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Objective To investigate the main chemical constituents of the low polarity extracts from pinusmassoniana Lamb. leaves and their synergetic activity with fluconazole against fluconazole-resistant Candida albicans. Methods The pinusmassoniana leaves were extracted with 80% ethanol, and then the extracts were extracted by petroleum ether to obtain the low polarity extracts. The chemical components were detected by GC-MS and elucidated by the comparison with the standard mass spectral data. The relative contents in percentage were calculated using the area normalization method. The minimal inhibitory concentrations (MIC80) of fluconazole-resistant Candida albicans strains by the low polarity extracts in combination with fluconazole were determined by checkerboard microdilution assay. Results 30 components were detected from the low polarity extracts, and 17 components were identified. The minimum inhibitory concentration (MIC80) of the 80% ethanol extracts, the low polarity extracts and the petroleum ether extracts from the pinusmassoniana leaves combined with fluconazole against fluconazole-resistant Candida albicans were 7.81 μg/ml, 31.25 μg/ml and >250 μg/ml, respectively. Conclusion The 80% ethanol extracts of pinusmassoniana leaves and its low polarity extracts have synergistic activity combined with fluconazole onfluconazole-resistant Candida albicans. The diterpenoids (53.99%) may be the effective components of the low polarity extracts.
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Objective: To investigate the low polarity components in the stems of Uvaria macrophylla Roxb. var.microcarpa(Champ.)Finet et Gagnep.(Annonaceae). Methods: The dry stems of the title plant were extracted by re-fluxing with 95% ethylalcohol(80℃),and the obtained aqueous alcohol solution was evaporated to remove alcohol,andthen the ethyl alcohol extracts were extracted with petroleum ether(PE)to obtain a PE extract. The chemical constitu-ents in the PE extract were analyzed by GC-MS and identified by comparison of the obtained MS data with the standardmass spectral data. The relative contents in percentage were calculated for the constituents using the area normalizationmethod. Results: Ten compounds were identified,in which the palmitic acid(16.76%),4(14)- 11- eucalypene(15.31%),and selinene(14.45%)were the main components. Conclusion: The low polarity components in the stemsof Uvaria macrophylla Roxb. var. microcarpa(Champ.)Finet et Gagnep. mainly consisted of naphthalenes(31%),fol-lowed by sesquiterpenoids(29.76%).
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OBJECTIVE： To compare low-polarity volatile constituents in supercritical CO2 extract from the roots and stem of Ilex asprella and its effects on the proliferation of IEC-6 in vitro， and to provide reference for making full use of wild resources of I. asprella and expanding its medicinal parts. METHODS： The low-polarity volatile constituents were extracted from the root and stem of I. asprella with supercritical fluid CO2 extraction（SFE-CO2）. The chemical constituents were analyzed by GC-MS. IEC-6 cells were treated with different concentrations of supercritical CO2 extracts （0， 1， 5， 10， 20， 40， 60， 80， 100 μg/mL） from roots or stems of I. asprella. MTT assay was used to detect the relative viability， and cell proliferation curve was drawn and EC50 of each extract were calculated. RESULTS： Sixty-two and forty-six low-polarity volatile constituents were identified from supercritical CO2 extract in the roots and stem of I. asprella with GC-MS； there were 24 common constituents totally， mainly including pelargonic acid（14.18％ and 6.14％），octanoic acid（10.59％ and 4.35％），hexanoic acid（8.63％ and 10.86％），paeonol（7.79％ and 6.00％），2-methyl-3-phenyl-propanal（6.3％ and 0.58％），acetic acid（1.72％ and 33.77％） in root and stem， respectively. The results of cell culture in vitro showed that when the concentration of supercritical CO2 extract from the roots and stems of I. asprella was lower （≤60 μg/mL）， it could significantly promote the proliferation of IEC-6 cells and their EC50 were 16.35， 20.20 μg/mL， respectively； when the concentration of the extract was higher （≥80 μg/mL）， it showed cytotoxicity and inhibited the proliferation of IEC-6 cells. CONCLUSIONS： There are similar species of volatile constituents in roots and stems of I. asprella and similar in vitro bioactivity of the supercritical CO2 extracts to IEC-6 cells. The short-chain fatty acids may be the active ingredient to promote cell proliferation， while paeonol may be the cytotoxic active ingredient.
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Based on the electric field shielding and insulation technology, the single electrode dielectric barrier discharge ion source ( DBDI ) has the characteristics of uniform discharging, stability, and high ionization energy, and thus can be used to detect various samples with a large range of polarity. However, the ionization energy is too high to reduce the background signal noise, and thus affects the detection effectiveness to low polarity and low boiling point samples. To enhance the detection effectiveness to these samples, a method of eliminating electrons of single electrode DBDI by using external metal electrodes was developed in this study. Then, the single electrode DBDI was improved by an external needle electrode and an external metal net, respectively. The mechanism of those external metal electrodes was discussed, and the experimental studies were carried out. The results showed that the external metal net technology had an advantage in improving signal to noise ratio ( SNR ) , and the enhancement of SNR for the detection of isoprocarb, perfluorooctanoic acid and SudanⅢwas about 5-6 times. Based on the technology, a method for determination of Sudan Ⅲ in chili powder was developed. The recoveries, RSD and LOD were 83. 7%-94. 6% , 5. 6%-9. 0% and 23 mg/kg, respectively. The external metal electrode technique has broadened the detection range of single electrode DBDI to the field of low polarity, low boiling point and complex samples.
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Objective: To study the low-polarity chemical constituents from the whole plants of Scrophularia dentata grown in Tibet. Methods: The compounds were isolated and purified by various column chromatography. Their structures were elucidated by means of spectral analyses (MS, 1H-NMR, and 13C-NMR). Results: Fifteen compounds were isolated and identified as oleanolic acid (1), 3-O-acetyloleanolic acid (2), stigmast-4-en-3-one (3), stigmast-4, 22-dien-3-one (4), 2, 6-dimethoxybenzoquinone (5), cerevisterol (6), cinnamic acid (7), spinasterol (8), β-sitosterol (9), 2-tritriacontanone (10), 2-(4-hydroxyphen-yl)-ethyl 1-dodecyloctadecanoate (11), apigenin (12), chrysoeriol (13), medioresinol (14), and syringaresinol (15). Conclusion: All the compounds are firstly isolated from this plant and compounds 2-6 and 10-15 are isolated from the plants of this genus for the first time.