Composition and some biological activities of the essential oil of Callicarpa americana (L.)
ABSTRACT The essential oil profile of Callicarpa americana was examined. Samples were collected from Lafayette county in north central Mississippi, and GC-MS data and retention indices were used to identify 67 oil components. Humulene epoxide II (13.9%), alpha-humulene (10.0%), 7-epi-alpha-eudesmol (9.4%), beta-pinene (8.8%), and 1-octen-3-ol (8.5%) were the major components of the steam-distilled oil. The oil was selectively toxic toward the cyanobacterium Oscillatoria perornata compared to Oscillatoria agardhii and the green alga Selenastrum capricornutum, with complete growth inhibition at 28.5 microgram/mL. The oil was only mildly phytotoxic and antifungal.
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ABSTRACT: Pecan scab (caused by Fusicladium effusum) limits the productivity of pecan in the southeastern USA. Alternatives to conventional fungicides should be biorational, of low environmental risk with a lower risk of fungicide resistance. Research showed that metabolites from the nematode symbiont Photorhabdus luminescens suppress pecan scab, but the bioactive molecules had not been identified. Extracts from P. luminescens were investigated using a bioactivity-directed fractionation approach to identify the constituent(s) responsible for the activity. High throughput antifungal bioautography assays against Colletotrichum gloeosporioides, C. fragariae, and C. acutatum were used to guide the fractionation. One of the metabolites was purified and identified as trans-cinnamic acid (TCA) using silica gel chromatography followed by semi-preparative high-performance liquid chromatography. In vitro tests confirmed toxicity of TCA to C. gloeosporioides, C. fragariae, and C. acutatum at 10 and 100 μg mL−1 using fungal bioautography inhibition screening plates. The antimycotic activity of TCA was tested in vitro against F. effusum. Zone of inhibition tests, and tests with TCA incorporated into agar showed TCA toxicity to F. effusum at concentration 148–200+ μg mL−1. Further tests incorporating TCA into liquid media demonstrated that TCA arrested all growth of F. effusum at a concentration even as low as 64 μg mL−1. Naturally occurring antimicrobial products might offer an alternative to disease control in crops, helping in minimizing the risk of fungicide resistance, while also minimizing any negative impact on the environment. Additional research is warranted to determine the potential to use TCA as a suppressive agent for pecan scab and other diseases.Journal of Pest Science 03/2014; 87(1). DOI:10.1007/s10340-013-0519-5 · 2.66 Impact Factor
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ABSTRACT: Essential oils from fresh leaves of Sclerocarya birrea (A. Rich.) Hochst. were extracted by steam distillation. The oil yield from plant collected during the hot season (February) was 0.10±0.02 and 0.24±0.01% from plant collected during the cold season (August). GC/FID and GC/MS analysis allowed us to identify a total of 49 compounds, representing 98% of the hydrodistillate. The oils contained about 96% sesquiterpenes among which 38±0.034% of 7-epi-α-selinene during the hot season and 51.7±0.12% of 7-epi-α- selinene during the cold. The main components of the oil from the hot period were 7-epi-α-selinene (38±0.03%), α-muurolene (25±0.03%), valencene (17±0.06%), β-selinene (4.3±0.01), β-caryophyllene (3.2±0.02) allo-aromadendrene-epoxide (1.5±0.03) and 14-hydrox-α-humulene (1.5±0.03). The essential oil from the cold season was characterized by 7-epi-α-selinene (51.7±0.12%), β-selinene (15.1±0.2%), valencene (12.9±0.05%), α-selinene (8.1±0.03) and β-caryophyllene (1.8±0.02%). This is the first report of these components in the essential oil of Sclerocarya birrea.Journal of medicinal plant research 09/2011; 5(18):4640-4646. · 0.88 Impact Factor
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ABSTRACT: Plant essential oils are secondary metabolites which show broad spectrum antimicrobial activity. Chemically essential oils are aromatic liquids with specific volatile odour or flavor and a combination of benzene derivatives, terpenes various hydrocarbons and straight chain compounds. Essential oils isolated from different plant species contain lectins, polypeptides, alkaloids, phenols, quinines, flavones, flavonoids, terpenoids, tannins and coumarins and show activity against bacteria, fungi, viruses, protozoans, helminthes and insects. Minor constituents or smaller molecules having less than twenty carbon atoms constitute essential oils having a chemical structure, C 10 H 16 and show a characteristic transparency due to their volatility on contact with air. These phytochemicals, possess mixed functional groups, are too complex in structure and act more efficiently even against drug resistant microbes because of high volatility at a very low temperature and quick spread in the environment and medium. Essential oils are used for perfuming, flavoring, food preservation and also in aromatherapy for treatment of cancer. These are also used as alternative medicine, show very high lethality against pathogens and least residual effect in the body.