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Trop J Nat Prod Res, June 2022; 6(6):938--942 ISSN 2616-0684 (Print)
ISSN 2616-0692 (Electronic)
938
© 2022 the authors. This work is licensed under the Creative Commons Attribution 4.0 International License
Tropical Journal of Natural Product Research
Available online at https://www.tjnpr.org
Original Research Article
Dodoneine, its Bicyclic Lactone and a Dihydroxylupeol Palmitate from Tapinanthus
globiferus
John V. Anyam1, John B. Nvau2*, Kachollom Thomas2, Eman Santali3, Irvine A. Gray4, John. O. Igoli 1,4
1Department of Chemistry, Joseph Sarwuan Tarka University, Makurdi, Nigeria
2Department of Chemistry, Plateau State University, Bokkos, Nigeria
3Department of Pharmaceutical Chemistry, College of Pharmacy, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia.
4Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, G4 0RE, Glasgow UK
Introduction
Mistletoes are hemiparasitic plants that grow on the branches
of shrubs and trees. They carry out their photosynthesis independently
but obtain water and minerals from the host plant.1 While Tapinanthus
globiferus, along with other members of the parasitic mistletoe family,
poses a serious threat to mature parkland trees across the African
savannah, the mistletoe plants are used extensively by African
traditional medicine practitioners for the treatment of various human
and animals ailments.2 Extracts of mistletoe have been used to manage
or treat high blood pressure, respiratory distress, diabetes, dysentery,
diarrhea and cancer.2-6 Previous studies on the phytochemical
constituents of mistletoes have identified saponins, triterpenoids,
flavonoids and their glycosides.7-9 Tapinanthus globiferus
(Loranthaceae) is used in traditional medicine to treat diabetes mellitus,
stroke, ulcers and headache.10-13 . Its extracts have also demonstrated
good anti-inflammatory, antibacterial and antioxidant activities.
Previous studies have reported the isolation of lupeol acetate from the
plant.7 However, not much has been reported on its biological activities,
ethnobotanical uses and its secondary metabolites. This report is on the
isolation and characterization of some of the plant’s secondary
metabolites.
*Corresponding author. E mail: Johnnvau5@gmail
Tel: +2348035807728
Citation: Anyam JV, Nvau JB, Thomas K, Eman S, Gray AI, Igoli JO.
Dodoneine, its Bicyclic Lactone and a Dihydroxyl-lupeol palmitate from
Tapinanthus globiferus. Trop J Nat Prod Res. 2022; 6(6):938-942
http://www.doi.org/10.26538/tjnpr/v6i6.19
Official Journal of Natural Product Research Group, Faculty of Pharmacy,
University of Benin, Benin City, Nigeria.
Materials and Methods
General Experimental procedure
Silica gel 60 (0.063-0.200 mm, Merck, Germany) was used for the
column chromatography and silica gel 60F254 on aluminum sheets (0.2
mm thickness, Merck, Germany) for TLC plates. The solvents (hexane,
ethyl acetate and methanol) were commercially obtained and were
redistilled. NMR spectra were acquired on a Bruker AVIII 400 MHz
spectrophotometer using CDCl3 and chemical shifts are reported in ppm
relative to TMS.
Plant source and collection of plant materials
The aerial parts (stem and leaves) of T. globiferus were collected from
species growing on Parkia biglobosa trees in Quanpan Local
government area of Plateau State. The Plant was identified at the
Department of Plant Technology, School of Forestry, Jos, Nigeria. A
voucher specimen with herbarium number FS-345 was deposited at the
School Herbarium.
Extraction/ isolation
The air-dried powder (500 g) of the aerial parts of the plant was
successively extracted with hexane and methanol for 48 hours each. The
solvents were recovered using a simple distillation apparatus. The
methanol extract (10 g) was weighed and dissolved in 50 mL of
methanol and partitioned between chloroform and water. This was
repeated five times and the chloroform or organic layers were pooled
together and concentrated to yield 3.0 g of extract. This was dissolved
in chloroform and adsorbed with 20 g of silica gel. The slurry was
allowed to dry into a free-flowing powder and later introduced into a
glass column packed with silica gel in hexane. The column was eluted
using hexane: ethyl acetate (100:0, 90:10, 80:20, 70:30. 60:40, 50:50,
40:60, 30:70,20:80, 10:90) and ethyl acetate: methanol (100:0, 90:10
and 80:20). Fractions were collected in flasks (100 mL) and monitored
by TLC resulting in 12 major fractions. Fraction 10 (500 mg) eluted
with 100 mL of 90:10 mixture of ethyl acetate: methanol was further
purified by column chromatography eluted with hexane: ethyl acetate
7:3, 6:4, 1:1, 1:2, 1:3 and 1:4 to yield compounds 1, 2 and 3. These
compounds were analyzed using 1H and 13C and 2D NMR. Their
structures were elucidated using the spectral data and comparison with
literature reports.
ARTI CL E I NF O
ABSTRACT
Article history:
Received 11 January 2022
Revised 11 June 2022
Accepted 23 June 2022
Published online 02 September 2022
Tapinanthus globiferus is a mistletoe plant used in traditional medicine throughout Africa. A
chloroform extract of the aerial parts of the plant epiphytic to Parkia biglobosa trees was
fractionated using silica gel column chromatography. Three compounds identified as 7, 15-
dihydroxy-lup-20-(29)-ene-2--palmitate, (R)-6-[(S)-2-hydroxy-4-(4-hydroxyphenyl) butyl]-5,
6-dihydropyran-2-one (Dodoneine) and (1R,5S,7S)-7-[2-(4-hydroxyphenyl)ethyl]-2,6-
dioxabicyclo[3.3.1]nonan-3-one (Dodoneine bicyclic lactone) were obtained. Their structures
were determined using NMR and mass spectroscopic methods, as well as comparison to literature
reports. This is an initial report on the isolation of these compounds from Tapinanthus globiferus.
Keywords: Tapinanthus globiferus, Dodoneine, Dodoneine bicyclolactone, Lupeol palmitate,
Mistletoe.
Copyright: © 2022 Anyam et al. This is an open-
access article distributed under the terms of the
Creative Commons Attribution License, which
permits unrestricted use, distribution, and reproduction
in any medium, provided the original author and
source are credited.
Trop J Nat Prod Res, June 2022; 6(6):938--942 ISSN 2616-0684 (Print)
ISSN 2616-0692 (Electronic)
939
© 2022 the authors. This work is licensed under the Creative Commons Attribution 4.0 International License
Results and Discussion
Characterization of compound 1
Compound 1 gave a purple spot on TLC, typical (on spraying with
vanillin-sulfuric acid reagent and heating) or characteristic of
terpenoids. The 1H-NMR spectrum for compound 1 displayed proton
signals for seven tertiary methyl groups at δH (ppm) 0.86, 0.87, 0.89,
0.89, 1.01, 1.01, 1.10 and 1.72; two nonequivalent methylene protons
at 4.71 (1H, d, J = 2.3 Hz, H-29a) and 4.62 (1H, d, J = 1.9 Hz, H-29b)
and three oxygen-bearing methine protons at 4.99 (1H, dd, J = 11.6, 4.7
Hz, H-3), 4.18 (1H, dd, J = 5.2, 12.2 Hz, H-7) and 3.83 (1H, dd, J =
11.1, 4.9 Hz, H-15) typical of a substituted lupane skeleton14, 15. Also, a
triplet of doublets at δH 2.36 (1H, td, J = 11.0, 5.6 Hz) further suggested
a lupane triterpenoid skeleton. Furthermore, comparison with literature
revealed the signals to be identical to those for lupeol, excepting the
oxymethine signal at δH 3.19.18 There is a strong methyl signal at 0.86
and other overlapping protons indicating a long chain hydrocarbon.9
The 13C-NMR of compound 1, indicated seven methyl groups, nine
methylenes, (one of which was an olefinic carbon), eight methines
including three oxygen bearing carbons and six quaternary carbons. The
remaining signal at δC 173.7 ppm (ester carbonyl) and other several
overlapping aliphatic carbons were for the palmitic acid side chain9. The
HSQC spectrum identified the protons and the corresponding carbon
atoms bearing them. In the HMBC spectrum, the proton at δH 4.49 at
position C-3 of the lupeol skeleton indicated a long-range correlation
with the ester carbonyl (δC = 173.7) of the palmitic acid showing that the
fatty acid is esterified to the hydroxyl group at position C-3 of the
lupeol. The 1D and 2D NMR (H-H COSY, HSQC, HMBC) data; and
comparisons with published data9 identified the compound 1 as 7,
15-dihydroxy-lup-20-(29)-ene-3--palmitate (Figure 1).
Characterization of compound 2
The 1H-NMR spectrum for compound 2 revealed signals for two
symmetrical protons at δH 6.69 (2H, dd, J = 8.5, 2.5 Hz) and 7.07 (H, d,
J = 8.5 Hz) suggesting a para-substituted benzene ring16. Two vinylic
proton signals were observed at δ 6.03 (H, dt, J = 10.4, 1.5 Hz) and 6.88
(H, dt, J = 9.7, 4.3 Hz) indicating the presence of a cis-double bond
attached to a ring carbonyl or a lactone type ring17. Signals between δH
1.70 to δ 4.65 ppm indicated the presence of aliphatic chains. Also, two
signals at δH 1.70 and 2.17 were for hydroxyl groups. The 13C-NMR
spectrum also showed a carbonyl lactone signal at δC 163.8ppm (C-2),
two olefinic carbons at δC 121.5 and 145.3, two aromatic CH signals at
δC 129.7 (C-2 and C-6), 115.5 (C-3 and C-5) and two quaternary
aromatic carbons at δC 133.5 and 154.0 for C-1 and C-4 respectively.
Six aliphatic carbons signals at δC 29.7 to 77.9 ppm were also observed
in the 13C-NMR spectrum. The compound was identified as (R)-6-[(S)-
2-hydroxy-4-(4-hydroxyphenyl) butyl]-5, 6-dihydropyran-2-
one.(Figure 1) and its NMR spectral data were in agreement with
literature reports.16
Characterization of compound 3
The compound 3 has great similarities with compound 2 in its proton
and carbon spectra. The 1H-NMR had similar identical protons at δH
6.75 (H, d, J = 8.4 Hz) and 7.02 (H, d, J = 8.3 Hz) also for a para-
substituted benzene ring17. The two vinylic proton signals at δ 6.03 and
6.88 ppm observed in compound 2 were absent in compound 3 and were
replaced by two aliphatic proton signals. This suggests a reduction of
the double bond of the lactone ring in 2 and formation of a
tetrahydropyran ring fused to the lactone ring. This was confirmed by
the eight aliphatic proton signals observed between δH 1.58 to δ 4.89
and only one hydroxyl signal at δH 2.17. The 13C-NMR spectrum
displayed signals at δC 170.2 for the carbonyl of a lactone ring17 and at
65.0, 66.1, and 73.3 for three oxygenated aliphatic carbon atoms
including the extra oxygenated carbon from the tetrahydropyran ring.
Using the information and correlations in its 1H, 13C, HMBC, HSQC
and COSY spectra and compared to literature reports, the compound
was identified as (1R,5S,7S)-7-[2-(4-hydroxyphenyl)ethyl]-2,6-
dioxabicyclo[3.3.1]nonan-3-one (3) (Figure1). Tapinanthus globiferus
can now be considered chemotaxonomically as a true member of the
mistletoe family, based on the foregoing, because compounds 1, 2, and
3 have previously been isolated from other Loranthaceae species.16,19-20
The bioactivity of these compounds has been well documented, which
lends credence to some of the plant's ethnomedicinal uses.
Compound 1: 7, 15-dihydroxy-lup-20-(29)-ene-3-
-
palmitate
Compound 2: (R)-6-[(S)-2-hydroxy-4-(4-hydroxyphenyl)
butyl]-5, 6-dihydropyran-2-one
Compound 3: (1R,5S,7S)-7-[2-(4-hydroxyphenyl)ethyl]-2,6-
dioxabicyclo[3.3.1]nonan-3-one
Figure 1: Structure of isolated compounds 1, 2 and 3
Table 1: 1H- and 13C-NMR chemical shifts for compound 1 in CDCl3
Trop J Nat Prod Res, June 2022; 6(6):938--942 ISSN 2616-0684 (Print)
ISSN 2616-0692 (Electronic)
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© 2022 the authors. This work is licensed under the Creative Commons Attribution 4.0 International License
Position
Experimental
Literature19
Chemical shift (δ ppm) (mult. J (Hz))
Proton
Carbon
Proton
Carbon
1
1.65, 0.89
38.4
-
38.6
2
1.58
23.7
-
24.0
3
4.49 (t, 1.89)
80.3
4.45
80.4
4
-
37.6
-
37.8
5
0.68
53.1
-
52.3
6
1.52, 1.37
27.9
-
28.3
7
4.18 (dd, 11.6, 4.7)
72.6
4.14
72.7
8
-
48.1
-
48.1
9
1.27
50.3
-
50.4
10
-
37.2
-
37.4
11
1.44, 1.18
20.6
-
20.8
12
1.63, 1.04
25.2
-
25.0
13
1.65
37.5
-
37.6
14
-
48.9
49.2
15
3.83 (dd, 11.1, 4.9)
68.0
3.79
68.3
16
1.95, 1.21
45.5
-
45.9
17
-
42.5
-
42.8
18
1.55
47.9
-
48.3
19
2.38
47.6
-
47.8
20
-
150.3
-
10.5
21
1.96, 1.46
30.1
30.3
22
1.90, 1.06
39.7
-
39.9
23
0.95 (s)
16.5
-
16.7
24
0.77 (s)
27.9
-
28.1
25
0.83 (s)
15.6
-
15.8
26
1.04 (s)
10.9
--
11.2
27
0.98 (s)
8.3
-
8.6
28
0.80 (s)
42.6
-
42.8
29
4.71 (d, 2.3), 4.62 (d, 1.9)
109.7
4.66, 4.57
109.9
30
1.69 (s)
19.5
19.6
Palmitic acid
ester side
chain
2.31 (t, 7.5, H-2')
1.63 (m, H-3')
1.28 (m, H-4)
1.28 (m, H5'-H-15')
0.90 (t, H-16')
173.7 (C-1’) 34.8 (C-
2’), 25.2 (C-3’), 29.4
(C-4’), 22.7-29.9 (C-
5’- C-15’)
14.1 (C-16’)
173.91 (C-1’), 35.’5 (C-2’), 25.38 (C-3’
), 29.82 (C-4’ ), 29.69 (C-5’ ), 29.59
(C-6’ ), 29.49 (C-7’ ), 29.39 (C-8’ ),
29.92 (C-9’ ), 29.9’ (C-10’ ), 29.89 (C-
11’ ), 29.87 (C-12’ ), (C-13’), 32.15 (C-
14’), 22.92 (C-15’ )
14.36 (C-16’)
Table 2: 1H- and 13C-NMR chemical shifts for Compound 2
Trop J Nat Prod Res, June 2022; 6(6):938--942 ISSN 2616-0684 (Print)
ISSN 2616-0692 (Electronic)
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© 2022 the authors. This work is licensed under the Creative Commons Attribution 4.0 International License
Position
Experimental
Literature16
Chemical shift (δ ppm) (mult. J (Hz))
1H
13C
HMBC
1H
13C
1
-
-
-
-
2
-
163.8
-
-
164.7
3
6.03 (dt, 10.4, 1.5)
121.5
C-5
6.02 (dt, 10.4, 1.5)
121.6
4
6.88 (dt, 9.7, 4.3)
145.3
6.88 (dt, 9.7, 4.3)
145.9
5
2.38 (2H, m)
29.7
2.38 (2H, m)
29.9
6
4.65 (m)
77.9
4.64 (dddd, 7.7, 7.7, 7.7, 5.4)
77.5
7
2.01 (m), 1.80 (m)
42.2
2.00 (dt, J ) 14.7, 8.2 Hz, 1H ; 1.78 (m, 1H, H-1′),
42.4
2’
3.89 (m)
68.8
3.80 (br multiplet, 1H)
69.0
3’
1.70 (2H, m)
39.6
1.72 (m, 2H),
39.7
4’
2.65 (2H, m)
31.0
C-1',C-6''
2.60 (m, 2H)
31.2
1”
-
133.5
C-4, C-6
-
133.9
2”
7.07 (d, 8.5)
129.7
C-4', C-4'', C-6''
6.98 (d, J ) 8.5 Hz, 2H,
129.8
3”
6.69 (dt, 8.5, 2.5)
115.5
C-5
6.69 (dt, J) 8.5, 2.5 Hz, 2H)
115.7
4”
-
154.3
-
-
154.6
5”
6.69 (dt, 8.5, 2.5)
115.5
6.69 (dt, 8.5)
115.7
6”
7.07 (d, 8.5)
129.7
C-4', C-2'', C-4''
6.98 (d, 8.5)
129.8
4''-OH
2.17 (br s)
2.15 (br s,)
-
2'-OH
1.70 (br s)
1.5 (br s)
-
Table 3: 1H- and 13C-NMR Chemical Shifts for Compound 3
Position
Experimental
Literature16
Literature20
Chemical shift (δ ppm) (mult. J (Hz))
1H
13C
HMBC
1H
13C
1H
13C
1
4.89
73.3
C-3
4.87 (m)
73.3
4.87 (m, 1H, >CH-O)
74.7
2
-
-
-
3
-
170.2
170.3
172.4
4
2.72, 2.84
36.6
36.5
2.6 (cm, 4H)
36.8
5
4.38
66.1
C-3, C-6, C-7
4.34 (br s)
66
4.34 (br s, 1H, >CH-O)
66.8
7
3.73
65
3.65 (m)
65
3.65 (m, 1H, >CH-O)
65.5
8
1.58, 1.99
37.1
1.98 (m)
37.1
1.98 (m, 3H)
37.6
9
1.92, 2.02
30
1.92 (m)
29.9
1.92 (m, 1H)
30.1
1'
1.73, 1.83
38
1.7 (m)
38
1.7 (cm, 3H)
38.6
2'
2.57, 2.71
30.6
2.6 (m)
30.7
2.6 (cm, 4H)
31.1
1”
-
133.8
-
133.6
133.3
2”
7.03
129.6
7.02 (d, 8.3)
129.5
6.99 (dt, J) 8.5, 2.4 Hz, 2H, meta-
phenol)
130
3”
6.75
115.5
C-1'', C-5''
6.75 (d, 8.4)
115.5
6.71 (dt, J) 8.5, 2.5 Hz,2H, ortho-
phenol)
115.9
4”
-
154
, C-4'',
-
154.1
155.9
5”
6.75
115.5
6.75 (d)
115.5
6.71 (dt, J) 8.5, 2.5 Hz,2H, ortho-
phenol)
115.9
6”
7.03
129.6
7.02 (d)
129.5
6.99 (dt, J) 8.5, 2.4 Hz, 2H, meta-
phenol)
130
4''-OH
2.17 (s)
-
-
-
Conclusion
Trop J Nat Prod Res, June 2022; 6(6):938--942 ISSN 2616-0684 (Print)
ISSN 2616-0692 (Electronic)
942
© 2022 the authors. This work is licensed under the Creative Commons Attribution 4.0 International License
7, 15-dihydroxy-lup-20-(29)-ene-2--palmitate, (R)-6-[(S)-2-
hydroxy-4-(4-hydroxyphenyl) butyl]-5, 6-dihydropyran-2-one and
(1R,5S,7S)-7-[2-(4-hydroxyphenyl)ethyl]-2,6-
dioxabicyclo[3.3.1]nonan-3-one were isolated and characterized from
Tapinanthus globiferus. This is an initial report of these compounds
from this plant material.
Conflict of Interest
The authors declare no conflict of interest.
Authors’ Declaration
The authors hereby declare that the work presented in this article is
original and that any liability for claims relating to the content of this
article will be borne by them.
Acknowledgements
The Authors are grateful to the staff of Natural Products Laboratory of
Plateau State University, Bokkos, Nigeria and Strathclyde Institute of
Pharmacy and Biomedical Sciences, University of Strathclyde,
Glasgow UK for their technical support and spectroscopic analysis.
EYS thanks Taif University Research Support project number
(TURSP-2020/330).
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