Inhibitory Effects of Extracts and Isolates from Kigelia africana Fruits against Pathogenic Bacteria and Yeasts
Kigelia africana (Lam.) Benth. (Bignoniaceae) is a
reputed traditional remedy for various human ailments such as skin
diseases, microbial infections, melanoma, stomach troubles,
metabolic disorders, malaria and general pains. In spite of the fruit
being widely used for purposes related to its antibacterial and
antifungal properties, the chemical constituents associated with the
activity have not been fully identified. To elucidate the active
principles, we evaluated the antimicrobial activity of fruit extracts
and purified fractions against Staphylococcus aureus, Enterococcus
faecalis, Moraxella catarrhalis, Escherichia coli, Candida albicans
and Candida tropicalis. Shade-dried fruits were powdered and
extracted with hydroalcoholic (1:1) mixture by soaking at room
temperature for 72 h. The crude extract was further fractionated by
column chromatography, with successive elution using hexane,
dichloromethane, ethyl acetate, acetone and methanol. The
dichloromethane and ethyl acetate fractions were combined and
subjected to column chromatography to furnish a wax and oil from
the eluates of 20% and 40% ethyl acetate in hexane, respectively. The
GC-MS and GC×GC-MS results revealed that linoleic acid, linolenic
acid, palmitic acid, arachidic acid and stearic acid were the major
constituents in both oil and wax. The crude hydroalcoholic extract
exhibited the strongest activity with MICs of 0.125-0.5 mg/mL,
followed by the ethyl acetate (MICs = 0.125-1.0 mg/mL),
dichloromethane (MICs = 0.250-2.0 mg/mL), hexane (MICs = 0.25-
2.0 mg/mL), acetone (MICs = 0.5-2.0 mg/mL) and methanol (MICs =
1.0-2.0 mg/mL), whereas the wax (MICs = 2.0-4.0 mg/mL) and oil
(MICs = 4.0-8.0 mg/mL) showed poor activity. The study concludes
that synergistic interactions of chemical constituents could be
responsible for the antimicrobial activity of K. africana fruits, which
needs a more holistic approach to understand the mechanism of its
 V. Roodt, “Kigelia africana” In: The Shell Field Guide to the Common
Trees of the Okavango Delta and Moremi Game Reserve. Gaborone,
Shell Oil, Botswana, 1992, pp. 176-180.
 S. Saini, H. Kaur, B. Verma, S. K. R. Singh, “Kigelia africana (Lam.)
Benth. An overview.” Natural Product Radiance, vol. 8, 2009, pp. 190-
 P. J. Houghton, “The sausage tree (Kigelia africana): Ethnobotany and
recent scientific work.” South African Journal of Botany, vol. 68, 2002,
 L. S. Gill, “Ethanomedical uses of plants in Nigeria”, Uniben Press,
Benin City, Nigeria, 1992, pp. 143.
 Oliver-Bever B. (1986). “Medicinal plants in tropical West Africa.”
Cambridge University Press; Cambridge, London, New York, New
Rochelle, Melbourne, Sydney, pp. 240-245.
 J. M. Watt, M. G. Breyer-Brandwijk, “The medicinal and poisonous
plants of southern and eastern Africa.” E. and S. Livingstone Ltd.
Edinburgh and London, 1962, pp. 52.
 M. F. Khan, P. Dixit, N. Jaiswal, A. K. Tamrakar, A. K. Srivastava, R.
Maurya, “Chemical constituents of Kigelia pinnata twigs and their
GLUT4 translocation modulatory effect in skeletal muscle cells.”
Fitoterapia, vol. 83, 2012, pp. 125-129.
 P. J. Houghton, D. N. Akunyili, “Iridoids from Kigelia pinnata bark.”
Fitoterapia, vol. 64, 1993, pp. 473-474.
 Y. G. Gouda, A. M. Abdel-Baky, F. M. Darwish, K. M. Mohamed, R.
Kasai, K. Yamasaki, “Iridoids from Kigelia pinnata DC. fruits.”
Phytochemistry, vol. 63, 2003, pp. 887-892.
 C. R. Weiss, S. V. K. Moideen, S. L. Croft, P. J. Houghton, “Activity of
extracts and isolated naphthoquinones from Kigelia pinnata against
Plasmodium falciparum.” Journal of Natural Products, vol. 63, 2000,
 D. N. Akunyili, P. J. Houghton, “Monoterpenoids and naphthoquinones
from Kigelia pinnata.” Phytochemistry, vol. 32, 1993, pp. 1015-1018.
 S. M. El-Sayyad, “Flavonoids of the leaves and fruits of Kigelia
pinnata.” Fitoterapia, vol. 52, 1982, pp. 189-191.
 T. R. Govindachari, S. J. Patankar, N. Viswanathan, “Isolation and
structure of two new dihydroisocoumarins from Kigelia pinnata.”
Phytochemistry, vol. 10, 1971, pp. 1603-1606.
 K. Inoue, H. Inouye, C. C. Chen, “A naphthoquinone and a lignan from
the wood of Kigelia pinnata.” Phytochemistry, vol. 20, 1981, pp. 2271-
 O. T. Asekun, E. Olusegun, O. Adebola, “The volatile constituents of
the leaves and flowers of Kigelia africana Benth.” Flavour and
Fragrance Journal, vol. 22, 2007, pp. 21-23.
 O. M. Grace, M. E. Light, K. L. Lindsey, D. A. Mulholland, J. van
Staden, A. K. Jager, “Antibacterial activity and isolation of active
compounds from fruit of the traditional African medicinal tree Kigelia
africana.” South African Journal of Botany, vol. 68, 2002, pp. 220-222.
 R. Jeyachandran, A. Mahesh, “Antimicrobial evaluation of Kigelia
africana (Lam).” Research Journal of Microbiology, vol. 2, 2007, pp.
 M. A. A. Sikder, A. K. M. N. Hossian, A. B. Siddique, M. Ahmed, M.
A. Kaisar, M. A. Rashid, “In vitro antimicrobial screening of four
reputed Bangladeshi medicinal plants.” Pharmacognosy Journal, vol. 3,
2011, pp. 72-76.
 R. Badoni, D. K. Semwal, U. Rawat, “Fatty acid composition and
antimicrobial activity of Celtis australis L. fruits.” Journal of Scientific
Research, vol. 2, 2010, pp. 397-402.
 CLSI, “Clinical and Laboratory Standards Institute, Methods for
Dilution Antimicrobial Susceptibility Tests for Bacteria that Grow
Aerobically, Approved Standard M7-A6.” National Committee for
Clinical Laboratory Standards, 6th edition, Fort Wayne, Ind, USA, 2003.
 S. K. Kothiyal, D. K. Semwal, R. Badoni, U. Rawat, “GC-MS analysis
of fatty acids and the antimicrobial activity of Ilex dipyrena Wallich
leaves.” Asian Journal of Traditional Medicines, vol. 5, 2010, pp. 153-