Cevanine-type steroidal alkaloids from the bulbs of Fritillaria cirrhosa D. Don.

Eight previously undescribed cevanine-type steroidal alkaloids, cirrhosinones I-N and cirrhosinols A-B, along with five known analogs, were isolated from the bulbs of Fritillaria cirrhosa D. Don. Their structures were elucidated on the basis of comprehensive analysis of HRESIMS, 1D and 2D NMR spectroscopic data, and single-crystal X-ray diffraction analyses. All compounds revealed weak NO inhibitory activities in the LPS-stimulated NR8383 cells at the concentration of 20 µM, with inhibition ratios ranging from 5.1% to 14.3%.

Steroidal alkaloids and their glycosides from the bulbs of Fritillaria unibracteata.

Seven undescribed steroidal alkaloids, including two jervine-type steroidal alkaloids, fritiunibras A-B (1-2), and five cevanine-type steroidal alkaloid glycosides, fritiunibras C-G (3-7), along with six known cevanine-type steroidal alkaloids and their glycosides (8-13) were isolated from the bulbs of Fritillaria unibracteata Hsiao et K. C. Hsia. Their structures were determined by interpretation of comprehensive spectroscopic and single-crystal X-ray diffraction analysis. The absolute configurations of sugar moieties were determined by HPLC analysis and compared with standards after hydrolysis and derivatization. Furthermore, their inhibitory effects on NO production and cytotoxic activities were evaluated.

Essential oil composition and larvicidal activity of Toddalia asiatica roots against the mosquito Aedes albopictus (Diptera: Culicidae).

The aim of this research was to determine larvicidal activity of the essential oil derived from roots of Toddalia asiatica (L.) Lam. and the isolated constituents against the larvae of the Culicidae mosquito Aedes albopictus. Essential oil of T. asiatica roots was obtained by hydrodistillation and analyzed by GC and GC-MS. A total of 58 components of the essential oil of T. asiatica roots were identified. The essential oil has almost same content of (35.41 %) of sesquiterpenoids and monoterpenoids (31.87 %). The principal compounds in T. asiatica essential oil were geraniol (9.84 %), D-limonene (7.52 %), isopimpinellin (6.62 %), α-gurjunene (6.25 %), and 4-vinylguaiacol (5.94 %). Based on bioactivity-directed fractionation, geraniol, D-limonene, and isopimpinellin were isolated from T. asiatica root essential oil. Geraniol, D-limonene, and isopimpinellin exhibited strong larvicidal activity against A. albopictus with LC(50) values of 30.13, 19.84, and 32.05 µg/ml, respectively, while the essential oil of T. asiatica had an LC(50) value of 69.09 µg/ml. The result indicated that the essential oil of T. asiatica roots and the three isolated constituents have potential for use in control of A. albopictus larvae and could be useful in search of newer, safer, and more effective natural compounds as larvicides.

Chemical composition and insecticidal activity of the essential oil of Illicium pachyphyllum fruits against two grain storage insects.

The aim of this research was to determine chemical composition and insecticidal activity of the essential oil of Illicium pachyphyllum fruits against two grain storage insects, Sitophilus zeamais and Tribolium castaneum, and to isolate any insecticidal constituents from the essential oil. The essential oil of I. pachyphyllum fruits was obtained by hydrodistillation and analyzed by GC-MS. A total of 36 components of the essential oil were identified, with the principal compounds in the essential oil being trans-ρ-mentha-1(7),8-dien-2-ol (24.56%), D-limonene (9.79%), caryophyllene oxide (9.32%), and cis-carveol (5.26%) followed by ß-caryophyllene (4.63%) and bornyl acetate. Based on bioactivity-guided fractionation, the three active constituents were isolated and identified as trans-ρ-mentha-1(7),8-dien-2-ol, D-limonene and caryophyllene oxide. The essential oil of I. pachyphyllum fruits exhibited contact toxicity against S. zeamais and T. castaneum adults, with LD(50) values of 17.33 µg/adult and 28.94 µg/adult, respectively. trans-p-Mentha-1(7),8-dien-2-ol (LD(50) = 8.66 µg/adult and 13.66 µg/adult, respectively) exhibited stronger acute toxicity against S. zeamais and T. castaneum adults than either caryophyllene oxide (LD(50) = 34.09 µg/adult and 45.56 µg/adult) and D-limonene (LD(50) = 29.86 µg/adult and 20.14 µg/adult). The essential oil of I. pachyphyllum possessed fumigant toxicity against S. zeamais and T. castaneum adults with LC(50) values of 11.49 mg/L and 15.08 mg/L, respectively. trans-p-Mentha-1(7),8-dien-2-ol exhibited stronger fumigant toxicity against S. zeamais and T. castaneum adults, respectively, with LC(50) values of 6.01 mg/L and 8.14 mg/L, than caryophyllene oxide (LC(50) = 17.02 mg/L and 15.98 mg/L) and D-limonene (LC(50) = 33.71 mg/L and 21.24 mg/L). The results indicate that the essential oil of I. pachyphyllum fruits and its constituent compounds have potential for development into natural insecticides or fumigants for the control of insects in stored grains.

Control of bromate and THM precursors using ozonation combined system / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To investigate the feasibility of reducing THM precursors and controlling bromate taste and odor in drinking water taken from the Yellow River by an ozonation combined system.</p><p><b>METHODS</b>The appropriate ozone dosage was determined, and then the changes of TOC, UV254 and THM formation potential (THMFP) in the combined system were evaluated.</p><p><b>RESULTS</b>One mg/L ozone could effectively remove taste and odor and meet the maximum allowable bromate level in drinking water. The pre-ozonation increased THMFP, but the conventional treatment system could effectively reduce the odor. The bio-ceramic filter could partly reduce CHCl3FP, but sometimes might increase CHCl2BrFP and CHClBr2FP. The biological activated carbon (BAC) filter could effectively reduce CHCl3FP and CHCl2BrFP, but increase CHClBr2FP. Compared with other filters, the fresh activated carbon (FAC) filter performed better in reducing THMFP and even reduced CHClBr2FP.</p><p><b>CONCLUSION</b>The combined system can effectively reduce taste, odor, CHCl3FP, and CHCl2BrFP and also bring bromate under control.</p>

Reduction of precursors of chlorination by-products in drinking water using fluidized-bed biofilm reactor at low temperature / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To investigate the reduction of chlorination by-products (CBPs) precursors using the fluidized-bed biofilm reactor (FBBR).</p><p><b>METHODS</b>Reduction of total organic carbon (TOC), ultraviolet absorbance (UV254), trihalomethane (THM) formation potential (THMFP), haloacetic acid (HAA) formation potential (HAAFP), and ammonia in FBBR were evaluated in detail. Results The reduction of TOC or UV254 was low, on average 12.6% and 4.7%, respectively, while the reduction of THMFP and HAAFP was significant. The reduction of ammonia was 30%-40% even below 3 degrees C, however, it could quickly rise to over 50% above 3degrees C. Conclusions The FBBR effectively reduces CBPs and ammonia in drinking water even at low temperature and seems to be a very promising and competitive drinking water reactor for polluted surface source waters, especially in China.</p>