Phytotoxicity of Secondary Metabolites Isolated from Flourensia oolepis S.F.Blake

The aim of this study was to isolate the active principles of Flourensia oolepis S.F.Blake (Asteraceae), which completely inhibited the germination of Raphanus sativus seeds at 10 mg/ml. Flavanone pinocembrin and sesquiterpene ilicol, were isolated by bioassay‐guided fractionation. They were active both against monocot and dicot seeds. Pinocembrin was the most active compound, with an IC₅₀(germination) value of 0.24, 3.40, 3.28, and 3.55 mM against Panicum miliaceum, Avena sativa, Lactuca sativa, and R. sativus, respectively; ilicol, however, exhibited IC₅₀(germination) values of 0.67, 2.73, 5.25, and 9.66 mM for the same species, respectively. Pinocembrin and ilicol inhibited root growth and showed IC₅₀(root growth) values of 0.199, 14.68, 8.05, 7.69 mM , and 1.22, 2.90, 7.35, 8.07 mM , against P. miliaceum, A. sativa, L. sativa, and R. sativus, respectively. Pinocembrin and ilicol reduced Allium cepa cell division without chromosome aberrations.     

Chemistry and Biology of the Genus Flourensia (Asteraceae)

Flourensia species are dominant plants that are adapted to semidesertic and desertic regions. It is believed that they are successful plants because they employ several protection mechanisms, including the formation of a waxy film on their aerial parts to protect them from dehydration. This waxy film contains chemical compounds that are capable of inhibiting the growth of other plants and of acting as allelopathic and herbicidal agents and as germination inhibitors. These plants also limit herbivory, and they exhibit insecticidal, insect antifeedant, antibacterial, antifungal, antialgal, and antitermite activities. Sesquiterpenes, flavonoids, benzofurans, chromenes, coumarins, lupan triterpenes, aliphatic lactones, and aromatic and acetilenic compounds have all been isolated from the organic extracts of Flourensia species. Monoterpenes, sesquiterpenes, and aliphatic hydrocarbons are the main constituents found in their essential oils. This review is an overview of the chemical constituents and of the biological activities of Flourensia species.     

Minor alkamides from Heliopsis longipes S.F. Blake (Asteraceae) fresh roots

From the fresh roots of Heliopsis longipes three new minor alkamides: longipinamide A (N-isobutyl-8,10-diynoic-3Z-undecenamide), longipenamide A (N-isobutyl-syn-8,9-dihydroxy-2E,6Z-decadienamide) and longipenamide B (N-isobutyl-syn-6,9-dihydroxy-2E,7E-decadienamide); three known alkamides: affinin (spilanthol, N-isobutyl-2E,6Z,8E-decatrienamide), N-isobutyl-2E,6Z-decadienamide and N-isobutyl-2E-decenamide; and 11 other known compounds were isolated. The structures of the three new minor alkamides were established by 1D and 2D NMR spectroscopy including ¹H, ¹³C, DEPT, COSY, HSQC, and HMBC experiments, as well as by EI and FAB⁺ mass spectrometry. To our knowledge, this is the first report of the isolation of linear dihydroxyalkamides as natural products.     

Chemical constituents from Cymbaria dahurica L. (Scrophulariaceae)

Phytochemical study of Cymbaria dahurica L. afforded 16 compounds, including 12 flavonoids (1–12) and 4 iridoids (13–16). Structure elucidation of these compounds was generated by a combination of spectroscopic means (ESI-MS, ¹H and ¹³C NMR) and comparisons with the published data. This is the first report of isolation of compounds (1–6, 10–16) from C. dahurica and compounds (5, 10, 12) from the family Scrophulariaceae, respectively. The chemotaxonomic data can support the genus Cymbaria being accepted as a member of transitional taxa between the family Scrophulariaceae and Orobanchaceae.     

Chemical constituents from Gentianella turkestanorum (Gentianaceae)

Phytochemical investigation of Gentianella turkestanorum (Gentianaceae) afforded nineteen compounds, including six xanthones (1–6), two triterpenoids (7–8), eight flavones (9–16) and three iridoids (17–19). Here, we firstly reported that 1-hydroxy-3,5-dimethoxyxanthone (4), 1, 8-dihydroxy-3-methoxyxanthone (5), apigenin (9), quercetin (10), luteolin-7-O-glucoside (12) and three other compounds (1, 8-dihydroxy-3-methoxyxanthone (5), apigenin-7-O-gluco (1″ → 3‴) glucoside (15) and luteolin-7-O-gluco (1″ → 3‴) glucoside (16)) could be isolated from G. turkestanorum. The occurrence of chemical data and the sequence data might be employed as common constituents of the genera Gentianella, Lomatogonium and Swertia.     

Chemical constituents from Cremanthodium brunneo-pilosum S. W. Liu

Fourteen compounds were isolated from Cremanthodium brunneo-pilosum, including two steroids (1 and 14), five sesquiterpenoids (2–6), six flavonoids (7–12) and one isoflavone (13). Graveolide (2) was obtained from a plant for the first time. 5,7-Dihydroxy-3,6,3′,4′-tetramethoxy-flavone (9), centaureidin (10) and tectoridin (13) have not been isolated from the family Compositae. The chemotaxonomic data support the relationship between this species and others in the family Compositae.     

Chemical constituents from Lespedeza cuneata G. Don (Leguminosae)

Phytochemical investigation of Lespedeza cuneata led to the isolation of seventeen compounds including three steroids (β-sitosterol 1, β-sitosterol-6′-linolenoyl-3-O-β-d-glucopyranoside 3, and β-sitosterol glucoside 13), nine flavonoids (quercetin 4, kaempferol 5, isovitexin 8, hirsutrin 9, nicotiflorin 10, vitexin 11, astragalin 12, trifolin 14, and isorhamnetin 17), two phenolics (benzyl-β-d-glucopyranoside 7 and homovanillyl alcohol 16), one carotenoid (loroxanthin 2), one lignin (7R,8S–dihydrodehydrodiconiferyl alcohol 15), and one hexose (pinitol 6) on the basis of their spectroscopic data. Among these compounds, 2, 3, 7, 15 and 16 were reported for the first time from the genus Lespedeza. The taxonomic significance of these isolated compounds was also summarized.     

Chemical constituents from the leaves of Cinnamomum parthenoxylon (Jack) Meisn. (Lauraceae)

Phytochemical investigation of the ethanolic extract from the leaves of Cinnamomum parthenoxylon (Jack) Meisn. led to the isolation of (3R, 4R, 3′R, 4′R)-6,6′-dimethoxy-3, 4, 3′, 4′-tetrahydro-2H, 2′H-[3, 3′]bichromenyl-4, 4′-diol (1), 4-hydroxybenzaldehyde (2), 1,2,4-trihydroxybenzene (3), kaempferol-3-O-α-l-rhamnoside (4), herbacetin (5), quercetin-3-O-α-l-rhamnoside (6), daucosterol (7), and β-sitosterol (8). The structures were established by extensive analysis of their MS and NMR spectroscopic data and comparison with literature data. In the present research, all of the isolated compounds 1–8 are reported for the first time in the species C. parthenoxylon. Compounds 1–6 were firstly isolated from genus Cinnamomum. Compounds 1, 3, 5 and 6 have not been reported from any species in Lauraceae family. The chemotaxonomic significance of the isolated compounds is discussed.     

Chemical constituents from the aerial parts of Meconopsis horridula (Papaveraceae)

Chemical investigation of the aerial parts of Meconopsis horridula led to the isolation and structural identification of nine flavonoids, two alkaloids and five terpenoids. Their structures were determined by comparison of ¹H and ¹³C NMR data with those reported in literature. The discovery of alkaloid cavidilinine (11) and two pentacyclic triterpenoids (15 and 16) from M. horridula provides evidence to support the view that Fumarioideae and Papaveroideae should be combined into a single family Papaveraceae.     

Chemical constituents from Ilex urceolatus

Twenty-four compounds were obtained from the extract of the leaves of I. urceolatus, which were divided into saturated fatty alcohols (1 and 2), triterpenoids (3–8 and 14–16), lignanoids (9, 20 and 22), coumarins (10 and 19), flavonoids (11–13, 21, 23 and 24) and others (17 and 18). Among them, compounds 1, 2, 17 and 18 were firstly obtained from the genus Ilex, others were isolated from this species for the first time. The chemotaxonomic relationships between I. urceolatus and other species of genus Ilex were also discussed. As a result, the isolated compounds closely matched the ones obtained in other species of the genus.     

Chemical constituents from Cyclocarya paliurus (Batal.) Iljinsk

A novel triterpenoid, cyclocarioside K, together with fifteen known compounds, including seven triterpenoids (2–8), five flavonoids (9–13), three phenolic derivatives (14–16), was obtained from the leaves of Cyclocarya paliurus (Batal.) Iljinsk (Juglandaceae). Their structures were elucidated by spectroscopic methods, including two-dimensional NMR experiments (HSQC DEPT and HMBC). The chemotaxonomic relationships were also discussed. As a result, 3, 4-secodammarane triterpenoids and kaempferol glycosides may represent phytochemical fingerprints for C. paliurus, and C. paliurus has close relationships with other species of Juglandaceae.     

Chemical constituents from Laggera pterodonta

A phytochemical investigation on the aerial parts of Laggera pterodonta resulted in the isolation and identification of fourteen compounds, including six sesquiterpenoids (1–6), five flavonoids (7–11), one lignan (12), and two pyrrole alkaloids (13, 14). Among them, compounds 1–3, 7–9, and 11 are the characteristic class of secondary metabolites of L. pterodonta. Compounds 4 and 5 were firstly isolated from L. pterodonta and this is the first report of the presence of compounds 6, 10, and 12 from the genus Laggera. Pyrrole alkaloids 13 and 14 may serve as potential chemotaxonomic markers for L. pterodonta and could be used to distinguish among species of Compositae.     

Chemical constituents from the roots of Cichorium glandulosum Boiss. et Huet (Asteraceae)

A phytochemical investigation of the roots extract of Cichorium glandulosum led to the isolation and characterization of fourteen compounds, including five sesquiterpene lactones (1–5), five flavonoids (6–10), and four lignans (11–14). Their structures were determined by spectroscopic data analysis and comparison with the literatures. This is the first report of the crystal data of lactucopicrin (1). This is the first time to report the isolation of 6,8,11-epi-desacetylmatricarin (2), desacetylmatricarin (3), ixerisoslde C (4), magnodelavin (5), 2ʹ,4-dihydroxy-4ʹ-methoxy-6ʹ-O-β-glucopyranoside dihydrochalcone (6), (−)-evofolin B (7), isoquercitrin (8), myricetin 7-methyl-ether-3-O-glucoside (9), (+)-medioresinol (12), 4-O-methylcedrusin [2-(3ʹ,4ʹ-dimethoxyphenyl)-3-hydroxymethyl-2,3-dihydro-7-hydroxybenzofuran-5-propan-1-ol] (13), and (2R,3S)-samwirin A (14) from C. glandulosum. Among them, compounds 5, 9, 13, and 14 were obtained from Asteraceae family for the first time. The chemotaxonomic significance of all the isolates 1–14 was discussed.     

Chemical constituents of Physochlaina physaloides (L.) G. Don (Solanaceae)

The study of the whole plants of Physochlaina physaloides (L.) G. Don. has led to the isolation of eight alkaloids (1–6, 18, and 25), fourteen flavonoids (9, 11–17, and 19–24), two coumarins (7 and 10), one iridoid (8). The structures of these compounds were identified spectroscopically, and nuclear magnetic resonance (NMR) data were compared with previously reported data. This is the first study to describe the isolation and identification of compounds 1–3, 7, and 10–25 in P. physaloides. The chemotaxonomic significance of these compounds in the genus Physochlaina and its closely related genera was discussed.     

Chemical constituents from Polygonum capitatum Buch-Ham. ex D. Don

This work describes the isolation and characterization of thirty-one compounds from Polygonum capitatum Buch-Ham. ex D. Don, including two triterpenes (1–2), ten flavonoids (7–16), nine lignans (17–25), nine phenolic compounds (4–7, 26–31) and one anthraquinones (3). Their structures were elucidated on the basis of various spectroscopic methods (UV, IV and NMR, including 2D experiments). It was the first report of compounds 13, 15, 17, 24, 25, 28, 29, 30, 31 from the genus Ploygonum, and the first report of compounds 13, 15, 17, 24, 25 from the family Polygonaceae.     

Chemical constituents from Scutellaria hainanensis C. Y. Wu

Seventeen compounds were obtained from the extract of the whole plant of Scutellaria hainanensis C. Y. Wu. Including eleven flavonoids (1–4 and 7–13), two phenylpropanoids (16 and 17), one pyridinium derivative (5), one ester (6), one phenolic derivative (14), and one lignanoid (15). Compound 5 was a synthetic intermediate, newly identified as a natural product. The chemotaxonomic relationship between S. hainanensis C. Y. Wu and other species of genus Scutellaria were also discussed. As a result, the isolated glycoside compounds closely matched the ones obtained in other species of the genus.     

Chemical constituents from the aerial parts of Impatiens hypophylla Makino var. hypophylla

Seven flavonoids such as luteolin (1), luteolin 7-O-β-glucopyranoside (2), luteolin 3'-O-β-glucopyranoside (3), chryseriol (4), apigenin (5), apigenin 7-O-β-glucopyranoside (6) and astragalin (7) and one coumarin, scopoletin (8) were isolated from the aerial parts of Impatiens hypophylla Makino var. hypophylla (Family: Balsaminaceae). Structures of these compounds were elucidated on the basis of spectroscopic methods. All these compounds were isolated for the first time from I. hypophylla var. hypophylla.