Elsie F. Guimarães

Variability in essential-oil composition of Piper marginatum sensu lato.

This paper contains data on the chemical composition of the essential oils of 22 leaf samples of Piper marginatum Jacq. collected in different areas and ecosystems of the brazilian Amazon, as well as an overview of the available literature. The species presents a large synonymy based on their different leaf characteristics and distinct scents where some of them smell like anise or very close compounds. By GC, GC/MS, and cluster analysis, we identified seven chemotypes for the leaf oils. The main components found in chemotype I were safrole (1) and 3,4‐(methylenedioxy)propiophenone (2). The chemotype II was dominated by 3,4‐(methylenedioxy)propiophenone (2) and p‐mentha‐1(7),8‐diene (10). The major compounds identified in chemotype III were 3,4‐(methylenedioxy)propiophenone (2), myristicin (3), (E)‐β‐ocimene (11), and γ‐terpinene (12). In the chemotype IV, the principal constituents were β‐caryophyllene (13), α‐copaene (14), and 3,4‐(methylenedioxy)propiophenone (2). The chemotype V was dominated by (E)‐isoosmorhizole (6), (E)‐anethole (8), and isoosmorhizole (7). The main compounds found in the chemotype VI were 2‐methoxy‐4,5‐(methylenedioxy)propiophenone (4), methoxy‐4,5‐(methylenedioxy)propiophenone isomer 5, and (E)‐isoosmorhizole (6). The major constituents in chemotype VII were β‐caryophyllene (13), bicyclogermacrene (15), and (E)‐asarone (9).

Essential Oil of Piper permucronatum Yuncker (Piperaceae) from Rio de Janeiro, Brazil

Abstract The chemical composition of the essential oil of Piper permucronatum Yuncker from Rio de Janeiro, Brazil was analyzed by GC and GC/MS. The oil consisted mainly of sesquiterpenes and a small percentage of monoterpenes. A total of 33 compounds were identified. The major components found in the oil were δ-cadinene (12.7%), γ-muurolene (7.4%), α-cadinol (6.9%), β-caryophyllene (6.8%), T-muurolol (32%), α-muurolene (2.9%) and γ-elemene (2.7%).

Essential Oil Composition of Peperomia serpens (Sw.) Loud

Abstract The fresh- and dried-leaf oils and the fresh-leaf concentrate of Peperomia serpens were obtained by hydrodistilla-tion and SPME, and analyzed by GC and GC/MS. The main compounds identifed in the hydrodistilled fresh-leaf oil were (Z)-nerolidol acetate (42.9%) and (E)-nerolidol (31.3%). The major constituents found in the SPME fresh-leaf headspace were α-humulene (49.1%) and β-caryophyllene (35.1%). The hydrodistilled dried-leaf oil was dominated by (Z)-nerolidol acetate (36.6%) and (E)-nerolidol (29.1%). It seems that the hydrolysis of α-humulene, identifed only in the SPME fresh-leaf headspace, was responsible by the appearance of (E)-nerolidol in the fresh- and dried-leaf oils, followed by isomerization and acetylation to produce (Z)-nerolidol acetate, being all the process heat provoked.

Essential Oil of Piper cernum Vell. var. cernum Yuncker from Rio de Janeiro, Brazil

Abstract The essential oil from fresh leaves of Piper cernum Veil. var. cernum Yuncker from Rio de Janeiro, Brazil was isolated by hydrodistillation and analyzed through a combination of GC and GC/MS. Compounds representing 92.9% of the oil volatiles were identified. Twenty six constituents were identified according to their retention indices and mass spectra. The major constituents of the oil were cis-dihydroagarofuran (32.3 %), α-pinene (10.2 %), β-pinene (7.4 %), 10-epi-γ-eudesmol (7.1 %) and elemol (6.7 %).

Essential Oil Composition of Piper demeraranum (Miq.) C. DC

Abstract Four samples of aerial parts of Piper demeraranum were collected in the municipalities of Belém and Ananindeua, Pará state, brazilian Amazon. The samples were hydro distilled and the resulting oils were analyzed by GC and GC-MS. Seventy-four compounds were identified in the oils. The oils of samples 1–4 showed very similar chromatographic profiles presenting limonene (20.2%, 31.0%, 40.3% and 30.6%), sabinene (12.9%, 17.0%, 22.7% and 18.2%), β-pinene (7.7%, 8.2%, and 14.4% and 10.7%) and α-pinene (7.3%, 6.1%, 12.3% and 7.6%) as their main constituents. The other components were found in minute amounts in the essential oil samples. Based in these results we are attributing the occurrence of the same specimen of Piper demeraranum for the different collected samples and at diferent collection sites.

Essential Oil Composition of Piper cyrtopodon (Miq.) C. DC

Abstract Six samples of aerial parts of Piper cyrtopodon were collected in the brazilian Amazon. The samples were hydro distilled and the resulting oils analyzed by GC and GC-MS. Eighty-four compounds were identified in the oils. The main compounds found in the oil of sample 1 were β-caryophyllene (19.2%), bicyclogermacrene (13.0%), germacrene D (10.0%), spathulenol (8.4%) and ot-cubebene (5.1%); in the oil of sample 2 were a mixture of bicyclogermacrene plus curzerene (23.3%) with the predominance of the former, beyond germacrene D (17.9%), spathulenol (6.9%) and p-cymene (6.3%); in the oil of sample 3 were β-caryophyllene (34.6%), bicyclogermacrene (21.4%), germacrene D (13.6%), and ot-pinene (7.5%); in the oil of sample 4 were elemicin (26.8%), germacrene D (14.8%), bicyclogermacrene (14.0%) and ot-pinene (4.7%); in the oil of sample 5 were β-caryophyllene (18.1%), bicyclogermacrene (14.9%), germacrene D (13.6%), elemicin (10.1%) and ot-cubebene (6.7%); in the oil of sample 6 were epi-ot-bisabolol (26.3%), ot-cadinol (9.5%), bicyclogermacrene (8.3%) and germacrene D (7.5%). The presence of bicyclogermacrene and germacrene D was observed in all analysed sample oils of P. cyrtopodon, but their chromatographic profiles were very distinguishable if compared together, mainly for the higher percentage compounds. The chemical variation between the sample oils seems to depend of environment aspects existing in the plant collection sites. Our previous works with the Amazon Piper has showed that their essential oil composition was rich in terpenoids compounds for some species and phenylpropanoids for others.