selected subjects with mild hypercholesterolemia. Fifty-one consumed margarine without sitostanol ester (the control group), and 102 consumed margarine containing sitostanol ester (1.8 or 2.6 g of sitostanol per day). Results. The margarine containing sitostanol ester was well tolerated. The mean one-year reduction in serum cholesterol was 10.2 percent in the sitostanol group, as compared with an increase of 0.1 percent in the control group. The difference in the change in serum cholesterol concentration between the two groups was -24 mg per deciliter (95 percent confidence interval, -17 to -32; P0.001). The respective reductions in low-density lipoprotein (LDL) cholesterol were 14.1 percent in the sitostanol group and 1.1 percent in the control group. The difference in the change in LDL cholesterol concentration between the two groups was -21 mg per deciliter (95 percent confidence interval, -14 to -29; P0.001). Neither serum triglyceride nor high-density lipoprotein cholesterol concentrations were affected by sitostanol. Serum campesterol, a dietary plant sterol whose levels reflect cholesterol absorption, was decreased by 36 percent in the sitostanol group, and the reduction was directly correlated with the reduction in total cholesterol (r

Six triterpenoids, two sterols, and two phenolic constituents were isolated from the methanol extract of sclerotia of Inonotus obliquus (Hymenochaetaceae). Their chemical structures were identified as lanosterol (1), 3β-hydroxylanosta-8,24-dien-21-al (3), inotodiol (5), trametenolic acid (6), lanosta-8,25-dien-3,22,24-triol (7), β-sitosterol (2), ergosterolperoxide (4), betulin (8), 2,5-dihydroxy-benzaldehyde (9), and 3,4-dihydroxybenzalacetone (10) on the basis of spectroscopic methods and comparison with the literature. Among these compounds, 9 was isolated for the first time from this mushroom. To the best of our knowledge, the present study marks the first chemical investigation of I. obliquus from Alaska. Among the isolated compounds, compounds 1, 3, 4, 5, 6, 8, 9, and 10 were evaluated for in vitro cytotoxic activity against A 549 (human alveolar basal epithelial carcinoma cells), L1210 (mouse lymphocytic leukemia cells), COLO 205 (colorectal adenocarcinoma cells), MCF-7 (breast cancer cells), and HL-60 (human leukemia) cancer cell lines. 3β-Hydroxylanosta-8,24-dien-21-al (3) and tramentenolic acid (6) exhibited modest cytotoxic effects against L1210 cells with IC50s of 62.5 and 34.4 μM, and betulin (8) showed weak cytotoxic effects against A549 and HL-60 with IC50s of 81.2 and 87.5 μM, respectively. In addition, 3,4-dihydroxybenzalacetone (10) exhibited the strongest cytotoxic activities against A549 and HL-60 cells with IC50 values of 23.6 and 21.7 μM, respectively.

Hypovitaminosis D and a low calcium intake contribute to increased parathyroid function in elderly persons. Calcium and vitamin D supplements reduce this secondary hyperparathyroidism, but whether such supplements reduce the risk of hip fractures among elderly people is not known. Methods. We studied the effects of supplementation with vitamin D3 (cholecalciferol) and calcium on the frequency of hip fractures and other nonvertebral fractures, identified radiologically, in 3270 healthy ambulatory women (mean [+/- SD] age, 84 +/- 6 years). Each day for 18 months, 1634 women received tricalcium phosphate (containing 1.2 g of elemental calcium) and 20 micrograms (800 IU) of vitamin D3, and 1636 women received a double placebo. We measured serial serum parathyroid hormone and 25-hydroxyvitamin D (25(OH)D) concentrations in 142 women and determined the femoral bone mineral density at base line and after 18 months in 56 women. Results. Among the women who completed the 18-month study, the number of hip fractures was 43 percent lower (P = 0.043) and the total number of nonvertebral fractures was 32 percent lower (P = 0.015) among the women treated with vitamin D3 and calcium than among those who received placebo. The results of analyses according to active treatment and according to intention to treat were similar. In the vitamin D3-calcium group, the mean serum parathyroid hormone concentration had decreased by 44 percent from the base-line value at 18 months (P 0.001) and the serum 25(OH)D concentration had increased by 162 percent over the base-line value (P 0.001). The bone density of the proximal femur increased 2.7 percent in the vitamin D3-calcium group and decreased 4.6 percent in the placebo group (P 0.001). Conclusions. Supplementation with vitamin D3 and calcium reduces the risk of hip fractures and other nonvertebral fractures among elderly women

Sterols play crucial roles as membrane components and precursors of steroid hormones (e.g., brassinosteroids, BR). Within membranes, sterols regulate membrane permeability and fluidity by interacting with other lipids and proteins. Sterols are frequently enriched in detergent-insoluble membranes (DIMs), which organize molecules involved in specialized signaling processes, including auxin transporters. To be fully functional, the two methyl groups at the C-4 position of cycloartenol, a precursor of plant sterols, must be removed by bifunctional 3β-hydroxysteroid dehydrogenases/C-4 decarboxylases (3βHSD/D). To understand the role of 3βHSD/D in Arabidopsis development, we analyzed the phenotypes of knock-out mutants and overexpression lines of two 3βHSD/D genes (At1g47290 and At2g26260). Neither single nor double knock-out mutants displayed a noticeable phenotype; however, overexpression consistently resulted in plants with wrinkled leaves and short inflorescence internodes. Interestingly, the internode growth defects were opportunistic; even within a plant, some stems were more severely affected than others. Endogenous levels of BRs were not altered in the overexpression lines, suggesting that the growth defect is not primarily due to a flaw in BR biosynthesis. To determine if overexpression of the sterol biosynthetic genes affects the functions of membrane-localized auxin transporters, we subjected plants to the auxin efflux carrier inhibitor, 1-N-naphthylphthalamic acid (NPA). Where-as the gravity vectors of wild-type roots became randomly scattered in response to NPA treatment, those of the overexpression lines continued to grow in the direction of gravity. Overexpression of the two Arabidopsis 3βHSD/D genes thus appears to affect auxin transporter activity, possibly by altering sterol composition in the membranes.

We have identified the function of the Arabidopsis DIMINUTO/DWARF1 (DIM/DWF1) gene by analyzing the dim mutant, a severe dwarf with greatly reduced fertility. Both the mutant phenotype and gene expression could be rescued by the addition of exogenous brassinolide. Analysis of endogenous sterols demonstrated that dim accumulates 24-methylenecholesterol but is deficient in campesterol, an early precursor of brassinolide. In addition, we show that dim is deficient in brassinosteroids as well. Feeding experiments using deuterium-labeled 24-methylenecholesterol and 24-methyldesmosterol confirmed that DIM/DWF1 is involved in both the isomerization and reduction of the delta 24(28) bond. This conversion is not required in cholesterol biosynthesis in animals but is a key step in the biosynthesis of plant sterols. Transient expression of a green fluorescent protein-DIM/DWF1 fusion protein and biochemical experiments showed that DIM/DWF1 is an integral membrane protein that most probably is associated with the endoplasmic reticulum

Del cuerpo fructífero de Suillus luteus se extrajeron e identificaron, con base en el análisis de sus espectros de masas,  dieciséis compuestos, los cuales corresponden al ácido palmítico, oléico, linolénico y linoléico, octadecanoato de etilo, ergosta-7,22-dien-3β-ol, ergosta-7-en-3β-ol, estigmasterol , ergosta-3,5,7,9(11),22-pentaeno, ergosta-2,5,7,9(11),14,22-hexaeno, 23-metil-estigmast-3,5,7,22-tetraeno, 23-metil-estigmast-3,5,7,9(11),22-pentaeno, ergosta-4,6,15(16),22-tetraen-3-ona,  ergosta-1,5,7,9(11),22-pentaen-3-ona, ergosta-5,7,9(11),22-tetraen-3β-ol y ergosta-5,6,7-trihidroxi-7,22-dien-3β-ol. Siendo este un hongo tan poco estudiado, todos los compuestos, a excepción de los ácidos grasos, se reportan aquí por primera vez.

La composición de la fracción esterólica de los hongos Ganoderma australe, Ganoderma lucidum, Amanita rubescens, Licoperdon perlatum, Lentinula edades, Coltricia hammata. Lacearía laccata, Suillus luteus, Panus panoides, Macrolepiota colombiana y Agaricus bisporus se estableció mediante la técnica combinada CG-EM. La cuantificación individual de los esteróles presentes en esta fracción se realizó igualmente por CG-EM usando estigmasterol como estándar interno. Los resultados demostraron qyxe. Agaricus bisporus solo contiene ergosterol y por ello, adicionalmente, se esmdio su fracción esterólica a diferentes etapas de desarrollo del hongo.

3-Hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) catalyzes the irreversible conversion of 3-hydroxy-3-methylglutaryl coenzyme A to mevalonate and is considered a key regulatory step controlling isoprenoid metabolism in mammals and fungi. The rate-limiting nature of this enzyme for isoprenoid biosynthesis in plants remains controversial. To investigate whether HMGR activity could be limiting in plants, we introduced a constitutively expressing hamster HMGR gene into tobacco (Nicotiana tabacum L.) plants to obtain unregulated HMGR activity. The impact of the resulting enzyme activity on the biosynthesis and accumulation of particular isoprenoids was evaluated. Expression of the hamster HMGR gene led to a 3- to 6-fold increase in the total HMGR enzyme activity. Total sterol accumulation was consequently increased 3- to 10-fold, whereas end-product sterols such as sitosterol, campesterol, and stigmasterol were increased only 2-fold. The level of cycloartenol, a sterol biosynthetic intermediate, was increased more than 100-fold. Although the synthesis of total sterols appears to be limited normally by HMGR activity, these results indicate that the activity of one or more later enzyme(s) in the pathway must also be involved in determining the relative accumulation of end-product sterols. The levels of other isoprenoids such as carotenoids, phytol chain of chlorophyll, and sesquiterpene phytoalexins were relatively unaltered in the transgenic plants. It appears from these results that compartmentation, channeling, or other rate-determining enzymes operate to control the accumulation of these other isoprenoid end products.