Lipids Classes, Fatty Acids, Fat Soluble Vitamins, and Molecular Species of the Triacylglycerol of Baphia nitida and Gliricidia sepium Seed Oils

Abstract

Oil was extracted from the seeds of B. nitida and G. sepium and evaluated for its fatty acid composition, lipid profile, fatty acid distribution, fat soluble vitamins, unsaponifiable matter content, and molecular speciation of triacylglycerol. C18:2 was the predominating fatty acid found in the oils of B. nitida (50.00 ± 0.20 g/100 g fatty acids) and G. sepium (32.20 ± 0.30 g/100 g fatty acids) while the neutral lipids were the dominating lipid class in the oils of B. nitida (95.50 ± 0.70 g/100 g oil) and G. sepium (98.00 ± 0.30 g/100 g oil). Molecular species with equivalent carbon chain number C₄₈ were mainly present in the oils of B. nitida (39.6 ± 0.2%) and G. sepium (33.4 ± 0.0%). Digalactosyldiacylglycerol was the major glycolipid found in B. nitida (54.08 ± 0.10%) while both digalactosyldiacylglycerol (34.47 ± 0.50%) and digalactosylmonoacylglycerol (43.71 ± 0.20%) were found to be dominantly present in the oil of G. sepium. Phosphatidylethanol amine was the most abundant phospholipid found in B. nitida (97.70 ± 0.10%) while lyso phosphatidylethanol amine was the most abundant in G. sepium (74.22 ± 0.30%). Vitamins A and E were the two fat soluble vitamins detected in both oils while the gas chromatography-mass spectrometry result of the unsaponifiable matters revealed the presence of phytol, dodecatrienol, campesterol, stigmasterol, beta sitosterol, beta amyrin, beta tocopherol, stigmast-7-en-3-ol, stigmast-4-en-3-one, and hydrocarbons.

Keywords:

• Baphia nitida
• Fatty acids
• Gliricidia sepium
• Lipid classes
• Triacylglycerol

INTRODUCTION

Oils from seeds are both edible and non-edible depending on the composition, which can be improved in terms of their properties. They are often available as raw materials for chemical and industrial applications; due to the high demand and economic importance of these seed oils to the chemical industries, attention has been focused on the cultivation and characterization of the underutilized ones for possible development and uses.[1] Baphia nitida and Gliricidia sepium fall into this group of underutilized seed oils. Baphia nitida is a tree that is about 10 m high with the trunk to about 45 cm in diameter with slender branches forming an umbrella-shaped crown; it is usually an under storey tree of wetter parts of the coastal area. The tree is often planted in villages as an ornamental or shade tree and as a source of medicines and dye. Gliricidia sepium is a small bushy-topped tree, shorthole and about 6–8 m high. The tree is pinkish when in flower. It is quick growing and easily propagated by seed or cuttings and it is commonly grown as an ornamental.[2]

Crude seed oils contain varying substances that may undesirably influence flavour, colour, or keeping quality.[3] Materials, such as free fatty acids, waxes, colour bodies, mucilaginous materials, phospholipids, carotenoids, and gossypol (a yellow pigment found only in cottonseed oil), contribute other undesirable properties in oils used for edible and, to some extent, industrial purposes.[4] In a previous study, the authors reported the proximate composition of the seeds, metal composition of the seeds and oils, and the physicochemical properties of the oils of Baphia nitida and Gliricidia sepium with an oil yield of 27.14 ± 0.20% from the seed of B. nitida and 24.70 ± 0.50% from the seed of G. sepium.[5] But the fatty acid composition and molecular species of the lipid classes are yet to be reported. In continuation of the study on the search for novel seed oils, the authors’ objective was to investigate the fatty acid composition, lipid classes, distribution of fatty acids, fat soluble vitamins, and molecular speciation of the triacylglycerols of the oils of Baphia nitida and Gliricidia sepium.

MATERIALS AND METHODS

Materials

Seeds of Baphia nitida and Gliricidia sepium were collected from the University of Ibadan, Oyo State, Nigeria. They were identified at the Herbarium Unit, Botany Department of the University of Ibadan. The seeds were manually separated, cracked, and ground separately in a laboratory mill and stored in a cellophane bag at 4°C prior to analysis. Solvents and chemicals used in this study were of analytical grade and were purchased from S.D. Fine Chemicals, Mumbai, India. Silica coated TLC plates (20 × 20 cm) were procured from Sigma-Aldrich, Chemical Co., Steinheim, Germany.

Extraction of Oil

Oil was extracted from the seeds of B. nitida and G. sepium using a soxhlet extractor with n-hexane for 10 h.[6,7] Fatty acid methyl esters of both oils were prepared by refluxing the oils at 70°C for 3 h in 2% sulphuric acid in methanol.[8] The esters were extracted into ethyl acetate, washed free of acid, and passed over anhydrous sodium sulphate. The ethyl acetate extracts were recovered using a rotary evaporator. The fatty acid composition was analyzed using an Agilent 6890 N series gas chromatography (Santa Clara, CA, USA) equipped with a FID detector on a split injector. A fused silica capillary column (DB-225, 30 × 0.32 m i.d., J & W Scientifics, Agilent Technology, Santa Clara, CA, USA) was used with the injector and detector temperature maintained at 230 and 250°C, respectively. The oven temperature was programmed at 160°C for 2 min and finally increased to 230°C at 4°C/min. The carrier gas was nitrogen at a flow rate of 1.5 mL/min. The area percentages were recorded with a standard Chemstation Data System (Oshawa, Canada).

Determination of the Fat Soluble Vitamins

The separation and quantification of the fat soluble vitamins (A and E) in the oils of B. nitida and G. sepium was achieved using HPLC (1100 series, Agilent, Santa Clara, CA, USA) equipped with a thermostated column compartment (G1316A, Hewlett-Packard, Waldbronn, Germany), variable wavelength detector (G1314A, Hewlett-Packard, Waldbronn, Germany), quaternary pump (G1311A, Hewlett-Packard, Waldbronn, Germany), and a degasser (G1379A, Hewlett-Packard, Waldbronn, Germany). The automated system (HPLC) is driven by Chemstation software. The mobile phase was water and acetonitrile (5:95 v/v). The flow rate was 1.5 mL/min. The vitamins were monitored using a UV detector at 210 nm and 35°C.[9,10]

Separation of Different Classes of Lipids

The oils of B. nitida and G. sepium were separated on a 1 g scale into neutral lipids, glycolipids, and phospholipids by silica gel column chromatography using a glass column 20 cm × 2 cm OD packed with 30 g of activated silica gel (60–120 mesh). Neutral lipids, glycolipids, and phospholipids were eluted successively using chloroform, acetone, and methanol, respectively. The lipid fractions were screened by TLC for the identification of components using hexane–ethyl acetate (90:10, v/v) as the developing solvent for neutral lipids, chloroform–methanol–water (65:25:4, v/v/v) for glycolipids and phospholipids.[11] The eluted spots were identified using different spray reagents, such as iodine vapors for neutral lipids, ammonium molybdate–perchloric acid for phospholipids and α-naphthol for glycolipids.[12] The individual fractions were pooled, distilled under vacuum to remove solvent, and weighed for quantification. The individual lipid fractions were converted into fatty acid methyl esters by refluxing with 2% sulphuric acid in methanol for 3 h. The esters were extracted into ethyl acetate, washed with distilled water, and dried over anhydrous sodium sulphate; then the fatty acid profile was analyzed using gas chromatography (GC) as described above.

Molecular Speciation of the Triacylglycerols

A reverse phased HPLC analysis was performed on HP-1100 series HPLC equipped with an evaporative light scattering detector (ELSD) 2000 (Alltech ELSD 2000, Alltech Associates Inc., Deerfield, IL, USA). About 25 μL of triacylglycerols (1 mg/ml) was injected into the SGERP column (250 SS 4.6-W5C18-RS, Darmstadt, Germany). The molecular species of the triacylglycerols were eluted within 10 min using an isocratic mobile phase of 95:5 (v/v) of acetone/isopropanol at a flow rate of 1 mL/min. The molecular species were identified by their equivalent carbon numbers (ECN), by injecting reference triacylglycerols mixture and also by comparing with the literature data. The operating conditions for ELSD are drift tube temperature 30°C, flow of nitrogen 1.5 L/min with impactor ‘on’ mode.

Quantification of Phospholipids

The phospholipids isolated from the oils using column chromatography were quantified with normal phase HPLC equipped with a quaternary pump and an evaporative light scattering detector (ELSD 2000, Alltech, Deerfield, IL, USA). The operating temperature of the ELSD was 50°C and nitrogen was used as the nebulizing gas at a flow rate of 1.5 L/min. HPLC separation was made on a LiChrosorb Si 60 (5 μm, 20 × 3.0 mm i.d., Merck, Darmstadt, Germany) at a solvent flow rate of 1 mL/min. A binary gradient system composed of eluant A (chloroform/methanol/ammonium hydroxide [80:19.5:0.5, v/v/v]) and eluant B (chloroform/methanol/ammonium hydroxide/water [60:34:0.5:5.5, v/v/v/v]) was used following the solvent elution profile: eluant A for 10 min; followed by a linear increase in eluant B to 100% and held for 15 min. Identification of the phospholipids was carried out by comparing them with the retention time of respective commercial standards. Calibration curves for each phospholipid were drawn by injecting different concentrations and these were used to quantify the individual phospholipids as described by Avalli and Contarini.[13]

Determination of the Glycolipids

The glycolipids were quantified on a reversed phase HP-1100 series HPLC equipped with an evaporative light scattering detector (ELSD, 2000, Alltech Associates Inc., Deerfield, IL, USA). About 25 μL of the glycolipids fraction (1.0 mg/ml) was injected in the SGERP column (250 SS 4.6-W 5C18-RS, Darmstadt, Germany). The components of the glycolipids were eluted within 15 min using a mobile phase composed of chloroform and methanol (95:5 v/v) at a flow rate of 1.0 ml/min. The ELSD (Alltech) was maintained at an evaporating temperature of 60°C and gas (nitrogen) flow rate of 2.7 L/min.

Identification of Unsaponifiables of the Seed Oils

Oil (2 g) was dissolved in 25 ml of 2 M ethanolic potassium hydroxide and refluxed for 1 h. The reaction mixture was later diluted to 150 ml with distilled water and transferred into a separating funnel. The unsaponifiable matter was then extracted three times with 50 ml diethylether. The ether extract was first washed with 100 ml aqueous solution of 0.5 M potassium hydroxide in order to remove any residual fatty acids. This was further washed with distilled water until it was free of potassium hydroxide, dried over anhydrous sodium sulphate, and concentrated using a rotary evaporator.[14] The unsaponifiables were identified by gas chromatography-mass spectrometry (GC-MS) analysis using Agilent (Palo Alto, CA, USA) 6890N gas chromatography equipped with an HP-1 MS capillary column connected to an Agilent 5973 mass spectrometer operating in the EI mode (70 ev; m/z 50–550; source temperature 230°C and quadruple temperature 150°C). Structural assignments were made based on interpretation of mass spectrometric fragmentation and confirmation by comparison of retention time as well as fragmentation pattern of authentic compounds and the spectral data obtained from the Wiley and NIST libraries.

RESULTS AND DISCUSSION

Fatty Acid Composition

The result of the fatty acid composition of B. nitida and G. sepium is presented in Table 1. C18:2 is the predominant fatty acid in the oils of B. nitida (50.00 ± 0.20 g/100 g fatty acids ) and G. sepium (32.20 ± 0.30 g/100 g fatty acids). This was also reported as the major fatty acid in the seed oil of Hura crepitans from Nigeria[15] unlike in the case of apple and pear seed oils.[16] C18:1 was found to be 15.90 ± 0.50 g/100 g fatty acids in B. nitida and 23.80 ± 0.50 g/100 g fatty acids in G. sepium. C18:0 was found to be higher in G. sepium (19.20 ± 0.10 g/100 g fatty acids) than B. nitida (1.80 ± 0.10 g/100 g fatty acids). C16:1 was not detected in B. nitida but it was found to be 0.20 ± 0.20 g/100 g fatty acids in G. sepium. The presence of C16:0 was also found to be higher in G. sepium (16.00 ± 0.30 g/100 g fatty acids) than B. nitida (1.60 ± 0.50 g/100 g fatty acids). C22:0 was found to be 17.00 ± 0.10 g/100 g fatty acids in B. nitida and 1.80 ± 0.20 g/100 g fatty acids in G. sepium. C22:1 was found to be 1.30 ± 0.50 g/100 g fatty acids in B. nitidabut was not detected in G. sepium. The result showed C24:0 fatty acid to be higher in B. nitida (8.1 ± 0.30 g/100 g fatty acids) than in G. sepium (1.9 ± 0.20 g/100 g fatty acids). The high unsaturation and presence of C18:2 suggest the application of these oils in oleochemical industries. The unsaturated points are areas where different functional groups could be introduced into oil to modify it in order to improve its properties; this predominant unsaturated C18:2 fatty acid could allow for this modification resulting in the conversion of the oil to other compounds, which have great industrial applications. These plants and their seeds are readily available but discarded as waste in Nigeria. They are underutilized placing them as more advantageous over the well known others that are expensive and competitive in the market.

Table 1  Fatty acid composition (g/100 g fatty acids) of B. nitida and G. sepium seed oils

Fatty acids	B. nitida	G. sepium
16:0	1.60 ± 0.50	16.00 ± 0.30
16:1	ND	0.20 ± 0.20
18:0	1.80 ± 0.10	19.20 ± 0.10
18:1	15.90 ± 0.50	23.80 ± 0.50
18:2	50.00 ± 0.20	32.20 ± 0.30
18:3	0.70 ± 0.10	1.20 ± 0.30
20:0	0.80 ± 0.10	3.50 ± 0.60
20:1	2.80 ± 0.30	0.20 ± 0.20
22:0	17.00 ± 0.10	1.80 ± 0.20
22:1	1.30 ± 0.50	ND
24:0	8.1 ± 0.30	1.9 ± 0.20
Unsaturated	70.70	57.60
Saturated	29.30	42.40
Values are mean ± standard deviation of triplicate determinations.
ND: Not detected.

Table 2  Lipid classes (g/100 g oil) of the oils from B. nitida and G. sepiu m

Lipid class	B. nitida	G. sepium
Neutral lipids	95.50 ± 0.70	98.00 ± 0.30
Glycolipids	4.10 ± 0.10	1.90 ± 0.60
Phospholipids	0.50 ± 0.30	0.10 ± 0.80
Values are mean ± standard deviation of triplicate determinations.

Lipid Classes and Distribution of Fatty Acids

The percentage concentration of the lipid classes of the oils of B. nitida and G. sepium is shown in Table 2 while the percentage distribution of the fatty acid composition is presented in Table 3. The neutral lipids were found in B. nitida to be 95.50 ± 0.70 g/100 g oil and in G. sepium as 98.00 ± 0.30 g/100 g oil. Glycolipids were higher in B. nitida (4.10 ± 0.10 g/100 g oil) than G. sepium (1.90 ± 0.60 g/100 g oil). The phospholipids had the least concentration in the oils. It was found to be 0.50 ± 0.30 g/100 g oil in B. nitida and 0.10 ± 0.80 g/100 g oil in G. sepium. The fatty acids were distributed across the lipid classes in different amounts. C18:2 was the most abundant fatty acid found in the neutral lipids of B. nitida (49.0 ± 0.4 g/100 g fatty acids) and G. sepium (32.1 ± 0.1 g/100 g fatty acids), the amount of which decreased in the glycolipids and phospholipids. The concentration of C16:0 was higher in the neutral lipids of G. sepium (17.0 ± 0.1 g/100 g fatty acids) than that of B. nitida (1.6 ± 0.2 g/100 g fatty acids). This amount increased in the glycolipids and phospholipids of both G. sepium and B. nitida. C16:1 was not detected in B. nitida but was only found in the neutral lipids of G. sepium (0.3 ± 0.0 g/100 g fatty acids). C18:0 was found to be 1.4 ± 0.2 g/100 g fatty acids in the neutral lipids of B. nitida and 17.6 ± 0.2 g/100 g fatty acids in the neutral lipids of G. sepium. The concentration of C18:0 increased in the glycolipids (4.0 ± 0.1 g/100 g fatty acids) as well as phospholipids (8.2 ± 0.1 g/100 g fatty acids) of B. nitida, but an increase was only noticed in the glycolipids of G. sepium (17.9 ± 0.2 g/100 g fatty acids). C20:0 was found to be high in the phospholipids of both B. nitida (2.7 ± 0.1 g/100 g fatty acids) and G. sepium (3.4 ± 0.1 g/100 g fatty acids). C22:1 was not detected in G. sepium but was only found in the neutral lipids (1.0 ± 0.1 g/100 g fatty acids) and glycolipids (0.7 ± 0.1 g/100 g fatty acids) of B. nitida.

Table 3  Fatty acid compositions (g/100 g fatty acids) in the lipid classes of B. nitida and G. sepium

B. nitida				G. sepium
Fatty acids	NL	GL	PL	NL	GL	PL
16:0	1.6 ± 0.2	8.8 ± 0.2	22.7 ± 0.2	17.0 ± 0.1	30.9 ± 0.1	32.5 ± 0.2
16:1	ND	ND	ND	0.3 ± 0.0	ND	ND
18:0	1.4 ± 0.2	4.0 ± 0.1	8.2 ± 0.1	17.6 ± 0.2	17.9 ± 0.2	16.2 ± 0.1
18:1	13.7 ± 0.1	13.2 ± 0.3	12.6 ± 02	25.8 ± 0.1	22.8 ± 0.1	25.1 ± 0.2
18:2	49.0 ± 0.4	35.6 ± 0.1	17.6 ± 0.1	32.1 ± 0.1	22.8 ± 0.1	17.5 ± 0.1
18:3	0.7 ± 0.2	1.0 ± 0.2	1.0 ± 0.1	1.1 ± 0.1	2.1 ± 0.2	ND
20:0	0.6 ± 0.1	1.1 ± 0.1	2.7 ± 0.1	3.1 ± 0.3	2.4 ± 0.1	3.4 ± 0.1
20:1	2.2 ± 0.1	2.0 ± 0.1	1.1 ± 0.2	0.7 ± 0.1	ND	1.7 ± 0.2
22:0	18.2 ± 0.1	18.0 ± 0.1	19.6 ± 0.2	1.7 ± 0.2	ND	3.6 ± 0.1
22:1	1.0 ± 0.1	0.7 ± 0.1	ND	ND	ND	ND
24:0	11.6 ± 0.1	15.6 ± 0.2	14.5 ± 0.1	1.3 ± 0.2	1.1 ± 0.1	ND
Unsaturated	66.6	52.5	32.3	59.5	47.7	44.3
Saturated	33.4	47.5	67.7	40.5	52.3	55.7
Values are mean ± standard deviation of triplicate determinations.
ND: Not detected; NL: neutral lipids; GL: glycolipids; PL: phospholipids.

Triacylglycerol Molecular Species Composition

Molecular species with equivalent carbon chain number C₄₈ were dominantly present in B. nitida (39.6 ± 0.2%) and G. sepium (33.4 ± 0.0%) as shown in Table 4. Molecular species C₃₆ were not detected in G. sepium but was found in B. nitida (0.1 ± 0.0%). C₄₆ species were found to be higher in G. sepium (33.0 ± 0.2%) than in B. nitida (4.0 ± 0.0%). Molecular species with equivalent carbon chain number C₅₂ were found to be higher in B. nitida (39.0 ± 0.1%) than G. sepium (4.3 ± 0.1%). C₅₆ species were also found to be higher in B. nitida (11.6 ± 0.1%) than in G. sepium (2.0 ± 0.1%).

Table 4  Triacylglycerol molecular species composition (wt%) of B. nitida and G. sepium

ECN	Expected molecular species	B. nitida	G. sepium
C36	LnLnLn	0.1 ± 0.0	ND
C42	LLL/LLNO/PLLn/SLnLn	1.1 ± 0.1	1.5 ± 0.1
C44	LnOO/OLL/SLLN/PLL/PLnP	4.0 ± 0.0	14.0 ± 0.2
C46	POL/OOL/PLP	4.0 ± 0.0	33.0 ± 0.2
C48	SLnS/OOO/POP	39.6 ± 0.2	33.4 ± 0.0
C50	BLL/BOLn	0.2 ± 0.1	10.6 ± 0.1
C52	BOL/BPL/SLB	39.0 ± 0.1	4.3 ± 0.1
C54	BOO/BPO/SLB	0.4 ± 0.0	1.2 ± 0.2
C56	SOB	11.6 ± 0.1	2.0 ± 0.1
Values are mean ± standard deviation of triplicate determinations.
ND: Not detected; Ln: linolenic acid; L: linoleic; O: oleic acid; P: palmitic acid; S: steric acid; B: behenic acid.

Glycolipids and Phospholipids

The result of the glycolipids present in the oils of B. nitida and G. sepium is presented in Table 5 while that of the phospholipids composition is shown in Table 6. Digalactosyldiacylglycerol was the major glycolipid found in B. nitida (54.08 ± 0.10%) while both digalactosyldiacylglycerol (34.47 ± 0.50%) and digalactosylmonoacylglycerol (43.71 ± 0.20%) were found to be dominantly present in the oil of G. sepium. Monogalactosylmonoacylglycerol was only detected in G. sepium (3.50 ± 0.10%) but not in B. nitida. Monogalactosyldiacylglycerol was found to be higher in B. nitida (20.98 ± 0.10%) than in G. sepium (18.30 ± 0.40%). Phosphatidylethanol amine was the dominant phospholipid found in B. nitida (97.70 ± 0.10%) while lyso phosphatidylethanol amine was dominantly present in G. sepium (74.22 ± 0.30%). Phosphatidyl inositol and phosphatidyl choline were found in trace amounts.

Table 5  Glycolipids composition (%) of the oils of B. nitida and G. sepium

Seed oils	MGDG	DGDG	DGMG	MGMG
B. nitida	20.98 ± 0.10	54.08 ± 0.10	24.94 ± 0.50	ND
G. sepium	18.30 ± 0.40	34.47 ± 0.50	43.71 ± 0.20	3.50 ± 0.10
Values are mean ± standard deviation of triplicate determinations.
ND: Not detected; MGDG: monogalactosyldiacylglycerol; DGDG: digalactosyldiacylglycerol; DGMG: digalactosylmonoacylglycerol; MGMG: monogalactosylmonoacylglycerol.

Table 6  Phospholipids composition (%) of the oils of B. nitida and G. sepium

Seed oils	PE	LPE	PI	PC
B. nitida	97.70 ± 0.10	2.30 ± 0.10	Trace	Trace
G. sepium	25.78 ± 0.20	74.22 ± 0.30	Trace	Trace
Values are mean ± standard deviation of triplicate determinations.
PE: Phosphatidylethanol amine; LPE: lyso phosphatidylethanol amine; PI: phosphatidyl inositol; PC: phosphatidyl choline.

Unsaponifiable Composition

The unsaponifiable matter of the oils were isolated and identified using GC-MS. The result is presented in Table 7. Hydrocarbons found in the oils includes; hexadecane, octadecane, eicosane, docosane, cyclotetracosane, dodecadiene, octadecene, hexacosene, tricosane, and heptacosane. Other compounds are phytol, dodecatrienol, campesterol, stigmasterol, beta sitosterol, beta amyrin, beta tocopherol, stigmast-7-en-3-ol, and stigmast-4-en-3-one.

Table 7  Unsaponifiable composition of B. nitida and G. sepium

B. nitida	G. sepium
Hexadecane	Octadecane
Octadecane	Dodecadiene
Eicosane	Octadecene
Phytol	Phytol
Dodecatrienol	Docosene
Docosane	Cyclotetracosane
Tetracosane	Hexacosene
Cyclotetracosane	Tricosane
Campesterol	Beta tocopherol
Stigmasterol	Heptacosane
Beta sitosterol	Campesterol
Beta amyrin	Stigmasterol
	Beta sitosterol
	Stigmast-7-en-3-ol
	Stigmast-4-en-3-one

Fat Soluble Vitamins

The fat soluble vitamins were determined using HPLC equipped with a thermostated column compartment and variable wavelength detector. The result obtained is presented in Table 8. Vitamins A and E were found in the oils of B. nitida and G. sepium. Vitamin A was found to be 0.0283 ppm in B. nitida and 0.1980 ppm in G. sepium while vitamin E was 0.6564 ppm in B. nitida and 0.7290 ppm in G. sepium.

Table 8  Fat soluble vitamins (ppm) of B. nitida and G. sepium

Vitamins	B. nitida	G. sepium
A	0.0283	0.1980
E	0.6564	0.7290
Values are mean ± standard deviation of triplicate determinations.

CONCLUSION

The oils of Baphia nitida and Gliricidia sepium were analyzed for their fatty acid composition, lipid classes, fatty acid distribution in the lipid fractions, fat soluble vitamins, and molecular speciation of the triacylglycerols. The result showed that C18:2 fatty acid was dominant in the oils of B. nitida and G. sepium. Neutral lipids were predominantly present in these oils while molecular species with equivalent carbon chain number C48 were majorly present in the oils. Digalactosyldiacylglycerol was the dominant glycolipid found in B. nitida while digalactosylmonoacylglycerol was dominant in G. sepium. Vitamins A and E were found in the oils in low concentrations while phosphatidylethanol amine and lyso phosphatidylethanol amine were the main phospholipids found in the oils. The oil yield of the Baphia nitida and Gliricidia sepium was above 20%. The edibility of these oils will be dependent on the antinutritional factors present in the oil, which needs to be checked. The toxicity of these oils will also have to be evaluated.

ACKNOWLEDGMENTS

The authors would like to thank the Department of Chemistry, University of Ibadan for allowing the use of materials and equipment. The authors wish to thank the Third World Academy of Sciences (TWAS) for awarding Adewuyi Adewale a research fellowship and also India Institute of Chemical Technology (IICT) for creating an enabling research atmosphere.