Volatile Constituents of the Stem and Leaves of Cordia Species from Mountain Forests of Pernambuco (North-eastern Brazil)

GC and GC/MS: The ods obtained from different parts of each species were analyzed by GC and GC/MS, and identification was made on the basis of comparison of retention indices (18) as well as by the computerized matching of the obtained mass spectra with those stored in the NIST mass spectral library of the GC/MS data system and the other published mass spectra (19). The retention indices were obtained by co-injecting the oil sample with a C^sub 11^-C^sub 36^ linear hydrocarbon mixture (retention index from 900 to 1099 range was obtained by extrapolation).

GC: The ods were analyzed using a Hewlett-Packard 5890 SERIES II equippedwithaflame ionisation detector (FID) and a J & W Scientific DB-5 fused silica capillary column (30 m x 0.25 mm x 0.25 pm); column temperatures were programmed from 35°C for 2 min, raised to 180C° at 4°C/min, then increased to 280°C at 20°C/min for integrating purposes. Injector and detector temperatures were 250°C and 280°C, respectively. Hydrogen was used as carrier gas, flow rate 1.5 mL / min, split mode (1:100). Injection volume, 1.5 µL solution of about 10 mg of oil in ethyl acetate. GC/MS: The od analyses were carried out using a Hewlett-Packard 5971 GC/MS fitted with the same column and temperature program as that for the GC experiments. The carrier gas was He, flow rate 1 mL/min, split mode (1:100). Injected volume: 1 µL of 1/100 dduted solution in ethyl acetate. Mass spectra were taken at 70 eV Scanning speed was 0.5 scan/sec from m/z 40 to 550.

Results and Discussion

The hydrodistiUation of the leaves and stem of two Cordia species gave different yields: The highest od yields were obtained from the stem (1.1%) and leaves (1.0%) of C. curassavica when compared to the yields of the stem (0.5%) and leaves (0.6%) of C. globosa.

The results obtained by GC and GC/MS analysis of the ods from different parts of the two Cordia species are shown in Table I according to their elution order on the DB-5 column. According to the data presented in Table I, it can be seen that the chemical profiles of the oils from stem and bark of both species differ quite a lot.

A total of 38 components were identified in the ods of C. globosa, which represented about 93.6% and 97.5% of the ods from leaves and stem of C. globosa, respectively. However, 47 components were identified in the oils of C. cu rassavica, which represented about 97.4% and 98.9% of the ods from leaves and stem, respectively.

The main components of the leaf and the stem oils from Cordia species coUected at mountain forests in Pernambuco are compared in Table II. The oils of both species contained a predominance of sesquiterpenes, where the major percentages were found in the bark ods (96.6%) of C. curassavica and leaf oils (84.2%) of C. globosa. The leaf od of C. curassavica also contains a majormonoterpene fraction (37.4%). β-Phellandrene (25.3%), cubebol (23.9%) and β-caryophyUene (39.0%) were the main constituents of the leaf oil of C. curassavica and C. globosa, respectively. In contrast, 1-endo-bourbonanol (20.2%) and spathulenol (27. 1%) were the principal components of the stem oil of C. globosa and C. curassavica, respectively.