Essential Oil from the Fruits of Fissistigma bracteolatum and Fissistigma maclurei

Aims: The aim of this study was to isolate essential oils from the fruits of Fissistigma bracteolatum and Fissistigma maclurei (Annonaceae) and investigate the volatile constituents present they contained. Study Design: The study involves the hydrodisitillation of essential oils from the air-dried fruit samples of F. bracteolatum and F. maclurei and analysis of their chemical compositions by GC and GC-MS. Original Research Article Hung et al.; CSIJ, 17(3): 1-7, 2016; Article no.CSIJ.29572 2 Place and Duration of Study: Fruits of F. bracteolatum and F. maclurei were collected from Pù Mát National Park, Nghệ An Province, Vietnam, in May 2014. Analysis of the oil samples was performed between June and August, 2014. Methodology: About 500 g of air-dried fruit samples was shredded and their oils were obtained by separate hydrodistillation for 4 h at normal pressure, according to the Vietnamese Pharmacopoeia specifications. The chemical constituents of the distilled oils were analyzed by means of gas chromatography-flame ionization detector (GC-FID) and gas chromatography coupled with mass spectrometry (GC-MS). Results: The main constituents in the fruit of F. bracteolatum are α-pinene (15.5%) and δ-cadinene (11.0%), with significant amounts of β-caryophyllene (8.0%) and germacrene D (7.0%) while spathulenol (21.2%) and β-cubebene (10.6%) are the quantitatively significant compounds of F. maclurei fruit. Conclusion: The present oil compositions of fruit of F. bracteolatum and F. maclurei were reported for the first for these species and the results were found to differ from previous studies on other parts of the plants.

Till moment there are no reports on the chemical constituents of essential oils from the fruits of the studied plant species. This paper reports for the first time the components of fruit volatile of both F. bracteolatum and F. maclurei grown in Vietnam.

Hydrodistillation of Essential Oil
Briefly, 500 g of the pulverized sample were carefully introduced into a 5 L flask and distilled water was added until it covers the sample completely. Hydrodistillation was carried out in an all glass Clevenger-type distillation unit designed according to the specification [14]. The volatile oils distilled over water and were collected separately in the receiver arm of the apparatus into a clean and previously weighed sample bottles. The oils were kept under refrigeration until the moment of analyses.

Analysis of Essential Oil
Gas chromatography (GC) analysis was performed on an Agilent Technologies HP 6890 Plus Gas chromatograph equipped with a FID and fitted with HP-5MS column (30 m x 0.25 mm, film thickness 0.25 µm, Agilent Technology). The analytical conditions were: carrier gas H 2 (1 mL/min), injector temperature (PTV) 250ºC, detector temperature 260ºC, column temperature programmed from 60ºC (2 min hold) to 220ºC (10 min hold) at 4ºC/min. Samples were injected by splitting and the split ratio was 10:1. The volume injected was 1.0 µL. Inlet pressure was 6.1 kPa. The relative amounts of individual components were calculated based on the GC peak area (FID response) without using correction factors.
An Agilent Technologies HP 6890N Plus Chromatograph fitted with a fused silica capillary HP-5 MS column (30 m x 0.25 mm, film thickness 0.25 µm) and interfaced with a mass spectrometer HP 5973 MSD was used for the GC/MS analysis, under the same conditions as those used for GC analysis. The conditions were the same as described above with He (1 mL/min) as carrier gas. The MS conditions were as follows: Ionization voltage 70eV; emission current 40 mA; acquisitions scan mass range of 35-350 amu at a sampling rate of 1.0 scan/s. The identification of constituents was performed on the basis of retention indices (RI) determined by co-injection with reference to a homologous series of n-alkanes, under identical experimental conditions. Further identification was performed by comparison of their mass spectra with those from NIST [15] and the home-made MS library built up from pure substances and components of known essential oils, as well as by comparison of their retention indices with literature values [16].
There is dirt of literature on the volatile compositions of both fruit oils and as a result the present study may represent the first of its kind. The observed compositional variations between the present oil samples and previous studies may be attributed to the different plant parts being analysed. It is well known that different parts of the same plant accumulate different phytochemicals. For example F. scandens leaf oil comprised mainly of (E)-β-ocimene and limonene while campherenone and (E)-βocimene were identified in higher proportions in the stem oil.
Literature information revealed that the chemical constituents of some Vietnamese grown Fissistigma have been studied and reported ( Table 2). Although ubiquitous monoterpene and sesquiterpenes were the main compounds identified in this study, it is evident that each sample has its own compositional pattern different from each other.

CONCLUSION
In the present investigation of chemical constituents of essential oils from the fruits of F. bracteolatum and F. maclurei were found to be different from previous investigated oil samples from other parts of the plant.

CONSENT
It is not applicable.

ETHICAL APPROVAL
It is not applicable.