4427-76-3Relevant articles and documents
Tissue distribution and biosynthesis of 1,2-saturated pyrrolizidine alkaloids in Phalaenopsis hybrids (Orchidaceae)
Froelich, Cordula,Hartmann, Thomas,Ober, Dietrich
, p. 1493 - 1502 (2006)
Phalaenopsis hybrids contain two 1,2-saturated pyrrolizidine monoesters, T-phalaenopsine (necine base trachelanthamidine) and its stereoisomer Is-phalaenopsine (necine base isoretronecanol). T-Phalaenopsine is the major alkaloid accounting for more than 90% of total alkaloid. About equal amounts of alkaloid were genuinely present as free base and its N-oxide. The structures were confirmed by GC-MS. The quantitative distribution of phalaenopsine in various organs and tissues of vegetative rosette plants and flowering plants revealed alkaloid in all tissues. The highest concentrations were found in young and developing tissues (e.g., root tips and young leaves), peripheral tissues (e.g., of flower stalks) and reproductive organs (flower buds and flowers). Within flowers, parts that usually attract insect visitors (e.g., labellum with colorful crests as well as column and pollinia) show the highest alkaloid levels. Tracer feeding experiments with 14C-labeled putrecine revealed that in rosette plants the aerial roots were the sites of phalaenopsine biosynthesis. However active biosynthesis was only observed in roots still attached to the plant but not in excised roots. There is a slow but substantial translocation of newly synthesized alkaloid from the roots to other plant organs. A long-term tracer experiment revealed that phalaenopsine shows neither turnover nor degradation. The results are discussed in the context of a polyphyletic molecular origin of the biosynthetic pathways of pyrrolizidine alkaloids in various scattered angiosperm taxa. The ecological role of the so called non-toxic 1,2-saturated pyrrolizidine alkaloids is discussed in comparison to the pro-toxic 1,2-unsaturated pyrrolizidine alkaloids. Evidence from the plant-insect interphase is presented indicating a substantial role of the 1,2-saturated alkaloids in plant and insect defense.
A practical method for building linear and cyclic triamines from (2-trimethylsilyl)ethanesulfonamides (SES-amides)
Parker, Laurie L.,Gowans, Nicholas D.,Jones, Stephen W.,Robins, David J.
, p. 10165 - 10171 (2007/10/03)
SES-chloride has been obtained in higher yield and purity by improving Weinreb's original procedure, allowing efficient access to the primary SES-amide. Linear triamines can be built conveniently from the SES-amide in high yields, with the potential for orthogonal protection. The modified Richman-Atkins cyclisation of SES-amides allows access to novel biologically interesting triazamacrocycles with combinations of three-, four-, five- and six-carbon bridges within the ring. Purification of the free macrocyclic amines by distillation greatly simplifies the workup, increasing the practicability of multi-gram scale synthesis. Although CsF sometimes provided undesirably low yields in the deprotection step, alternative fluoride sources were found to be unsuitable for the deprotection of SES-triazamacrocycles.
Diamine and Triamine Analogs and Derivatives as Inhibitors of Deoxyhypusine Synthase: Synthesis and Biological Activity
Lee, Young Bok,Park, Myung Hee,Folk, J. E.
, p. 3053 - 3061 (2007/10/03)
Deoxyhypusine synthase catalyzes the initial step in the posttranslational formation of the amino acid hypusine ε-(4-amino-2-hydroxybutyl)lysine> in eukaryotic initiation factor 5A (eIF-5A). eIF-5A and its hypusine modification are believed to be essential for cell growth.A number of compounds related to diamines and triamines were synthesized and tested as inhinitors of this enzyme.The findings indicate that the long chain triamines 2a and 2b and their guanyl derivatives 3a, 3b, 4a, and 4b exert inhibition by binding to enzyme through only a portion of their structures at any one time.The inhibition exhibited by N-ethyl-1,7-diaminoheptane 20 and its guanyl derivative 21 supports this notion and is evidence for participation of the secondary amino group in binding to enzyme.There is preliminary evidence that amidino and isothiuronium groups may also serve as basic centers for binding to enzyme.Few of the compounds tested here were comparable in inhibitory potency to 1-guanidino-7-aminoheptane (GC7) the most effective known inhibitor of deoxhypusine synthase, and none proved nearly as efficient as GC7 in inhibiting the enzyme in Chinese hamster ovary cells.Hence, unlike the antiproliferative effect of GC7, for which there is evidence of cause by interference with deoxhypusine synthase catalysis (Park, M.H.; Wolff, E.C.; Lee, Y.B.; Folk, J.E.J.Biol.Chem. 269, 1994, 27827-27832), the effective growth arrest exerted by several of the newly synthesized compounds cannot be attributed to inhibition of hypusine synthesis.
