花卉中醌类及苯丙素类化合物与食疗

分析了中医食疗药膳学与现代营养学的关系,重点介绍了花卉中醌类及苯丙素类食疗因子,介绍了常见食疗花卉食品并进行了展望。     

Citrus phenylpropanoids and defence against pathogens. Part II: Gene expression and metabolite accumulation in the response of fruits to Penicillium digitatum infection

The effect of infection of Citrus sinensis (var. Navelina) fruits with Penicillium digitatum was studied at gene expression and metabolite levels. In this study, expression of genes involved in the phenylpropanoid pathway was studied in the flavedo (outer coloured part of the peel) and albedo (inner white part) in response to pathogen infection. Results of the time-course experiment showed that maximal expression of 10 out of 17 phenylpropanoid genes analysed occurred at 48 h post-inoculation, when decay symptoms started to appear, and mRNA levels either kept constant or decreased after 72 h post-inoculation. To further investigate the putative involvement of the phenylpropanoid pathway in the defence of citrus fruit, changes in the metabolic profile of both tissues infected with P. digitatum was studied by means of HPLC-PDA-FD. Metabolite accumulation levels along the time course suggest that flavanones, flavones, polymethoxylated flavones and scoparone are induced in citrus fruit in response to P. digitatum infection, although with different trends depending on the tissue.     

Floral Phenylpropanoid Cocktail and Architecture of Bulbophyllum vinaceum Orchid in Attracting Fruit Flies for Pollination

It is widely believed that most orchid flowers attract insects by using deception or chemical rewards in the form of nectar. Flowers of Bulbophyllum vinaceum produce a large array of phenylpropanoids that lure tephritid fruit fly males and also act as floral reward, which the flies subsequently convert to pheromone components. The major floral volatile components identified are methyl eugenol (ME), trans-coniferyl alcohol (CF), 2-allyl-4,5-dimethoxphenol (DMP), and trans-3,4-dimethoxycinnamyl acetate, whereas the minor components are eugenol, euasarone, trans-3,4-dimethoxy cinnamyl alcohol, and cis-coniferyl alcohol. Among the various floral parts, the lip (which is held in a closed position up against the sexual organs) has the highest concentration of the major compounds. An attracted male fly normally lands on one of the petals before climbing up onto and forcing the “spring loaded” floral lip into the open position, hence exposing the floral sexual organs. The architecture and location of chemical attractants of the lip compel the fly to align itself along the lip’s longitudinal axis in a precise manner. As the fly laps up the compounds and moves towards the base of the lip, it passes the point of imbalance causing the lip to spring back to its normal closed position. The fly is catapulted headfirst into the column cavity, and its dorsum strikes the protruding sticky base of the hamulus and adheres to it. The momentum of the fly and the structural morphology of the long stiff hamulus act to pry out the pollinia from its anther cover. Hence, the pollinarium (pollinia + hamulus) is detached from the flower and adhered to the fly’s dorsum. In this unique mutualistic association, both species receive direct reproductive benefits—the flower’s pollinarium is transported for cross pollination, and the fly is offered a bouquet of phenylpropanoids (synomone) that it consumes, converts, and/or sequesters as sex pheromonal components, thus enhancing sexual attraction and mating success.     

Volatiles of the Balkan endemic Daucus guttatus ssp. zahariadii and cultivated and wild-growing D. carota – A comparison study

The hydrodistilled essential oil obtained from the aerial parts of Daucus guttatus Sibth. & Sm. ssp. zahariadii Heywood, an endemic plant species of the Balkan Peninsula, as well as solvent extracts and essential oils from different parts of Daucus carota L. have been analysed by GC and GC–MS and screened for antimicrobial activity against 12 bacterial and two fungal strains. The volatiles of the two plant taxa differed significantly in both their chemical identity and antimicrobial effect. The dominant constituent of D. guttatus oil was apiol (43.3%), which was absent from all samples of D. carota. The diethyl ether extract of D. carota inhibited the growth of the yeast Candida albicans while the oil of D. guttatus at 25 mg/ml had no effect on the growth of the fungal organisms tested. Additionally, the oil of D. guttatus showed prominent antibacterial activity against a pathogenic Corynebacterium pyogenes.     

Evaluation of the antioxidant activity of five endemic Ligustrum species leaves from Taiwan flora in vitro

Leaves from the plant species belonging to the genus Ligustrum are widely used as tea or herbal medicine in Europe, China, and Japan. The antioxidant properties of five Ligustrum species from Taiwan were compared using in vitro antioxidant methods such as DPPH radical scavenging, TEAC, and FRAP assays. Cell-based antioxidant methods were used, including Fe²⁺/ascorbate-induced lipid peroxidation on brain homogenate and AAPH-induced erythrocyte haemolysis. The amounts of major phenolic compounds from the Ligustrum species, including phenylpropanoids, flavonoids, and iridoids, were determined by spectrophotometric methods. The results showed that all Ligustrum species exhibited antioxidant, radical-scavenging, anti-haemolytic, and lipid peroxidation-inhibiting activities at different magnitudes of potency. A significant correlation was found between antioxidant activity and the amount of antioxidant components, in particular, total phenolics and phenylpropanoids. Among all Ligustrum species from Taiwan, Ligustrum morrisonense is presented as potential source of natural antioxidants.