Chemical Composition of the Essential Oil of Hyptis Suaveolens

Abstract

The chemical composition of Hyptis suaveolens was investigated and twenty three compounds were abundant enough to be identified by GC-MS.

Introduction

The Hyptis geneus (Lamiaceae) is composed of 400 species that mainly occur in tropical America [1,2,3]. Most of these plants are highly aromatic and also found in the other parts of the world; particularly as a weed in the wet tropic region of the Northern Territory, Australia [4,5,6]. The genus Hyptis is known to be used for traditional medicine for the treatment of various illness and has been found to possess significant pharmacological activity [7,8,9,10,11,12], including tumorigenic [13,14,15,16], antifertility [17,18] mycotoxic and phytotoxic activities [19]. H. suaveolens has recently been shown to possess insecticidal properties [20] as well as grain protectant from Cowpea weevil during storage [21]. The terpenes content of distilled volatile oils have been known to differ enormously due to different geographical locations and between different species of the same plant (22, 23). This genus possesses a diverse range of biological activities that led us to investigate the chemical composition of essential oil obtained by hydrodistillation from the leaves of Hyptis suaveolens Poit. The chemical constitutents of this specie was also compared with two other species, H. mutabilis [22] and H. emoryi [24].

Results and Discussion

The essential oil obtained after hydrodistillation of the leaves of H. suaveolens gave an average yield of 0.1 %. The main constitutents were 1, 8-cineole (32%) and β- caryophyllene (29%) Fig. 1. Enormous difference in the concentration levels of these two major components were found in the three species, H. suaveolens , H. mutabilis [22] and H. emoryi [24], as shown in the Table 1. This significant variation of the major components permit an easy differentiation between these three species.

Fig. 1. Major components, 1,8- cineole and β-caryophyllene and others only found in Hyptis suaveolens

Fig. 1. Major components, 1,8- cineole and β-caryophyllene and others only found in Hyptis suaveolens

Table 1. A comparison of chemical composition of the essential oils from Hyptis sp. A = H. suaveolens; B = H. emoryi [24]; C = H. mutabilis [22].

Component	A	B	C
α-Thujene	0.3	7.0	1.80
α-Pinene	2.5	6.6	0.30
Camphene	0.02	1.1	-
Sabinene	3.9	T	0.33
β-Pinene	4.2	5.0	0.51
Myrcene	0.6	1.8	1.85
α-Phellandrene	2.0	T	-
α-Terpinene	-	-	0.74
p-Cymene	-	-	15.14
Limonene	-	5.6	-
β-Phellandrene	-	0.8	-
1, 8-Cineole	32	6.9	5.67
cis- β-Ocimene	-	-	0.74
γ-Terpinene	0.7	0.1	1.93
α-Terpinolene	0.3	T	-
Cimenenol	-	-	0.33
Linalool	0.06	1.3	1.77
Fenchol	0.3	-	-
Camphor	-	1.3	-
4-Borneol	-	11.9	-
4-Terpinenol	2.3	1.9	0.34
α-Terpineol	0.2	-	0.43
Carvone	-	0.7	-
Neral	-	2.0	-
Bornyl acetate	-	0.6	-
Thymol	-	-	7.85
Carvacrol	-	-	0.35
δ-Elemene	-	-	1.44
Eugenol	1.2	-	-
α-Copaene	1.8	-	-
β-Elemene	1.0	-	-
β-Caryophyllene	29	2.5	12.35
α-Humulene	1.6	T	2.95
α-Bergamotene	2.0	-	-
Aromadendrene	0.5	-	0.59
γ-cadinene	0.1	6.7	-
δ-cadinene	0.5	1.4	-

T = Trace

Table 1. A comparison of chemical composition of the essential oils from Hyptis sp. A = H. suaveolens; B = H. emoryi [24]; C = H. mutabilis [22].

Component	A	B	C
α-Thujene	0.3	7.0	1.80
α-Pinene	2.5	6.6	0.30
Camphene	0.02	1.1	-
Sabinene	3.9	T	0.33
β-Pinene	4.2	5.0	0.51
Myrcene	0.6	1.8	1.85
α-Phellandrene	2.0	T	-
α-Terpinene	-	-	0.74
p-Cymene	-	-	15.14
Limonene	-	5.6	-
β-Phellandrene	-	0.8	-
1, 8-Cineole	32	6.9	5.67
cis- β-Ocimene	-	-	0.74
γ-Terpinene	0.7	0.1	1.93
α-Terpinolene	0.3	T	-
Cimenenol	-	-	0.33
Linalool	0.06	1.3	1.77
Fenchol	0.3	-	-
Camphor	-	1.3	-
4-Borneol	-	11.9	-
4-Terpinenol	2.3	1.9	0.34
α-Terpineol	0.2	-	0.43
Carvone	-	0.7	-
Neral	-	2.0	-
Bornyl acetate	-	0.6	-
Thymol	-	-	7.85
Carvacrol	-	-	0.35
δ-Elemene	-	-	1.44
Eugenol	1.2	-	-
α-Copaene	1.8	-	-
β-Elemene	1.0	-	-
β-Caryophyllene	29	2.5	12.35
α-Humulene	1.6	T	2.95
α-Bergamotene	2.0	-	-
Aromadendrene	0.5	-	0.59
γ-cadinene	0.1	6.7	-
δ-cadinene	0.5	1.4	-

T = Trace

Materials and Methods

Plant Material

Plant material was collected around Darwin and a vaucher specimen has been deposited at the Northern Territory University Herbarium.

Distillation of the Essential Oils

Fresh leaves were hydrodistilled for three hours to give pale yellow essential oil in 0.1 % yield (w/w) [25]. The oil was dried over anhydrous sodium sulphate and analysed with GC-MS for identification of its components.

GC-MS Analysis

The component of the oils were identified by GC-MS analysis using a Varian Saturn GC-MS instrument. Capillary GLC was carried out by using at 25.0m OV101 glass capillary column. The column was programmed at 90 °C for 10 min to 180 °C at a rate of 2 °C/min, then kept at 180 °C for 30 min. Helium was used as a carrier gas. Mass spectra were taken at 70 eV. The gc/ms data system contains the National Bureau of Standards (NBS) mass spectral library and Registry of Mass Spectral Data [26] were used to help verify the identity of individual components by mass spectral comparison. Identification of the separated components were also carried out by using authentic specimens and private library of essential oil constituents.