Chemical Composition of Leaf and Fruit Essential Oils of Hoslundia opposita Vahl Grown in Nigeria

Hydrodistilled leaves and fruits of Hoslundia opposita yielded 0.54% and 0.65%v/w of essentials oils. Investigation by GC and GC-MS revealed that the bulk of the oils were constituted by oxygenated monoterpenes (81.3 and 81.4% for the leaves and fruits, respectively). The principal constituents of the leaf oil were 1, 8-cineole (72.3%), terpineol (7.2%), sabinene (4.5%), thymol (4.2%) and car-3-ene (3.7%).The fruit oil had abundance of camphor (69.5%), linalool (5.4%) and limonene (2.5%). Key word: Lamiaceae Hoslunda opposite Essential oil composition 1, 8-cineole Camphor INTRODUCTION Forestry Research Institute of Nigeria (FRIN), Ibadan Hoslundia opposita Vahl (family Lamiaceae) is an Voucher Number FH10086637-0). herbaceous perennial shrub widely grown in Nigeria, where it is commonly known as Oke ota by the Igbos and Oil Isolation: Pulverized leaves and fruits of H. opposita Efirin odan by the Yorubas [1]. The plant is widely used were separately hydrodistilled for 3h in a Clevenger-type in folk medicine for the treatment of abdominal pains, oral apparatus, according to the British Pharmacopoeia wounds, sore throats, epilepsy, mental disturbance and specification [9]. The resulting oils were separately malaria [1, 2]. Biological activities of the plant extracts collected, preserved in a sealed sample tube and stored such as, antimalarial, anticonvulsant and antimicrobial under refrigeration until analysis. activities [3-5] confirmed its use in folk medicine. Phytochemical investigations of the plant led to the Gas Chromatography: GC analyses were performed isolation of 5, 7-dimethyl-6-methylflavone, hoslundiol and on an orion micromat 412 double focusing gas euscaphic acid [6]. Four abietane-type esters, 3-Ochromatography system fitted with two capillary benzylhosloppone, 3-O-cinnamoylhosloppone, 3-Ocolumns coated with CP-Sil 5 and CP-Sil 19 (fused benzoylhinokol and 3-O-benzoylhosloquinone [4] were silica, 25m × 0.25mm, 0.15μm film thickness) and also isolated from the plant. Earlier works on the leaf flame ionization detector (FID). The volume essential oil of Benin, Cameroon and Ivory Coast grown injected was 0.2μL and the split ratio was 1:30. H. opposita revealed that the oil were of germacrene D Oven temperature was programmed from 50-230°C and -caryophyllene chemotypes [7,8]. respectively. Qualitative data were obtained by electronic In continuation of our systematic studies of the integration of FID area percents without the use of essential oil of Nigerian grown medicinal plants, we correction factors. investigated the leaf and fruit essential oils of H. opposita grown in Nigeria. Gas Chromatography/mass Spectrometry: A Hewlett EXPERIMENTAL 250S double focusing mass spectrometer was used. Plant Materials: The fresh leaves and fruits of Hoslundia conditions were: ionization voltage 70ev, ion source opposita were obtained in Ilorin, Kwara State, Nigeria. temperature 230°C. The GC was fitted with a 25m × Identification was carried out at the herbarium of the 0.25mm, fused silica capillary column coated with CP-Sil 5. where voucher specimens were deposited (Herbarium Packard (HP 5890A) GC interfaced with a VG Analytical 70 Helium was the carrier gas at 1.2ml/min. The MS operating Am-Euras. J. Agric. & Environ. Sci., 8 (1): 40-43, 2010 41 The film thickness was 0.15μm. The GC operating Table 1 shows the retention indices, relative conditions were identical with those of GC analysis. The percentages, mass spectra data and identities of the MS data were acquired and processed by online desktop constituents of the oils. A total of 19 and 25 compounds computer equipped with disk memory. The percentage that represent 96.7 and 98.7% of the leaf and fruit oils were compositions of the oil were computed in each case from identified from their retention indices and mass spectra, GC peak areas. The identification of the components was respectively. based on the retention indices (determined relative to the Oxygenated and Hydrocarbon monoterpenes retention times of series of n-alkanes) and mass spectra constituted 81.3 and 9.7% of the leaf oil while the with those of authentic samples and with data from percentage composition of hydrocarbon sesquiterpenes Literature (10 12). and aromatic compounds were 2.5 and 5.2%, respectively. DISCUSSION oxygenated monoterpenes, with 1, 8cineole (72.3%) as Pulverized leaves and fruits of Hoslundia opposita on (1.1%) were found in significant proportions. Linalool hydrodistillation afforded oil in the yield of 0.54 and 0.65 (0.3%), campholenal (0.2%), cis-sabinene hydrate %v/w, respectively. (0.2%) existed as minor constituents of the oil. The oil was characterized by the abundance of the major constituent. terpineol (7.2%) and terpine-4-ol Table 1: Chemical composition (%) of the fruit and leaf oils of Hoslundia opposita %Composition ----------------------------------------------Compound RI Fruit Leaf Mass spectra data a b thujene 926 0.6 0.2 152,135,109,93,67,55 pinene 933 1.2 136,121,105,93,79,67 Sabinene 971 0.7 4.5 136,121,107,93,77,69 pinene 976 3.4 0.1 136, 121,93,79,67,51 Myrcene 990 0.4 136,121,105,93,69,53 Car-2-ene 1001 0.3 136,121,93,79,65,53 Car-3-ene 1009 3.7 136,121,93,79,67,55 Limonene 1027 2.5 136,121,93,67,53,44 Benzyl alcohol 1028 1.2 108,91,79,77,65,53 1,8 cineole 1029 1.2 72.3 154,139,108,93,81,43 Cis ocimene 1035 0.1 136,121,105,93,79,67 Cis-â-ocimene 1040 0.7 136,121,105,93,79,67 Trans ocimene 1045 1.2 136,125,105,91,79,67 terpinene 1057 1.1 136,125,105,93,77,65 Terpinolene 1087 0.2 136,121,105,93,79,51 Linalool 1098 5.4 0.3 139,121,93,71,55,43 campholenal 1124 0.2 119,108,93,79,67,55 Camphor 1140 69.5 152,137,108,95,69,51 Borneol 1162 1.0 136,121,110,95,67,55 Terpine-4-ol 1175 0.6 1.1 154,136,111,93,71,45 terpeneol 1188 0.6 7.2 136,121,111,95,67,55 Cis-sabinene hydrate 1198 0.2 154,136,121,111,93,43 Linalyl acetate 1127 0.7 136,121,93,80,67,55 Neral 1238 1.2 135,119,109,95,69,53 Geranial 1268 1.2 139,123,111,93,69,53 Thymol 1290 4.2 150,135,111,91,79,65 Carvacrol 1298 1.0 150,135,111,91,79,65 Eugenol 1354 0.7 164,149,121,91,65,51 cubebene 1390 1.1 204,164,121,91,79,69 elemene 1391 0.3 161,139,121,105,67,53 Caryophyllene 1418 0.7 204,189,133,105,91,43 Cis-âfarnesene 1456 0.5 204,161,139,91,69,55 Germacrene D 1479 0.8 204,147,105,91,79,67 bisabolene 1509 0.1 204,161,105,91,67,41 cadinene 1523 0.1 204,161,119,105,81, Acetyleugenol 1525 0.4 207,167,149,131121,115 Gossonorol 1637 0.7 208,157,135,119,105,77 Total 96.7 98.7 Compounds are listed in order of elution from Silica Capillary Column coated on CP-Sil 5; retention indices on fused Silica Capillary Column coated with a b