玄参属植物中环烯醚萜类成分及其生物活性研究进展

本文综述了近年来从玄参属植物中分离得到的所有环烯醚萜类成分及其生物活性,为该属植物及该类成分的深入开发和利用提供参考。     

The Genus Cryptocarya: A Review on Phytochemistry and Pharmacological Activities

Cryptocarya (the laurel family) is a large genus of great economic plants found in tropics and subtropics. Plants of this genus are a rich resource of essential oils, and pharmacological compounds. An overview of phytochemistry and pharmacological aspect is not yet available. This review aims to establish insightful information on phytochemistry, and pharmacological values. The literature collection is based on keywords ‘Cryptocarya’, ‘phytochemistry’, and ‘pharmacology’ using a broad panel of scientific sources, such as Google Scholar, Sciencedirect, and Wiley. Since the 1950s, Cryptocarya plants have been the main object in various phytochemical studies, by which about 390 metabolite compounds were isolated. Alkaloids, α-pyrones, and flavonoids could be seen as the main classes of Cryptocarya isolates. Cryptocarya constituents displayed potential pharmacological values such as anti-inflammatory, antimicrobial, antioxidative, antiviral, vasorelaxant activities, especially cytotoxicity.     

Phytochemistry and the systematics and ecology of Loasaceae and Gronoviaceae (Loasales)

A screening for iridoid compounds of 78 of 315 species from all major groups in Gronoviaceae and Loasaceae has been carried out. The results were compared to the systematic concepts in the family and distribution and ecology of the taxa. Iridoids are present in at least some species of all genera screened. Some simple, monomeric compounds (e.g., loganin, sweroside) are found in all major groups of the two families and represent the basic iridoid inventory. Other compounds are restricted to certain taxonomic groups: nine-carbon iridoids (e.g., deutzioside) are restricted to Mentzelia (Loasaceae subfam. Mentzelioideae), hetero-oligomeric iridoids (e.g., tricoloroside methyl ester, acerifolioside) are restricted to two small groups in Loasa (Loasa ser. Macrospermae and ser. Floribundae, Loasaceae subfam. Loasoideae), and oleosides (e.g., 10-hydroxyoleoside dimethyl ester) are restricted to the large genus Caiophora sensu Weigend). The distribution of certain iridoid compounds thus confirms some of the generic limits. Iridoid phytochemistry does not correlate with systematic entities above the generic level nor does it in any way correlate with the morphological evolution of taxa. Conversely, the amount and complexity of iridoid compounds present in taxa correlate positively with the aridity of their habitat and the extent of mammalian herbivore pressure.     

Ethnobotany, phytochemistry and pharmacology of Uncaria (Rubiaceae)

The Uncaria genus is an important source of medicinal natural products, particularly alkaloids and triterpenes. The collected information is an attempt to cover the more recent developments in the ethnobotany, pharmacology and phytochemistry of this genus. During the past 20 years, alkaloids, terpenes, quinovic acid glycosides, flavonoids and coumarins have been isolated from Uncaria. Fifty-three novel structures are reported in this review. The species in which the largest number of compounds has been identified is the Peruvian Uncaria tomentosa or 'cat's claw.' Pharmacological studies are described according to cytotoxicity, anti-inflammatory, antiviral, immunostimulation, antioxidant, CNS-related response, vascular, hypotensive, mutagenicity and antibacterial properties. The potential for development of leads from Uncaria continues to grow, particularly in the area of immunomodulatory, anti-inflammatory and vascular-related conditions. The information summarized here is intended to serve as a reference tool to practitioners in the fields of ethnopharmacology and natural products chemistry.     

Occurrence of flavonoids in different Lamiaceae taxa for a preliminary study on their evolution based on phytochemistry

In this work, the continuation of the study of the plant evolution based on phytochemistry was presented. Flavonoids were used to draw a Sporne evolution diagram of selected Lamiaceae taxa. From a phytochemical evolution standpoint, results showed similarities and differences with regard to the previous work on iridoids. In addition, analogies and diversities from the phylogenetic tree based on molecular and genetic data were evidenced. Findings suggest again the potentiality to further use phytochemical data for the evaluation of Lamiaceae evolution.     

Iridoids in Hydrangeaceae

The content of glycosides in Kirengeshoma palmata and Jamesia americana (Hydrangeaceae) have been investigated. The former contains loganin and secoiridoids, including the alkaloid demethylalangiside. The latter contains no iridoids, but the known glucosides arbutin, picein and prunasin. In order to futher investigate the chemotaxonomy of the family Hydrangeaceae, the distribution of the iridoid and secoiridoid glucosides as well as the known biosynthetic pathways to these compounds have been reviewed. However, only a few genera of the family has been investigated. Loganin, secologanin, and derivatives of these are common. The genus Deutzia is characteristic in containing more structurally simple iridoids in which C-10 has been lost during biosynthesis. Such compounds have so far only been reported from the genus Mentzelia (Loasaceae). The taxonomic relationships between Hydrangeaceae and the closely related Cornaceae and Loasaceae is discussed and found to agree well with recent DNA sequence results.     

A review of the ethnomedicinal uses,phytochemistry and pharmacology of the <Emphasis Type="Italic">Pleiocarpa</Emphasis> genus

Pleiocarpa genus is a flowering plant from the Apocynaceae family which are rich sources of phytochemicals and have been reported to be useful in the treatment of gastrointestinal ailments, fever, malaria, pain, diabetes and cancer. The aim of this review is to present the past and current ethnomedicinal uses, phytochemistry and the pharmacology of Pleiocarpa genus which are underexploited as revealed through this review in order to enhance its potential source of phytochemical leads in medicine. Some pharmacological activities of these plants based on their acclaimed ethnomedicinal uses have been investigated by various researchers. The chemical profile of the genus is limited to alkaloids and triterpenoids, where indole alkaloids may be considered as important taxonomical markers.     

Benzoxazinoids and iridoid glucosides from four Lamium species

A new class of compounds for the plant family Lamiaceae, benzoxazinoids, was found in Lamium galeobdolon. From the aerial parts of the species were isolated the new 2-O-beta-D-glucopyranosyl-6-hydroxy-2H-1,4-benzoxazin-3(4H)-one (6-hydroxy blepharin) together with four known benzoxazinoids, DHBOA-Glc, blepharin, DIBOA, DIBOA-Glc, as well as harpagide, 8-O-acetyl-harpagide and salidroside. Eight known iridoid glucosides, 24-epi-pterosterone and verbascoside were isolated from Lamium amplexicaule, L. purpureum and L. garganicum. The iridoids, 5-deoxylamiol and sesamoside, as well as the phytoecdysone, 24-epi-pterosterone, were found for the first time for the genus Lamium. The phytochemical data are discussed from a systematic and evolutionary point of view.     

Iridoid patterns in Galium L. and some phylogenetic considerations

From 19 species of Galium, members of 6 European sections of the genus, 24 compounds were isolated, namely 16 iridoid glucosides, 2 secoiridoid glucosides and 6 triterpene saponins (the later found only in G. rivale (Sibth. & Sm. Griseb.) The iridoid content was analyzed by thin layer chromatography - densitometry. An effort was made to clarify interspecies relationships, based on the obtained results and previous data. Generally, a nearly uniform iridoid pattern in the studied species was observed. Nevertheless, some distinctions gave reason the following chemical characters to be treated as taxonomic markers: iridoids, secogalioside (characteristic of G. mollugo group), iridoids V1 and V2 (G. humifusum Bieb. and G. verum L.), 6-acetylscandoside (G. incurvum group and G. verum) and the triterpene saponins, rivalioside A and rivalioside C (characteristic of G. rivale). The studied species regarding to the iridoids could be attributed to three lines of evolutionary differentiation. One line is leading to the differentiation of G. rivale. It contains specific triterpenoids as well as iridoid acids, which show parallel development of both glyceraldehyde 3-phosphate/pyruvate and mevalonate biosynthetic routes in this species. A second line includes G. mollugo and G. incurvum species groups and the species G. humifusum and G. verum. Variety of iridoid esters, hydroxy and carboxy derivatives of iridoids and secoiridoids characterised this line. Third line comprises the remaining studied species, members of different sections and species groups. They posses a nearly identical iridoid pattern, which suggests a convergent evolution regarding to the iridoids.     

Polyphenolics of Salvia--a review.

Salvia is an important genus widely cultivated and used in flavouring and folk medicines. The genus has attracted great interest so much so that it has been the subject of numerous chemical studies. It is a rich source of polyphenols, with an excess of 160 polyphenols having been identified, some of which are unique to the genus. A large number of these polyphenolic compounds are apparently constructed from the caffeic acid building block via a variety of condensation reactions. The nature of these polyphenols which have been reported is compiled in this report together with some bioactivity data in an effort to show the rapid development in the phytochemistry and the therapeutic applications of the Salvia species.     

Chemotaxonomy of Plantago. Iridoid glucosides and caffeoyl phenylethanoid glycosides

Data for 34 species of Plantago (Plantaginaceae), including subgen. Littorella (= Littorella uniflora), have been collected with regard to their content of iridoid glucosides and caffeoyl phenylethanoid glycosides (CPGs). In the present work, 21 species were investigated for the first time and many known compounds were found together with three new iridoid glucosides. Of these, arborescoside and arborescosidic acid, both of the uncommon type with an 8,9-double bond, were present in several species, while 6-deoxymelittoside was found only in P. subulata. The known compounds deoxyloganic acid, caryoptoside and rehmannioside D were isolated from the genus for the first time. The earlier reported occurrence of sorbitol in the family was confirmed, and this compound was shown by NMR spectroscopy to be the main sugar in the three species investigated for this. The combined data show that CPGs are present in all species investigated. With regard to the iridoids, the distribution patterns showed a good correlation with the classification of Rahn. Thus, aucubin is typical for the whole genus, while bartsioside and catalpol as well as 5-substituted iridoids are each characteristic for a subgenus in the family. Finally, the close relationship between Plantago and Veronica suggested by chloroplast DNA sequence analysis. could be corroborated by the common occurrence of the rare 8,9-unsaturated iridoids in these two genera.     

Veronica: Iridoids and cornoside as chemosystematic markers

The iridoid glucoside, ajugol, and the phenylethanoid glucoside, cornoside, have been isolated from species of Veronica (Plantaginaceae) for the first time. The presence of these compounds has been screened in 18 plant accessions belonging to 15 species of Veronica (Plantaginaceae), by isolation or NMR spectroscopy of crude extracts. In addition, the distribution of iridoids in the genus has been reviewed, using mainly the published data of isolated compounds. Using the recent expansion and reclassification of the genus based on DNA-sequence results as the model, we find that the genus is rather homogeneous with regard to the distribution of iridoid glucosides, aucubin and/or catalpol as well as 6-O-esters of catalpol being universally present in 10 of the 12 subgenera for which data exist. Only the two subgenera Pocilla and Chamaedrys deviate from this pattern. Pocilla is heterogeneous; in this subgenus, species in subsect. Agrestes contain the standard iridoid garniture, while species in subsect. Biloba do not contain the 6-O-esters of catalpol, but ajugol instead. Veronica intercedens (subsect. Subracemosae) differs from the remainder of the subgenus in only containing 5-hydroxylated iridoids (melittoside and globularifolin) and is so far the only species within the genus in which such compounds have been detected. These chemical differences are clearly reflected in the DNA-based phylogram of the subgenus. Subg. Chamaedrys appears homogeneous in lacking iridoids or only containing these in small amounts, but instead half of the investigated species contained the phenylethanoid glucoside cornoside. The distribution of this compound in angiosperms is reviewed; cornoside often substitutes iridoid glucosides in plants where these are expected to be present. The chemical results of Veronica fit in very well with the phylogenetic implications of the DNA-sequence results.     

Preliminary study on the phytochemical evolution of different Lamiaceae species based on iridoids

In this work, an interesting potential application of phytochemistry is reported. In particular, we employed the Sporne diagrams to provide information about the evolution of some different Lamiaceae species in relation to their content in secondary metabolites. In more details, fifteen species belonging to six different genera were studied i.e. Ajuga L., Galeopsis L., Melittis L., Sideritis L., Stachys L. and Teucrium L. The selected secondary metabolites were iridoids because of their wide occurrence and distribution within all the family, thus providing a more accurate and general overview. Nineteen different compounds of this class were identified in the studied species. The aim of this work was to verify if the evolutionary data available in literature for the studied species and based on molecular studies, matched with those obtained from a more phytochemical approach or not. The final objective was to ascertain a correspondence between these two opposite methods. The results of this study clearly showed that, only in some cases, this correspondence was present. This may suggest the possibility to use both methods for drawing phylogenetic trees of plants. Anyway, this study is not general and is quite limited in studied species and in collection areas and does not intend to affirm its absolute accuracy even though it may be a good starting point for future researches in this field.     

Iridoids of Cruckshanksia verticillata and their Chemosystematic importance

From Cruckshanksia verticillata, an endemic Chilean species of the family Rubiaceae, a new secoiridoid was isolated in addition to asperuloside and secologanin and identified as 7--methoxysweroside by spectroscopic means. The importance of the isolated iridoids in subfamilial classification of the genus Cruckshanksia is discussed.     

Chemotaxonomy of the Oleaceae: iridoids as taxonomic markers

The distribution and biosynthesis of iridoid glucosides in the Oleaceae is reviewed and five distinct biosynthetic pathways to iridoids have been identified in the family, deoxyloganic acid apparently being a common intermediate. Likewise, the distributions of caffeoyl phenylethanoid glycosides (CPGs), i.e. verbascoside and its analogues, as well as cornoside are listed. Iridoid glucoside data exist for 17 genera of Oleaceae and the occurrence of iridoids from the different biosynthetic pathways correlate extremely well with the phylogenetic classification inferred from recent chloroplast DNA sequence data. Thus the tribe Fontanesieae (Fontanesia) contains "normal" secoiridoids, Forsythieae (Abeliophyllum, Forsythia) contains cornoside and/or iridoids from the forsythide pathway, Myxopyreae (Myxopyrum, Nyctanthes) have iridoids from the myxopyroside pathway, and finally, the two tribes Jasmineae and Oleeae (the remaining genera) both contain iridoids from the oleoside pathway. Within Jasmineae, one group of Jasminum sp. is characterized by the presence of jasminin or similar compounds, while another group of Jasminum species and Menodora display derivatives of 10-hydroxyoleoside, compounds not present in the other group. CPGs are reported from about half of the species investigated. With regard to taxonomy at the order level, the chemical data might support a position within or close to Lamiales due to the common presence of CPGs, the iridoids being of less significance since they are of a type that are barely found elsewhere.     

香椿属中三萜类化学成分及生物活性研究进展

香椿属植物在我国民间应用广泛,自1846年香椿属建立以来,不少学者已经对本属植物进行各方面的研究,包括植物生态学和植物化学方面。但到目前为止还不曾见到对该属植物中化学成分和生物活性方面的研究进展进行综述报道。目前对香椿属植物化学成分及生物活性的报道相对集中在三萜类成分,此类成分也是香椿属所在的楝科其他植物特征性成分,该科植物中存在特有的新奇的三萜类成分,不论是化学成分还是生物活性方面都是是当前的研究热点。鉴于此作者对目前国内外报道的香椿属植物中三萜类成分的化学成分及其生物活性研究进行归纳总结,特别是香椿属中三萜的类型以及不同类型三萜代表性的生物活性进行系统归纳,以便为以后研究香椿属其他植物或进一步深入研究开发提供文献支持。     

The mosquito genome--a turning point?

Of the insects that serve as vectors for parasitic diseases, the genus Anopheles is the most important. Of the approximately 400 species, about twelve serve as vectors for human pathogens. Months have passed since the sequenced genomes of the malaria parasite, Plasmodium falciparum, and its vector, Anopheles gambiae, were published. Sequences were compared, gene and protein predictions were made, new research areas evolved and many ongoing projects gained new momentum. A general belief is that we are at a turning point: we are now in a position to tackle both the parasite and the vector from new angles and with new force, for example, by identifying new drug targets and obtaining a deeper insight into molecular mechanisms of the insect, the parasite and the interactions between them.