Lipoxygenase inhibition by novel fatty acid ester fromAnnona squamosaseeds

Abstract

Studies on the seeds of Annona squamosa yielded a novel lipoxygenase inhibitor fatty acid ester, (þ ) -annonlipoxy (1). Compound 1 was screened for its enzyme inhibitory activity against lipoxygenase (E.C.1.14.18.1), exhibiting activity with IC 50 69.05^5.06 mm. Baicalein (IC 50 22.6^0.5 mm) was used as a positive control. Crude extracts of Annona squamosa fruit pulp and seeds were screened for its enzyme inhibitory activity against lipoxygenase and acetylcholinesterase. The crude ethanolic extract of fruit pulp and seeds of Annona squamosa also exhibited lipoxygenase activity with 22.2 and 26.7% inhibition, while the pet.ether extract of seeds of A. squamosa exhibited 52.7% inhibition at a concentration of 40 mg/200 ml. The crude ethanolic extract of seeds of Annona squamosa was also bioassayed for acetylcholinesterase inhibition and it was found inactive.

Two new triterpenes fromAlstonia scholarisflowers

“…a double doublet at ¼ 3.45 (J 3,2 ¼ 4.50 Hz, J 3,2 ¼ 12.4 Hz) and a broad double doublet at ¼ 5.62 (J 6,7 ¼ 12.5 Hz, J 6,7 ¼ 4.0 Hz), which could be assigned to the hydroxyl bearing C-3 methine and to the vinylic C-6 protons, respectively. The chemical shift and coupling constants of the C-3 methine signal indicated an equatorial () orientation of the OH group (Sultana, 2008). The equatorial orientation () of the hydroxyl group was inferred from the chemical shift and coupling pattern of geminal C-3 proton at ¼ 3.45 (dd, J 3,2 ¼ 4.50 Hz, J 3,2 ¼ 12.40 Hz).…”

“…The C-12 vinylic proton resonating at ¼ 5.10 showed vicinal couplings with the C-11 methylene protons resonating at ¼ 1.52 and 1.62. The Homonuclear Hartmann Hahn spectrum (Atta-urRahman, Sultana, Jahan, & Choudhary, 2005;Fatima & Sultana, 2003a, 2003bSultana, 2008Sultana, , 2009) recorded with mixing delay of 100 ms showed that the C-3 methine proton is coupled with four protons i.e. with the C-1 and C-2 methylenic protons ( ¼ 1.23/1.25 and 1.61/1.81), respectively.…”

Annona squamosa

“…The seeds of Annona squamosa yielded a novel lipoxygenase inhibitor fatty acid ester, (+)-annonlipoxy (Sultana 2008). Annonlipoxy exhibited inhibitory activity against lipoxygenase with IC 50 of 69.05 mm.…”

Annona Squamosa L. (Annonaceae): Chemical Bioprospection and Biological Activity in Two Phenological Stages

“…From A. squamosa leaves, two main chemical classes were described: steroids and terpenoids (Savithramma et al, 2011). Particularly, acetogenins and benzylisoquinoline alkaloids isolated from this family have received special attention due to their variety and distribution in Annonaceae representatives in distinct stages of development, including A. squamosa (Yogesh, 1994 (Sultana, 2008), anti-HIV activity of diterpenes from A. squamosa (Wu et al, 1996), and anti-herpetic activity of ethanolic (Padmaja et al, 1995) The relation between biological potential of plants and the plant-environment interface is another point of interest in the A. squamosa studies. Seasonality, circadian cycle, ultraviolet radiation, and temperature, can be considered the main environmental factors involved in reducing and increasing the production rate of secondary metabolites (Taiz and Zeiger, 2008) since A. squamosa seems to show a greater control of transpiration through stomata closure in water deficit situation (Endres, 2007).…”