Isolation of ethyl cinnamate and a subtituted fluorene from Pycnanthus angolensis (Welw.) Warb.

Abstract

Before now, two compounds namely, 3-ethoxy-3,7-dimethyl-1,6-octadiene (ethyl linalool) and 1,2-benzenedicarboxylic acid diethyl ester (diethyl phthalate) have been isolated from the ethyl acetate fraction of Pycnanthus angolensis by column chromatography. In this study, the preparative thin-layer chromatography (p-TLC) of two previously obtained residues was carried out. The chemical and biological properties of the compounds obtained there from were evaluated. This exercise led to two isolates (NG-1b and NG-3b) whose identities have been revealed to be ethyl cinnamate (cinnamic acid, ethyl ester) and 9-oximino-2,7-diethoxy fluorene (2,7-diethoxy-9H-fluoren-9-one oxime) respectively using the MS and IR spectral techniques. The compounds were surprisingly strongly bacteriostatic against Escherichia coli but recorded no activity against Staphylococcus aureus and Candida albicans.

Evaluation of Antioxidant Activity of Cinnamic Acid and Some of its Derivatives

“…Warb using column chromatography (CC) and preparative column chromatography (p TLC) and characterized by IR and GC/MS techniques. 17 Its refractive index was found to be 1.658.…”

Antioxidant Activity of Compounds Isolated From Pycnanthus Angolensis (Welw.) Warb and Byrophyllum Pinnatum (Lam.) Oken

“…The identities of these compounds have been established to be ethyl cinnamate (cinnamic acid, ethyl ester), 3-ethoxy-3,7-dimethyl-1,6octadiene (ethyl linalool), 9-oximino-2,7-diethoxyfluorene (2,7-diethoxy-9H-fluoren-9-one oxime), 1,2benzenedicarboxylic acid diethyl ester (diethyl phthalate), ethyl 1,6-dihydro-2-methyl-4-hydroxy-6-oxo-3-pyridine carboxylic acid, ethyl ester (1, 6-dihydro-2-methyl-4hydroxy-6-oxo-3-nicotinic acid, ethyl ester, 1-ethoxy-2hydroxy-4-prophenyl guaethol and 17-(1ʹ-cyclobutan)-2ʹone-3-hydroxy)-(3β,17β)-spiro(androst-5-ene, respectively using a combination of MS and IR spectral techniques. [12][13][14][15] Figure 1. Structures of the studied compounds Table 1.…”

“…Previous studies by the lead author and co-workers have led to seven compounds namely, ethyl cinnamate (cinnamic acid, ethyl ester) (NG-1b), 3-ethoxy-3,7-dimethyl-1,6-octadiene (ethyl linalool) (NG-2), 9-oximino-2,7-diethoxyfluorene (2,7diethoxy-9H-fluoren-9-one oxime) (NG-3b), 1,2benzenedicarboxylic acid diethyl ester (diethyl phthalate) (NG-4c), ethyl 1,6-dihydro-2-methyl-4-hydroxy-6-oxo-3pyridine carboxylic acid, ethyl ester (1,6-dihydro-2-methyl-4-hydroxy-6-oxo-3-nicotinic acid, ethyl ester (NG-5a), 1ethoxy-2-hydroxy-4-prophenyl guaethol (KF-1a) and 17-(1ʹcyclobutan)-2ʹ-one-3-hydroxy)-(3β,17β)-spiro(andorst-5-ene, (KF-2) from the plants. [12][13][14][15] This present study was done by subjecting the crude extracts and the seven isolated compounds to antioxidant tests with a view of confirming or disproving the reported uses in ethno-medicine for the treatment/management of inflammatory conditions which arise from the debilitating incidence of free-radicals.…”

“…The powders were extracted with cold 96 % ethanol at room temperature (27 ± 2 0 C) for 72 h. The obtained filtrates were then evaporated to dryness in-vacuo on a rotary evaporator (R205D, Shensung BS & T, China). The extracts, NG-1b, NG-2, NG-3b, NG-4c, NG-5a, KF-1a and KF-2 previously isolated from chromatographic separations of organic fractions of the two plants [12][13][14][15] were kept in appropriately labelled amber bottles and then stored in a refrigerator at -4 0 C prior to the antioxidant tests.…”