Synthesis And Complexation Study Of The Conformational Isomer Of Cyclotetrachromotropylene

Chromotropic acid reacts with formaldehyde to give the boat and chair conformers (25a and 25b respectively) of cyclotetrachromotropylene, 25, under different reaction conditions. At room temperature, 25b was isolated in which upon heating can convert to the thermodynamically more stable 25a. Conformer 25a is best synthesized via reflux in high yield (~ 90 %). In contrast, 25b can only be synthesized at room temperature giving a moderate yield of 20-25 %

FT-IR analysis on the inclusion complex of Β-Cyclodextrin with quercetin, naringenin, 3-Hydroxyflavone and chrysin via different preparation methods / Noor Amilia Khosim, Ainnie Rahayu Abdullah and Marina Mokhtar

Flavonoids are used widely in the pharmaceutical industry due to their anti-oxidative and anti-inflammatory properties. However, most of the flavonoids are poorly water-soluble. These experiments were conducted to prepare the inclusion complex of β-Cyclodextrin with selected flavonoids such as Quercetin, Naringenin, 3-Hydroxyflavone and Chrysin. The methods used in complexing the host and guest molecules are modified physical mixture, kneading and freeze drying method by using the molar ratio of 1:1. The complexations of the flavonoids tested were analyzed by the Fourier Transform Infrared (FT-IR)spectroscopy. Analysis results suggested that the best method to complex β-Cyclodextrin with Quercetin and Chrysin, were via modified kneading method. Complexation of Naringenin and 3-Hydroxyflavone was best done via modified freeze drying and physical mixture method respectively

Antioxidant activity and phytochemical investigation on Pereskia bleo (kunth) D. C. (jarum tujuh bilah) / Nor Aziyah Bakhari, Ainnie Rahayu Abdullah and Hasnah Osman

Phenolic, flavonoid and tannin content of dried Pereskia bleo were investigated using the well established method via UV-Vis Spectrometry. Pereskia bleo has phenolic content the highest followed by flavonoid and tannin content. A study of antioxidant activities of dried sample of Pereskia bleo was carried out by using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assay. The plant shows moderate antioxidant activity. Pereskia’s leaves from ethyl acetate extract showed the highest antioxidant activity (66.32 %) followed by Pereskia’s leaves from methanol extract (61.76 %). The total phenolic content showed a good correlation with antioxidant activity but not the total flavonoid and tannin content