Chemical Variability of Ravensara aromatica essential oils

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Chemical Variability of Ravensara aromatica
essential oils
Unité de Recherche en Partenariat  Forêts et
Biodiversité  Madagascar ________________________
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. Andrianoelisoa Hanitra Encadreurs Danthu P,
Menut C , Chaix G,, Collas de Chatelperron P,
Ramanoelina P, Bry A, Rakotovao Z Etudiants
Stagiaires April 2008
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Objective of our study

• This study of the determinants of the
  variability of chemical composition of Ravensara
  aromatica essential oils was done to assist the
  producers to product essential oils with required
  quality by providing them chemotype repartition
  chart and handbook

• Essential oils extracted from leaves of
  individual trees are analysed by gas
  chromatography and gas chromatography coupled
  with mass spectrometry.
• More than 500 samples were analysed.
• Obtained chemical data are statistically treated.
  Factorial analyses and Hierarchical clustering
  were performed.

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Hierarchical Clustering
Methyl chavicol
Methyl eugenol
Limonene
A-terpinene
Sabinene
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Five Classes were determined by statistical
analysis and considered as chemotypes

• The Five chemotypes (calledd by the main
  component) are on confirming
• Chemotype 1 with methyl chavicol
• Chemotype 2 with methyl eugenol
• Chemotype 3 with a-terpinene
• Chemotype 4 with sabinene
• Chemotype 5 with limonene

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NIRS (Near Infrared Spectroscopy)

• Near infrared spectroscopy (NIRS) is used more
  and more in several fields where chemical
  analysis (usually costly and time consuming)
  needed
• NIRS is a fast technique for qualitative and
  quantitative analysis of organic materials
  compare to chemical analysis
• We have used successfully this new tool for
  determining chemotypes and had allowed us to
  cluster our leaf samples into three classes and
  oil ones into five classes which were already
  established before.

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Ravensara aromatica leaves Spectra Data
Aromatic
Terpenic
- 3 chemical classes were identified
Methyl Chavicol

• Absorption spectra were realized directly on
  dried leaves

Methyl Eugenol
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Ravensara aromatica essential OilsChemical Data
Terpenic
Aromatic
Methyl eugenol
- 5 chemical classes as obtained before (PCA
results on chemical composition) were determined
Methyl chavicol
Absorption spectra were taken in transmittance on
oils
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Are they chemotypes? Yes

• Stability of the oil chemical composition along
  one year has been verified and confirmed.
• 2. Stability of the oil chemical composition from
  generation to generation has been verified and
  confirmed by the study performed on sexual and
  vegetative propagation (cutting)

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Spatial Repartition of Ravensara aromatica
chemotype in its distribution area
1- Anosibe anALa

• No aromatic chemotype but only terpenic ones
  (limonene in Red and a-terpinene in Green) are
  present in this part of forest

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2-Didy Forest

• All chemotypes are present but the forest are
  mainly constituted by limonene chemotype in Red

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3- Raboana Forest

• Only aromatic chemotypes methyl chavicol in Blue
  and methyl eugenol in Green constitute this
  forest with prevalence of methyl chavicol one

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Conclusion

• Five chemotypes issued from two different
  biosynthesis pathways were highlighted
• the shikimic acid pathway (chemotype 1 and 2)
  rich in aromatic compounds
• the mevalonic acid pathway (chemotypes 3, 4 and
  5) rich in monoterpenic compounds
• Chemotype repartition charts were established in
  three studied areas