New Chemotypes of Origanum x applii (Domin) Boros from Uruguay

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1 J. Essent. Oil Res., 6, 38'd-3'd3 qu\jaug 1'd94) New Chemotypes of Origanum x applii (Domin) Boros from Uruguay E. Dellacassa," G. Mahler, D. Szwedzki, P. Moyna and E. Alonso! Cdtedra de Fannacognosia 'Cdtedra da Botdnica, Facultad de Quimica Universidad de la Republica Gral. Flores 2124, Montevideo, Uruguay M. Maffei Dipartimento di Biologia Vegetale, Unicersita di Torino Viale Mattioli 25, Torino, Italy Received: December 1993 ABSTRACT: Essential oils obtained from the dried plants harvested in full bloom of Origanum x applii (Domin) Boros from Uruguay, were analyzed by ce. Three different local populations (O.A. 1030, a.a and a.a. 1032) were considered and statistically compared. Twenty-seven oil constituents were identified. The major oil components for a.a and O.A were respectively thymol (26.41%), linalyl acetate ( %) and y-terpinene ( %), while a.a had higher percentages of p-cymene (20.80%), terpinen-4-o1 (17.00%) and sabinene (.5.32%). A clear chemotypic partition was present between a.a and the two other populations. KEY WORD INDEX: Origanum x applii, Lamiaceae, essential oil composition, chemotypes, thymol, linalyl acetate, p-cymene, terpinen-4-ol. INTRODUCTION: Origanum species have been cultivated in Uruguay for long time as flavoring agents and, to a minor extent, as medicinal plants. O. xapplii (Domin) Boros (1), described as a hybrid between 0. vulgare (2-4) and O. rnajorana (4-7), was found to be the only Origanum cultivated in Uruguay. In contrast with the abundant information on the parent species, little is known about the oil composition of O. x applii. Three representative populations of O. x applii were selected. Even though no morphological difference could be found among the chemotypes, they were also chosen because ofdistinctive "sensorial" properties attributed to each of them by their local use. In this paper, we describe the chemical composition of the oils of some populations of 0. x applii and report the existence of new chemotypes. "Address for correspondence /94/ $04.00/G Allured Publishing Corp. 389

2 390 JOURNAL OF ESSENTIAL OIL RESEARCH Table I. Percentage composition of the essential oils from some Origanum x applii populations O.A O.A.1031 a.a.1032 a-pinene camphene ~-pinene sabinene myrcene a-terpinene Iimonene 1,8-cineole (Z}-~-ocimene y-terpinene (E}-~-ocimene p-cymene terpinolene 3-octanol ~-bourbonene linalool linalyl acetate ~-caryophyllene terplnen-a-ol ~-farnesene* n-hurnulene" a-terpineol germacrene D 8-cadinene* y-cadinene* thymol carvacrol Total *tentative identification EXPERIMENTAL: Plant Material-Three local populations: Aleman Blanco ( ), Toledo (0.A.1031) and Negro Criollo (0.A.1032) ofo. xappliiwere obtained frocrops cultivated in southern Uruguay (Depto. de Canelones, Pando). Plants were collecte in full bloom between November and December, air-dried and stored at 4 C unprocessed. Voucher specimens have been deposited in the Herbarium of the Botanic Department of the Facultad de Quimica, Universidad de la Republica, Montevide (MVFQ).

3 JOURNAL OF ESSENTIAL OIL RESEARCH 391 o Distances 10 O.A O.A O.A.1032 A Figure lao Tree diagram from the cluster analysisperformed on the oil components of Table I. The two populations Aleman Blanco (O.A. 1030) and Toledo (O.A. 1031) showed close statistical linkage. PC linalyl acetate p-cymene. o terpinen-4-ol )'terpinene. thymol. sabinene -1 carvacrol aterpineol I myrcene 1.: 1 " ~AII other 5 compounds 4 PC PC3 - Figure lb. Scatter plot of essential oil component factor scores on the three main axis of the PCA. Thymol, carvacrol and some monoterpenes were clearly partitioned. B Oil Extraction and Analysis-Fifty g of dry flowers were distilled for 1 h using a Clevenger-type apparatus (8). Theoil contentwas determinedon a dryweightbasis (% vol! drywt.). Oils were injected into a split/splitless injector (10 sec splitless) of a Hewlett Packard 5890A gas chromatograph equipped with FID. Separation was performed with a 50 m x0.2 mm x0.3 11m HP-FFAP columnwith the following temperature program: 60 C isothermal for 1 min, then at the rate of5 C/min to 200 C held for 10 min; Injector220 C; Detector230 C. Peak areas were calculated with a Hewlett Packard 3396 integrator. Peak identification was based on R t comparison with pure standards.

4 392 JaURNAL or ESSENTIAL OIL RESEARCH Statistical Analysis-Cluster Analysis (CA) and Principal Component Analysis (PC were performed on essential oils by using a Systat 5.2 software for Macintosh as describe elsewhere (10,11). RESULTS AND DISCUSSION: The oil contentof flowering plants was 0.55% for a. 1030,1.32% for a.a and 2.15% for a.a The GC analyses of the oils revealed tj presence of 27 compounds, including mono- and sesquiterpenes and phenols (Table I). The major constituents for a.a and a.a were thymol, linalyl acetate ai terpinen-i-ol, whereas a.a differed by higher percentages of p-cymene, sabine and carvacrol along with very low percentages of thymol and germacrene D (Table I) The oil composition of O. xapplii previously reported by Xifreda (1) does not correspol to the analyses reported for the three chemotypes under study. In addition, no similariti were observed between our samples and O. majorana (5) or O. oolgare (2). However, hi percentages of terpinen-t-ol and y-terpinene have already been observed in SOT populations O. majorana var. tenuifolium, while carvacrol was the main constituent O. Ollites and 0. dubium (9). To obtain more information about possible partition between the three populations, d: from Table I were statistically processed using CA and PCA. CA revealed (Figure la) t presence of two clusters, the first made by a.a and a.a. 1031, which were clos. statisticallylinked, and the second clustermadeby a.a with a distance indicating 1 linkage with the other populations. PCA was calculated in order to individualize which constituents were responsible for this partition. The results of this analysis are shown Figure lb. The percent of total variance explained by the three PCs was vely high. P (64.6%) was characterized by positive component loadings for a.a and a.a. 10 while PC2 (35%) had positive component loadings associated to a.a The results of this study revealed, among the 0. x applii populations considered, presence of two distinct chemotypes: one represented by local populations Aleman Blat (a.a. 1030) and Toledo (a.a. 1031); and another belonging to the local population Ne Criollo (a.a. 1032). ACKNOWLEDGMENTS: The authors are grateful to the technical staff of Calpando the samples, PEDECIBA Project PNUD URU for financial support. Authors: Mahler and D. Szwedzki would like to thank LN.LA. (Instituto Nacional de Investigac Agropecuaria) for research grants. REFERENCES L C. C. Xifreda, Sobre oreganos culticados en Argentina. Kurtziana, 16, (1983). 2. L. Zhangwan and Z. Thonghui, Studies on the components ofessential oilsojelshotziasplenc and Origanum vulgare. Yaoxue Xuebao, 18, (1983). 3. I. Nykanen, High resolution gas chromatographic-mass spectrometric determination of flavour composition oj wild marjoram (Origanum vulgare L.) cultivated in Finlc Z. Lebensrn. Unters. Forsch., 183, (1986). 4. Y. Han, Rhyu, Gas chromatographic characterization ojoregano and other selected spic«the Labiatae family. J. Food Sci., 44, (1979). 5. M. E. Kornaitis, Composition ofthe essential oil ofmarjoram (Origanum majorana L.). F Chern., 45, (1992). 6. R. Caniato, E. M. Cappelletti and R. Filippini, Substitution oj Thymus mastichina Origanum majorana in commercial samples. Fitoterapia, 60, (1989). 7. E. Sarer, J.J.C. Scheffer and A. Svendsen, Monoterpenes in the essential oil of Origa majorana. J. Med. Plant Res. Planta Med., 46, (1982).

5 JOURNAL OF ESSENTIAL OIL RESEARCH D. J. Charles and J. E. Simon, Comparison ofextraction methodsfor the rapid determination ofessential oil content and composition ofbasil (Ocimum spp.). J. Amer. Soc. Hort. Sci., 115, (1990). 9. N. Arnold, B. Bellomaria, G. Valentini and H. J. Arnold, Comparative study ofthe essential oils from three species oforiganum growing wild in the Eastern Mediterranean Region. J. Essent. Oil Res., 5, (1993). 10. T. Sacco, V. Peracino and M. Maffei, Phenotypic plasticity in Mentha viridis lavanduliodora. J. Essent. Oil Res., 4, (1992). 11. M. Maffei,V. Peracino and T. Sacco, Multivariate methodsfor aromatic plant«:an application to mint essential oils. Acta Hortic., 330, (1993)...