Metabolism of hygrine in Atropa,Hyoscyamus and Physalis

Three-month-old plants of Physalis alkekengi, Atropa belladonna and Hyoscyamus niger were fed via the roots with either d( + ) or l( - )-hygrine-[2′- ¹⁴C]. The feeding experiments were terminated after 7 days when the following alkaloids were isolated from the paired groups of plants: tigloidine, 3α-tigloyloxytropane and cuscohygrine from Physalis; hyoscyamine from Hyoscyamus and from Atropa. In contrast to Datura these genera appear to use both hygrine enantiomers in the biosynthesis of the tropane ring.     

Alkaloids of some south american erythroxylum species

Fourteen South American species of Erythroxylum representing four sections of the genus were examined for tropane and related alkaloids. The alkaloid content of the dried material ranged from 0.002 to 0.20 %. Commonly, the alkaloids involved were esters of various tropanols with benzoic and phenylacetic acids. A new alkaloid, nortropacocaine, was isolated from E. mamacoca. Mass spectrometry indicated the existence of other new bases, cuscohygrine and, in some species dihydrocuscohygrine. Chemotaxonomic implications are discussed.     

Stereochemistry of tropane alkaloid formation in Datura

Five-month-old Datura innoxia plants were fed via the roots with either d(+)-hygrine-[2′-¹⁴C] or l(?)-hygrine-[2′-¹⁴C]. After 7 days the root alkaloids 3α,6β-ditigloyloxytropane, 3α,6β-ditigloyloxytropan-7β-ol, hyoscine, hyoscyamine and cuscohygrine were isolated from both groups of plants. d(+) but not l(?)-hygrine acts as a precursor for the tropane alkaloids whereas both enantiomers appeared to serve equally well in the biosynthesis of cuscohygrine.     

Alkaloids of Duboisia hopwoodii

Leaf and root collections of Duboisia hopwoodii were made from Alice Springs in central and Western Australia. From D. hopwoodii collected at Alice Springs were isolated nornicotine, nicotine, myosmine and N-formylnornicotine; cotinine, N-acetylnornicotine, anabasine, anatabine, anatalline and bipyridyl were detected by GC/MS. Root material contained hyoscyamine, scopolamine, nicotine and nornicotine; N-formylnornicotine was detected by GC/MS. D. hopwoodii from Western Australia yielded nicotine, nornicotine, hyoscyamine and metanicotine. Root material contained nornicotine, hyoseyamine, myosmine and N-formylnornicotine, GC/MS detected cotinine and N-acetylnornicotine.     

N-oxides of hyoscyamine and hyoscine in the solanaceae

The N-oxides of (−)-hyoscyamine and (−)-hyoscine have been prepared and characterized. Two N-oxides of hyoscyamine have been isolated from species of Atropa,Datura,Hyoscyamus,Scopolia andMandragora,andoneN-oxideofhyoscinehasbeenisolatedfromspeciesofthefirstfourgenera.     

Distribution of alkaloids in Anthocercis littorea and A. viscosa

The distribution of tropane alkaloids in organs of Anthocercis littorea and A. viscosa is reported. The following alkaloids have been isolated: atropine (hyoscyamine), apoatropine, noratropine (norhyoscyamine), littorine, hyoscine, norhyoscine, meteloidine, 3α, 6β-ditigloyloxytropan-7β-ol, 6β-tigloyloxytropan-3α-ol, 3α-tigloyloxytropane, tigloidine, tropine, ψ-tropine, (?)-tropan-3α-6β-diol, cuscohygrine and unknown bases.     

Distribution of littorine and other alkaloids in the roots of datura species

Littorine, various tropoyl and tigloyl esters and cuscohygrine are components of the roots of all nine Datura species studied. The genus exhibits a uniform alkaloid spectrum and its inclusion, with Solandra, in the tribe Datureae is supported on phytochemical grounds.     

Hydroxytropane tiglates in the roots of Mandragora species

Roots of Mandragora autumnalis and M. vernalis contain hyoscyamine, hyoscine, cuscohygrine, apoatropine 3α-tigloyloxytropane and 3,6-ditigloyloxytropane. Belladonnine is present in the dried roots but could not be detected in fresh roots. No major differences were found in the alkaloids present in the two species. This is the first time the presence of tiglic acid esters has been reported in Mandragora species and the significance of this in the chemotaxonomy of the genus is indicated.     

Tropane alkaloids from Anthocercis and Anthotroche

In addition to known tropane alkaloids, 3α-iso-butyryloxytropan-6β-ol and 3α-n-butyryloxytropane have been characterized as respective components of the aerial parts of two subspecies of Anthocercis albicans. Aponoratropine, not previously recorded as a natural product, has been detected in the leaves of Anthotroche myoporoides and A. walcottii; similarly aponorhyoscine is indicated as a component of the roots of a subspecies of Anthocercis genistoides.     

Alkaloids of Datura suaveolens

The alkaloid mixture of Datura suaveolens shows distinct differences compared with that of other tree daturas. Aerial parts contain in addition to hyoscine, apohyoscine, norhyoscine, atropine and noratropine, a relatively high proportion of tigloyl esters—3α,6β-ditigloyloxytropan-7β-ol, 6β-tigloyloxytropan-3α,7β-diol,3α-tigloyloxytropan-6β,7β-diol (meteloidine) and (—)- and (±)-3α-tigloyloxytropan-6β-ol. The roots contain hyoscine, meteloidine, atropine, littorine, 3α-acetoxytropane, 6β-(α-methylbutyryloxy)-3α-tigloyloxytropane, 3α,6β-ditigloyloxytropan-7β-ol, 3α-tigloyloxytropan-6β-ol, tropine and cuscohygrine. Other, as yet uncharacterized, bases are present in the plant. Norhyoscine is a principal alkaloid of the corollas.     

Formation of acetyltropine in Datura callus cultures

The production of tropoylesters in suspension cultures of Datura innoxia stem callus was significantly stimulated by dl-tropic acid, phenylpyruvate or tropine, but was little affected by l-phenylalanine or l-ornithine. Analyses have shown that acetyltropine is synthesized in large quantities by cultured cells when tropine has been supplied to various cultures of D. innoxia and D. tatula. Acetyltropine has been isolated from either the culture medium or cells supplied with tropine. These results indicate that tropine absorbed by the cultured cells of Datura is esterified predominantly by acetic acid to form acetyltropine, instead of other tropane alkaloids.     

′6β-propanoyloxy-3α-tigloyloxytropane,a new alkaloid from Datura innoxia

A new alkaloid, shown by spectroscopic and degradative means to be 6β-propanoyloxy-3α-tigloyloxytropane has been isolated from Datura innoxia r     

Biosynthesis of tropane ester alkaloids in Datura

Datura meteloides plants were fed via the roots with [1″,2′-¹⁴C]tigloyl hygroline and as a control, [2′-¹⁴C]hygrine. After a week the alkaloids were isolated and degraded. Despite hydrolysis of the putative precursor it was possible, by label ratio, to show that esterification occurs after, and not before, the tropane ring has been synthesized. Hygroline is proposed as a possible intermediate.     

Alkaloid production by plants regenerated from cultured cells of Datura innoxia

Cellular aggregates in Datura innoxia suspension cultures give rise to large numbers of shoots when such aggregates are cultured in the light on an auxin-free agar medium supplemented with kinetin. These shoots form roots on a kinetin-free medium to develop into complete plants. Most of the regenerated plants are diploid, and the frequencies of ancuploid or polyploid plants are much lower than might be expected from the distribution of chromosome number in the cultured cells. During root ditterentiation and plant development, scopolamine synthesis is initiated and there is a progressive increase in the alkaloid content. Consequently, the general pattern of alkaloid composition is restored to a normal state in the majority of the regenerated plants including aneuploid or polyploids. Nevertheless, some of the plants show an abnormal expression in alkaloid metabolism, such as the complete hydrolysis of scopolamine in the dried leaves.     

δ-N-Methylornithine: a natural constituent of Atropa belladonna

δ-N-Methylornithine, a tropane alkaloid precursor, is shown for the first time to be a natural plant constituent; it was isolated in radioactive form after feeding [5-¹⁴C]- and [5-³H]ornithine to Atropa belladonna. This finding supports the deduced role of δ-N-methylornithine in tropane alkaloid biosynthesis.     

托烷类生物碱生物合成机理及其生物工程研究进展

托烷类生物碱主要包括阿托品、莨菪碱、山莨菪碱、东莨菪碱和樟柳碱,是主要抗胆碱类药物。解析药用茄科植物托烷类生物碱合成的分子调控机制以及研发高产托烷类生物碱的植物生物反应器一直是近几年的研究热点。该文对近年来国内外有关托烷类生物碱在不同茄科植物中的合成部位、分子调控和利用转基因技术研发高产托烷类生物碱的发根生物反应器的研究进展进行综述,并对可能存在的问题以及应用前景进行了展望。     

Un gradient metabolique: Rapport scopolamine/hyoscyamine dans les feuilles du Duboisia myoporoides en fonction de leur niveau d'insertion et du stade de croissance

Hyoscine and hyoscyamine are the main alkaloids in the Australian plant Duboisia myoporoides. The ratio of hyoscine/hyoscyamine depends both on the developmental stage of the plant and on the position of the leaves on the stem; this ratio is considered as a ‘metabolic gradient’. It is a permanent metabolic marker of a given physiological state.     

Nitrogen-containing non-steroidal secondary metabolites of Solanum, Cyphomandra, Lycianthes and Margaranthus

Of the 49 species of Solanum studied, cuscohygrine has been detected in 25, solamine and related amines in 17 and solamine-derived amides in 16. Five species of Cyphomandra examined all contained both amines and amides. From roots of Margaranthus solanaceus cuscohygrine has been isolated which probably occurs, too, in roots of Lycianthes rantonnettii. The distribution of these compounds throughout the taxa could be of chemotaxonomic value.