Flavonoids of Garcinia kola Seeds

Abstract

Garcinia kola Heckel (Guttiferae), known in commerce as "bitter kola", is used extensively in African traditional medicine for the treatment of various diseases. In our investigations, the most common usage was found to be for the treatment of coughs and mouth infections. The plant is also used for the treatment of liver disorders. It is served in Nigerian homes to guests as an adjunct to the true kola nut. Garcinia species have been reported to be used BS an aphrodisiac (1) and for the treatment of diarrhea and dysentery (2).Earlier work on the phytochemistry of Garcinia species resulted in the isolation of triterpenes (3), xanthones (4) , and biflavonoids (5,6) from various species.As part of a continuing project to study the constituents of plants used in Nigerian ethnomedicine, we have investigated the flavonoids of G. kola seeds.Simple flavonoids: apigenin-5,7,4'-trimethylether (500 mg), apigenin -4'methylether (150 mg), and fisetin (3',4',7-trihydroxyflavonol) (280 mg) were isolated together with the biflavonoids: amentoflavone (5',8"--biapigenin) (500 mg), kolaflavanone 1-3'-11-3-14'-114'-1-5-11-5-1-7-11-7~ctahydroxy-11-3'-methoxy-3/8"-biflavanone (350 mg) and GBI 11-3-14'-114'-1-5-11-5-1-7-11-7-heptahydroxy-3/8"-biflavanone (120 mg).Although apigenin was not isolated in this work, flavonoids based on apigenin represent 60% of the total flavonoids present in the diethylether fraction of G. kola seeds. The bifIavonoids isolated belong to both the GB-kolavanone and the amentoflavone series, both types have been isolated previously from the Guttiferae.The use of the plant in the treatment of liver disorders could be attributed to the presence of biilavonoids in G. kola since complex flavonoids such as silybin are known antihepatotoxic agents. The isolated compounds are the major seed flavonoids of this plant, minor constituents are yet to be characterized and the constituents of the other fractions have not been investigated. EXPERIMENTAL PLANT ~~mm.-Seeds of G. kola were bought from the local market a t Nsukka and authenticated by our Department of Botany. A voucher specimen (UN/PHARM 080-OA) has been deposited in the Pharmacy Herbarium, University of Nigeria Nsukka. EXTRACTION AND IsommoN.-Air dried and peeled seeds of G. kola were milled to a coarse powder after removal of the soft brown testa. Seed powder (3.5 kg) was defatted with petrcleum ether (bp W 0 ) and later extracted with acetone. The concentrated extract was digested successively with benzene (8 hrs.), diethylether (10 hrs.), and ethyl acetate (a0 hrs.).The benzene and ethyl acetate fractiops were set aside for further analysis. The diethylether fraction was chromatographed on a silica gel column; benzene, benzene-ethanol (various ratios) and ethanol were the eluants. The compounds were purified by preparative tlc (silica gel and cellulose) with n-butanol-water-acetic acid-acetone (7:1:1:2); toluene-ethyl acetate-formic acid (5:4:1) and 15% aqueous acetic acid as the solvent systems. IDENTIFICATION OF mvoNoms.-The flavonoid 5,7, dihydroxy-l'-rn...

The effect of oral administration of the mixture of honey and garcinia kola on the kidney of wistar rats

“…The seed of G. kola contains 1-3, 8-11 benzophenones, Garcinia biflavonones (GB-1, GB-2) and kolaflavonone (Cotterih et al, 1978). Apigenin based flavonoids represent 60% of the total flavonoids present in the diethyl ether fraction of G. kola seeds (Iwu and Igboko, 1982). The seed of G. kola has similarly been used to prevent and treat colic and headache (Ayensu, 1978), jaundice, high fever and liver disorders (Iwu, 1991), skin infections, sexual dysfunction and stomach pain (Braid, 1991) and as a spermatogenic agent (Adesanya et al, 2007).…”

“…Its alkaloid and bioflavonoids content are said to relax muscles (Braid, 1989). G. kola stem bark contains a complex mixture of phenolic compounds such as bioflavonoid, xanthones and benzophenone (Iwu and Igboko, 1982) as well as several organic compounds which confer on it some antimicrobial and antifungal properties (Bohn, 1968). Garcinia kola is found in rain forest and swamps and grows to about 12m in height.…”

Extraction, purification and nuclear magnetic resonance (NMR) assignment of garcinoic acid from Garcinia kola (bitter kola) fruit

“…Several heterocyclic compounds have been isolated from this source (Iwu and Igboko, 1982;Kabangu et al, 1987;Terashima et al, 1999) including -tocotrienoloic acid 5, which is also known as garcinoic acid (Delle Monache et al, 1984;Terashima et al, 1997;Terashima et al, 2002;Mazzini et al, 2009). Apart from its antioxidant (Terashima et al, 1997;Terashima et al, 2002) and DNA polymerase inhibition (Maloney and Hecht, 2005), numerous, mainly anecdotal, effects resulting from the ingestion of these nuts are appreciated by people using them (Adebisi and Song, 2008).…”

Isolation and biological activity of compounds fromGarcinia preussii

“…In Ivory Coast, the leaves are taken as a decoction to relieve tooth pain (Visser, 1975). Previous phytochemical studies indicated that mostly xanthones (Kuete et al, 2007a), benzophenones (Ahmad et al, 2010), triterpenes (Chung et al, 1998), flavonoids, and biflavonoids (Iwu & Igboko, 1982) were found in the genus Garcinia and they exhibited antioxidant, antimicrobial, antiinflammatory, and antitumor activities (Hay et al, 2004).…”