871 resultados para CHEMISTRY, MULTIDISCIPLINARY
Resumo:
Four new (1-4) and seven known (5-11) benzaldehyde derivatives were characterized from the liquid fermentation cultures of Eurotium rubrum, an endophytic fungus that was isolated from the inner tissue of stems of the mangrove plant Hibiscus tiliaceus. The structures of these compounds were determined by extensive analysis of their spectroscopic data. Among these metabolites, compound 1, which was named as eurotirumin, possesses a new carbon skeleton with a cyclopentabenzopyran ring system.
Resumo:
A new fungus-derived benzodiazepine analogue, 2-hydroxycircumdatin C (1), and a compound which has been isolated from a natural resource for the first time, but has been previously synthesized, namely (11aS)-2,3-dihydro-7-methoxy-1H-pyrrolo[2,1-c][1,4]benzodiazepine-5,11(10H,11aH)-dione (2), along with five structurally related known alkaloids (3-7), were isolated from Aspergillus ochraceus, an endophytic fungus derived from the marine brown alga Sargassum kjellmanianum. Their structures were established on the basis of spectroscopic methods. The absolute configuration of I was determined through CD evidence. Compound 1 displayed significant DPPH radical-scavenging activity with an IC50 value of 9.9 mu M, which is 8.9-fold more potent than that of butylated hydroxytoluene (BHT), a well-known synthetic positive control.
Resumo:
BACKGROUND: Previously, tachyplesin gene (tac) has been successfully transferred into Undaria pinnatifida gametophytes using the method of microprojectile bombardment transformation. The objectives of this study were to compare and evaluate the performance of bubble-column and airlift bioreactors to determine a preferred configuration of bioreactor for vegetative propagation of transgenic U. pinnatifida gametophytes, and to then investigate the influence of light on vegetative propagation of these gametophytes, including incident light intensity, photoperiod and light quality to resolve the problems of rapid vegetative propagation within the selected bioreactor. RESULTS: Experimental results showed that final dry cell density in the airlift bioreactor was 12.7% higher than that in the bubble-column bioreactor under the optimal aeration rate of 1.2 L air min(-1) L-1 culture. And a maximum final dry cell density of 2830 mg L-1 was obtained within the airlift bioreactor using blue light at 40 mu mol m(-2) s(-1) with a light/dark cycle of 14/10 (h). Polymerase chain reaction (PCR) analysis indicated that genes (bar and tac) were not lost during rapid vegetative propagation within the airlift bioreactor. CONCLUSION: The airlift bioreactor was shown to be much more suitable for rapid vegetative propagation of transgenic U. pinnatifida gametophytes than the bubble-column bioreactor in the laboratory. The use of blue light allows improvement of vegetative propagation of transgenic U. pinnatifida gametophytes. (C) 2009 Society of Chemical Industry
Resumo:
Four new halogenated sesquiterpenes, 10-bromo-3-chloro-2,7-epoxychamigr-9-en-8a-of (1), 2,10 beta-dibromochamigra-2,7-dien-9 alpha-ol (2), (9S)-2-bromo-3-chloro-6,9-epoxybisabola-7(14),10-diene (3), and (9R)-2-bromo-3-chloro-6,9-epoxybisabola-7(14),10-diene (4), were characterized from the marine red alga Laurencia saitoi. In addition, two known halosesquiterpenes, 2,10-dibromo-3-chlorochamigr-7-en-9 alpha-ol (5) and isolaurenisol (6), were also isolated and identified. Their structures were established on the basis of extensive analysis of spectroscopic data.
Resumo:
Four new Daphniphyllum alkaloids. daphlongamines E-H (1-4, resp.), along with 19 known alkaloids, were isolated front the leaves of Daphniphyllum longeracemosum. Their structures were characterized by spectroscopic methods, especially 2D-NMR techniques. It is noteworthy that aconitine- and veatchine-type diterpenoid alkaloids were also isolated from this species.
Resumo:
A new rearranged chamigrane sesquiterpene, named laurenokamurin, was isolated from the marine red alga Laurencia okamurai. Its structure was determined on the basis of spectroscopic methods. (C) 2008 Bin Gui Wang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
Resumo:
A new cembranolide diterpene with a hydroperoxyl substitution was isolated from the marine soft coral Lobophytum crassum. The structure was elucidated on the basis of chemical and spectral methods.
Resumo:
The spectral properties of the glutaraldehyde-treated phycobilisomes were studied. The results showed that glutaraldehyde was effective in preventing phycobilisomes from dilution-induced dissociation and preserving the intra-phycobilisomes energy transfer.
Resumo:
The thermophily, fishing season and central fishing ground of Japanese pilchard (Sardinops melanosticta) were studied by using satellite remote sensing (SRS) and other methods in Haizhou Bay and Tsushima waters during 1986-1990. A rapid prediction method of fishing ground is presented. Moreover, the results indicated that the thermophilic values of the fish stock are 11-20 degrees C and both fishing grounds are in increasing temperature process from the beginning to the end of the fishing period. The Japanese pilchards gather vigorously at the sea surface temperature of 15-17 degrees C. The water temperature is a key factor affecting the fishing season and the catch of the fishing ground. The increasing temperature process restricts the fishing season development and central fishing ground formation. The accuracy of 15 predictions made in the Haizhou Bay fishing ground is up to 91.3%, and 37 predictions made in the Tsushima, fishing ground shorten the fish detection time by 13.4% - 22% on the average.
Resumo:
Two new aristolane sesquiterpenes, namely, aristolan-10-ol-9-one and aristolan-8-en-1-one, were isolated from the red alga Laurencia similis. Their structures were established on the basis of various NMR spectroscopic analyses, including 2D NMR techniques (H-1-H-1 COSY, HMQC, HMBC, and NOESY) and HR-FAB-MS. (c) 2007 Bin Gui Wang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
Resumo:
Two new brominated diterpenes, namely, laurendecumtriol and 11-deacetylpinnaterpene C, were isolated and identified from the marine red alga Laurencia decumbens. Their structures were established on the basis of various NMR spectroscopic techniques and HR-ESI-MS analyses. (c) 2007 Bing Gui Wang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
Resumo:
Cultivation of an endophytic fungus Aspergillus niger EN-13 that was isolated from the inner tissue of the marine brown alga Colpomenia sinuosa resulted in the characterization of a new naphthoquinoneimine derivative, namely, 5,7-dihydroxy-2-[1-(4methoxy-6-oxo-6H-pyran-2-yl)-2-phenylethylaniino]-[1,4]naphthoquinone. The structure of the new compound was established on the basis of various NMR spectroscopic analyses including 2D NMR techniques, EI-MS, and HR-ESI-MS. This compound displayed moderate antifungal activity. (c) 2007 Bin Gui Wang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
Resumo:
A new acylated iridoid glucoside, namely, 2'-O-(5-phenyl-2E, 4E-pentadienoyl)mussaenosidic acid, was isolated from the aerial parts of the mangrove plant Avicennia marina. The structure of the new compound was established on the basis of various NMR spectroscopic analyses, including 2D NMR techniques (H-1-H-1 COSY, HMQC, and HMBC) and HR-FAB-MS. This compound displayed moderate antioxidant activity.
Resumo:
new brominated C-15-acetogenin, namely, laurenidificin, was isolated from the marine red alga Laurencia nidifica. Its structure was determined on the basis of spectroscopic methods. (C) 2010 Bin Gui Wang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
Resumo:
During the period of the post-glacial transgression maximum (PGTM), there was a huge trumpet estuary in the modern Changjiang River Delta area. The location and the shape of the Paleo-Changjiang River Estuary (PCRE) were much different from those of the present Changjiang River Estuary. The study on the change of characteristics of tidal wave in the Changjiang River mouth area since the PGTM can help to understand better the dynamic development of the Changjiang River Delta. The course curves of tidal level and tidal current velocity during a single tidal cycle for 35 points are calculated, and characteristics of tidal waves in the PCRE and its adjacent area are compared with those of tidal waves in the modern Changjiang River mouth area. The results show that the tidal waves within the PCRE and in its adjacent area during the period of the PGTM belonged to standing wave or a mixture of standing wave and progressive wave. Since then, the tidal wave in the Changjiang River mouth become gradually to be progressive wave with the PCRE being filled and the Changjiang River mouth shifting southeastwards.