Search results for "Spermine"
showing 10 items of 54 documents
New insights into the role of spermine in Arabidopsis thaliana under long-term salt stress
2010
Polyamines (putrescine, spermidine and spermine) are traditionally implicated in the response of plants to environmental cues. Free spermine accumulation has been suggested as a particular feature of long-term salt stress, and in the model plant Arabidopsis thaliana the spermine synthase gene (AtSPMS) has been reported as inducible by abscisic acid (ABA) and acute salt stress treatments. With the aim to unravel the physiological role of free spermine during salinity, we analyzed polyamine metabolism in A. thaliana salt-hypersensitive sos mutants (salt overlay sensitive; sos1-1, sos2-1 and sos3-1), and studied the salt stress tolerance of the mutants in spermine and thermospermine synthesis …
Influence of agents that act on DNA and RNA synthesis on the activity of poly(ADP-Rib) polymerase
1975
The activity of poly(ADP-Rib) polymerase is enhanced in the presence of spermine and spermidine. Among the adenosine-like antibiotics tested, only formycin B and showdomycin cause an inhibition of the enzyme, which is competitive to NAD. The activity of poly(ADP-Rib) polymerase is not reduced by rifamycin, alpha-amanitin and 2-phenylethanol.
Rapid Self-Healing and Thixotropic Organogelation of Amphiphilic Oleanolic Acid–Spermine Conjugates
2021
Natural and abundant plant triterpenoids are attractive starting materials for the synthesis of conformationally rigid and chiral building blocks for functional soft materials. Here, we report the rational design of three oleanolic acid-triazole-spermine conjugates, containing either one or two spermine units in the target molecules, using the Cu(I)-catalyzed Huisgen 1,3-dipolar cycloaddition reaction. The resulting amphiphile-like molecules 2 and 3, bearing just one spermine unit in the respective molecules, self-assemble into highly entangled fibrous networks leading to gelation at a concentration as low as 0.5% in alcoholic solvents. Using step-strain rheological measurements, we show ra…
Perturbation of spermine synthase Gene Expression and Transcript Profiling Provide New Insights on the Role of the Tetraamine Spermine in Arabidopsis…
2011
The role of the tetraamine spermine in plant defense against pathogens was investigated by using the Arabidopsis (Arabidopsis thaliana)-Pseudomonas viridiflava pathosystem. The effects of perturbations of plant spermine levels on susceptibility to bacterial infection were evaluated in transgenic plants (35S::spermine synthase [SPMS]) that overexpressed the SPMS gene and accumulated spermine, as well as in spms mutants with low spermine levels. The former exhibited higher resistance to P. viridiflava than wild-type plants, while the latter were more susceptible. Exogenous supply of spermine to wild-type plants also increased disease resistance. Increased resistance provided by spermine was p…
Pattern of polyamines and related monoacetyl derivatives in chick embryo retina during development.
1994
Polyamines and related monoacetyl derivatives were studied in chick embryo retina during development (6th-19th day). Putrescine, which is high in the first phase of retinogenesis, is necessary to sustain both tissue proliferation and via N-acetylputrescine, gamma-aminobutyric acid synthesis. A later increase in spermidine and particularly spermine may play a role in the last phase of development when the retina reaches maturation. The presence of N1-acetylspermidine already at the 8th day indicates that in chick embryo retina, putrescine synthesis can depend on two separate pathways. The first involves ornithine decarboxylase activity; the second, spermidine/spermine N1-acetyltransferase an…
Free and conjugated polyamine content in Citrus sinensis Osbeck, cultivar Brasiliano N.L.92, a Navel orange, at different maturation stages
2004
Biogenic amines, synthesized during physiological metabolic processes of all living organisms, are present in food. At low concentrations, polyamines are essential for cell renewal and growth, but they can be detrimental when consumed in high amount through the diet as they could support abnormal cell growth pathologies. The daily human diet contains more putrescine than spermidine or spermine, mostly derived from fruits. In general, orange fruits contain high levels of put, a fact that could limit their utilization in the daily diet besides the benefits contributed by their strong antioxidant properties. There is therefore an increasing interest in finding plant foods with low polyamine co…
ChemInform Abstract: Synthesis of New Bis(tetrahydropyrrolo[3,4-b]carbazoles) with a Functionalized Diaryl Spacer.
2010
Some new bis(tetrahydropyrrolo[3,4-b]carbazoles) were synthesized by Diels–Alder reactions of in-situ generated indole-2,3-quinodimethanes with a variety of bismaleimides as dienophiles and also by reaction of dianilines with a succinic acid anhydride group incorporated into a biscarbazole. In a special reaction a spermine linker was introduced. The new biscarbazoles represent potential DNA ligands for the development of new antitumor active drugs.
Synthesis of new bis(tetrahydropyrrolo[3,4-b]carbazoles) with a functionalized diaryl spacer
2001
Some new bis(tetrahydropyrrolo[3,4-b]carbazoles) were synthesized by Diels–Alder reactions of in-situ generated indole-2,3-quinodimethanes with a variety of bismaleimides as dienophiles and also by reaction of dianilines with a succinic acid anhydride group incorporated into a biscarbazole. In a special reaction a spermine linker was introduced. The new biscarbazoles represent potential DNA ligands for the development of new antitumor active drugs.
Polyamines and ripening of photoreceptor outer segments in chicken embryos.
1995
Abstract Polyamines and their related monoacetyl derivatives were studied in rod outer segment (ROS) and cone outer segment (COS) of photoreceptor cells from chick embryo retina during eye development (7th–18th days). Putrescine was found to be necessary, in the second phase of retinogenesis, to sustain both ROS and COS differentiation and, after acetylation, γ-aminobutyric acid synthesis. On the other hand, spermidine and even more spermine intervene in the third phase of development when photoreceptors mature. Moreover, the presence of N1-acetylspermidine already at the 7th day indicates that in the outer segment of photoreceptor cells too, as in the whole retina, putrescine synthesis com…
Substance P inactivation by transglutaminase in vitro.
1992
Gamma(glutamyl5)spermine derivative of substance P (Spm-SP) was synthesized in vitro in the presence of purified guinea pig liver transglutaminase and Ca2+. The spermine adduct of the neuropeptide was purified by HPLC on a reversed-phase column and characterized by fast atom bombardment mass spectrometry. The biological activities of Spm-SP were tested by assaying, in comparison with substance P, its ability to induce both the contractions of smooth muscle in vitro and the edema formation in vivo. Spm-SP was shown not to elicit contractile responses in the isolated rat stomach strip and duodenum and not to antagonize the spasmogenic effect evoked by the native neuropeptide. Furthermore, Spm…