Theoretical bases of optimization of the modes of postharvest treatment of alkaloid-synthesizing medicinal plants

The method of disks in combination with thin-layer chromatography and spectrophotometry was used for a comparative evaluation of the efficiency of different methods of fixing and fermentation of medicinal plants (leaves). Medicinal plant species capable of synthesizing alkaloids of various structural types (isoquinoline derivatives including benzophenanthridines, bisbenzylisoquinoline, quaternary protoberberines, and aporphines, as well as steroid and diterpene alkaloids) were used. The methods of fixing and fermentation were shown to exert a substantial effect on both the qualitative and quantitative composition of alkaloids. This difference in the alkaloid composition was found to represent the superposition of three independent and, to a large extent, opposite processes: catabolism of alkaloids, interaction of alkaloids with each other, and resynthesis from primary precursors. The use of different methods of fixing and fermentation provides activation or inhibition of these processes, thereby making it possible to carry out target-oriented correction of the alkaloid composition of the medicinal plants studied.     

人工栽培山莨菪和野生山莨菪中4种托烷类生物碱含量的比较研究

为了评估人工栽培山莨菪的药用价值,采用高效液相色谱技术对人工栽培和野生山莨菪的地上部分和根中具有生物活性的4种托烷类生物碱：樟柳碱、山莨菪碱、东莨菪碱和阿托品的含量进行了测定。结果表明无论是人工栽培还是野生植物,地上部分中4种生物碱含量均远低于根,这解释了人们为什么用山莨菪的根而不是整株人药。在栽培植物的根中,一年生山莨菪中各生物碱含量均小于二年生山莨菪,其根中4种生物碱总量与野生根相比差异不是很明显;二年生山莨菪根中,4种生物碱总量以及樟柳碱、东莨菪碱和阿托品含量均比野生的高。这说明人工栽培的山莨菪,尤其是二年生山茛菪,同野生山莨菪一样具有一定的药用价值。     

生物碱的提取方法研究进展

生物碱是广泛存在于自然界天然植物中的碱性含氮有机化合物。大多数生物碱具有显著的生理活性,是许多药用植物的有效成分,提取与纯化是生物碱制备的关键环节。综述了生物碱制备的传统方法及新技术的应用进展,分析了它们的原理及优缺点,探讨了生物碱制备的发展前景。     

Phytochemical and antiulcerogenic properties of rhizomes from Simaba ferruginea St. Hill. (Simaroubaceae)

Simaba ferruginea (Simaroubaceae) is a Brazilian medicinal plant used in traditional medicine to treat several ailments, including gastric ulcers, fever, diarrhea, and dolorous and inflammatory processes. This study examines the chemical composition and antiulcerogenic effects of rhizomes from this plant. Bioassay-guided fractionation led to the isolation of two bioactive indole alkaloids called canthin-6-one (1) and 4-methoxycanthin-6-one (2). The alkaloid fraction and both alkaloids demonstrated potent antiulcerogenic effects when evaluated in gastric lesion-induced animals, as well as significant antinociceptive activity in mice. These results confirm and justify the popular use of S. ferruginea against gastric ulcers and dolorous processes.     

药用植物博落回形态与发育解剖学研究

博落回(Macleaya cordata)是罂粟科含有异喹啉生物碱的主要药用植物, 其生物碱提取物具有多种药理活性。目前对博落回的研究主要集中在生物碱的成分、活性和药理等方面, 对与其合成、运输、储藏密切相关的发育解剖结构及生物碱组织化学定位研究还未见报道。该文报道了温室中生长的博落回植株形态特征, 并结合徒手切片和改良碘化铋钾沉淀的方法对主要器官(根、茎、叶)的发育结构和生物碱组织化学染色进行了初步分析。结果表明, 博落回发育基本遵循一般双子叶植物的规律。根中生物碱出现在中柱鞘外的薄壁细胞和导管周围。茎和叶柄中的生物碱主要出现在维管束周围, 偶尔也出现在茎的髓细胞中。总体上, 茎中的生物碱积累量少于根。     

Comparison of tropane alkaloid spectra between Datura innoxia grown in Egypt and Bulgaria

The alkaloid spectra of Datura innoxia plants grown in Egypt and Bulgaria were investigated by GC-MS. Thirty-eight alkaloids were detected in the roots, leaves and fruits of the plants. Five new alkaloids for D. innoxia are reported. Alkaloid spectra of Egyptian and Bulgarian plants differ significantly in respect to their alkaloid composition and main alkaloids accumulated in the plant organs.     

Indole alkaloids from Aspidosperma rigidum and A. schultesii and their antiparasitic effects

Five oxindole alkaloids, three plumerane-type alkaloids, subtype haplophitine, and one aspidospermatane-type alkaloid, subtype tubotaiwine, were isolated from the medicinal plants Aspidosperma rigidum and A. schultesii. One compound was identified as the transoid conformer of 18-oxo-O-methylaspidoalbine which was not previously described. The antiparasitic activity of all compounds against Trypanosoma cruzi and Leishmania infantum and their non-specific cytotoxicity against mammalian cells were also determined.     

Comparative analysis of the chemical profile of wild and cultivated populations of Corydalis saxicola by high-performance liquid chromatography

Studies on the simultaneous determination and chemical fingerprinting of alkaloids in Corydalis saxicola Bunting. (Yanhuanglian) were performed for authentication purposes. Ninety samples prepared from different parts of C. saxicola, including whole plants, roots, stems, leaves and flowers, from wild and cultivated populations, were submitted to quantitative determination and fingerprint analysis. Five major alkaloids, namely, tetradehydroscoulerine, dehydroapocavidine, dehydroisoapocavidine, coptisine and dehydrocavidine, were quantitatively analysed by reversed-phase HPLC with acceptable recoveries (>98.2%). Chemical fingerprinting of C. saxicola was established and involved 11 markers. The results indicated that there were no obvious differences between the chemical profiles of wild and of cultivated C. saxicola populations, and that the mean alkaloid contents of the five marker compounds in cultivated populations were significantly higher than those of the wild plants. The highest content of total alkaloids (up to 28.8 mg/g) was found in roots of C. saxicola. The total alkaloids of the leaves were approximately 50% of those of roots, suggesting that the leaves may be employed as an alternative source of alkaloids. Chemical fingerprints and quantitative HPLC analysis will have a positive impact on the conservation and cultivation of this medicinal plant.     

Quantitative changes of the alkaloid complex in a submerged culture ofClaviceps paspali

Claviceps paspali FA produced high concentrations of alkaloid under submerged conditions. Their production was found to depend on the developmental stage and treatment of the filamentous culture inoculum. A medium containing Bacto-peptone with a constant composition of amino acids was selected for the preparation of the inoculum. A two-week fermentation in a synthetic medium with mannitol at 24 ± 1 °C resulted in an increased production of total alkaloids from the original value of 100–200 μg/mL to more than 2 000 μg/mL. Addition of tryptophan did not further increase the production of alkaloids but resulted in changes of the spectrum of some metabolites. 2,3-Dihydroxybenzoic acid accompanied the alkaloids in the fermentation medium. α-Hydroxyethyllysergamide was the predominant component of extracellular alkaloids (80 % in the first days of fermentation). During fermentation the level of this alkaloid continuously decreased while the concentration of the accompanying alkaloids,i.e. lysergamide and the corresponding minor isomers, increased. An erratum to this article is available at .     

Seasonal variation in the secondary chemistry of foliar and reproductive tissues of Delphinium nuttallianum

Plant secondary compounds are critical in affecting interactions between plants and their herbivores. The norditerpene alkaloids are secondary compounds in Delphinium (larkspur) species which are divided into two classes: the N-(methylsuccinimido) anthranoyllycoctonine (MSAL-type) and non MSAL-type, and are known to be toxic to herbivorous insects and livestock. Alkaloid concentrations were measured in a whole plant context in vegetative and reproductive tissues in Delphinium nuttallianum at different stages of plant maturity at two locations to explore how plant maturity affected alkaloid concentrations within a growing season. Alkaloid concentrations differed between vegetative and reproductive tissues, with vegetative tissues having significantly lower alkaloid concentrations than reproductive tissues. However, no systematic differences in alkaloid concentrations were observed at different plant maturity stages across the growing season. Based on the data we suggest that alkaloid allocation in different plant parts of D. nuttallianum is influenced by life history of the plant, consistent with plant defense theory. At one location, as pods mature the qualitative alkaloid composition changed through structural diversification of the alkaloids present. The ecological significance of this structural diversification awaits further exploration.     

Opium poppy capsule growth and alkaloid production is constrained by shade during early floral development

Morphinan alkaloids accumulate in the capsules of Papaver somniferum L. (opium poppy) most likely as defence against herbivory. Thus, capsule size is an important component of alkaloid yield. Shade during early cell division-dominated growth of reproductive structures generally reduces final fruit size more than shade during later cell expansion-dominated growth. The current study aimed to determine whether this response is found in opium poppy and the subsequent impact on alkaloid yield, composition and seed production. First the timing of key reproductive developmental events was resolved relative to macromorphological traits. Plants were then shaded during either (a) floral initiation, (b) early floral development or (c) capsule expansion before being harvested at maturation. Shade during floral initiation dramatically reduced final capsule size, alkaloid yield and seed number, and increased the concentration of precursor compounds relative to morphine, despite plants later returning to full sun. Shade during later capsule growth enhanced capsule size and alkaloid yield but had little effect on alkaloid composition or seed number. Thus, early developmental processes, including morphine biosynthesis, appear to have a relatively greater demand for carbohydrates compared with later processes. Crop management practices and environmental factors that limit carbohydrate availability during early development are thus predicted to have significant negative impacts on alkaloid production and reproductive success.     

药用植物甾体生物碱的药理作用及合成途径

甾体生物碱是药用植物中广泛存在的一类代谢产物,是一类具有降压、止咳、平喘、抗肿瘤等生物活性的天然产物。目前,甾体生物碱的合成代谢途径、分离纯化、鉴别及生物学功能研究已成为国内外天然产物研究的热点之一。对药用植物甾体生物碱的药理作用进行了综述,并根据萜类物质合成途径,推测总结了甾体生物碱的合成相关途径和参与该途径的关键酶及其基因克隆的研究进展,以期为药用植物甾体生物碱的代谢途径与基因表达调控及应用研究提供参考。     

The Alkaloids of Fungi

Examination of different species of local fungi, grown on two nutritive solutions of different composition, for alkaloid formation was investigated. The formation of alkaloids was confined to four species, namely: Geotrichum candidum, Mucor hiemalis, Aspergillus flavus and Rhizopus nigricans. A comparative study of the growth as well as the formation of alkaloids by these species and by Claviceps purpurea NRRL was carried out. Methods were also described with which the different alkaloids produced by the experimental strains were identified. Peptides as well as clavine type alkaloids were detected in all cases except with Mucor hiemalis where a compound corresponding to ergosine was the only alkaloid present.     

Alkaloid chemotypes of Glaucium flavum (Papaveraceae) from Bulgaria

The alkaloid pattern of Glaucium flavum Crantz. from four natural populations in Bulgaria were investigated and six aporphine, two protopine and one morphinane alkaloids were determined. In accordance with the particular content and composition of alkaloids and the different localities of the species three alkaloid chemotypes were suggested. The first one contains aporphines and protopines with a main alkaloid glaucine. The second chemotype contains again aporphine and protopine alkaloids but the main alkaloid is isocorydine and the third chemotype contains besides these two types of alkaloids and the morphinane alkaloid salutaridine.     

Cell type-specific protoberberine alkaloid accumulation inThalictrum flavum

Berberine is a common benzylisoquinoline alkaloid with potent antimicrobial properties, which suggest it functions to protect some plants from pathogen challenge. Berberine was identified as the major alkaloid in meadow rue (Thalictrum flavum ssp. glaucum), a medicinal member of the Ranunculaceae, and was detected in seeds and all organs of the plant. The high level of berberine in roots, rhizomes, and older petioles is mainly responsible for the intense yellow color of these organs. In rhizomes, protoberberine alkaloids were detected throughout the pith and, to a lesser extent, the cortex, but were absent from the vascular tissues. Similarly, protoberberine alkaloids were detected in the rib parenchyma of older petioles. In roots, alkaloid accumulation was detected only in the endodermis at the onset of secondary growth. Rather than being sloughed off, the endodermis was found to undergo extensive anticlinal division leading to an expanding cellular cylinder that ultimately displaced all external tissues. Endodermal-specific protoberberine alkaloid accumulation continued throughout root development, but was extended to include 3 to 4 layers of smaller pericycle cells in the oldest roots near the base of the stem. The cell type-specific accumulation of antimicrobial alkaloids and the unusual development of the endodermis and pericycle in T. flavum roots support the putative role of berberine in plant defense.     

The effect of plant alkaloids on in vitro rumen microbial fermentation

Crude alkaloid extracts from green Italian Ryegrass differed from those extracted from the ensiled grass with particular respect to the perloline moiety. Free perloline and crude alkaloid extracts from both silage and grass inhibited the production of volatile fatty acids in the fermentation of glucose by rumen microbes. With silage as fermentation substrate alkaloid extracts from silage and from grass (0.200 mg/l) caused a decrease in both substrate utilization ( P< < 0.01) and proportion of methane in the gas phase ( P< < 0.01). Molar proportions of acetate were also significantly decreased ( P < 0.01) with a corresponding increase in the proportion of propionate ( P < 0.01). These effects were not observed when grass nuts were used as the fermentation substrate. The results suggest that it is not the alkaloids per se that affect rumen microbial metabolism.     

Medicinal plants used in Jeddah,Saudi Arabia: Phytochemical screening

Ethnobotanical and phytochemical studies are useful to discover new drugs. Phytochemical screening is an important step in the detection of the bioactive components existing in medicinal plants that are used in traditional medicine. Very few phytochemical studies investigating medicinal plants used in traditional medicine exist in Saudi Arabia. Eighty-five medicinal plants used in traditional medicine in Jeddah, Saudi Arabia are investigated here for the first time. This research aims to screen of 85 medicinal plants used in traditional medicine in Jeddah for the presence of secondary metabolites, and to answer the following question: Is the ethnomedicinal importance of medicinal plants used in Jeddah conform to their secondary metabolite content. Ethnobotanical fieldwork took place in Jeddah from August 2018 to September 2019. Eighty-five different plant species belonging to 37 families were identified. Screening of 85 medicinal plants was performed for the presence of alkaloids, glycosides, flavonoids, tannins, saponins and resins using standard methods. The most commonly distributed phytochemical compounds among medicinal plants used were glycosides (82%; 70 species), tannins (68%; 58 species), alkaloids (56%; 48 species), saponins (52%, 44 species) and flavonoids (35%; 30 species). On the other hand, the least commonly distributed compounds were resins (31%; 26 species). All the six groups of secondary metabolites were found in seeds of Cuminum cyminum L., Pimpinella anisum L. and Trigonella foenum-graecum L. It can be said that the ethnomedicinal importance of these 85 medicinal plants used in Jeddah conform to their secondary metabolite content. More research should be carried out on the quantitative analysis of phytochemicals in these 85 medicinal plants used in traditional medicine in Jeddah. Furthermore, there is a need to focus phytochemical screening on ethnobotanical studies to complete research into traditional medicine which leads to the discovery of new drugs.     

Opium poppy and Madagascar periwinkle: model non-model systems to investigate alkaloid biosynthesis in plants

Alkaloids represent a large and diverse group of compounds that are related by the occurrence of a nitrogen atom within a heterocyclic backbone. Unlike other types of secondary metabolites, the various structural categories of alkaloids are unrelated in terms of biosynthesis and evolution. Although the biology of each group is unique, common patterns have become apparent. Opium poppy ( Papaver somniferum ), which produces several benzylisoquinoline alkaloids, and Madagascar periwinkle ( Catharanthus roseus ), which accumulates an array of monoterpenoid indole alkaloids, have emerged as the premier organisms used to study plant alkaloid metabolism. The status of these species as model systems results from decades of research on the chemistry, enzymology and molecular biology responsible for the biosynthesis of valuable pharmaceutical alkaloids. Opium poppy remains the only commercial source for morphine, codeine and semi-synthetic analgesics, such as oxycodone, derived from thebaine. Catharanthus roseus is the only source for the anti-cancer drugs vinblastine and vincristine. Impressive collections of cDNAs encoding biosynthetic enzymes and regulatory proteins involved in the formation of benzylisoquinoline and monoterpenoid indole alkaloids are now available, and the rate of gene discovery has accelerated with the application of genomics. Such tools have allowed the establishment of models that describe the complex cell biology of alkaloid metabolism in these important medicinal plants. A suite of biotechnological resources, including genetic transformation protocols, has allowed the application of metabolic engineering to modify the alkaloid content of these and related species. An overview of recent progress on benzylisoquinoline and monoterpenoid indole alkaloid biosynthesis in opium poppy and C. roseus is presented.