Cyclisation of farnesyl pyrophosphate to γ-bisabolene in tissue cultures of Andrographis paniculata

1982 ◽  
pp. 268-270 ◽  
Author(s):  
Panayiotis Anastasis ◽  
Isabel Freer ◽  
Christopher Gilmore ◽  
Hugh Mackie ◽  
Karl Overton ◽  
...  
Keyword(s):  
Andrographis Paniculata ◽  
Farnesyl Pyrophosphate ◽  
Tissue Cultures

Paniculides A, B, and C, bisabolenoid lactones from tissue cultures of Andrographis paniculata

1968 ◽  
pp. 1493 ◽  
Author(s):  
A. J. Allison ◽  
D. N. Butcher ◽  
J. D. Connolly ◽  
K. H. Overton
Keyword(s):  
Andrographis Paniculata ◽  
Tissue Cultures

scholarly journals Biosynthesis of trans,trans- and cis,trans-farnesols by soluble enzymes from tissue cultures of Andrographis paniculata

1974 ◽  
Vol 144 (3) ◽  
pp. 585-592 ◽  
Author(s):  
K H Overton ◽  
F M Roberts
Keyword(s):  
Hydrogen Atom ◽  
Alcohol Dehydrogenase ◽  
Chemical Synthesis ◽  
Andrographis Paniculata ◽  
Tissue Cultures ◽  
Trans Isomers ◽  
Free System ◽  
Liver Alcohol Dehydrogenase ◽  
A Cell ◽  
Soluble Enzymes

A cell-free system obtained from tissue cultures of Andrographis paniculata produces 2-trans,6-trans-farnesol (trans, trans-farnesol) and 2-cis,6-trans-farnesol (cis,trans-farnesol) (5:1), incorporating 10% of the radioactivity from 3R-[2-14C]mevalonate. There is total loss of3H from 3RS-[2-14C,(4S)-4-3H1]mevalonate and total retention from the (4R) isomer in both the trans, trans-farnesol and cis,trans-farnesol formed. When 3RS-[2-14C,5-3H2]mevalonate is used as substrate, there is total retention of3H in the trans, trans-farnesol, but loss of one-sixth of the3H in the cis,trans-farnesol. With (1R)- and (1S)-[4,8,12-14C3,1-3H1]-trans, trans -farnesol and (1R)- and (1S)-[4,8,12-14C3,1-3H1]-cis,trans-farnesol as substrates, the label is lost from the (1R)-cis,trans and (1S)-trans, trans isomers but retained in the (1R)-trans, trans and (1S)-cis,trans isomers; this shows that the pro-1S hydrogen is exchanged in the conversion of trans, trans-farnesol into cis,trans-farnesol and the pro-1R hydrogen in the conversion of cis,trans-farnesol into trans, trans-farnesol. (1R)-[1-3H1]-trans, trans-Farnesol and (1R)-[1-3H1]-cis,trans-farnesol have been synthesized by asymmetric chemical synthesis and exchanged with liver alcohol dehydrogenase. Both the trans- and the cis-alcohol exchange the pro-1R hydrogen atom.

Biosynthesis of γ-bisabolene in tissue cultures of Andrographispaniculata

1984 ◽  
Vol 62 (10) ◽  
pp. 2079-2088 ◽  
Author(s):  
Panayiotis Anastasis ◽  
Isabel Freer ◽  
Christopher Gilmore ◽  
Hugh Mackie ◽  
Karl Overton ◽  
...  
Keyword(s):  
Double Bond ◽  
Absolute Configuration ◽  
Callus Cultures ◽  
Side Chain ◽  
Farnesyl Pyrophosphate ◽  
Tissue Cultures ◽  
Free System ◽  
Redox Mechanism ◽  
X Ray ◽  
Ring Carbon

Experiments with intact callus cultures of Andrographispaniculata and a derived cell-free system have established that: (1) the biosynthesised γ-bisabolene has the Z-configuration 6; (2) the biosynthetic intermediate is a 6-trans-13 and not a 6-cis-15 farnesyl pyrophosphate; (3) in paniculide B 17, and probably also in γ-bisabolene 14, the ring carbon derived from C-2 of mevalonate is anti to the side chain; (4) mevalonolactone and trans,trans-famesyl pyrophosphate are incorporated into γ-bisabolene without hydrogen loss respectively from C-5 and C-1; cyclisation to the bisabolenyl cation therefore does not involve prior trans to cis isomerisation of the terminal double bond of farnesol by a redox mechanism; (5) taken together with our previous findings, it is established that Andrographis cultures contain two independently functioning enzymes: (i) a trans,trans- to cis,trans-farnesol isomerase, and (ii) a trans,trans-farnesyl pyrophosphate isomerase-cyclase. The absolute configuration of paniculide B has been established by an X-ray cristallographic analysis of its bis-p-bromobenzoate.

Stereochemistry of the leucine 2,3-aminomutase from tissue cultures of Andrographis paniculata

1981 ◽  
pp. 80 ◽  
Author(s):  
Isabel Freer ◽  
Giuseppe Pedrocchi-Fantoni ◽  
Douglas J. Picken ◽  
Karl H. Overton
Keyword(s):  
Andrographis Paniculata ◽  
Tissue Cultures

Comparison of Choriocarcinoma and Normal Placenta

1971 ◽  
Vol 29 ◽  
pp. 324-325
Author(s):  
John C. Garancis ◽  
Roland A. Pattillo ◽  
Robert O. Hussa ◽  
Jon V. Straumfjord
Keyword(s):  
Cell Lines ◽  
Small Cells ◽  
Tissue Cultures ◽  
Glycogen Depletion ◽  
Cell Surfaces ◽  
Intercellular Spaces ◽  
Concomitant Increase ◽  
Gestational Choriocarcinoma ◽  
Cytoplasmic Glycogen ◽  
Normal Placenta

Two different cell lines (Be-Wo and Jar) of human gestational choriocarcinoma have been maintained in continuous tissue culture for a period of four and two years respectively without losing the ability to elaborate human chorionic gonadotropin (HCG). Tissue cultures, as revealed by electron microscopy, consisted of small cells with single nuclei. In some instances cell surfaces were provided with microvilli but more often the intercellular spaces were narrow and bridged by desmosomes. However, syncytium was not formed. Endoplasmic reticulum (ER) was poorly developed in both cell lines, except in some Be-Wo cells it was prominent. Golgi complex, lysosomes and numerous free ribosomes, as well as excessive cytoplasmic glycogen, were present in all cells (Fig. 1). Glycogen depletion and concomitant increase of ER were observed in many cells following a single dose of 10 ugm/ml of adrenalin added to medium (Fig. 2).

Freeze-Fracture Studies of Membranes in Developing Sieve Elements in a Plant Tissue Culture

1980 ◽  
Vol 38 ◽  
pp. 636-637
Author(s):  
R. D. Sjolund ◽  
C. Y. Shih
Keyword(s):  
Plant Tissue ◽  
Cultured Cells ◽  
Freeze Fracture ◽  
Tissue Cultures ◽  
Sieve Elements ◽  
Intact Plants ◽  
Plant Tissue Cultures ◽  
Whole Plants ◽  
Energy Dependent ◽  
Similar Elements

The differentiation of phloem in plant tissue cultures offers a unique opportunity to study the development and structure of sieve elements in a manner that avoids the injury responses associated with the processing of similar elements in intact plants. Short segments of sieve elements formed in tissue cultures can be fixed intact while the longer strands occuring in whole plants must be cut into shorter lengths before processing. While iyuch controversy surrounds the question of phloem function in tissue cultures , sieve elements formed in these cultured cells are structurally similar to those of Intact plants. We are particullarly Interested In the structure of the plasma membrane and the peripheral ER in these cells because of their possible role in the energy-dependent active transport of sucrose into the sieve elements.

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