6-nitro-iso-vanillic acid,an unusual chromogen from the genus Cortinarius

6-Nitro-iso-vanillic acid, a new natural product, has been isolated from the fruit bodies of an Australian toadstool belonging to Cortinarius (Sericeocybe).     

大型真菌抗氧化活性小分子次生代谢产物的研究进展

大型真菌是菌物中形成大型子实体的一类真菌,该类群中食药用资源极为丰富,许多种类具有显著的抗氧化活性。本文综述了国内外有关大型真菌具抗氧化活性的小分子次生代谢产物的化学结构及其活性的研究概况,以期对大型真菌的活性筛选、化学分析和开发利用提供借鉴。     

Antibacterial halogenated metabolites from the Malaysian Laurencia species

Two halogenated C15 acetogenins, named lembyne-A and lembyne-B, have been isolated from an unrecorded Laurencia species collected off the Malaysian waters. Their structures were deduced on the basis of spectroscopic evidence. Previously known elatol and iso-obtusol showed potent antibacterial activity against some marine bacteria.     

Molecular identification of co-occurring Cortinarius and Dermocybe species from southeastern Australian sclerophyll forests

 The ability of restriction fragment length polymorphism (RFLP) analysis of the rDNA internal transcribed spacer (ITS) region to discriminate 10 co-occurring Cortinarius and Dermocybe species at a southeastern Australian sclerophyll forest site was assessed. Using the basidiomycete-specific primers ITS1F and ITS4B, some taxa were separated on the basis of individual RFLP patterns derived using the restriction endonucleases Hae III or Hinf I. Combined data from both endonucleases were, however, required to separate all taxa [Dermocybe austro-veneta Clel. (Moser & Horak), C. rotundisporus Clel. & Cheel, C. archeri Berk., C. sinapicolor Clel., C. violaceus (L.: Fr.) S.F.Gray, C. radicatus Clel. and four morphologically-distinct, but unidentified Cortinarius spp.]. ITS sequence comparisons confirmed that D. austro-veneta belongs in Dermocybe, that C. rotundisporus is correctly placed in subgenus Phlegmacium, and suggest that Australian C. violaceus collections are not conspecific with northern hemisphere C. violaceus. Accepted: 4 March 1999     

Antibacterial serrulatane diterpenes from the Australian native plant Eremophila microtheca

Chemical investigations of the aerial parts of the Australian plant Eremophila microtheca resulted in the isolation of three serrulatane diterpenoids, 3-acetoxy-7,8-dihydroxyserrulat-14-en-19-oic acid (1), 3,7,8-trihydroxyserrulat-14-en-19-oic acid (2) and 3,19-diacetoxy-8-hydroxyserrulat-14-ene (3) as well as the previously reported compounds verbascoside (4) and jaceosidin (5). Acetylation and methylation of the major serrulatane diterpenoid 2 afforded 3,8-diacetoxy-7-hydroxyserrulat-14-en-19-oic acid (6) and 3,7,8-trihydroxyserrulat-14-en-19-oic acid methyl ester (7), respectively. The antibacterial activity of 1–7 was assessed against a panel of Gram-positive and Gram-negative bacterial isolates. All of the serrulatane compounds exhibited moderate activity against Streptococcus pyogenes (ATCC 12344) with minimum inhibitory concentrations (MICs) ranging from 64–128 μg/mL. Serrulatane 1 demonstrated activity against all Gram-positive bacterial strains (MICs 64–128 μg/mL) except for Enterococcus faecalis and Enterococcus faecium. This is the first report of natural products from E. microtheca.     

Acetylcholinesterase inhibitors from the toadstool Cortinarius infractus

Inhibition of acetylcholinesterase (AChE) and therefore prevention of acetylcholine degradation is one of the most accepted therapy opportunities for Alzheimer´s disease (AD), today. Due to lack of selectivity of AChE inhibitor drugs on the market, AD-patients suffer from side effects like nausea or vomiting. In the present study the isolation of two alkaloids, infractopicrin (1) and 10-hydroxy-infractopicrin (2), from Cortinarius infractus Berk. (Cortinariaceae) is presented. Both compounds show AChE-inhibiting activity and possess a higher selectivity than galanthamine. Docking studies show that lacking π–π-interactions in butyrylcholinesterase (BChE) are responsible for selectivity. Studies on other AD pathology related targets show an inhibitory effect of both compounds on self-aggregation of Aβ-peptides but not on AChE induced Aβ-peptide aggregation. Low cytotoxicity as well as calculated pharmacokinetic data suggest that the natural products could be useful candidates for further drug development.     

Antibacterial metabolites synthesized by psychrotrophic bacteria isolated from cold-freshwater environments

The ability of three psychrotrophic Gram-negative bacilli isolated from Chilean Patagonian cold freshwater rivers to produce bioactive metabolites was evaluated. The strains were isolated from cold waters rivers and identified by their biochemical properties and 16S rRNA gene analysis. The metabolites fractions showing antibacterial activity were obtained by solvent extraction and partially characterized by gas–mass chromatography (GC-MS). Antibacterial activity of the fractions was evaluated by an agar-well diffusion test upon 14 bacterial strains, both Gram positive and Gram negative. Thermal and proteolytic resistances of the antibacterial metabolites fractions were also evaluated. Molecular analysis allows the identification of the three Patagonian strains as Pseudomonas sp. RG-6 (Pseudomonas brenneri 99.6 % identity), Pseudomonas sp. RG-8 (Pseudomonas trivialis 99.6 % identity) and Yersinia sp. RP-3 (Yersinia aldovae 99.5 % identity). These extracts were able to inhibit both Gram-positive and Gram-negative bacteria but not Listeria monocytogenes. The antibacterial activity of the filtrated supernatants was lost at temperatures ≥60 °C, and was not affected by proteinase K treatment. The chemical structure of the active molecule remains to be elucidated, although the GC-MS analysis of the filtrates suggests that compounds like sesquiterpenes derivatives from β-maaliene or δ-selinene could be responsible of this antibacterial activity. Pristine cold freshwater streams showed to be interesting sources of metabolites-producing microorganisms with antibacterial activity.     

Bioactive compounds from the edible mushroom Cortinarius caperatus

Six compounds, 5-(1-hydroxyethyl)dihydrofuran-2(3H)-one (1), 4-ethoxy-4-oxobutanoic acid (2), 4-ketononanoic acid (3), methyl(2-acetylaminoethyl)sulfoxide (4), methyl benzoate (5) and p-hydroxybenzoic acid (6) were isolated from the fruiting bodies of Cortinarius caperatus. Compounds 1, 3, 5, and 6 inhibited growth of Flammulina velutipes mycelia. Compounds 2, 3, 5, and 6 exhibited growth regulatory activities toward rice seedlings, while compounds 3, 5, and 6 regulated the growth of lettuce. Compound 4 was first isolated from a natural source. In addition, the activity of compound 6 against rice was compared with those of its analogs.     

Cytotoxic activity and mechanism of action of metabolites from the Goniothalamus genus

The World Health Organization estimates that 4 billion people or 80 % of the population use plants for curative purposes or for their natural health benefits. Accordingly, biodiversity is an important source of active natural products especially used in traditional medicine as healers transmitted knowledge of traditional usage of medicinal plants from generation to generation whereas pharmacologically active compounds within remained obscure. The present review documents cytotoxicity and anti-cancer potential of known compounds of the Goniothalamus species from the Annonaceae family existing in tropical and subtropical Asia and being intensively used for medicinal purposes.     

The presence of orellanine in spores and basidiocarp from Cortinarius orellanus and Cortinarius rubellus

This is the first report quantifying the orellanine content in basidiospores. The toxin content and tissue distribution of orellanine were determined from Cortinarius orellanus (Fr.) Fr. and Cortinarius rubellus Cooke. Basidiospores, the basidiocarp, divided into cap and stem, and mycorrhiza roots were analyzed to determine the amount of orellanine by reversed phase high performance liquid chromatography and thin layer chromatography. The orellanine contents in spores were 0.31% (C. orellanus) and 0.09% (C. rubellus). In caps, we found the toxin content to be 0.94% (C. orellanus) and 0.78% (C. rubellus), in stems 0.48% (C. orellanus) and 0.42% (C. rubellus) and in mycorrhiza roots from C. rubellus we determined the orellanine contents to 0.03%. In addition, extracts from the different structures of the basidiocarp of C. orellanus and C. rubellus, with an orellanine content corresponding to 25 nmol, inhibited the growth of Bacillus subtilis.     

药用大型真菌灵芝中的三萜酸类成分研究

目的对灵芝中的三萜类成分进行结构与活性研究。方法通过氯仿对灵芝新鲜子实体的乙醇提取物进行萃取,进一步通过硅胶柱层析、中压液相(ODS色谱柱)、制备型HPLC对氯仿提取物中的化学成分进行分离、纯化。通过UV、ESI-MS、HRESI-MS、~1H-NMR、~(13)C-NMR、HSQC、HMBC、NOESY等光谱技术对所分离得到的化合物进行准确的结构鉴定。通过α-葡萄糖苷酶抑制模型对所分离得到的三萜类化合物进行活性评价。结果从灵芝子实体中分离鉴定了7个三萜类成分,分别为:(1)Ganoderic acid X1,(2)Ganoderic acid C,(3)Deacetyl-ganoderic acid F,(4)Ganoderic B,(5)Lucienic acid A,(6)7-hydroxy-3,11,15-trioxo-lanosta-8-en-24→20sLactone,(7)Methyl lucidenate D2。化合物1和6显示了一定的α-葡萄糖苷酶抑制活性。结论灵芝中的主要化学成分类型为羊毛脂烷型三萜及其降碳衍生物,其中化合物1为未见报道的新化合物。该类成分显示了一定的α-葡萄糖苷酶抑制作用,具有较好的研究前景。     

Chemical variability of the volatile metabolites from the Caribbean corals of the genus Gorgonia

The chemical composition of the investigated gorgonians showed a high level of individual variation and the colonies, according to their major contributors, were assigned to 10 distinct chemical profiles, among which A, C, E, and G were the most abundant ones. From the metabolites identified in the present study, either by means of GC/MS or using NMR techniques after conventional separation procedures, the novel cyclic ether 5,10-epoxymuurolane is found in significant quantities in D and I chemical profiles. Furanotriene, isofuranotriene and furanodiene could be referred as the most common metabolites of the genus, since they are found in 6 out of 10 chemical profiles. Isosericenine is, also, a significant contributor of H and I chemical profiles. A number of sesquiterpene hydrocarbons, such as curzerene, bicyclogermacrene, valencene, beta-bourbonene and beta-elemene, along with the oxygenated sesquiterpenes elemanolide and furoventalene, are present at varying concentrations in the majority of the chemical profiles. Metabolites of high discriminant value are: alpha-himachalene for the K chemical profile, alpha-santalene and its oxygenated derivatives for the G chemical profile and the three geometrical isomers of germacrone for the F chemical profile. Several chemical profiles showed narrow geographic distribution. Most of the chemical profiles are located in the north, while F inhabits mainly southern sites and the others are equally distributed. Finally, 91% of the chemical profiles of the gorgonian colonies appeared to grow in all depths, while 9% did not inhabit deep-water environments. Most chemical profiles are less frequent at higher water depths with the exception of chemical profiles A and C.     

Two New Ergosterol Derivatives from the Basidiomycete Cortinarius glaucopus

Two new sterols 1 and 2 and five known ones 3 – 7 were isolated for the first time from the fruiting bodies of Cortinarius glaucopus. Their structures were established by 1‐ and 2D‐NMR spectra and HR‐FABS‐MS. The relative configuration of 1 was firmly determined by comparison of the observed ¹H–¹H couplings and NOESY correlations, with those predicted for the computed geometries of the conformers. Calculations were performed by means of DFT with the B3LYP functional at 6‐31 + G(d,p) level of theory, in CHCl₃ as the solvent. The structures of the new ergosterol derivatives, called glaucoposterol A ( 1 ) and B ( 2 ), were thus established as (3S,5R,7R,10R,13R,17R,20S,22R,23R,24R)‐5,6‐epoxy‐3,7,23‐trihydroxystrophast‐8‐en‐14‐one and (22E,3S,5S,9S,10R,13R,17R,20R,24R)‐3,5‐dihydroxyergosta‐6,8(14),22‐trien‐15‐one, respectively. Moreover, the configuration of known strophasterol C ( 3 ) was determined as (3S,5R,6S,7R,10R,13R,17R,20S,22S,24R). Glaucoposterol A ( 1 ) and strophasterol C ( 3 ) represent the second finding in nature of steroids with the rare strophastane skeleton.     

Secondary metabolites of plants from the genus Saussurea: chemistry and biological activity

The Asteraceae family comprises ca. 1000 genera, mainly distributed in Asia and Europe. Saussurea DC., as the largest subgenus of this family, comprises ca. 400 species worldwide, of which ca. 300 species occur in China. Most plants in China grow wild in the alpine zone of the Qingzang Plateau and adjacent regions at elevations of 4000 m. Plants of the genus Saussurea (Asteraceae) are used in both traditional Chinese folk medicine and Tibet folklore medicine, since they are efficacious in relieving internal heat or fever, harmonizing menstruation, invigorating blood circulation, stopping bleeding, alleviating pain, increasing energy, and curing rheumatic arthritis. A large number of biologically active compounds have been isolated from this genus. This review shows the chemotaxonomy of these compounds (215 compounds) such as sesquiterpenoids (101 compounds), flavonoids (19 compounds), phytosterols (15 compounds), triterpenoids (25 compounds), lignans (32 compounds), phenolics (23 compounds), and chlorophylls (11 compounds). Biological activities (anti‐inflammatory, anticancer, antitumor, hepatoprotective, anti‐ulcer, cholagogic, immunosuppressive, spasmolytic, antimicrobial, antiparasitic, antifeedant, CNS depressant, antioxidant, etc.) of these compounds, including structure–activity relationships, are also discussed.     

Secondary metabolites of plants from the genus cipadessa: chemistry and biological activity

The plants of genus Cipadessa, which are distributed across India and southwest of China, have been used as natural insecticides, as well as folk medicines for the treatment of a range of maladies such as diabetes, dysentery, malaria, piles, snake poison, rheumatism, etc. This article reviews the chemical constituents that have been isolated from Cipadessa species to date, including their biological activities. The compounds listed are tetranortriterpenoids (limonoids), diterpenoids, sesquiterpenoids, flavonoids, steroids, and some others.     

Deoxyaustrocortilutein and deoxyaustrocortirubin,tetrahydroanthraquinones from the Genus Cortinarius

The hydroxylated tetrahydroanthraquinones deoxyaustrocortilutein and deoxyaustrocortirubin have been isolated from fruit bodies of a red Australian toadstool belonging to Cortinarius; the structures are proved by chemical correlation with their co-metabolites austrocortilutein and austrocortirubin.     

Screening of the genus Cercospora for secondary metabolites

Screening of 61 species of Cercospora grown on a potato-agar medium showed the presence of the phytotoxin cercosporin in 24 of them, and of dothistromin in 8. Some strains of C. beticola produce a yellow phytotoxin (CBT). The new metabolites cercosporin esters, ligustrone A, B, C, taiwapyrone, 3-methoxy-2,5,7-trihydroxy-1,4-naphthaquinone, cis-4,6-dihydroxymellein and ( ? )-11-acetyldehydrocurvularin were isolated besides the known cynodontin, ( ? )-dehydrocurvularin, (+ )-mellein and cis-3S,4S-4-hydroxymellein.     

小单胞菌属次级代谢产物及其生物活性研究进展

小单胞菌属(Micromonospora)为稀有放线菌,广泛分布在土壤、海洋和动植物中,其所产代谢产物不仅具有抗菌、抗肿瘤、抗HIV等多种生物活性,而且化学结构新颖多样。本文从化学结构分类、生物活性等方面对近几年已报道的小单胞菌属来源的重要天然产物做了简要综述,以期为小单胞菌天然产物的开发和应用奠定基础。     

Polyploidy in the Australian leptodactylid frog genus Neobatrachus

Karyotypic analysis of six species of the Australian leptodactylid frog genus Neobatrachus showed that N. pictus, N. centralis, N. pelobatoides and N. wilsmorei are diploid (2n=24) while N. sudelli and N. sutor are tetraploid (4n=48). Polyploidy has not been reported previously among Australian anurans. Idiograms of the six species indicate that they are similar to the other Australian leptodactylids so far discribed. DNA values of the tetraploids are approximately double the values for diploids. Tetraploid nuclear and cell sizes are greater compared with diploids but total body size shows no increase. At diakinesis in primary spermatocytes of tetraploids, mainly tetravalents together with a few bivalents are present. Silver staining of metaphase spreads clearly demonstrates the location of NORs at the secondary constrictions and their frequent association in the tetraploid N. sutor. Nucleolar number in interphase nuclei provides a reliable guide for distinguishing tetraploid from diploid frogs in the absence of chromosome analysis and can be determined for both living and preserved specimens. The possible origins and relationships of the tetraploid species are discussed.