Three short sediment cores (12-32 cm) Tiga turus sedimen pendek (12-32 cm) telah diambil di Laut China Selatan dalam bulan Mei (pos-Monsun Timur Laut) dan September 2007 (pra-Monsun Timur Laut). Kepekatan jumlah karbon organik (TOC) yang diperoleh adalah antara

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Abstract:Obesity is a complex multifactorial disease. Adipocytes arise from pluripotent mesenchymal stem cells (MSC), which are also capable of differentiation into bone, muscle, or cartilage. Adipogenesis involves lineage commitment, mitotic clonal expansion, and terminal differentiation. Understanding these mechanisms, as well as when and how to turn them on or off, may allow development of new therapeutic approaches to obesity, diabetes, and cardiovascular disease. The most abundant non-lipid component of olive plant is the polyphenol oleuropein (Ole). We found that Ole modulates adipocyte differentiation, fat accumulation and adipogenic gene expression in human MSCs (hMSC). Ole blocks adipogenesis in a dose-dependent manner. Using RT-PCR to monitor gene expression, we found that Ole down-regulates the expression of adipogenic genes PPARγ2, LPL (lipoprotein lipase), and aP2 (lipid binding protein), while it upregulates PPARδ expression. In addition, in the presence of Ole, we were able to achieve transdifferentiation and dedifferentiation, allowing fat cells to assume other fates. These results demonstrate the potential utility of Ole for the treatment of obesity, diabetes, and related disorders, which are associated with increased fat mass. Because it modulates adipocyte differentaion, Ole may also be useful for the treatment of cachexia and lipodystrophy.

The aim of this research project is to study the effect of para-substituents on the physical properties of 2,6-ditert-butyl phenol derivatives as a vegetable oil chain-breaking radical scavenger. In this theoretical studies, Gaussian 09 quantum mechanical software package at the theoretical level of DFT B3LYP/6-31G(d,p) were employed to evaluate the optimized geometry at the local minimum of total potential energy structures. The physical parameters such as the total electronic energy, the strength and the length of hydrogen bonding, the O-H antioxidants parameters(bond length, bond strength, Wiberg bond index), and the dipole moment of the molecules involved were assessed at the same theoretical level by using Natural Bond Orbital method. The para-substituents in consideration were -H, -CH 3 , -OH, -OCH 3 and propyl ester (COOCH 2 CH 2 CH 3 ). Results showed that hydroxyl (-OH) para derivative formed the strongest transition-state complex (24.5 kJ/mol) with C9-hydroperoxyl radical of methyl linoleate followed by -OCH 3 (23.7 kJ/mol), -CH 3 (21.8 kJ/mol), -H (21.4 kJ/mol), and -COOCH 2 CH 2 CH 3 (20.7 kJ/mol). However, the para-derivative of propyl ester (-COOCH 2 CH 2 CH 3 ) has the lowest Wiberg bond index of O-H bond (0.653) compared to the other derivatives of the 2,6-ditert-butyl phenol [-H (0.661), -CH 3 (0.663), -OCH 3 (0.664), -OH (0.665)]. This means that the derivatives with hydroxyl or propyl ester group at para-position should be more effective as an antioxidant for high-linoleic vegetable oil rather than the available commercial BHT where the substituent is methyl group.

The aim of this research project is to study the performance of two antioxidants, TBHQ (1) and BHA (2) as a chain-breaking radical scavenger of the selected vegetable oil which contained high oleic fatty acid constituent i.e. canola oil. Experimental studies involved heating the vegetable oil in the forced air-flow oven for 15 days at 60ºC. Samples subjected for peroxide value determination were analysed at 0, 1, 3, 6, 10 and 15 days of exposure. For the theoretical investigation, Gaussian 09 software package at the theoretical level of DFT B3LYP/6-31G(d,p) were used to evaluate the physical parameters of the antioxidants (TBHQ and BHA), the homo-chain of tri-oleic TAG (3) with hydroperoxide group at carbon-11 and its radical, and the transition-state complex of the two components in questions. The selected physical parameters such as the total electronic energy (SCF energy), the stabilization energy, the hydrogen bond distance of the complex, the properties of the O-H of antioxidant (bond length, bond dissociation energy, Wiberg bond-index), and the dipole moment, were then utilized to correlate with the actual performance of the two antioxidants. Experimental results showed that TBHQ exhibit better performance than BHA in inhibiting the production of hydroperoxides in canola oil. These experimental observations were in line with the theoretical results where all the physical parameters except hydrogen bond distance support the findings.