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International Journal of Chemical Studies 2016; 4(5): 80-87
P-ISSN2349–8528
E-ISSN 2321–4902
IJCS 2016; 4(5): 80-87
© 2016 JEZS
Received: 11-07-2016
Accepted: 12-08-2016
Gloria Ihuoma Ndukwe
Department of Chemistry,
Rivers State University of
Science and Technology, Nkpolu-
Oroworukwo P.M.B. 5080 Port
Harcourt, Rivers State, Nigeria
Chukwunonye Moses Ojinnaka
Department of Pure & Industrial
Chemistry, University of Port
Harcourt, East/West Road
P.M.B. 5323 Choba, Rivers
State, Nigeria
Adebola Omowumi Oyedeji
Department of Chemical and
Physical Sciences, Walter Sisulu
University, Private Bag X1,
Mthatha 5117 Eastern Cape,
South Africa
Correspondence
Chukwunonye Moses Ojinnaka
Department of Pure & Industrial
Chemistry, University of Port
Harcourt, East/West Road
P.M.B. 5323 Choba, Rivers
State, Nigeria
Novel bioactive triterpenoid saponin from the
fruits of Napoleonaea imperialis P. Beauv
(Lecythidaceae)
Gloria Ihuoma Ndukwe, Chukwunonye Moses Ojinnaka and Adebola
Omowumi Oyedeji
Abstract
Napoleonaea imperialis P. Beauv (Lecythidaceae) is a medicinal plant commonly found in South-Eastern
Nigeria. The ripe fruits were extracted and partitioned into hexane, chloroform, n-butanol and aqueous
fractions. These fractions were earlier tested and shown to possess anti-bacterial activities. The
chloroform extract was chromatographed and purified to give compounds 1-5 whose structures were
elucidated using ir,
1
H and
13
C-nmr as methyl-1,3,5-triene-tricyclopentadecanoate (1); 5-methyl-5-toluyl-
3,4,6-trihydropyran-2-one (2, napoleonapyran-2-one); 4-ethoxy-bicyclodecylbenzoate (3); 3β-O-[β-D-
glucopyranosyl(1→2)][β-D-glucopyranosyl(1→4)][β-D-glucopyranosyl]-16α,22α,24,28-tetrahydroxy-
21-β-O-angeloxyolean-12-ene-29-al (4, napoleon aside -B) and 3-O-[β-D-glucopyranosyl]-1,4–dimethyl-
2,4,5,10-tetrahydroxy–bicyclodecane (5).
Keywords: Napoleonaea imperialis, Lecythidaceae, fruits, structure, napoleonapyran-2-one, napoleon
aside-B
1. Introduction
There are ten species in the genus, Napoleonaea
[1]
, but Napoleonaea imperialis and
Napoleonaea vogelli are the most common species found in Southern Nigeria. The bark of
Napoleonaea vogelli and Napoleonaea imperialis are used locally as cough medicine. The
seed pulp of some species of Napoleonaea is eaten
[2]
. Different parts of Napoleonaea
imperialis P. Beauv are used in traditional medicine for treatment of infectious diseases
[3, 4]
.
The chemistry and pharmacology of different species of Napoleonaea have been reported
[5-11]
.
In our previous studies, the fruits of Napoleonaea imperialis showed great potentials as a
molluscicide
[12]
and anti-bacterial agent
[13]
. In continuation of our studies, we report the
isolation and characterization of novel compounds from the extracts of Napoleonaea
imperialis that were earlier shown to be bioactive
[13]
.
2. Experimental
2.1 General
The n-butanol, deuterated chloroform, deuterated methanol and deuterated DMSO used for
this work were analytical grade. All other solvents used were re-distilled. The NMR spectra
were taken on Bruker 600 MHz and Bruker 400 MHz operating at 600.1 MHz and 400.22
MHz for proton and 150.89 MHz and 100.63 MHz for carbon 13 respectively. NMR of pure
compounds were processed using Bruker software. All samples were run at 25
o
C. NMR
spectra were calibrated using solvent signals (
13
C : CDCl3 77.23ppm, DMSO-d6(CD3SOCD3)
39.51ppm,
13
C : CD3OH 49.2ppm ) or a signal of the proton of the partly or non deuterated
solvent (
1
H : CHCl3 in CDCl3 δ7.24ppm, DMSO in DMSO-d6 δ2.50ppm,
1
H : CH3OH in
CD3OD -3.31ppm, 4.78ppm) with tetramethylsilane as internal reference. Chemical shifts (δ)
are expressed in ppm. Structural elucidation was based on the interpretation of
1
H,
13
C, DEPT
90°, DEPT 135°,
1
H-
1
H COSY, NOESY,
1
H-
13
C direct correlation (HSQC) and
1
H-
13
C long-
range correlation (HMBC). Ultra violet (UV) spectra were recorded on Perkin Elmer Lambda
25 UV-Visible spectrophotometer. Fourier transform infrared (FT-IR) spectra were recorded
on Perkin Elmer Spectrum FT-IR spectrophotometer. Analytical thin layer chromatography
(TLC) was carried out on silica gel Merck F254 precoated plates. Detection was made under
ultraviolet light at wavelength 254nm and by spraying reagent (anisaldehyde − sulphuric acid)