Indole alkaloids from the seeds of Centaurea cyanus (Asteraceae)
ABSTRACT Preparative RP-HPLC analysis of a methanol extract of the seeds of Centaurea cyanus afforded four indole alkaloids: moschamine, cis-moschamine, centcyamine and cis-centcyamine, the latter two being new natural products. Structures of these compounds were elucidated by comprehensive spectroscopic analyses. General toxicity of the isolates was determined by Brine Shrimp Lethality bioassay.
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ABSTRACT: Essential oil composition of Centaurea kilaea flowers, stems and C. cuneifolia flowers were investigated by GC, GC/MS. Flowers and stems of C. kilaea afforded very low essential oil yield <0.01% (v/w). Nineteen and twenty compounds were identified in the flower and stem oils which represent 59.5% and 77.6% of the C. kilaea oil respectively. The main components of the C. kilaea flower oil were hexadecanoic acid 26.2%, tetradecanoic acid 18.1%, β-Eudesmol 3.3% and decanoic acid 3.1%. The stem oil contains hexadecanoic acid 55.5% and β-Eudesmol 3.2%. Flowers of C. cuneifolia afforded very low essential oil yield <0.01% (v/w). Twenty five compounds were identified in the flower oil of C. cuneifolia which represent 69.92% of the oil. The main components of this oil include hexadecanoic acid 32.9%, tetradecanoic acid 14.4%, heptacosane 6.1% and nonacosane 4.3%. Essential oils obtained from both species have saturated fatty acids and alkanes as the major components, but both oils also contain minor amounts of sesquiterpenes.
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ABSTRACT: Centaurea aucheri (DC.) Wagenitz is one of the species of Asteraceae that has not been the subject of many investigations. Different species of this genus have been used in traditional medicine. In this investigation C. aucheri was collected from Khanesorkh of Kerman and the essential oil of the aerial parts of plant was extracted by Clevenger apparatus and analyzed by GC-MS. Identification of the components of oils were based on their retention indices and mass spectra data in comparison with those reported in literatures. The amount of essential oil was 0.16% and 22 substances consisting 80.03% of the composition of the essential oil were identified. The main compounds were caryophyllene oxide (19.44%), β-caryophyllene (14%), Geremacrene-D (13.38%). The essential oil was rich in sesquiterpene oil. INTRODUCTION The large genus Centaurea (Asteraceae, Cardueae) comprises about 500 species, which are predominantly distributed around the Mediterranean area and in west Asia (1). In Iran this genus has 74 annual to perennial herbaceous species that are widespread around the country (2). Some species of Centaurea genus such as C. cyanus and C. scabosia have anti-pyretic, analgesic, cardiotonic activities and are useful for liver and skin diseases and relif of thestomach-ache (3, 4). Centaurea aucheri (DC.) Wagenitz is a perennial herb that approximately grows all over of the country (5). A literature search showed that no report on the analysis of secondary metabolites of this plant is available. Studies on the volatile constituents are limited to C. cineraria subsp. umbrosa and C. napifolia (6), C. mucronifera and C. chrysantha (7), C. pseudoscabiosa subsp. pseudoscabiosa and C. hadimensis (8) and C. kotschyi var. kotschyi and C. kotschyi var. decumbens from Turkey(9), C. pelia, C. thessala subsp. drakiensis, C. zuccariniana, C. raphanina subsp. mixta, C. spruneri from Greece (1,10) and C. calcitrapa and C. solstitialis from the USA (11,12,13). Other studies deal only with partially characterized essential oils of C. calcitrapa, C. gloriosa and C. moschata (13-16). Secondary metabolites which have been isolated from Centaurea species are: flavonoids, nor-isopernoides, elemanolides, elemanes, germa-crenolides and eudesmanolides (16-19), flavonoid sulfate (20), sesquiterpene lactones (21, 22) and Indole alkaloids (23). This investigation describes the volatile oil constituents of Centaurea aucheri (DC.) Wagenitz. from Iran.
09/2010; 14(3):186-194. DOI:10.1016/S0123-9392(10)70110-7