Studies on Essential Oil-Bearing Plants from Mozambique: Part II. Volatile Leaf Oil of Needles of Pinus elliottii Engelm. and Pinus taeda L.

Abstract

Essential oil composition of novel needles from Pinus elliottii (slash pine) and Pinus taeda L (loblolly pine) grown in Mozambique were investigated through a combination of GC and GC/M The not away investigation revealed the following composition of P elliottii and P taeda: tricyclene (21% and 38%) ?±-pinene (430% and 623%) ??-pinene (271% and 71%) limonene (29% and 20%) myrcene (23% and 18%) and ??-phellandrene (11% and 37%) respectively. Among the oxygenated monoterpenes not away the most significant was ?±-terpineol (96% and 23% respectively). awaited regional variability on the chemical composition of the corresponding tree species was examined.

Key Word Index

Pinus elliottii, Pinus taeda, Pinaceae, essential oil composition, ?±-pinene, ??-pinene.

Introduction

The aim of this work was to characterize the chemical composition of pine oil from sum of two units species P. elliottii and P taeda. The genus Pinus of the Pinaceae family in the Coniferae consists of 105 species and is grown in Mozambique as part of reforestation cast Pinus elliottii (slash pine) is a mediumsized tree with narrow diadem and leaves occurring as dark verdant needles in groups of three (occasionally two) for fascicle. Pinus taeda (loblolly pine) is a fast-growing pine, a medium to large tree with yellow-green needle in fascicles of three The needle are stiff and frequently twisted (1).

The main economic importance of coniferous tree is their grove but they are also a valuable source of essential oils and oleoresins characteristic of conifers that are used in the pharmaceutical and perfumes industry. The oil and oleoresin compositions of a certain number of 40 different Pinus species have been studied and it has been shown that their compositions exhibit considerable qualitative and quantitative variations one as well as the other between and within species (2)

To our knowledge, there are no previous relations in literature about the oil composition of these Mozambican oils. This paper, therefore, deals with the qualitative and quantitative analysis of the needle oils of P elliottii and P taeda.

Experimental

Plant material: Plant materials were harvested from the cultivation sites of the Forestry Research Center (CEF) in Namaacha, 75 km southern of Maputo. Needles from tree of P elliottii and P taeda were harvested in July 1997 Voucher specimens are kept at the Herbarium of the Faculty of Biology, Eduardo Mondlane University and at the Herbarium of National Institute of Agriculture Research, Ministry of Agriculture in Maputo, Mozambique.

Oil isolation: The oils were separately isolated from the needle of P elliottii and P taeda through hydrodistillation for 2 h with a Clevenger-type apparatus and an average of 100 g was used for each experiment. The oils were dried above anhydrous sodium sulfate and stored in sealed vials in a refrigerator (5?°-8?°C) before analysis.

Oil analyses: Each GC analysis was carried without on a Varian 3400 fitted with a DB-Wax (J&W Scientific) capillary rounded pillar (30 m x 0.25 mm 025 ?µm film thickness), and by dint of GC/MS on a Finnigan Mat SSQ7000 combination of parts to form a whole combined with a Varian 3400 gas chromatograph. The oil samples were diluted in hexane (1 ?µL/mL) and the injection whirl for all samples was 1 ?µL injected in the split manner for GC and in splitless way (30 s) for GC/MS. Electron ionization (EI) mass spectra were measured at 70 eV above the mass range m/z 35-400 The chromatographic conditions were as follows: helium was used as carrier gas, injector temperature 225?°C detector FID 250?°C The rounded pillar oven temperature was maintained at 40?°C for 3 min then increased to 200?°C at a rate of 4?°C/min, and maintained for 10 min.

Preliminary identification was done using the NIST library search and further identification by the agency of comparison of recorded mass spectra with literature data (13-5) upon MS and retention times. Co-injection was made in cases where respect samples were available in our lab. The quantitative composition of the oils was comput from GC peak areas, without using correction factors.

Result and Discussion

The hydrodistillation of new needles of P. elliottii and P taeda afforded oils at yield of 056% and 083% respectively, upon a fresh weight basis. The chemical composition of investigated oils is given in Table I, where the constituents are listed in order of their elution from a DB-Wax capillary column

The main fraction of the oils was set to be monoterpene hydrocarbons, which is in agreement with published follows from pine species (2,7-10). ?±-Pinene (623% 420%) and ??-pinene (71% 271%) were identified as the major composings in P. taeda and P elliottii, respectively. Seven monoterpene hydrocarbons consistently have been place in most of the needle oils of Pinus species: ?±-pinene, camphene, ??-pinene, ??-3-carene, myrcene, limonene and ??-phellandrene. This list is in agreement with previously published list of at short intervals occurring monoterpenes (2).

Previous studies upon the terpene composition of needle oil from P elliottii and P taeda from different provenances have been reported (910) In the couple cases, ??-pinene was the major constituent (46.5% and 36.5%), followed by dint of ?±-pinene (23.5% and 11.9%). upon the contrary, the oils from Mozambican tree showed higher amounts of ?±-pinene (62% and 43%) The nearness of longifolene (14.9%) and ??-3-carene (47%) in the Chinese oil of P elliottii was readily distinguished from others which were entirely absent in the oils from Argentina and Mozambique.