16เอกสารอ้างอิงMachana, S., Weerapreeyakul, N.*, Barusrux, S., Thumanu, K. and Tanthanuch, W. FTIR microspectroscopy discriminates anticancer action on human leukemic cells by extracts of Pinus kesiya; Cratoxylum formosum ssp. pruniflorum and melphalan. Talanta May 15.:
18สารต้านมะเร็งจากพืชสมุนไพร ซินโครตรอนยืนยันสารต้านมะเร็งจากพืชสมุนไพรelectro-magnetic radiation created in a synchrotron,presentation on a specific application of synchrotron radiation.
19การใช้แสงอินฟราเรดวิเคราะห์สิ่งมีชีวิต A motion of diatomic molecules as a springStretching vibrationsabsorbance5001000150020002500300035004000Wavenumbers (cm-1)ccHow does IR detect biologcal sample? Because this sample contain biochemical molecule, which contain various function group.Each chemical bond in a molecule will absorb IR energy, then vibrates at a frequency which is characteristic of that bond.A group of atoms in a molecule (e.g. CH2) may have multiple modes of oscillation caused by the stretching and bending motions of the group as a whole. If an oscillation leads to a change in dipole in the molecule, then it will absorb a photon which has the same frequency.In chemical analysis, IR spectrum will show as wave number which correlate to wave lengthHHHHBending vibrations1OHNCHIGHLOW400025002000180016001550650Wavenumber(cm-1)H=HHHwavelength (cm)cc
20อินฟราเรดสเปกตรัม C C H H H H 1650 cm-1(N–H) bending(C=O) stretchingBiomedical samples comprise a mixture of proteins, nucleic acids, lipids and carbohydrates, and this complexity is reflected in the IR absorption spectra they produce.The amide I band at around 1650 cm-1 which results principally from the (C=O) stretching vibrations of protein amide bonds;The amide II band close to 1549 cm-1 resulting from a combination of the (N–H) bending and (C–N) stretching vibrations of the amide bonds;the (C=O) stretching of lipids at about 1740 cm-1; and the antisymmetric nas(PO2) stretching of nucleic acids and phospholipids near 1225 cm1.Many biological samples have highly specific vibrational signatures that form a database for discriminating various states
21โครงสร้างทุติยภูมิของโปรตีน random coil - helix - sheetThis amide I band composes of 80% from the C=O stretching vibration of the amide group, coupled to the in-plan N-H bending and C-N stretchingamide I band consists of a series of overlapped component bands which occurs as a result of the secondary structures present in proteins.