Aim To modify the structure of resibufogenin by using Ginkgo bilobasuspension. Methods Young leaves of Ginkgo biloba were differentiated into callus in MS medium withonly 2,4-D as plant growth regulator. The callus wa...Aim To modify the structure of resibufogenin by using Ginkgo bilobasuspension. Methods Young leaves of Ginkgo biloba were differentiated into callus in MS medium withonly 2,4-D as plant growth regulator. The callus was then transferred aseptically to liquid MSmedium exoge-nously supplemented with appropriate concentration of 6-BA, NAA and 2,4-D to establishsuspension cell culture system. Resibufogenin was administered into the well-grown cell cultures andincubated for 4 d. The products dissolved in the liquid phase of the cultures were extracted andpurified by silica gel column chromatography gradiently eluted with petroleum ether and acetonesystem. Results One transformed product was obtained in 40% yield after 4 d incubation, which wasidentified as 3-epi-resibufogenin on the basis of FAB MS, ~1H NMR and ^(13)C NMR spectroscopicanalysis and corresponding data reported in literature. Conclusion G. biloba suspension cultures canbe used as an enzyme system to biotransform resibufogenin, an animal-originated bufadienolide, into3-epi-resibufogenin.展开更多
Deacetoxy-13-oxo sinenxan A (1) was converted to 9a-hydroxy-13-oxo-2a, 5a, 10b-triacetoxy-4(20),11-taxadiene (2) and 10b-hydroxy-13-oxo-2a,5a,9a-triacetoxy- 4(20), 11- taxadiene (3) by Ginkgo cell suspension cultures ...Deacetoxy-13-oxo sinenxan A (1) was converted to 9a-hydroxy-13-oxo-2a, 5a, 10b-triacetoxy-4(20),11-taxadiene (2) and 10b-hydroxy-13-oxo-2a,5a,9a-triacetoxy- 4(20), 11- taxadiene (3) by Ginkgo cell suspension cultures in 45% and 15% yields, respectively.展开更多
The ultrastructure observation, energy spectrum analyses and study on sieve elements in gingko (Ginkgo biloba. L) root phloem showed: 1) The inside wall had a large retention of small grains with a diameter of 3- 4 μ...The ultrastructure observation, energy spectrum analyses and study on sieve elements in gingko (Ginkgo biloba. L) root phloem showed: 1) The inside wall had a large retention of small grains with a diameter of 3- 4 μm, and the outside wall membrane structure wrapped P-protein body with a kernel of high electronic density. 2) The growth had the typical process of programmed cell death (PCD), i.e. the cell karyoplasm condensed, chromatins congealed and contracted and gradually agglomerated to the periphery of the nuclear membrane, and accordingly a nuclear of malformation appeared; the endoplasmic reticulum extended and connected and merged mutually, and the shallow part fused with the cell membrane. After packing the cell organelle, the endoplasmic reticulum divided the cell into several combined necrotic corpuscles of different sizes, the cell organelles collapsing with the cell and gathering abundantly in the inside cell wall. There were two kinds of degradation for the mitochondria: One was that the electronic density of the matrix decreased, the ridges died out to be cavitations gradually, and the double-layer membrane broke and ruined; the other was that parts of the territorial structure of the membrane broke, and the substance it contained escaped. 3) The ultrastructure of the course of gingko root phloem developing from cell with protein thin wall into sieve elements might make out that the P-protein body was produced in PCD and developed with retention in the combined necrotic corpuscle. 4) The P-protein had higher contents of S, K, P than the sieve elements wall tissue, and the percentage composition of S was 4.64%, which was more than twice the composition in the cell wall with 2.14 %. According to the observation through transmission electron microscope that showed the P-protein had high electronic density, we might affirm that it was a P-protein body with S, P. The composition of K was 21.62%, 1.52 times that of the cell wall which was 14.23%. The existing of high quantity of P, S, K in P-protein body showed P-protein body was the main cell organelle for nourishment material in phloem, especially for sugar transportation.展开更多
Investigate the influence of culture media to growth and flavonol glycoside synthesis of calli introduced from seedling of \%Ginkgo biloba\%. 6 cell lines were selected from calli by hypoxia stress. Among these cell l...Investigate the influence of culture media to growth and flavonol glycoside synthesis of calli introduced from seedling of \%Ginkgo biloba\%. 6 cell lines were selected from calli by hypoxia stress. Among these cell lines the best one TZ\|1 which growth index was 4.12 and the flavonol glycoside content was 1.25% in dried cell which was enhanced 257.1% compared with callus. The stability in subcultures was investigated: The average content of flavonol glycoside was 1.25% in dried cells and the growth index was 3.99 during 6 subcultures. Which variation coefficient was separately 0.065 and 0.048. The results show that hypoxia stress is a efficient method to select suspension cell line of higher productivity of flavonol glycoside.展开更多
文摘Aim To modify the structure of resibufogenin by using Ginkgo bilobasuspension. Methods Young leaves of Ginkgo biloba were differentiated into callus in MS medium withonly 2,4-D as plant growth regulator. The callus was then transferred aseptically to liquid MSmedium exoge-nously supplemented with appropriate concentration of 6-BA, NAA and 2,4-D to establishsuspension cell culture system. Resibufogenin was administered into the well-grown cell cultures andincubated for 4 d. The products dissolved in the liquid phase of the cultures were extracted andpurified by silica gel column chromatography gradiently eluted with petroleum ether and acetonesystem. Results One transformed product was obtained in 40% yield after 4 d incubation, which wasidentified as 3-epi-resibufogenin on the basis of FAB MS, ~1H NMR and ^(13)C NMR spectroscopicanalysis and corresponding data reported in literature. Conclusion G. biloba suspension cultures canbe used as an enzyme system to biotransform resibufogenin, an animal-originated bufadienolide, into3-epi-resibufogenin.
基金This work is supported by the National Natural Science Foundation of China(to Jungui Dai,No.30100230).
文摘Deacetoxy-13-oxo sinenxan A (1) was converted to 9a-hydroxy-13-oxo-2a, 5a, 10b-triacetoxy-4(20),11-taxadiene (2) and 10b-hydroxy-13-oxo-2a,5a,9a-triacetoxy- 4(20), 11- taxadiene (3) by Ginkgo cell suspension cultures in 45% and 15% yields, respectively.
文摘The ultrastructure observation, energy spectrum analyses and study on sieve elements in gingko (Ginkgo biloba. L) root phloem showed: 1) The inside wall had a large retention of small grains with a diameter of 3- 4 μm, and the outside wall membrane structure wrapped P-protein body with a kernel of high electronic density. 2) The growth had the typical process of programmed cell death (PCD), i.e. the cell karyoplasm condensed, chromatins congealed and contracted and gradually agglomerated to the periphery of the nuclear membrane, and accordingly a nuclear of malformation appeared; the endoplasmic reticulum extended and connected and merged mutually, and the shallow part fused with the cell membrane. After packing the cell organelle, the endoplasmic reticulum divided the cell into several combined necrotic corpuscles of different sizes, the cell organelles collapsing with the cell and gathering abundantly in the inside cell wall. There were two kinds of degradation for the mitochondria: One was that the electronic density of the matrix decreased, the ridges died out to be cavitations gradually, and the double-layer membrane broke and ruined; the other was that parts of the territorial structure of the membrane broke, and the substance it contained escaped. 3) The ultrastructure of the course of gingko root phloem developing from cell with protein thin wall into sieve elements might make out that the P-protein body was produced in PCD and developed with retention in the combined necrotic corpuscle. 4) The P-protein had higher contents of S, K, P than the sieve elements wall tissue, and the percentage composition of S was 4.64%, which was more than twice the composition in the cell wall with 2.14 %. According to the observation through transmission electron microscope that showed the P-protein had high electronic density, we might affirm that it was a P-protein body with S, P. The composition of K was 21.62%, 1.52 times that of the cell wall which was 14.23%. The existing of high quantity of P, S, K in P-protein body showed P-protein body was the main cell organelle for nourishment material in phloem, especially for sugar transportation.
文摘Investigate the influence of culture media to growth and flavonol glycoside synthesis of calli introduced from seedling of \%Ginkgo biloba\%. 6 cell lines were selected from calli by hypoxia stress. Among these cell lines the best one TZ\|1 which growth index was 4.12 and the flavonol glycoside content was 1.25% in dried cell which was enhanced 257.1% compared with callus. The stability in subcultures was investigated: The average content of flavonol glycoside was 1.25% in dried cells and the growth index was 3.99 during 6 subcultures. Which variation coefficient was separately 0.065 and 0.048. The results show that hypoxia stress is a efficient method to select suspension cell line of higher productivity of flavonol glycoside.
基金We thank the National Outstanding Youth Foundation by NSF of ChinaTrans-Century Training Program Foundation for the Talents by the Ministry of Education for financial support.
