Volatile composition and antimicrobial activity of twenty commercial frankincense essential oil samples

Trees from the genus Boswellia (Burseraceae) are traditionally used as a medicine, a fumigant, in various cosmetic formulations and in aromatherapy in several countries around the world. This plant produces a commercial oil known as frankincense which has a woody, spicy and haunting smell. Frankincense oil has several pharmacological properties, of which many elude to the anti-infective potential. Variation in the chemical composition of this oil has been reported in literature. These factors prompted an investigation to study the commercial frankincense oils from various international suppliers. Twenty essential oils were analyzed by gas chromatography coupled to mass spectrometry. Considering the major constituents, the oils were found to be qualitatively similar. However, there was immense quantitative variation for certain oil constituents. The components identified and their range in the oils include α-pinene (2.0–64.7%); α-thujene (0.3–52.4%); β-pinene (0.3–13.1%); myrcene (1.1–22.4%); sabinene (0.5–7.0%); limonene (1.3–20.4%); p-cymene (2.7–16.9%) and β-caryophyllene (0.1–10.5%). The antimicrobial activity (minimum inhibition concentration assay) of the oils was investigated against five reference test organisms and the activity ranged from 4–16 mg/ml (Staphylococcus aureus); 1.5–8.3 mg/ml (Bacillus cereus); 4.0–12.0 mg/ml (Escherichia coli); 2.0–12.8 mg/ml (Proteus vulgaris) and 5.3–12.0 mg/ml (Candida albicans).     

连翘挥发油成分分析

从连翘果实中提取了挥发油,用气相色谱-质谱联用法分析其挥发油的化学成分,鉴定出β-蒎烯、香桧烯、α-蒎烯等56个化合物,并用气相色谱测定了挥发油中各成分的相对含量,其鉴定率达93.37％。     

Characteristic Odor Components of Citrus reticulata Blanco (Ponkan) Cold-pressed Oil

Citrus reticulata Blanco (ponkan) cold-pressed oil and its oxygenated fraction were studied by analytical (GC and GC/MS) and sensory analyses. The monoterpene group was predominant, accounting for more than 89.6% (w/w), of which limonene was the most abundant (80.3%). Among the oxygenated compounds, octanal and decanal were the major ones among 12 aldehydes accounting for >1.5%; six alcohols were identified with a total concentration of >0.7%, while oxides, ketones and esters did not quantitatively or qualitatively contribute to the oil. Sniffing the ponkan cold-pressed oil and its oxygenated fraction demonstrated that octanal and decanal were the characteristic odor components of ponkan. Reconstruction of the ponkan aroma model and its sensory evaluation by a hedonic test were performed, showing that, in addition to octanal and decanal which played important roles, (R)-(+)-limonene contributed to the aroma model as a background component, making the aroma model very similar to that of the original.     

Effects of Citrus sinensis (L.) Osbeck epicarp essential oil on growth and morphogenesis of Aspergillus niger (L.) Van Tieghem

Essential oils from different plant parts are known for their antimicrobial activity but the antifungal effects of essential oil from Citrus sinensis (L.) Osbeck epicarp on growth and morphogenesis of Aspergillus niger has not been observed so far. The mycelial growth was inhibited at 2.5 and 3.0 μg/ml of oil in Potato Dextrose Broth and Agar medium, respectively. These concentrations were fungicidal under the test conditions. The fungitoxicity of oil did not change even at exposure to 100 °C and autoclaving. The main changes observed under light and scanning electron microscopy after oil treatment were loss of cytoplasm in fungal hyphae, and budding of hyphal tip. The hyphal wall and its diameter became markedly thinner, distorted and resulted in cell wall disruption. The flattened and empty hyphal tips bifurcated into bud like structures. GC-MS studies of the oil revealed the presence of 10 chemical constituents. Limonene has been found to be major component (84.2%).