D-arabino-hex-1-enitol from the inactive fraction of Acalypha wilkesiana var. lace-acalypha (Muell &Arg.)

Abstract

Different herbal preparations of Acalypha.wilkesiana var. lace - acalypha (Muell & Arg.) are employed in traditional medicine for the treatment and management of disease conditions such as wounds, tumors, hypertension, inflammations, skin infections, gastroenteritis amongst many others. Ethyl 3, 4, 5-trihydroxybenzoate (ethyl gallate) and 1, 2, 3-benzenetriol (pyrogallol) have previously been isolated from the active fractions of this plant. However, this present study was done to isolate compound(s) from one of the inactive fractions. Hence, a short silica-gel column chromatography of the inactive fraction (5A) furnished a compound designated as 3 [ R f 0.15; [ n ] 20 D 1.0300 ]. The structure of 3 has been established to be D-arabino-hex-1-enitol-1, 5-anhydro-2-deoxy (1, 5-anhydro-2-deoxy-D-enopyranose-arabino-hex-1-enitol) by a combination of 1 H NMR, 13 C NMR, MS and IR spectral techniques. Compound 3 recorded no antibacterial activity against B. subtilis , S. aureus and Ps. aeriginosa . However, it demonstrated very weak antibacterial activities against E. coli and S. typhi. which were slightly better than the activity furnished by 5A. Furthermore, it was observed that 3 was inactive against C. albicans . Surprisingly, the crude extract and butanol fraction generally demonstrated comparably stronger antimicrobial activities than 3 implying that the purification of the crude extract did not improve the activity demonstrated by 3 .