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Plant Physiol Biochem ; 108: 191-202, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27448793


Silymarin, a Silybum marianum seed extract containing a mixture of flavonolignans including silybin, is being used as an antihepatotoxic therapy for liver diseases. In this study, the enhancing effect of gamma irradiation on plant growth parameters of S. marianum under salt stress was investigated. The effect of gamma irradiation, either as a single elicitor or coupled with salinity, on chalcone synthase (CHS) gene expression and silybin A + B yield was also evaluated. The silybin A + B content in S. marianum fruits was estimated by liquid chromatography-mass spectrometry (LC-MS/MS). An increase in silybin content was accompanied by up-regulation of the CHS1, CHS2 and CHS3 genes, which are involved in the silybin biosynthetic pathway. The highest silybin A + B production (0.77 g/100 g plant DW) and transcript levels of the three studied genes (100.2-, 91.9-, and 24.3-fold increase, respectively) were obtained with 100GY gamma irradiation and 4000 ppm salty water. The CHS2 and CHS3 genes were partially sequenced and submitted to the NCBI database under the accession numbers KT252908.1 and KT252909.1, respectively. Developing new approaches to stimulate silybin biosynthetic pathways could be a useful tool to potentiate the use of plants as renewable resources of medicinal compounds.

Aciltransferases/genética , Cardo Mariano/genética , Silimarina/metabolismo , Aciltransferases/metabolismo , Frutas/genética , Frutas/metabolismo , Raios gama , Regulação da Expressão Gênica de Plantas , Germinação , Cardo Mariano/metabolismo , Cardo Mariano/efeitos da radiação , Família Multigênica , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Medicinais/genética , Plantas Medicinais/metabolismo , Salinidade , Tolerância ao Sal , Sementes/crescimento & desenvolvimento , Silibina , Silimarina/genética
Ultrason Sonochem ; 21(5): 1752-62, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24768105


The aim of this study is to investigate modified TiO2 doped with C4H4O6HK as heterogeneous solid base catalyst for transesterification of non-edible, Silybum marianum oil to biodiesel using methanol under ultrasonication. Upon screening the catalytic performance of modified TiO2 doped with different K-compounds, 0.7 C4H4O6HK doped on TiO2 was selected. The preparation of the catalyst was done using incipient wetness impregnation method. Having doped modified TiO2 with C4H4O6HK, followed by impregnation, drying and calcination at 600 °C for 6 h, the catalyst was characterized by XRD, FTIR, SEM, BET, TGA, UV and the Hammett indicators. The yield of the biodiesel was proportional to the catalyst basicity. The catalyst had granular and porous structures with high basicity and superior performance. Combined conditions of 16:1 molar ratio of methanol to oil, 5 wt.% catalyst amount, 60 °C reaction temperature and 30 min reaction time was enough for maximum yield of 90.1%. The catalyst maintained sustained activity after five cycles of use. The oxidative stability which was the main problem of the biodiesel was improved from 2.0 h to 3.2h after 30 days using ascorbic acid as antioxidant. The other properties including the flash point, cetane number and the cold flow ones were however, comparable to international standards. The study indicated that Ti-0.7-600-6 is an efficient, economical and environmentally, friendly catalyst under ultrasonication for producing biodiesel from S. marianum oil with a substantial yield.

Biocombustíveis/efeitos da radiação , Cardo Mariano/química , Cardo Mariano/efeitos da radiação , Óleos Vegetais/química , Óleos Vegetais/efeitos da radiação , Ultrassom/métodos , Biocombustíveis/análise , Catálise , Diglicerídeos/química , Diglicerídeos/efeitos da radiação , Ésteres/síntese química , Ésteres/química , Oxirredução , Sementes/química , Sementes/efeitos da radiação , Titânio/química