Estela Guardado Yordi, Maria João Matos, Lourdes Santana, Eugenio Uriarte, Orlando Abreu and Enrique Molina Pérez
Abstract: Coumarins are a group of phytochemicals with multiple applications in different fields, such as food and medicine. Many of their benefits are based on the different activities that they display, within which stand antioxidant properties. However, some conflicting evidences suggest the need to clarify or estimate the safety aspects and genotoxicity of this group of compounds. In this sense it has been shown in previous studies that some of them have presented pro-oxidant activity in vitro and clastogenic activity in silico. Therefore, in this paper chemical structures of coumarins that come from several natural sources were studied. These coumarins belong to the chemical subclasses: simple coumarins, furocoumarins, dihydrofurocoumarins, pyranocoumarins, phenylcoumarins and biscoumarins. Thepre-selected database was formed taking into account topological-structural information, using molecular descriptors from the TOPSMODE approach. A virtual screening, that used a structure-clastogenic activity model and linear discriminant analysis (LDA) technique, was also performed. Several natural coumarins showed clastogenic activity in silico. For this family, the QSTR associated the probability of being active to the presence of hydroxy and methoxy groups in the molecules. It is of positive contribution of the fragment that forms the bay region of the pyranocoumarinic system. These in silico results may contribute to the safe design of new foods, nutraceuticals or drugs. It may also be important in the prevention of cancer, in which pathology these substances show pro-oxidant activity.
Keywords: Coumarins, clastogenic activity, pro-oxidant activity, TOPSMODE approach.
Pages: 241 – 257 | Full PDF Paper
Lipase Catalysis for Transesterification Produces Biodiesel Using Coconut Oil as Main Raw Material Source
Tran Thi Be Lan, Phan Ngoc Hoa
Abstract: Transesterification is a chemical method that has been studied to convert fat and oil into biodiesel. Inorganic catalysts often have high catalysis activity and reusability, so they have been predominant for biodiesel production at the industrial scale; however, they often cause severe pollution. Recently, bio-catalytic transesteriﬁcation has received considerable attention due to its favorable conversion rate and relatively simple processing performance for the production and puriﬁcation of biodiesel. In this study, two lipases from Candida rugosa and Porcine pancreas was used to catalyze the transesterification of coconut oil in order to produce biodiesel. The results have shown that the catalysis ability of the lipase from Candida rugosa in the transesterification of coconut oil is better than that of Porcine pancreas. The use of the lipases from Candida rugosa and Porcine pancreas reached the oil conversion level of 62.55% and 59.72%, respectively. The better conditions of the enzymes and the reaction were also studied.
Keywords: Transesterification, lipase, Candida rugosa, Porcine pancreas, biodiesel, coconut oil.
Pages: 258 – 267 | Full PDF Paper
Ahmed M. Eed, Adam H. Burgoyne
Jojoba (Simmondsia chinensis (Link) Schneider) is a desert shrub which tolerates saline, alkyle soils and drought. The seeds contain a characteristic liquid wax of economic importance in industry as a machine lubricant and cosmetics. A major problem in seed propagation is that jojoba is a dioecious plant whose its sex is not easily determined prior to flowering (3-4 years from germination). To overcome this phenomenon, asexual propagation using vegetative methods such as cutting can be used. This research was conducted to find out the effect of different plant growth regulators (PGRs) and rooting media on jojoba rhizogenesis. An experiment was carried out in a factorial completely randomized block design (FCRBD) with three replications, each with sixty cuttings per replication in fiberglass house of Jojoba Naturals Corporation at Yemen.
The different rooting media used were peat moss + perlite + vermiculite (1:1:1), peat moss + perlite (1:1), and peat moss + sand (1:1). Plant materials used were semi-hard wood cuttings of jojoba plants with length of 15 cm. The cuttings were collected in the month of June during 2012 and 2013 from the sub-terminal growth of the mother plants of Amman farm and introduced to Yemen. They were wounded, treated with Indole butyric acid (IBA), α-naphthalene acetic acid (NAA), or Indole-3-acetic acid (IAA), all at 4000 ppm (part per million) and cultured on different rooting media under intermittent mist propagation conditions. IBA gave significantly higher percentage of rooting (66.23%) compared to NAA and IAA in all media used. However, the lowest percentage of rooting (5.33%) was recorded with IAA in the medium consisting of peat moss and sand (1:1). No significant difference was observed at all types of PGRs used with rooting media in respect of root length. Maximum number of roots was noticed in medium consisting of peat moss, perlite, and vermiculite (1:1:1); peat moss and perlite (1:1), and peat moss and sand (1:1) using IBA, NAA, and IBA respectively. The interaction among rooting media was statistically significant with respect to rooting percentage character. Similarly, the interaction among PGRs was significant in terms of rooting percentage and also root length characters. The results demonstrated suitability of propagation of jojoba plants by semi-hard wood cuttings.
Keywords: Cutting, IBA, jojoba, propagation, rooting.
Pages: 268 – 275 | Full PDF Paper