The production of alkaloids in Annona cacans seedlings is affected by the application of GA4+7 + 6-Benzyladenine

The Annonaceae family presents alkaloids with ecological functions and pharmacological interest. This is the first study to evaluate if the application of plant growth regulators to seeds of this family alters the production of alkaloids over time from germination. This study was carried out in four sequential stages of Annona cacans Warm. development from the resumption of embryo during seed imbibition with the application of plant regulator GA₄₊₇ + 6-Benzyladenine. The concentration of total alkaloids was quantified using the oxoaporphine alkaloid liriodenine as reference standard. In addition, the liriodenine concentration was measured and the profile evaluated by ultra-high-performance liquid chromatography (UHPLC). Results have shown that alkaloids are present in all phases and in all tissues, at higher concentrations in roots (up to 100 times). The proportion of total alkaloids and liriodenine was modified in response to the application of plant regulators. Roots doubled the content of alkaloids and liriodenine. In cotyledonary leaves, the amount of total alkaloids decreased; however, liriodenine remained unchanged. Our results have shown that the use of plant growth regulators based on gibberellins and cytokinins modified the production of alkaloids in tissues in a specific way.     

Influence of seasonal variation on the phenology and liriodenine content of Annona lutescens (Annonaceae)

Annona lutescens Saff. (Annonaceae) grows as a native tree in Chiapas, Mexico in Tropical Dry Forest habitat. Like most Annonaceae, it biosynthesizes benzylisoquinoline alkaloids, mostly liriodenine. To determine the influence of seasonal changes in the accumulation of liriodenine, the monthly variation of liriodenine content in roots, stems and leaves of mature and young trees was observed. These parts of young and mature A. lutescens trees were collected monthly over a 1 year period and the alkaloids were extracted; the liriodenine was quantified by high-resolution liquid chromatography. The phenological stages of the species were also assessed (leaf development, flowering and fruiting) using the Biologische Bundesanstalt, Bundessortenamt und Chemische Industrie (BBCH) scale. The analysis of both young and mature trees showed a significant increase in the liriodenine concentration occurs within roots during the dry season, which coincides with leaf fall. A significant decrease also occurred at the beginning of the rainy season (the period of leaf growth); the liriodenine content for the next rainy season did not reach the levels of the previous dry season. The climatic variation induced phenological and physiological changes in this species.     

Antimicrobial alkaloids from Zanthoxylum tetraspermum and caudatum

Two benzophenanthrene alkaloids, 8-acetonyldihydronitidine and 8-acetonyldihydroavicine were isolated from Zanthoxylum tetraspermum stem bark along with liriodenine, sesamin, lichexanthone and (+)-piperitol-gamma,gamma-dimethylallylether. The species endemic to Sri Lanka, Z. caudatum, contained sesamin, savinin, liriodenine, decarine and 8-O-desmethyl-N-nornitidine. 8-Acetonyldihydronitidine and 8-acetonyldihydroavicine showed significant antibacterial activity while the former along with liriodenine was strongly antifungal. Savinin exhibited potent spermicidal activity. Both savinin and sesamin exhibited significant insecticidal activity.     

Aporphine alkaloids from Phoebe pittieri

The wood and bark of Phoebe pittieri afforded 1,2,3-trimethoxy-9,10-methylenedioxynoraporphine and 1,2,9-trimethoxy-10-hydroxynoraporphine (noraporphine), which are new alkaloids, and norpurpureine and reticuline, which have not been reported from this source before.     

单面针的生物碱研究

自芸香科(Rutaceae)花椒属植物单面针(Zanthoxylum nitidum var. fastuosum How ex Huang)的根皮中分得五种已知生物碱:乙氧基白屈菜红碱(ethoxychelerythrine)(Ⅰ);氯化光花椒碱(nitidine chloride)(Ⅱ);去甲基白屈菜红碱(des-N-methychelerythrine)(Ⅲ);α—别隐品碱(α-allocryptopine)(Ⅳ);鹅掌揪宁(liriodenine)(Ⅴ).     

Liriodenine, early antimicrobial defence in Annona diversifolia

Annonaceae aporphine alkaloids, of which liriodenine is the most abundant, have not been extensively studied from a biological standpoint. The goal of this study was to investigate the role of liriodenine in antimicrobial defense during early developmental stages in Annona diversifolia. The fungi Rhizopus stolonifer and Aspergillus glaucus, which are responsible for seed deterioration, were isolated during imbibition, and their antifungal activity was determined by diffusion, macrodilution, and metabolic inhibition assays using purified liriodenine and alkaloid extracts obtained from embryos, radicles, and roots at early developmental stages. The presence of liriodenine in extracts was quantified by high-performance liquid chromatography. Purified liriodenine and alkaloidal extracts inhibited both fungi, and there was a positive relationship between extract activity and amount of liriodenine contained therein. The quantity of liriodenine present in extracts suggests its importance in controlling other phytopathogens.     

Flavonoid glycosides and isoquinolinone alkaloids from Corydalis bungeana

Two flavonol O-glycosides identified as the 3-O-alpha-arabinopyranosyl(1'-->6')-beta-glucopyranoside 7-O-beta-glucopyranosides of kaempferol and quercetin were isolated from the whole plant of Corydalis bungeana Turcz. together with eight known flavonol O-glycosides. Two isoquinolinone alkaloids were also obtained from the same source, including the new derivative, 6,7-methylenedioxy-2-(6-acetyl-2,3-methylenedioxybenzyl)-1(2H)-isoquinolinone. The structures were determined by spectroscopic methods (NMR and high-resolution MS).     

Knockdown of berberine bridge enzyme by RNAi accumulates (<Emphasis Type="Italic">S</Emphasis>)-reticuline and activates a silent pathway in cultured California poppy cells

Reticuline is a key compound in the biosynthetic pathway for isoquinoline alkaloids in plants, which include morphine, codeine and berberine. We established cultured California poppy (Eschscholzia californica) cells, in which berberine bridge enzyme (BBE) was knocked down by RNA interference, to accumulate the important key intermediate reticuline. Both BBE mRNA accumulation and enzyme activity were effectively suppressed in transgenic cells. In these transgenic cells, end-products of isoquinoline alkaloid biosynthesis, such as sanguinarine, were considerably reduced and reticuline was accumulated at a maximum level of 310 μg/g-fresh weight. In addition, 1 g-fresh weight of these cells secreted significant amounts of reticuline into the medium, with a maximum level of 6 mg/20 mL culture medium. These cells also produced a methylated derivative of reticuline, laudanine, which could scarcely be detected in control cells. We discuss the potential application of RNAi technology in metabolic modification and the flexibility of plant secondary metabolism.     

Guaiane sesquiterpenes from Magnolia watsonii

The leaves and the trunk barks of Magnolia watsonii afforded two biosynthetic intermediates of dehydrocostuslactone (watsonol A and watsonol B) along with the neolignans, magnolol, hōnokiol and obovatol, and the aporphine alkaloids, liriodenine and asimilobine.     

Geovanine,a new azaanthracene alkaloid from Annona ambotay aubl.

The new azaanthracene geovanine was isolated from the trunkwood of Annona ambotay Aubl. together with liriodenine, O-methylmoschatoline and other known substances, the flavonoids kaempferol, quercetin, (+)-dihydrokaempferol, (+)-dihydroquercetin, (±)-eriodictiol and (+)-catechin and the steroids sitosterol and 5α-stigmastan-3,6-dione.     

Chemical constituents from the leaves and branches of Annona coriacea Mart. (Annonaceae)

The phytochemical investigation of the leaves and branches of Annona coriacea Mart. (Annonaceae) led to the isolation and characterization of eight compounds: five isoquinoline-derived alkaloids, including pukateine (1), liriodenine (4), anonaine (5), obovanine (6), and norisocorydine (7); one terpene lactone known as loliolide (3); one benzoic acid derivative, 2-methoxybenzoic acid (2), and 3,4,5-trimethoxyphenol (8). All compounds, except liriodenine, are being described for the first time in the species A. coriacea, and their chemophenetics relationships were discussed. The structures were elucidated by extensive analyses of 1D and 2D NMR (COSY, HSQC, and HMBC) spectroscopy in combination with MS, and the data were compared with literature values. The NMR dataset of pukateine and obovanine was reviewed. Our results showed that A. coriacea is a typical species of the Annonaceae family and an important source of aporphine alkaloids with chemophenetic relationships with Xylopia, Duguetia, Guatteria, Artabotrys, and Goniothalamus genera.     

Diterpenes and other constituents from Croton draco (Euphorbiaceae).

Croton draco (Euphorbiaceae) from Guadalupe, San José, Costa Rica was collected in July 1992 and phytochemically studied (leaves, seeds, wood, bark, sap and flowers separately). Commonly known compounds such as 1-hydroxyjunenol, p-hydroxybenzaldehyde, p-methoxybenzoic acid, 3,4,5-trimethoxycinnamyl alcohol, the coumarin scopoletin, the nor-terpenoids 9-dehydrovomifoliol and 2,3-dihydrovomifoliol were obtained. Taspine, two aporphinic alkaloids, the diterpenes 9(11)-dehydrokaurenic acid, hardwikiic acid, the corresponding new 12-oxo derivative as well as five clerodanes and a phorbol ester were also isolated. Three clerodanes were not previously described and their NMR spectroscopical data and MS fragmentation patterns are reported.     

Alkaloids from Isopyrum thalictroides L

Three new bisbenzylisoquinoline alkaloids, isopyruthaldine, isopythaldine and isothalmidine, containing new type of bridges were isolated from roots and rhizomes of Isopyrum thalictroides. The known isoquinoline alkaloids, reticuline, isocorydine. columbamine and palmatine, obtained from the aerial parts, are new for the genus Isopyrum. All structures were elucidated by spectroscopic analysis.     

Sesquiterpenes and alkaloids from Cleistopholis patens

The root bark of Cleistopholis patens collected in Ghana yielded two sesquiterpenes and five alkaloids. The sesquiterpenes have been characterised as the acyclic methyl-(?)-(trans)-(trans)-10,11-dihydroxyfarnesoate and its monocyclic derivative methyl-(+)-10-hydroxy-6,11-cyclofarnes-7(14)-enoate. The alkaloids were of the unusual aza-polycyclic and naphthyridine groups and included one new member of both classes. Examination of stem bark samples from the same source and from Sierre Leone showed the presence of the sesquiterpenes and the oxoaporphine alkaloid liriodenine but neither of the rarer alkaloid types.     

Alkaloids from leaves of Annona salzmannii and Annona vepretorum (Annonaceae)

Phytochemical investigation of the leaves of Annona salzmannii and Annona vepretorum (Annonaceae) led to the identification of seven aporphine alkaloids, anonaine, asimilobine, norcorydine, lanuginosine, liriodenine, lysicamine and oxonantenine, as well as, 1,3,6,6-tetramethyl-5,6,7,8-tetrahydro-isoquinolin-8-one and vomifoliol. Liriodenine, anonaine, asimilobine and norcorydine were found in A. salzmannii, while liriodenine, oxonantenine, lanuginosine, lysicamine, vomifoliol and 1,3,6,6-tetramethyl-5,6,7,8-tetrahydro-isoquinolin-8-one were found in A. vepretorum. All these compounds are being described for the first time in the leaves of A. salzmannii and A. vepretorum. This is the first report of 1,3,6,6-tetramethyl-5,6,7,8-tetrahydro-isoquinolin-8-one in the Annonaceae. The NMR data for oxonantenine, lanuginosine and lysicamine were reviewed.     

3-dehydromitragynine: An alkaloid from Mitragyna speciosa

An investigation of the fresh leaves of Mitragyna speciosa has resulted in the isolation of a new alkaloid in addition to the indole alkaloids previously reported. The new alkaloid is the 3-dehydro derivative of mitragynine and its structure was elucidated by spectral means and chemical transformations. (-)-Epicatechin was also isolated from the leaves.     

Aporphine alkaloids and lignans in heartwood of Liriodendron tulipifera

The following compounds were isolated from heartwood of Liriodendron tulipifera: glaucine, dehydroglaucine, asimilobine, N-acetylnornuciferine, norushinsunine, liriodenine, O-methylatheroline, (+)-syringaresinol, (+)-syringaresinol dimethyl ether and syringaldehyde. The occurrence of 1-benzyltetrahydroisoquinoline alkaloids also has been indicated by mass spectroscopy. Some characteristic spectral properties of these aporphine alkaloids and their probable biosynthetic pathways are discussed.     

Aporphinoid alkaloids and other constituents from Lettowianthus stellatus

Two new aporphinoid alkaloids, f1ttowianthine and 11-methoxylettowianthine were isolated from the root bark of Lettowianthus stellatus, together with the new sesquiterpene 11-hydroxyguaia-4,6-diene and the known compounds liriodenine, (Z)-7-octadecen-9-ynoic acid, methyl (2E,6E,10R)-10,11-epoxy-3,7,11-trimethyl-2,6-dodecadienoate, methyl (2E,6E,10R)-10,11-dihydroxy-3,7,11-trimethyl-2,6-dodecadienoate , and 3,4,5-trimethoxyphenol. The structure elucidation was achieved by spectroscopic methods.     

Flavonol tetraglycosides and other constituents from leaves of Styphnolobium japonicum (Leguminosae) and related taxa

Two flavonol tetraglycosides comprising a trisaccharide at C-3 and a monosaccharide at C-7 were isolated from the leaves of Styphnolobium japonicum (L.) Schott and characterised as the 3-O-alpha-rhamnopyranosyl(1-->2)[alpha-rhamnopyranosyl(1-->6)]-beta-glucopyranoside-7-O-alpha-rhamnopyranosides of quercetin and kaempferol. The 3-O-alpha-rhamnopyranosyl(1-->2)[alpha-rhamnopyranosyl(1-->6)]-beta-galactopyranoside-7-O-alpha-rhamnopyranoside of kaempferol, the 3-O-alpha-rhamnopyranosyl(1-->2)[alpha-rhamnopyranosyl(1-->6)]-beta-glucopyranosides of kaempferol and quercetin and the 3-O-alpha-rhamnopyranosyl(1-->2)[alpha-rhamnopyranosyl(1-->6)]-beta-galactopyranoside of kaempferol were also obtained from this species for the first time. Some or all of these flavonol tetra- and triglycosides were detected in 17 of 18 specimens of S. japonicum examined from living and herbarium material, although the most abundant flavonoid in the leaves was generally quercetin 3-O-alpha-rhamnopyranosyl(1-->6)-beta-glucopyranoside (rutin). The triglycosides, but not the tetraglycosides, were detected in herbarium specimens of Styphnolobium burseroides M. Sousa, Rudd & Medrano and Styphnolobium monteviridis M. Sousa & Rudd, but specimens of Styphnolobium affine (Torrey & A. Gray) Walp. contained a different profile of flavonol glycosides. The flavonol tetra- and triglycosides of S. japonicum were also present in leaves of Cladrastis kentukea (Dum. Cours.) Rudd, a representative of a genus placed close to Styphnolobium in current molecular phylogenies. An additional constituent obtained from leaves of Styphnolobium japonicum was identified as the maltol derivative, 3-hydroxy-2-methyl-4H-pyran-4-one 3-O-(4'-O-p-coumaroyl-6'-O-(3-hydroxy-3-methylglutaroyl))-beta-glucopyranoside.     

Isoquinoline-derived alkaloids and one terpene lactone from the leaves of Duguetia pycnastera (Annonaceae)

The phytochemical investigation from the leaves of Duguetia pycnastera Sandwith (Annonaceae) led to the isolation and identification of ten compounds: nine isoquinoline-derived alkaloids, including five aporphines, anonaine, isopiline, O-methylisopiline, nornuciferine, and norstephalagine; three oxoaporphines, O-methylmoschatoline, liriodenine, and lysicamine; and one tetrahydroprotoberberine, isocorypalmine; in addition, one C₁₁-terpene lactone known as loliolide. The isolated compounds (except for O-methylmochatoline and lysicamine) are described for the first time in the species and their chemophenetics relationships were discussed. The occurrence of loliolide is reported for the first time in the Duguetia. The structure elucidation of these compounds was established by extensive analyzes of 1D and 2D NMR spectroscopy in combination with MS. The NMR spectroscopic data for norstephalagine and isocorypalmine were reviewed.