Phytochemical analysis and biological evaluation of the aerial parts from Symphytum anatolicum Boiss. and Cynoglottis barrelieri (All.) Vural & Kit Tan (Boraginaceae)

The present study is focused on the phytochemical analysis of the aerial parts of Symphytum anatolicum and Cynoglottis barrelieri (Boraginaceae). Their methanol extracts were subjected to qualitative LC-MS analysis, sixteen secondary metabolites have been identified from S. anatolicum and eighteen from C. barrelieri, respectively. Sixteen among all are phenolic derivatives (phenolic acids and flavonoids) and six belong to pyrrolizidine alkaloids (PAs) in the form of bases and/or N-oxides (PANOs). The observed chemical profiles are discussed chemotaxonomically as both species share the same tribe Boragineae. Caffeic acid and its derivatives together with quercetin- and kaempferol-glucosides were among the common metabolites, as they were identified in both studied plant species. Furthermore, their total phenolic and flavonoid contents were determined. Antioxidant capacity was evaluated by different chemical assays, together with their in vitro enzyme inhibitory properties towards cholinesterases (AChE and BChE), α-amylase and α-glucosidase. The results showed that C. barrelieri exhibited strong antioxidant activity, while S. anatolicum displayed good enzyme inhibitory effects contributing to a very interesting profile for further applications.     

Pyrrolizidine alkaloids from Echium glomeratum (Boraginaceae)

The methanolic extract of the whole plant of Echium glomeratum Poir. (Boraginaceae) has afforded five pyrrolizidine alkaloids, three that were (7S, 8R)-petranine (1), (7S, 8S)-petranine (2), and (7R, 8R)-petranine (3a) or (7R, 8S)-petranine (3b), comprising a tricyclic pyrrolizidine alkaloids subclass; and two that were known but to the species: 7-angeloylretronecine (4) and 9-angeloylretronecine (5). All compounds were tested against a human tumor panel for cytotoxicity; no activity was observed (EC(50) values>20mug/ml).     

Chemical constituents from Piper boehmeriifolium (Miq.) Wall. ex C. DC

The chemical investigation of whole plants Piper boehmeriifolium (Miq.) Wall. ex C. DC. led to the isolation of 22 compounds, including two lignans (1–2), sixteen amide alkaloids (3–18), one diterpene (19), two monoterpenes (20–21), and one phenylpropanoid (22). Their structures were elucidated by extensive spectroscopic analyses including NMR, MS, and by comparison with the literature. Compounds 1–2, 6–7, 11–12, 14, and 17–22 were firstly isolated from P. boehmeriifolium, while compounds 2, and 19–20 were isolated from Piper genus for the first time. The chemotaxonomic significance of these isolated compounds is discussed.     

Chemical constituents from Melodinus cochinchinensis (Lour.) Merr. and their chemotaxonomic significance

A phytochemical investigation on the twigs and leaves of Melodinus cochinchinensis (Lour.) Merr. resulted in the isolation and identification of 22 compounds, including seven sesamin-type lignans (1–7), three pentacyclic triterpenes (8–10), one anthraquinone (11), one flavanone (12), two phenolic compounds (13 and 14), five aspidosperma-type indole alkaloids (15–19), and three eburnan-type indole alkaloids (20–22). The structures of these compounds were elucidated by means of spectroscopic analysis, including HREIMS together with 1D and 2D NMR experiments, and comparison with reported data. Among them, compounds 1/4, 2/5, and 3/6 are three pairs epimers at C-7''. Compounds 1–6, 8 and 11 were firstly isolated from the family Apocynaceae, whereas 17 was isolated from Melodinus species for the first time. Compound 8 was only found in Juglans hopeiensis, while 11 was only found in roots of Rubia cordifolia. Compounds 1–6, 8, 11 and 15–22 could be considered as chemotaxonomic markers for M. cochinchinensis. Furthermore, the chemotaxonomic significance and distribution of these isolates in Melodinus genus are discussed in detail.     

Chemical constituents from Dictamnus dasycarpus Turcz.

Fifteen compounds (1–15) were isolated from Dictamnus dasycarpus Turcz. The structures of all compounds were elucidated on the basis of spectroscopic data. Their structures were identified as dictamnine (1), skimmianine (2), haplopine (3), γ-fagarine (4), dasycarine (5), glycolone (6), 8,9-dimethoxygeibalansine (7), 7,8-dimethoxymyrtopsine (8), 8-methoxyflindersine (9), 3-formylindole (10), kihadanin A (11), fraxinellone (12), β-sitosterol (13), radicol (14), and magnolol (15). Among them, compounds 10 and 15 were isolated for the first time in the genus Dictamnus and this is the first report of the presence of compound 14 in the Dictamni dasycarpus Turcz.     

Chemical constituents from the root bark of Dictamnus dasycarpus Turcz. (Rutaceae) and their chemotaxonomic significance

This work described the isolation and characterization of seven compounds from Dictamnus dasycarpus Turcz., including one new ester, (2R)-4-(2,2-dimethyl-5-oxotetrahydrofuran-3-yl)-2-hydroxypent-3-anoic acid ethyl ester (1); and six known glycosides (2–7). The structure of compound 1 was elucidated on the basis of extensive spectral analyses, including IR, HR-ESIMS, 1D and 2D NMR (NOESY, HMBC and HSQC). All these compounds were described here for the first time from the genus Dictamnus. Moreover, the results provide further information about the diversity of compounds in the genus Dictamnus.     

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 Panzeria alaschanica Kupr. (Labiatae)

In this paper, twenty-two compounds including twenty-one flavonoids (1–21) and one alkaloid (22) were isolated from Panzeria alaschanica, in which seventeen flavonoids (1–2, 5–11, 13–20) were isolated from P. alaschanica and four flavonoid p-coumaroylglucosides (15–18) from the genus Panzeria for the first time. The occurrence of flavonoid p-coumaroylglucosides and alkaloids might be employed as the common characteristic constituents of the genera Panzeria, Leonurus, Lagochilus, Lagopsis and Marrubium.     

Chemical evidence for hybridity in Drosera (Droseraceae)

Naphthoquinone patterns found in Drosera hybrids between quinone-heterogenous parent species are reported here for the first time. Quinone patterns are constant in and characteristic for all taxa investigated. Each investigated parent species contains only one quinone isomer (either plumbagin or 7-methyljuglone), whereas all investigated hybrids between quinone-heterogenous parent species contain both isomers at almost equal concentrations, which indicates co-dominant heredity resulting from expression of both parental loci affecting regioselectivity in the biosynthesis of these acetogenic metabolites. This allows predictions on hybridity (and possibly on parentage) in some taxa of the genus.     

Chemical constituents of Gardneria ovata wall

A phytochemical investigation on the aerial parts of Gardneria ovata Wall resulted in the isolation and identification of 14 compounds, including three gardneria glycoalkaloids (1–2 and 6), seven gardneria alkaloids (3–5 and 7–10), and four oxindole alkaloids (11–14). The structure of compound 1 was elucidated by means of spectroscopic analysis, including HRESIMS together with 1D and 2D NMR experiments. Compounds 1–2 and 11–14 are the first time reported from of G. ovate, while the compounds 3–4, 6, and 8 are also the characteristic secondary metabolites of the title plant. The chemotaxonomic significance and distribution of these monoterpenoid indole alkaloids in Gardneria genus are discussed.     

Chemical constituents from Syringa reticulata (Bl.) Hara

A previously undescribed secoiridoid aglycone, syrinretin (1), together with a reported secoiridoid aglycone (2), three phenylethanoids (3, 4 and 6), phenolic acid (5) and two coumarins (7 and 8) were isolated from the stem bark of Syringa reticulata (Bl.) Hara (Oleaceae). The structures were elucidated from 1D and 2D NMR spectroscopic data by comparison with reported literature values. Compound 1 and compounds 2, 4–6 and 8 were identified in the genus Syringa for the first time. The chemotaxonomic significance of these compounds is also discussed.     

Chemical constituents from Pteris ensiformis Burm. (Pteridaceae)

Phytochemical study of Pteris ensiformis Burm. resulted in the isolation of eleven compounds, including three sesquiterpenoids (1–3), one alkaloid (5), one amino acid (6), one flavonoid (7), four phenolic acids (4, 8, 9 and 10), and one coumarin (11). Structures of these compounds were deduced from the ESI-MS and NMR data. This is the first report on the isolation of compounds 1, 2, 7 and 11 from P. ensiformis, compounds 6 and 9 from the genus Pteris, and compound 5 from the family Pteridaceae. In addition, a detailed discussion of the chemotaxonomic significance of these compounds was presented.     

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 of Odontites serotina (Lam.) Dumort. (Orobanchaceae)

The study of the whole plants of Odontites serotina (Lam.) Dumort. has led to the isolation of one nucleoside compound (2), three iridoids (1, 3, and 4), two phenylethanolic glycosides (6 and 8), four phenolic acids (5, 10, 12, and 15), and nine flavonoids (7, 9, 11, 13, 14, and 16–19). The structures of the compounds were identified by nuclear magnetic resonance (NMR) and high-resolution mass spectrometer. To the best of our knowledge, this is the first study to describe the isolation and identification of compounds 2–3, 6–8, 10, 12, 14–16, and 19 in O. serotina. The chemotaxonomic significance of these compounds was discussed.     

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 of Medinilla septentrionalis (W. W. Sm.) H. L. Li (Melastomataceae)

Our phytochemical investigation of the whole plants of Medinilla septentrionalis (W. W. Sm.) H. L. Li led to the isolation of five tannins (1–5), five phenolic acids and phenolic acid derivatives (6–10), four flavonoids (11–14), two triterpenes (15 and 16), and one hydantoin derivative (17). The structures of the obtained compounds were identified using spectrometric methods (¹H NMR, ¹³C NMR and MS). This is the first study reporting on the chemical constituent of M. septentrionalis and the chemotaxonomic relationships between Medinilla and other genera of Melastomataceae.     

Bothriospermum longistylum sp. nov. (Boraginaceae) from north China

Based on field investigations as well as morphological and molecular systematic studies we found a new species of Bothriospermum which can be easily distinguished from all other known congeneric species by its unlobed faucal appendages and very long styles. We conducted molecular phylogenetic analyses based on a combined dataset from nrITS, plastid rps16, trnL‐trnF and trnG‐trnS regions. The results indicated that the new species indeed belongs in Bothriospermum and that it is well separated from other congeneric clusters, but that the genus Bothriospermum is paraphyletic with Nihon and Thyrocarpus clusetered within it. As a result, Bothriospermum longistylum sp. nov. is described and illustrated here. A revised key to species of Bothriospermum and a distributional map are also presented.     

Phenylpropanoids and some nitrogen-containing constituents from the roots of Isatis indigotica Fort. (Cruciferae)

The present phytochemical investigations of Isatis indigotica Fort. resulted in the isolation of seven lignans (1–7), three aromatic glycosides (8–10), three nucleosides (11–13) and two bis-indole alkaloids (14–15). Among them, compounds 5, 6 and 9 were obtained from this genus for the first time. The chemotaxonomic importance of these compounds was also summarized.     

Chemical constituents isolated from Clematis akebioides (Maximowicz) Veitch

A phytochemical investigation of the aerial parts of Clematis akebioides (Maximowicz) Veitch led to the isolation of eighteen compounds, including two benzenoids (1, 2), one linear monoterpene glycoside (3), and fifteen triterpenoid saponins (4–18). The structural elucidation of these compounds was determined by using spectroscopic methods and comparison with the literature. All of these compounds were obtained from C. akebioides for the first time, and compounds 1, 2 and 18 were isolated from the Ranunculaceae family for the first time. Furthermore, the chemotaxonomic significance of these compounds was discussed.