@article{I_S_A. Hadi_Awang_2002, title={Ab initia Geometry-Optimization and NMR Studies of Chemical Constituents of Piper sarmentosum}, volume={21}, url={http://ojie.um.edu.my/index.php/MJS/article/view/8600}, abstractNote={<p>The structures of two compounds, ÃŽÂ³-asarone (1-ally1-2,4,5-trimethoxybenzene) $\mathbf{1}$ and asarylaldehyde (2,4,5-trimethoxybenzaldehyde) $\mathbf{2}$ from $Piper$ $sarmentosum$, locally known as Ã¢â‚¬ËœkadukÃ¢â‚¬â„¢, have been studied by HNMR, CNMR spectroscopy and quantum chemical calculations. The NMR shifts are calculated using Hartree Fock (HF) and Density Functional Theory (DFT) methods. We find that the $ab$ $initio$ calculations are very useful in assigning the NMR peaks and provide insights on the electronic factors affecting the NMR shifts.</p>}, number={1&2}, journal={Malaysian Journal of Science}, author={I, Noorbatcha and S, Hassan and A. Hadi, Hamid and Awang, Khalijah}, year={2002}, month={Apr.}, pages={143–147} }