Methylenedioxy- and methoxyflavones from Melicope coodeana syn. Euodia simplex

Three new natural products, 3,8-dimethoxy-5,7-dihydroxy-3′,4′-methylenedioxyflavone, 3,6,8-trimethoxy-5,7-dihydroxy-3′,4′-methylenedioxyflavone and 3,6,8,3′,4′-pentamethoxy-5,7-dihydroxyflavone were isolated from Melicope coodeana syn. Euodia simplex (Rutaceae) along with 3,6,3′-trimethoxy-5,7,4′-trihydroxyflavone and 3,3′-dimethoxy-5,7,4′-trihydroxyflavone. The structural assignments are based on ¹H and ¹³C NMR data, including discussion of the chemical shifts of C-2 in 3,5-dihydroxy- and 3-methoxy-5-hydroxyflavones. The presence of highly methoxylated and methylenedioxyflavones is characteristic of the genus Melicope, and the present findings support the recent transfer of Euodia simplex to Melicope.     

Prenylated acetophenones from Melicope obscura and Melicope obtusifolia ssp. obtusifolia var. arborea and their distribution in Rutaceae

Four prenylated acetophenones 2,6-dihydroxy-4-geranyloxyacetophenone (1), 4-geranyloxy-2,6,β-trihydroxyacetophenone (2), 2,6-dihydroxy-4-geranyloxy-3-prenylacetophenone (3), and 4-geranyloxy-3-prenyl-2,6,β-trihydroxyacetophenone (4) have for the first time been isolated from Melicope obscura (1 and 2) and Melicope obtusifolia ssp. obtusifolia var. arborea (3 and 4). The distribution of prenylated acetophenones in Rutaceae is reviewed and the results, including the new records, indicate that prenylated acetophenones are valuable as chemotaxonomic markers for the subfamily Rutoideae, tribe Xanthoxyleae sensu Engler.     

A polysaccharide from Lichina pygmaea and L. confinis supports the recognition of Lichinomycetes

The lichen-forming order Lichinales, generally characterized by prototunicate asci and the development of thalli with cyanobacteria, has recently been recognized as a separate class of ascomycetes, Lichinomycetes, as a result of molecular phylogenetic studies. As alkali and water-soluble (F1SS) polysaccharides reflect phylogeny in other ascomycetes, a polysaccharide from Lichina pygmaea and L. confinis was purified and characterized to investigate whether these F1SS compounds in the Lichinomycetes were distinctive. Nuclear magnetic resonance (NMR) spectroscopy and chemical analyses revealed this as a galactomannan comprising a repeating unit consisting of an α-(1→6)-mannan backbone, mainly substituted by single α-galactofuranose residues at the O-2- or the O-2,4- positions linked to a small mannan core. With the exception of the trisubstituted mannopyranose residues previously described in polysaccharides from other lichens belonging to orders now placed in Lecanoromycetes, the structure of this galactomannan most closely resembles those found in several members of the Onygenales in Eurotiomycetes. Our polysaccharide data support molecular studies showing that Lichina species are remote from Lecanoromycetes as the galactofuranose residues are in the α-configuration. That the Lichinomycetes were part of an ancestral lichenized group can not be established from the present data because the extracted polysaccharide does not have the galactofuranose residue in the β configuration; however, the data does suggest that an ancestor of the Lichinomycetes contained a mannan and was part of an early radiation in the ascomycetes.     

In vivo larvicidal activity of monoterpenic derivatives from aromatic plants against L3 larvae of Anisakis simplex s.l.

In view of the lack of an effective pharmacological treatment against human anisakiosis, a disease produced by L(3) larvae of the genus Anisakis present in raw fish, we studied the in vivo larvicidal effect of certain monoterpenic derivatives against L(3) of A. simplex s.l. The aldehydic monoterpene citral and the alcoholic citronellol, when they are administered together to the larvae of the nematode at the concentration of 46.90 mg/0.5 ml in olive oil, achieve 85.90% and 67.53% dead L(3), respectively, and also stop rats suffering gastrointestinal hemorrhages produced by the larvae.     

毛山小橘枝叶中生物碱类成分的研究

为了解毛山小橘(Glycosmis craibii)的化学成分,采用硅胶柱层析、ODS柱层析、Sephadex LH-20凝胶柱层析和高效液相色谱等现代色谱分离技术,从毛山小橘枝叶95%乙醇提取物中分离得到9个生物碱类化合物。根据化合物的理化性质和波谱数据,其结构分别鉴定为de-N-methyl-O-noracronycine (1)、去甲山油柑碱(2)、glycocitrine Ⅱ (3)、acrifoline (4)、3-hydroxy- 2, 4-dimethoxy-10-methyl-9-acridanone (5)、阿塔宁(6)、glycosolone (7)、3-(3?, 3?-dimethylallyl)-4, 8-dimethoxy-N-methyl-quinolin- 2-one (8)和4-methoxy-N-methyl-2-quinolone (9)。所有化合物均为首次从该植物中分离,其中化合物2、3、5、6和9为首次从山小橘属植物中分离得到。     

Sequential Main-Chain Proton and Carbon Resonance Assignments for Wild-Type Yeast Iso-1 Ferrocytochrome c and Identification of Secondary Structural Elements

Yeast iso-1 cytochrome c is a naturally occurring protein that possesses an unusually reactive Cysl02 that imbues iso-1 with a complicated solution chemistry which includes spontaneous dimerization and poorly characterized redox reactions. For this reason previous studies of this typical member of the c-type cytochromes have been relegated to variant proteins in which the 102 position has been mutated, with most common changes involving serine and threonine. However, we have determined sequential ¹H resonance assignments for the wild-type native protein because it is the actual participant in yeast mitochondrial electron transfer processes and because the wild-type native protein should be the fundamental assignment basis. In addition to ¹H resonance assignments for 97 of 106 amino acids, we have also provided an extensive database of long-range NOEs. Comparison of these NOEs and a chemical shift index based upon -H resonances has lead to identification of solution secondary structural elements that are consistent with the solid-state crystal structure. Although there is currently no efficient expression system that would facilitate isotope labeling of iso-1 cytochrome c, we tried to assess the usefulness of future heteronuclear experiments by using natural-abundance ¹H/¹³C HMQC experiments to unambiguously assign 35 -C resonances.     

Chemotaxonomy of the genus Xanthorrhoea

It was found that the composition of the resins produced by members of the genus Xanthorrhoea was sufficiently taxon-specific to allow the setting up of a chemotaxonomic key. A generalized procedure for the isolation of flavanoids from Xanthorrhoea resins is given together with details of all isolated components.     

中国吴茱萸属(广义)叶结构特征及其分类学意义北大核心CSCD

该研究以中国产芸香科广义吴茱萸属18种3变种为材料,于体视显微镜下观察叶结构特征。结果发现:(1)吴茱萸属叶脉为羽状脉。(2)二级脉有花环状弓形脉和简单弓形脉两种类型,极少数存在内二级脉,间二级脉存在或缺失。(3)三级脉不规则网状或极少数弱贯穿,边缘三级脉环状。(4)四级脉不规则网状或自由分支。(5)五级脉不规则网状或自由分支,脉间区发育差或中等,游离端小脉末端简单或管状异形,边缘末级脉大多数不完整,极少数环状。(6)基于重要的外部形态学特征和叶结构特征观察结果,编制了广义吴茱萸属植物的分组检索表。研究表明,吴茱萸属这些类群的二级脉与更高级脉序形成的结构极为稳定,同时又存在种间差异,故广义吴茱萸属植物叶结构特征可以为更准确地鉴定一些疑难种和混淆种提供佐证,具有重要的系统分类学价值。     

Purification and properties of methanol dehydrogenase from Methylophaga marina

Purification of methanol dehydrogenase from Methylophaga marina, in order to avoid the instability observed in crude extracts, was achieved initially by a rapid procedure using mainly an aqueous two-phase partition system composed of polyethylene glycol 1000 (50%, v/v) and potassium phosphate (50%, w/v). The purified enzyme gave a single band of protein after SDS-polyacrylamide gel electrophoresis. Antiserum raised against purified methanol dehydrogenase was used to detect possible protein contaminants in the enzyme preparation. The enzyme is an NAD-independent dehydrogenase containing pyrrolquinoline quinone (PQQ) as a prosthetic group. It is made of two apparently identical subunits giving a total MW of 145,000 for the native enzyme. The isoelectric point is 6.4. In addition to methanol and formaldehyde, multicarbon primary alcohols and aldehydes as well as secondary alcohols can be used as substrates. Except for ammonium chloride, which is a necessary activator in vitro, no effector was found which could modify the rate of enzyme activity under standard conditions of the assay. Although the main properties of this methanol dehydrogenase are similar to those already described in the literature, it does not belong in any of the five categories described by Anthony.     

马齿苋内生菌橘青霉和波兰青霉中抗青枯菌的活性物质

为了挖掘农作物病害生物防治新资源,以药用植物马齿苋(Portulaca oleracea)为材料,通过培养基种植法分离和纯化其根、茎、叶中的内生菌,以青枯菌(Ralstonia solanacearum)的抑菌试验评价其活性,采用菌落形态观察和ITS序列分析鉴定菌种。结果表明,从马齿苋筛选出2种具有抑制青枯菌的内生菌橘青霉(Penicillium citrinum)和波兰青霉(P. polonicum),采用液相与四极杆飞行时间串联质谱(UPLC-QTOF-MS)鉴定2种内生菌的主要活性物质为橘霉素,其对青枯菌的抑制效果比链霉素更好。因此,这为植物青枯病的生物防治提供科学依据。     

Palaeoneuroanatomy of Brachiosaurus

An overview of the palaeoneuroanatomy (brain and spinal cord) of the sauropod dinosaur Brachiosaurus is given. Although having a flexed brain configuration, Brachiosaurus presents on the whole a rather moderately derived neuroanatomical pattern. As other sauropods, Brachiosaurus shows an enlargement of the spinal cord in the sacral area. New Encephalization Quotients are calculated and found to be about 0.62 or 0.79 (depending on the body volume taken into consideration) when Hurlburt's formula is used. This suggests that Brachiosaurus, although it may not have been as a low encephalized taxon (by reptilian standards) as previously believed, did have an undersized relative brain volume.     

不结球白菜BcMPK4基因的分离及表达

为了进一步探讨植物MAPKs(mitogen-activated protein kinases)在植物防卫中的作用,该研究从不结球白菜抗病品种‘苏州青’中克隆到一个抗核盘菌(Sclerotinia sclerotiorum)相关基因,命名为BcMPK4(DDBJ登录号AB557751)。该基因核苷酸序列全长1 334bp,编码373个氨基酸,与已克隆的MPK4基因有不同程度的相似性。系统进化树分析表明,该基因在不同物种之间具有保守性。基因组DNA杂交表明,BcMPK4可能属于一个较小的多基因家族,属组成型表达。实时定量PCR检测表明,核盘菌能够诱导不结球白菜BcMPK4基因的转录表达;BcMPK4基因在不结球白菜叶片中的表达特征说明它可能参与寄主对核盘菌的抗性。     

New fungal genera, Tectonidula gen. nov. for Calosphaeria-like fungi with holoblastic-denticulate conidiogenesis and Natantiella gen. nov. for three species segregated from Ceratostomella

Two morphologically similar groups of ascomycetes with globose to subglobose perithecia, elongate necks, unitunicate asci floating freely at maturity, and hyaline ascospores currently placed in Calosphaeria s. lat. and Ceratostomella s. lat., respectively, are studied. The Calosphaeria-like fungi have groups of perithecia growing between cortex and wood, arranged in circular groups with converging necks and piercing the cortex in a common point; the asci with a shallow apical ring and U- to horseshoe-shaped hyaline ascospores are compared with Calosphaeria pulchella, the type species of the genus. Conidiogenesis of the investigated Calosphaeria-like fungi is holoblastic-denticulate; ramichloridium-like and sporothrix-like conidiophores and conidia were formed in vitro. Ascospore and ascus morphology, structure of the ascal apex, ascogenous system, mode of conidiogenesis and the large subunit rRNA sequences of this group differ considerably from C. pulchella and both groups are unrelated. Thus a new genus, Tectonidula, is described with two accepted species, T. hippocrepida and T. fagi; they are separated by ascospore and ascus morphology and holoblastic-denticulate conidiogenesis from the core species of Calosphaeria. The placement of Tectonidula among perithecial ascomycetes is discussed. The relationship of Tectonidula with Barbatosphaeria and two ramichloridium-like hyphomycetous genera Rhodoveronaea and Myrmecridium is investigated. Three species formerly attributed to Ceratostomella are studied. The revision of the herbarium type specimen and fresh material of Ceratostomella ligneola revealed that it is conspecific with Ceratostomella ampullasca and Ceratostomella similis. The LSU phylogeny clearly separated C. ligneola from Ceratostomella s. str. and morphologically similar Lentomitella. On the basis of molecular sequence data and detailed comparison of morphology of asci, ascospores and ascogenous system the genus Natantiella is described for C. ligneola with C. ampullasca and C. similis as its synonyms. Natantiella produced sterile mycelium in vitro.     

Phytochemical differentiation of Galanthus nivalis and Galanthus elwesii (Amaryllidaceae): A case study

The alkaloid patterns of two occasionally sympatric Galanthus nivalis and Galanthus elwesii populations were studied by GC/MS. Thirty-seven alkaloids were detected, 25 for G. nivalis and 17 for G. elwesii. Only five alkaloids were found to occur in both species. The populations of Galanthus differed in their alkaloid biosynthetic pathways. Thus, the alkaloid pattern of G. nivalis was dominated by compounds coming from a para–para′ oxidative coupling of O-methylnorbelladine. The predominant alkaloids in the roots of this species were found to belong to the lycorine and tazettine structural types; bulbs were dominated by tazettine, leaves by lycorine and flowers by haemanthamine type alkaloids. In contrast, the alkaloid pattern of G. elwesii was dominated mainly by compounds coming from an ortho–para′ oxidative coupling. The predominant alkaloids in G. elwesii roots, bulbs and leaves were those of homolycorine type, whereas the flowers accumulated mainly tyramine type compounds. The chemotaxonomical value of the alkaloids found in the studied species is discussed.     

桂木茎枝化学成分的研究

从桂木(Artocarpus nitidus subsp.lingnanensis)茎枝中分离得到13个化合物。通过波谱分析,分别鉴定为albanin A(1)、brosimone I(2)、cycloartocarpin A(3)、artotonkin(4)、albafuran A(5)、artocarpin(6)、artogomezianone(7)、β-香树素乙酯(8)、3,4-二羟基苯甲醛(9)、3,4-二羟基苯甲酸(10)、3-甲氧基-1,2-丙二醇(11)、β-谷甾醇(12)和β-胡萝卜苷(13)。这些化合物为首次从桂木中分离得到。     

A new species of Anthracotheriidae, Merycopotamus medioximus nov. sp. from the Late Miocene of the Potwar Plateau, Pakistan

New anthracotheriid remains, discovered by the H-GSP in well-dated localities from the Potwar plateau in the North of Pakistan, between 10.4 and 8.6 Ma, are described and attributed to Merycopotamus medioximus nov. sp. This new species displays an intermediate morphology between the older M. pusillus and the more recent M. dissimilis. These results permit to emend the Merycopotamus diagnosis. To cite this article: F. Lihoreau et al., C. R. Palevol 3 (2004).

Résumé

Une nouvelle espèce d'Anthracotheriidae, Merycopotamus medioximus nov. sp. du Miocène récent du plateau du Potwar, Pakistan. Des restes d'Anthracotheriidae, découverts par le H-GSP dans des localités bien datées du plateau du Potwar, au Nord du Pakistan, entre 10,4 et 8,6 Ma, sont décrits et attribués à Merycopotamus medioximus nov. sp. Cette nouvelle espèce possède une morphologie intermédiaire entre M. pusillus, espèce plus ancienne, et M. dissimilis, plus récente. Ces résultats permettent en outre d'émender la diagnose du genre Merycopotamus. Pour citer cet article : F. Lihoreau et al., C. R. Palevol 3 (2004).