Iridoid glucosides from Randia spinosa (Rubiaceae)

An iridoid glucoside: randinoside, along with five known iridoids: galioside, deacetylasperulosidic acid methyl ester, scandoside methyl ester, geniposide and gardenoside, were isolated from the stems of Randia spinosa. The structures were determined by spectroscopic analysis, including 2D NMR techniques.     

Iridoid glucosides of Paederota lutea and the relationships between Paederota and Veronica

In a chemical investigation of the water soluble compounds in Paederota lutea eight known iridoids were isolated together with a new one with a 8,9-double bond, namely paederotoside (10-O-benzoyl-6'-O-alpha-arabino(1-->6)-beta-glucopyranosyl arborescosidic acid) and the 6-hydroxy-flavone glucoside 4'-O-methylscutellarein 7-O-beta-glucopyranoside. The known iridoid glucosides were 8-epiloganic acid, gardoside, aucubin, catalpol and the 6-O-esters of catalpol: veronicoside, catalposide, amphicoside and verproside. The compounds isolated show that Paederota has a glycoside content almost identical to that of a general Veronica species, and this is in good agreement with the results from recent investigations of the phylogeny of Veronica and its closest relatives, where Paederota is placed as a sister-group next to Veronica. In an analysis of the iridoid glucosides from some of these relatives, it is shown that Veronica, Paederota, Picrorhiza and Veronicastrum are all characterized by containing 6-O-esters of catalpol. Some less closely related taxa namely: Lagotis, Wulfenia, Plantago, Aragoa and Globularia instead contain 10-O-esters of catalpol or aucubin.     

Iridoid glucosides and flavones from the aerial parts of Avicennia marina

Two new iridoid glucosides, namely, 2'-O-[(2E,4E)-5-phenylpenta-2,4-dienoyl]mussaenosidic acid (1; mussaenosidic acid = [1S-(1alpha,4aalpha,7alpha,7aalpha)]-1-(beta-D-glucopyranosyloxy)-1,4a,5,6,7,7a-hexahydro-7-hydroxy-7-methylcyclopenta[c]pyran-4-carboxylic acid) and 2'-O-(4-methoxycinnamoyl)mussaenosidic acid (2), were isolated from the aerial parts of the mangrove plant Avicennia marina. Beside that, one known iridoid glucoside, 2'-O-coumaroylmussaenosidic acid (3) and four known flavones (flavone = 2-phenyl-4H-1-benzopyran-4-one) including 4',5-dihydroxy-3',7-dimethoxyflavone (4), 4',5-dihydroxy-3',5',7-trimethoxyflavone (5), 4',5,7-trihydroxyflavone (6), and 3',4',5-trihydroxy-7-methoxyflavone (7) were also isolated and identified. The structures of these compounds were elucidated by NMR spectroscopy and by low- and high-resolution mass spectrometry. The chemotaxonomic significance of these findings was discussed. In addition, each isolated compound was evaluated for the ability of alpha,alpha-diphenyl-beta-picrylhydrazyl (DPPH) radical-scavenging activity.     

Iridoid glucosides from Thunbergia laurifolia

Two iridoid glucosides, 8-epi-grandifloric acid and 3′-O-β-glucopyranosyl-stilbericoside, were isolated from the aerial part of Thunbergia laurifolia along with seven known compounds, benzyl β-glucopyranoside, benzyl β-(2′-O-β-glucopyranosyl) glucopyranoside, grandifloric acid, (E)-2-hexenyl β-glucopyranoside, hexanol β-glucopyranoside, 6-C-glucopyranosylapigenin and 6,8-di-C-glucopyranosylapigenin. Strucural elucidation was based on the analyses of spectroscopic data.     

Iridoid glucosides from Kickxia abhaica D.A. Sutton from Scrophulariaceae

Two iridoid glucosides namely; 6-acetylantirrinoside (1), 6'-O-p-hydroxybenzoylantirrinoside (2) were isolated from the aerial parts of Kickxia abhaica. Beside that, three known iridoid glucosides, antirrinoside (3), antirride (4) and mussaenosidic acid (5), one flavone glycoside (6) and a hexitol, d-mannitol (7) were isolated. The structures of the iridoid glucosides 1-2 were established by 1D and 2D NMR spectral data, including COSY, HMQC and HMBC experiments, as well as HRMS.     

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.     

Compartmentation of cyanogenic glucosides and their degrading enzymes

Whereas high activities of β-glucosidase occur in homogenates of leaves of Hevea brasiliensis Muell.-Arg., this enzyme, which is capable of splitting the cyanogenic monoglucoside linamarin (linamarase), is not present in intact protoplasts prepared from the corresponding leaves. Thus, in leaves of H. brasiliensis the entire linamarase is located in the apoplasmic space. By analyzing the vacuoles obtained from leaf protoplasts isolated from mesophyll and epidermal layers of H. brasiliensis leaves, it was shown that the cyanogenic glucoside linamarin is localized exclusively in the central vacuole. Analyses of apoplasmic fluids from leaves of six other cyanogenic species showed that significant linamarase activity is present in the apoplasm of all plants tested. In contrast, no activity of any diglucosidase capable of hydrolyzing the cyanogenic diglucoside linustatin (linustatinase) could be detected in these apoplasmic fluids. As described earlier, any translocation of cyanogenic glucosides involves the interaction of monoglucosidic and diglucosidic cyanogens with the corresponding glycosidases (Selmar, 1993a, Planta 191, 191–199). Based on this, the data on the compartmentation of cyanogenic glucosides and their degrading enzymes in Hevea are discussed with respect to the complex metabolism and the transport of cyanogenic glucosides.     

Septal micropores in Zygozyma and their taxonomic significance

Septal micropores or plasmadesmal canals have been observed in two species of the lipomycetaceous genus Zygozyma. The presence of these canals is considered as further evidence for the connexion between the Lipomycetaceae and the Dipodascaceae. The genus Zygozyma has been emended.     

Nutlet sculpturing inScutellaria sect.Resinosa (Lamiaceae) and its taxonomic utility

Nutlet sculpturing of 22 taxa ofScutellaria sect.Resinosa, representing 18 of its 19 species, and the monotypic genusSalazaria was studied by scanning electron microscopy (SEM). The nutlets of sect.Resinosa, while remarkably variable among themselves, differed from hypothetically closely related sections in lacking circumferential banding and sessile glands. Species could be grouped by surface sculpturing into seemingly meaningful phenetic clusters.Scutellaria potosina var.platyphylla was sufficiently distinct micromorphically so as to be elevated to specific status asScutellaria platyphylla comb. and stat. nov. The significance of nutlet microcharacters within sect.Resinosa is discussed, especially as compared to closely related sections. The genusSalazaria had nutlet sculpturing quite different from all taxa belonging to sect.Resinosa.     

Aragoside and iridoid glucosides from Aragoa cundinamarcensis

From the water-soluble part of an extract of Aragoa cundinamarcensis were isolated seven iridoid glucosides, namely aucubin, catalpol, rehmannioside D, globularin, gardoside methyl ester, epiloganin and mussaenoside. The main glycoside isolated, however, was a new caffeoyl phenylethanoid triglycoside, named aragoside, containing two beta-gluco- and one alpha-arabinopyranosyl moieties which constituted almost 5% of the dry weight of the plant. Finally, sorbitol was found to be the main carbohydrate constituent of the plant. This distinctive combination of compounds is very similar to that reported from some species of Plantago. The present findings therefore support the results from a recently published molecular phylogenetic study of plastid and nuclear ribosomal DNA sequences, where Aragoa was found to be the closest relative to Plantago so far discovered.     

New polyacetylene glucosides from the florets of Carthamus tinctorius and their weak anti-inflammatory activities

Eight new linear polyacetylene glucosides (1–8), containing two C₁₀-, one C₁₃- and five C₁₄-acetylenes, together with three known polyacetylenes (9–11) were isolated from the florets of Carthamus tinctorius L. Their structures were elucidated by means of spectroscopic methods and chemical evidence. The absolute configurations of compounds 3–9 were confirmed by Snatzke and Gerards’s method, observing the induced circular dichroism after addition of dirhodium tetrakis (trifluoroacetate) [Rh₂(OCOCF₃)₄] in CHCl₃. All the isolated compounds (1–11) were also tested for inhibitory activities against LPS-induced NO production in murine macrophages and just showed weak activities at concentrations of 1 × 10⁻⁵ M.     

Nutlet sculpturing of selectedTeucrium species (Lamiaceae): A character of taxonomic significance

Nutlet sculpturing of 23Teucrium species belonging to six sections was studied. The nutlets of analysed species were characterized by the presence of the oil glands of various density. SectionTeucrium is well defined by very densely distributed trichomes and oil glands on nutlets. Trichomes on nutlets were absent in all other species, except inT. marum from sect.Chamaedrys. Sect.Polium is a homogeneous group, distinguished from the other sections. There are some similarities of this sect. with sect.Scordium. Species of sect.Chamaedrys are heterogeneous and overlap according to the surface sculpturing characters with the other sections. The significance of nutlet microcharacters as additional taxonomical markers in the infrageneric classification of the genusTeucrium is discussed.     

中国凤仙花科植物叶表皮特征及其分类学意义

利用光学显微镜观察凤仙花科106份样本材料、36种代表植物的叶表皮微形态特征。结果表明:该科植物叶表皮微形态特征种内稳定,对于种间及属间关系的界定具有重要的分类学价值。上表皮细胞的形状及垂周壁的式样种间差异明显,各分类群间有明显的界限,是种间界定的重要依据,因此上表皮微形态特征具有重要的的分类学价值,基于上表皮的微形态特征将研究的36种代表植物划分为5个类型。下表皮的微形态特征虽更为多样,种间差异显著,可用于种间界定,但对于属下划分难以提供有价值的性状。该科植物叶表皮微形态特征与宏观形态特征的相关性较弱,与地理分布格局的相关性较强,关系更为密切。同一地理分布区域内的种类宏观形态特征虽然差别明显,但叶表皮微形态特征却表现出较强的一致性,这似乎也反映了叶表皮微形态这一性状受环境饰变的影响比较明显。综上所述,叶表皮微形态特征可为凤仙花科的系统发育,尤其是凤仙花属种间界定提供有价值的分类学佐证     

Iridoid glucosides from Strychnos nux-vomica

From seeds of Strychnos nux-vomica three iridoids, 6'-O-acetylloganic acid, 4'-O-acetylloganic acid and 3'-O-acetylloganic acid were isolated together with two known iridoid glucosides, loganic acid and 7-O-acetylloganic acid. The structures of the compounds were established by ESI-MS and by 1D and 2D NMR spectroscopic methods.     

Iridoid glucosides from Utricularia australis and Pinguicula vulgaris (lentibulariaceae)

Utricularia australis contained 6-deoxycatalpol, a new iridoid glucoside, besides aucubin, gardoside and mussaenosidic acid. From Pinguicula vulgaris was isolated catalpol, globularin and 10-(Z)-cinnamoyl-catalpol, the latter being a new compound. Thus, the iridoids found in Lentibulariaceae belong to structural types which are common in Scrophulariaceae and related families.     

Developmental patterns of pedate leaves in tribe Areae (Araceae-aroideae) and their systematic implication

Based on observations of the development of pedate leaves in Araceae, including new observations onPinellia pedatisecta andTyphonium larsenii, two patterns were recognized. One pattern was found to be restricted toArisaema (Arisaematinae) andPinellia (Atherurinae), which may suggest monophyly between these two genera (subtribes).     

山矾科中原氏山矾复合体的叶形态特征及分类意义

该研究在形态学观察以及统计学分析的基础上,深入研究了山矾科中原氏山矾复合体的叶片形态学结构。结果表明:叶片质地在整个复合体中可分为革质、纸质2种类型,叶片大小变异幅度较大,除中原氏山矾(Symplocos kawakamii)、棱角山矾(S.tetragona)、蒙自山矾(S.henryi)均与其他种差异显著外,其余种均属于连续过度,叶片分形可以初步区分该复合体植物。该研究结果为中原氏山矾复合体的进一步研究提供了依据,对复合体的分类处理具有一定的分类学意义。     

Bis(monoterpenoid) indole alkaloid glucosides from Uncaria hirsuta

One novel bis(monoterpenoid) indole alkaloid glucoside, hirsutaside D (1), along with three known compounds, bahienoside A (2), bahienoside B (3) and neonaucleoside B (4), were isolated from the leaves of U. hirsuta. The structure of compound 1 was elucidated on the basis of extensive spectroscopic data analysis and chemical means. Characterization of compounds 2–4 was based on spectral analysis and comparison with the literature. Their cytotoxic effects on four human tumor cell lines were examined.     

Trichomes and stomata,and their taxonomic significance in theUrticales

Structure and ontogeny of stomata and trichomes have been studied in 23 species and 3 varieties of theUrticales. Stomata are anomocytic, more rarely paracytic; anisocytic and sometimes helicocytic and transitorial types are found inUrticaceae andDorstenia, rarely inArtocarpus. The ontogeny of anomocytic and actinocytic stomata is perigenous, of paracytic either mesogenous or perigenous, of anisocytic either mesogenous or mesoperigenous, and of helicocytic and transitional types mesogenous. Among trichomes eglandular unicellular (wide spread), bicellular or uniseriate filiform (Cannabis); glandular capitate with uni- or bicellular (Moraceae, Ulmaceae, Cannabaceae), uniseriate filiform (Ulmaceae) or multiseriate stalk (Cannabis); sunken glands (Artocarpus); uniseriate glandular with uniseriate stalk (Celtis), and stinging emergences (Urticaceae) have been observed. It is concluded that theUrticales represent a natural order with four families:Ulmaceae, Moraceae, Urticaceae andCannabaceae which are distinct but interrelated with each other.