Egyptian Pharmaceutical Journal

ORIGINAL ARTICLE
Year
: 2015  |  Volume : 14  |  Issue : 1  |  Page : 65--68

The composition of the lipoidal matter of the seeds of Pleiogynium timorense (DC.) Leenh


Ataa A Said1, Elsayed A Aboutabl2, Ahmed A Hussein3, Gehan F Abdel Raoof1,  
1 Department of Pharmacognosy, National Research Centre, Cairo, Egypt
2 Department of Pharmacognosy, Faculty of Pharmacy, Cairo University, Giza, Egypt
3 Chemistry of Medicinal Plants, National Research Centre, Cairo, Egypt

Correspondence Address:
Gehan F Abdel Raoof
Department of Pharmacognosy, National Research Centre, Dokki, Cairo
Egypt

Abstract

Background and objectives Nothing dealing with the chemistry of the seeds of Pleiogynium timorense (DC.) Leenh. could be traced in the available literature. The objective of the present work was to investigate the lipoidal matter from P. timorense seeds and to isolate and identify the major sterols and triterpenes in the petroleum ether extract. Materials and methods The petroleum ether extract of P. timorense seeds was prepared. The extract was subjected to column chromatography using silica gel (type 60-230 mesh) as an adsorbent. The unsaponifiable matter and fatty acid methyl esters were analyzed by GC/MS. Results and conclusion GC/MS analysis of the unsaponifiable matter from the petroleum ether extract of P. timorense seeds revealed the identification of 70.04% of unoxygenated compounds and 23.34% oxygenated compounds. Hydroxylated compounds, ketones, and steroidal compounds represent 23.24, 0.20, and 3.19%, respectively. 1-Heptene (66.47%) was the major compound in the USM, followed by butylated hydroxy toluene (21.07%). GC/MS analysis of fatty acid methyl esters showed that nine fatty acid methyl ester derivatives could be identified, representing 95.84% of the total composition. The major fatty acid was 9,12-octadecadienoic acid (linoleic acid) (33.8%). Saturated fatty acids represent 36.93% of the total fatty acid content, whereas monounsaturated and diunsaturated fatty acids represent 25.11 and 33.8% of the total fatty acid content, respectively. Column chromatography of the petroleum ether extract led to the isolation of two compounds [α-amyrin and 5,24(28)-cholestadien-24-methylen-3β-ol].



How to cite this article:
Said AA, Aboutabl EA, Hussein AA, Abdel Raoof GF. The composition of the lipoidal matter of the seeds of Pleiogynium timorense (DC.) Leenh.Egypt Pharmaceut J 2015;14:65-68


How to cite this URL:
Said AA, Aboutabl EA, Hussein AA, Abdel Raoof GF. The composition of the lipoidal matter of the seeds of Pleiogynium timorense (DC.) Leenh. Egypt Pharmaceut J [serial online] 2015 [cited 2021 Dec 2 ];14:65-68
Available from: http://www.epj.eg.net/text.asp?2015/14/1/65/154725


Full Text

 Introduction



Pleiogynium timorense (DC.) Leenh. (Anacardiaceae) is an evergreen tree indigenous to tropical and subtropical regions. It is known in Arabic as Gambozia and cultivated in Egypt as an ornamental plant [1],[2]. P. timorense has edible fruits used in the preparation of jellies, jams, and preserves [3],[4]. Previous phytochemical studies resulted in the isolation of quercetin, myricetin, rutin, quercitrin, hyperin, lupeol, and β-sitosterol from the leaves. Aqueous and alcoholic extracts of the leaves showed significant antimicrobial activity against Staphylococcus aureus and Bacillus subtilis [5]. The ethanolic extract of the leaves showed significant hypoglycemic, antioxidant, and anti-inflammatory properties. In addition, 12 phenolic compounds were isolated from the leaves of the plant, which include kaempferol, gallic acid, kaempferol-3-O-β-d-galactopyranoside, kaempferol-3-O-β-d-glucopyranoside, quercetin-3-O-β-d-galactopyranoside, quercetin-3-O-β-d-glucopyranoside, kaempferol-3-O-β-d-6½-methylglucuronopyranoside, kaempferol-3-O -β-d-glucuronopyranoside, myricetin-3-O-α-l-rhamnopyranoside, 3,5-di-O-galloylquinic acid, 1,4,6-tri-O-galloyl-β-d-glucopyranose, and 1,3,4,6-tetra-O-galloyl-β-d-glucopyranose [6]. Cyanidin-3-glucoside was isolated from the fruits [7], which is reported to have antioxidant activity. The present study was undertaken to investigate the lipoidal matter composition of P. timorense seeds.

 Materials and methods



Plant material

Fruits of P. timorense were collected from Zoo Garden, Giza, Egypt, in April 2010, and were kindly authenticated by Dr. Tereez Labib, Consultant of Plant Taxonomy at the Ministry of Agriculture and director of Orman Botanical Garden, Giza, Egypt, and confirmed by the taxonomist, Dr. M. El-Gebaly, NRC. The fruits were air-dried, and the seeds and the pericarp were separated, powdered, and stored in dark well-closed containers.

Preparation of the lipoidal matter

The powder of the air-dried seeds of P. timorense (800 g) was exhaustively extracted with light petroleum (60°-80°C) in a continuous extraction apparatus. The extract was evaporated under vacuum to yield 28 g of dry residue, representing 3.5% of the air-dried seeds.

Investigation of the lipoidal matter

Saponification of the petroleum ether extract

The petroleum ether extract (1 g) was subjected to saponification according to the method reported by Tsuda et al. [8]. Percentages of the unsaponifiable matter and the total fatty acid were found to be 38 and 60%, respectively.

Preparation of fatty acid methyl esters

Free fatty acids obtained by saponification were methylated according to the method reported by Finar [9].

GC/MS analysis

Both the unsaponifiable and the saponifiable fractions were studied to identify their contents using GC/MS analysis. The constituents were identified by comparison of their mass spectral fragmentation patterns with those of the available database libraries, Wiley (Wiley International, Colorado, USA) and NIST (Nat. Inst. St Technol., Colorado, USA), and/or published data [10],[11]. Quantitative determination was carried out on the basis of the peak area integration. GC/MS analysis of the unsaponifiable matter and fatty acid methyl esters of P. timorense seeds was carried out using conditions described in [Table 1].{Table 1}

The Experiment

An NMR Jeol ECA spectrometer (JEOL Corporation, Tokyo, Japan), 500 MHz for 1 H-NMR and 125 MHz for 13 C-NMR, using CDCl 3 as a solvent, was used. All chemical shifts (δ) are given in ppm units with reference to TMS as the internal standard, and the coupling constants (J) are given in Hz. The gas chromatograph was coupled with a mass spectrometer [an Agilent 6890 gas chromatograph coupled with an Agilent mass spectrometric detector, 70 eV (Agilent Technologies, Santa Clara, California, USA), ESR, Brucker, Elexsys, E 500 (Frankfurt, Germany)].

Extraction and isolation of major sterols and triterpenes

Air-dried powdered seeds of P. timorense (800 g) were exhaustively extracted with light petroleum (60°-80°C) in a continuous extraction apparatus. The extract was evaporated under vacuum to yield 28 g of extract, representing 3.5% of the air-dried powder. Part of the extract (20 g) was subjected to column chromatography using silica gel (type 60-230 mesh, 200 g; E. Merck, Darmstadt, Germany) as an adsorbent, and elution was carried out with n-hexane, followed by n-hexane-ethyl acetate mixtures of increasing polarity. Fractions (50 ml each) were collected and concentrated separately to a small volume. All fractions were screened by thin-layer chromatography on silica gel 60 F 254 plates using hexane: ethyl acetate (9 : 1) as the solvent system and P-anisaldehyde-sulphuric acid spray reagent, followed by heating at 110°C for 5 min. Similar fractions were pooled to form two major groups and the solvents were evaporated separately under reduced pressure.

Group 1

It contained one major spot (Rf = 0.38) of violet color with the P-anisaldehyde-sulphuric acid spray reagent. The fraction was freed of the solvent under reduced pressure; the residue was dissolved in the least amount of chloroform and subjected to purification by rechromatography on preparative thin-layer chromatography using hexane: ethyl acetate (8.5 : 1.5). The bands were eluted with chloroform. The chloroformic eluate was filtered and concentrated to a small volume to yield compound L 1 (5 mg).

Group 2

It contained one major spot (Rf = 0.3) of violet color, with the P-anisaldehyde-sulphuric acid spray reagent. The fraction was freed of the solvent under reduced pressure. The residue obtained was purified as in group I to yield compound L 2 (10 mg).

 Results and discussion



A total of 28 compounds were identified [Table 2] by GC/MS of the unsaponifiable matter, representing 96.68% of the total unsaponifiable content. The analysis revealed that the identified components consisted of 70.04% unoxygenated compounds and 23.34% oxygenated compounds: 23.24% hydroxylated compounds, 0.10% ketones, and 3.19% steroids. 1-Heptene (66.47%) was the major compound in the USM, followed by butylated hydroxy toluene (21.07%). About nine fatty acid methyl ester derivatives could be identified [Table 3], representing 95.84% of the total composition. The major fatty acids were 9,12-octadecadienoic acid (linoleic acid) (33.8%), followed by 9-octadecenoic acid (oleic acid) (24.14%) and 14-methyl-pentadecanoic acid 12.08%. Saturated fatty acids represent 36.93% of the total fatty acid content, whereas monounsaturated and diunsaturated fatty acids represent 25.11 and 33.8% of the total fatty acid content, respectively.{Table 2}{Table 3}

Compound L 1 : white powder (5 mg), m.p. (181°-183°C), a single spot in hexane : ethyl acetate (8.5 : 1.5) (Rf = 0.38), violet color with the P-anisaldehyde-sulphuric acid spray reagent.

Mass spectral data: 426(M + ), 411 (M + -CH 3 ), 409 (M +1 -H 2 O), 218 (100%) 203 (28%) and 189 (29%). The mass spectrum showed a molecular ion peak at m/z 426 for the molecular formula C 30 H 50 O, in addition to the following peaks at m/z 411(M + -CH 3 ), 409 (M +1 -H 2 O), 218 (M-208 (C 14 H 24 O), and 203 (218-CH 3 )+. On the basis of the spectral data, melting point, and comparison with an authentic sample, compound L 1 was identified as α-amyrin. This compound was previously isolated from P. timorense leaves [5]. This is the first report in the seeds of the plant.

Compound L 2 : white powder (10 mg), m.p. (142°-143°C), gave a single spot in hexane : ethyl acetate (8.5 : 1.5) (Rf = 0.3), gave violet color with the P-anisaldehyde-sulphuric acid spray reagent.

1 H-NMR spectral data of compound L 2 1 H-NMR, CDCl 3 : δ 5.35(H-6, broad s), δ 3.9(H-3, m), δ 4.6, δ 4.5 (H-28, s), δ 0.82(3H-18, s), δ 0.84(3H-19, s), δ 1.4 (3H-26,d, J=7 Hz), δ 1.4(3H-27,d, J = 7 Hz), δ 0.9 (3H-21,d, J=6.5 Hz), δ 2.2(H-25, m)

13 C-NMR in CDCl 3 spectral data of compound L 2 : The spectrum showed peaks at δ 140.813 (C-5), δ 147.5 (C-24), 129.7 (C-6), 111.3 (C-28), 67 (C-3), 19.3 (C-21), 11.8 (C-19,C18), 22.6 (C-26, C27), 30.9 (C-23), 33.8 (C-25), 34.5 (C-22), 35.6 (C-20). Thus, compound L 2 is identified as 5,24 (28)-cholestadien-24-methylen-3β-ol, which was isolated, for the first time, from the plant.

 Conclusion



This study showed the identification of 28 compounds of unsaponifiable matter from the seeds of P. timorense, which were identified by GC/MS. 1-Heptene (66.47%) was the major compound in the USM. About nine fatty acid methyl ester derivatives could be identified. The major fatty acid was 9,12-octadecadienoic acid (linoleic acid) (33.8%).

 Acknowledgements



The authors thank the National Research Centre, Egypt, for funding this work.

Conflicts of interest

There are no conflicts of interest.

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