The genus Rhaponticoides Vaill. (Asteraceae) in Turkey: a new species and first key

Turkish representatives of the genus Rhaponticoides Vaill. are examined. A key and distribution map of Rhaponticoides species occurring in Turkey are provided for the first time. R. hierroi Ö. Eren sp. nov., from Bakacak pass in the Western Taurus range, SW Anatolia, allied to R. mykalea (Hub.-Mor.) M. V. Agab. &; Greuter is described as a species new to science and illustrated. Its habitat conditions and conservation status are considered. Pollen micrographs of R. hierroi and R. mykalea are presented using scanning electron microscopy.     

Phenylpropanoid and flavonoid glycosides from the leaves of Clerodendrum infortunatum (Lamiaceae)

Clerodendrum infortunatum L. (syn.: Clerodendrum viscosum Vent.), a member of the Lamiaceae, yielded one undescribed jasmonic acid derivative, ten acteosides, and two flavonoids. The jasmonic acid derivative was identified as 6'-O-caffeoyl-12-glucopyranosyloxyjasmonic acid. The acteosides were identified as isoacteoside, acteoside, 2''-O-acetyl-martyonside, 3''-O-acetyl-martyonside, martynoside, brachynoside, leucosceptoside A, jionoside C, jionoside D, incanoside C. The flavonoids were identified as apigenin 7-O-glucuronide and acacetin 7-O-glucuronide. The structures of the isolated components have been identified by UHPLC-HRMS, 1D and 2D NMR spectroscopic analyses, spectrometric techniques, and in comparison with published NMR data. The absolute sugar configuration was determined by GLC-MS/MS analysis of the octylated derivative of the sugar moiety after hydrolysis. Among the known compounds, ten are reported for the first time from this species, while the acteoside leucosceptoside A and the two flavonoids have been isolated for the first time from the genus Clerodendrum. The chemophenetic significance of the compounds obtained from C. infortunatum is summarized in comparison to those found in other Clerodendrum species.     

Phenolic compounds from the leaves and stem bark of Pseudospondias microcarpa (A. Rich.) Engl. (Anacardiaceae)

Phytochemical study of the leaves and the stem bark of Pseudospondias microcarpa (A. Rich.) Engl. afforded eight phenolic compounds: scopoletin (1), ferulic acid (2), isovitexin (3), rhoifolin (4), quercetin 3-O-α-L-rhamnopyranoside (5), justicialoside A (6), granduloside A (7) and pithecellobiumol B (8). The structures of the isolated compounds were elucidated by spectroscopic means including 1D and 2D NMR and MS, and by comparison with previously reported data. This is the first report on the isolation of these compounds from the genus Pseudospondias. The chemotaxonomic significance of the isolated compounds within the family Anacardiaceae is discussed.     

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.     

The chemotaxonomic and medicinal significance of phenolic acids in Arctopus and Alepidea (Apiaceae subfamily Saniculoideae)

The occurrence of (R)-3′-O-β-d-glucopyranosylrosmarinic acid, rosmarinic acid and caffeic acid in two important South African medicinal plants is reported for the first time. (R)-3′-O-β-d-Glucopyranosylrosmarinic acid and rosmarinic acid were isolated and identified in several samples from three species of the genus Arctopus L. (sieketroos) and three species of the genus Alepidea F. Delaroche (ikhathazo), both recently shown to be members of the subfamily Saniculoideae of the family Apiaceae. The compounds occur in high concentrations (up to 15.3 mg of (R)-3′-O-β-d-glucopyranosylrosmarinic acid per g dry wt) in roots of Arctopus. Our results provide a rationale for the traditional uses of these plants, as the identified compounds are all known for their antioxidant activity, with rosmarinic acid further contributing to a wide range of biological activities. Furthermore, we confirm the idea that (R)-3′-O-β-d-glucopyranosylrosmarinic acid is a useful chemotaxonomic marker for the subfamily Saniculoideae.     

A new coumaronochromone and phenolic constituents from the leaves of Iris bungei Maxim.

A novel compound, irisbungin, which was isolated from the leaves of Iris bungei Maxim., was elucidated as 5,7,5′-trihydroxy-coumaronochromone by spectroscopic methods and literature data. Along with the new coumaronochromone, nine known compounds, ayamenin B, mangiferin, hispidulin, apigenin, 3-phenyllactic acid, syringic acid, vanillic acid, p-coumaric acid and 3′,5′-dimethoxy-4′-O-β-d-glucopyranosyl-cinnamic acid were also isolated. All of the compounds were first isolated from this species. The presence of irisbungin and mangiferin in I. bungei Maxim. has important systematic significance for this species and the Iris genus.     

Chemical markers in Veronica sect. Hebe. III

In a continued chemosystematic investigation of the water-soluble compounds in Veronica sect. Hebe, we have investigated two more of the species formerly classified as Parahebe. Both species contained mannitol in considerable amounts and in addition some glucosides of iridoid acids. Veronica cheesemanii was characterised by aucubin and its esters: 2′-O-benzoylaucubin and an aucubin diester named cheesemanioside. The main iridoid compounds in Veronica hookeriana were catalpol and its ester verminoside, but this species also contained the sugar ester methyl 1-O-benzoyl-3-α-glucuronosylglycerol and a caffeoyl phenylethanoid glycoside (CPG) named parahebeoside, a 2′-O-β-xylopyranosyl derivative of the known plantamajoside. The results show that the studied species of the former genus Parahebe are very different with regard to their chemical content. This is in agreement with the DNA sequence data and implies the genus was polyphyletic as previously circumscribed.     

Iridoids,monoterpenoid glucoindole alkaloids and flavonoids from Vinca major

A new secoiridoid glucoside, vinmajoroside (1), was isolated from the leaves of Vinca major L. along with 11 known compounds belonging to the secoiridoid ((7α)-7-O-methylmorroniside, 2), iridoid (loganin, loganic acid and 7-O-p-coumaroylloganin), monoterpenoid glucoindole alkaloid (5 (S)-5-carboxyvincoside and strictosamide), flavonoid (rutin, kaempferol 3-O-rutinoside and robinin), lignan (syringaresinol 4-O-β-glucopyranoside) and phenolic acid (chlorogenic acid) groups. The structure elucidation of the isolates was accomplished by extensive 1D and 2D-NMR experiments as well as ESI-MS. Secoiridoids and lignan were encountered for the first time in the genus Vinca.     

Constituents of the leaves of Pseuderanthemum carruthersii (Seem.) Guill. var. atropurpureum (Bull.) Fosb.

A new iridoid, 5β,6β-dihydroxyantirrhide (1) was isolated from the dried leaves of Pseuderanthemum carruthersii (Seem.) Guill. var. atropurpureum (Bull.) Fosb. (Acanthaceae), together with 13 known compounds, including two iridoids, linarioside and antirrhinoside; five phenylethanoids, echipuroside A, verbascoside, isoverbascoside, isomartynoside and osmanthuside B; and six flavonoids, luteolin 7-O-β-d-glucopyranoside, luteolin 7-O-rutinoside, apigenin 7-O-rutinoside, apigenin 6-C-α-l-arabinopyranosyl–8-C-β-l-arabinopyranoside, apigenin 6,8-di-C-α-l-arabinopyranoside and apigenin 6-C-β-d-xylopyranosyl–8-C-α-l-arabinopyranoside. Their chemical structures were elucidated by 1D and 2D NMR as well as HR-ESI-MS spectroscopic analysis. Some purified compounds were evaluated the acetylcholinesterase inhibition and cytotoxic activities against the HeLa cervical cancer cell line and the MCF-7 breast cancer cell line at the concentration of 100 μg/mL. Luteolin 7-O-β-d-glucopyranoside exhibited cytotoxic activities against both the HeLa cervical cancer cell line and the MCF-7 breast cancer cell line. Verbascoside and isoverbascoside showed strong cytotoxic activity against the MCF-7 breast cancer cell line. The tested compounds showed the AChE inhibitory activity fairly weak.     

Antifungal cinnamic acid derivatives from Persian leek (Allium ampeloprasum Subsp. Persicum)

A cinnamic imidate, (1Z,2E)-methyl 3-(-p-hydroxy-m-methoxyphenyl)-N-(-p-hydroxyphenethyl) acrylimidate, named persicoimidate (1), has been isolated and characterized from bulbs and seeds of Persian leek, Allium ampeloprasum Subsp. Persicum. Two cinnamic acid derivatives, N-feruloyl tyramine (2) and N-caffeoyl tyramine (3) were isolated from bulbs and seeds. Compound 2 has been previously reported from garlic and leek, while compound 3 is described in Allium plants for the first time. The chemical structures of the isolated compounds have been elucidated unambiguously by spectroscopic methods, including 2D NMR and MS. The isolated compounds were evaluated for their antifungal activity against four fungal pathogens, the soil-borne pathogen Penicillium italicum, the air-borne pathogens Aspergillus niger and Botrytis cinerea, and the antagonistic fungi Trichoderma harzianum to evaluate the possible involvement of such compounds in resistance to pathogen attack.     

Polyphenols isolated from antiradical extracts of Mallotus metcalfianus

Six flavonoids including two new flavones, luteolin 7-O-(4″-O-(E)-coumaroyl)-β-glucopyranoside), chrysoeriol-7-O-(4″-O-(E)-coumaroyl)-β-glucopyranoside) and a mixture of two pairs of diastereoisomeric flavonolignans, (±)-hydnocarpin 7-O-(4″-O-(E)-coumaroyl)-β-glucopyranoside)/(±)-hydnocarpin-D 7-O-(4″-O-(E)-coumaroyl)-β-glucopyranoside) with a 2:1 ratio were isolated from the whole plant of Mallotus metcalfianus Croizat, in addition to 10 known compounds. Their structures were evaluated on the basis of different spectroscopic methods, including extensive 1D and 2D NMR spectroscopy. Some extracts have moderate antimicrobial properties and interesting antiradical (DPPH) activity, as well as some compounds isolated from this species. Tannins were also identified in some active extracts.     

Natural products from Tolpis barbata (L.) Gaertn. (Asteraceae,Cichorieae)

One sesquiterpene lactone – 9α-hydroxy-3-deoxyzaluzanin C, three benzopyrans: desmethoxyencecalin (6-acetyl-2,2-dimethylchromene), desacetylripariochromen B and 6-(1-hydroxyethyl)-2,2-dimethylchromene, one coumarin – scopoletin and two eugenol derivatives were isolated from the roots of Tolpis barbata (L.) Gaertn, hitherto unexamined species. In the extract from aerial parts of the plant, five known phenolic compounds, namely: esculin, esculetin, chlorogenic acid (5-CQA), luteolin 7-O-glucoside and 3,5-dicaffeoylquinic acid (3,5-DCQA) were identified as major constituents. Except for the two coumarins – scopoletin and esculetin, which were previously obtained from Tolpis webbii Sch.Bip. and T. proustii Pit., the isolated and identified compounds have not been previously reported as constituents of Tolpis spp. Though benzopyrans were found in numerous species of the Asteraceae, their occurrence in the tribe Cichorieae has not been demonstrated before.     

Phytochemical investigation of Eremostachys moluccelloides Bunge (Lamiaceae)

Phytochemical investigation of the aerial parts of Eremostachys moluccelloides Bunge led to the identification of a new diterpene, 2β,14-dihydroxy −11-formyl- 12-carboxy-13-des-isopropyl-13-hydroxymethyl-abieta-8,11,13- triene- 16(17)- lactone (1), along with the known compounds 12, 18-dicarboxy-14-hydroxy-13-des -isopropyl-13-hydroxymethyl- abieta-8,11,13-triene-16(17)-lactone (2), 5-hydroxy-3′,4′,7-trimethoxyflavone (3), 5-hydroxy-4’,7-dimethoxyflavone (4), luteolin-7-O-β-glucoside (5), verbascoside (6), luteolin 7-O-(6″-O-β-D-apiofuranosyl) -β-D-glucopyranoside (7), chlorogenic acid (8), echinacoside (9), apigenin-7-O-β-D-glucoside (10), p-coumaric acid (11), vanillic acid (12), apigenin-7-O-(6″-E-p-coumaroyl)-β-D-glucopyranoside (13), apigenin-7-O-(3″,6″-E-p-dicoumaroyl)-β-glucoside (14), lamalbide (15), 6β-hydroxy-7-epi-loganin (16), phloyoside II (17) The structures were elucidated on the basis of 1D and 2D NMR spectroscopy, UV, MS and by comparison with compounds previously reported in the literature. Compounds 1–4, 8, 9, 11, 12, 14 have not been reported previously from any species within the genus Eremostachys. Compounds 1–14, 17 were obtained from this species for the first time. The chemotaxonomic significance of the isolated compounds is discussed.     

Veronica: Iridoids and cornoside as chemosystematic markers

The iridoid glucoside, ajugol, and the phenylethanoid glucoside, cornoside, have been isolated from species of Veronica (Plantaginaceae) for the first time. The presence of these compounds has been screened in 18 plant accessions belonging to 15 species of Veronica (Plantaginaceae), by isolation or NMR spectroscopy of crude extracts. In addition, the distribution of iridoids in the genus has been reviewed, using mainly the published data of isolated compounds. Using the recent expansion and reclassification of the genus based on DNA-sequence results as the model, we find that the genus is rather homogeneous with regard to the distribution of iridoid glucosides, aucubin and/or catalpol as well as 6-O-esters of catalpol being universally present in 10 of the 12 subgenera for which data exist. Only the two subgenera Pocilla and Chamaedrys deviate from this pattern. Pocilla is heterogeneous; in this subgenus, species in subsect. Agrestes contain the standard iridoid garniture, while species in subsect. Biloba do not contain the 6-O-esters of catalpol, but ajugol instead. Veronica intercedens (subsect. Subracemosae) differs from the remainder of the subgenus in only containing 5-hydroxylated iridoids (melittoside and globularifolin) and is so far the only species within the genus in which such compounds have been detected. These chemical differences are clearly reflected in the DNA-based phylogram of the subgenus. Subg. Chamaedrys appears homogeneous in lacking iridoids or only containing these in small amounts, but instead half of the investigated species contained the phenylethanoid glucoside cornoside. The distribution of this compound in angiosperms is reviewed; cornoside often substitutes iridoid glucosides in plants where these are expected to be present. The chemical results of Veronica fit in very well with the phylogenetic implications of the DNA-sequence results.     

Phytochemical investigation of Boscia angustifolia A. Rich. (Capparaceae)

Boscia angustifolia A. Rich. leaves were collected and subjected to a phytochemical investigation. Ten compounds; six flavonols, two coumarins, one methyl benzoate and one phthalate compound were isolated and identified for the first time from the studied taxa. Tamarixetin-3-O-β-sophoroside-7-O-methylether and rhamnocitrin-3-O-β-sophoroside are reported here as new natural compounds. The chemosystematic relationship between Boscia species is also discussed.     

Secondary metabolites from Scutellaria albida L. ssp. velenovskyi (Rech. f.) Greuter & Burdet

Fourteen compounds (Fig.1) were isolated from the aerial parts of Scutellaria albida L. ssp. velenovskyi (Rech. f.) Greuter & Burdet, including four iridoids (1–4) catalpol, macfadienoside, mussaenosidic acid, albidoside; four flavonoids (5–8) hispidulin 7-Ο-β-D-glucuronide, scutellarin, xanthomicrol, eriodictyol; four phenylethanoid glycosides (9–12) verbascoside, leucosceptoside A, martynoside, 2-(3-hydroxy-4-methoxy-phenyl)-ethyl-1-Ο-β-D-glucopyranoside; the sugar ester 6′-β-D-glucopyranosyl-E-p-coumarate (13), as well as the acetogenic glucoside (Z)-3-hexenyl-1-O-β-D-glucopyranosyl-(1 → 2)-β-D-glucopyranoside (14). The structures of the isolates were established by means of NMR and HRMS spectral analyses. This is the first phytochemical study on S. velenovskyi and the first report of an acetogenic glycoside in the genus Scutellaria L. A chemical review on the isolated secondary metabolites in this study has been carried out. The chemotaxonomic value of the isolates is also discussed. Based on the literature data, the analysis revealed that the chemical profile of S. velenovskyi is close to that of the taxa belonging to the S. albida group.     

Flavonoids from carnation (Dianthus caryophyllus) and their antifungal activity

A flavonoid glycoside, kaempferol 3-O-β-d-glucopyranosyl (1 → 2)-O-β-d-glucopyranosyl (1 → 2)-O-[α-l-rhamnopyranosyl-(1 → 6)]-β-d-glucopyranoside (1), along with two known C- and O-flavonoid glycosides (2 and 3, respectively), were isolated from carnation (Dianthus caryophyllus). The structures of the isolated compounds have been elucidated unambiguously by UV, MS, and a series of 1D and 2D NMR analyses. The isolated compounds and other flavonoid glycoside analogues exhibited antifungal activity against different Fusarium oxysporum f.sp. dianthi pathotypes.     

Chemical constituents from the roots of Fallopia multiflora var. Ciliinerve

Phytochemical investigations on the roots of Fallopia multiflora var. Ciliinerve led to the isolation of eighteen compounds, including six chromones [2-methyl-5- carboxymethyl-7-hydroxychromone (1), 2-methyl-5-methylcarboxymethyl-7- hydroxychromone (2), 2,5-dimethyl-7-hydroxychromone (3), 2-methyl-5-hydroxymeth-yl-7-hydroxychromone (4), 2-methyl-5-carboxylicacid-7-hydroxy-chromone (5), and 2,5-dimethyl-7-hydroxychromone-7-O-β-D-glucopyranoside (6)], three lignans [Isolariciresinol (8), 5-[4-(3,4-dimethoxyphenyl)-2,3-dimethylbutyl]-1,3-benzodioxole (9), and isolariciresinol-9-O-β-D-xylopyranoside (10)], four anthraquinones [physcion-8-O-β-D-glucopyranoside (11), emodin-8-O-β-D-glucopyranoside (12), Rhein (13), and Chrysophanol (14)], three isobenzofurans [5,7-dihydroxy-isobenzofuran (15), 5-methoxy-7-hydroxy-isobenzofuran (16), and 5-methoxy-isobenzofuran-7-O-β-D-glucoside (17)], one phenolic acid [2,5-diacethylhy-droquinone (7)], and one pyran [Zanthopyranone (18)]. Among them, compounds 1, 3, 6, 13 and 14 were reported from F. multiflora var. Ciliinerve for the first time, compounds 2, 8, 10 and 15–17 were isolated from the genus Fallopia for the first time, and compounds 4, 9 and 18 were isolated for the first time from Polygonaceae family. Furthermore, the isolation of compounds 5 and 7 were reported for the first time in plants. Their structures were identified by spectroscopic methods and compared with those previously published. The chemotaxonomic significance of these isolated compounds has also been discussed.     

Phytochemicals isolated from the root bark of Sarcocephalus latifolius (Sm.) E.A.Bruce

Phytochemical investigation of the root bark of Sarcocephalus latifolius resulted in isolation and identification of eight compounds, including triterpenoid glycosides (1-4), ethyl glucoside (5), monoterpene indole alkaloids (6-7), and sterol (8). The structure elucidation of isolated compounds was achieved on the basis of NMR and mass spectral data. Compounds 2-5 were isolated for the first time from this genus and their chemotaxonomic significance was discussed.     

(2S)-Prenylflavanones and taraxerane triterpenoids from Mallotus mollissimus

Three prenylflavanones, (2S)-5,7-dihydroxy-4′-methoxy-8-(3″,3″-dimethylallyl)flavanone (3), (2S)-5,4′-dihydroxy-7-methoxy-6-(3″,3″-dimethylallyl)flavanone (6), 8-prenylnaringenin (11), and a new epimeric pair (2″S/2″R)-(2S)-5,7-dihydroxy-4′-methoxy-6-(2″-hydroxy-3″-methylbut-3″-enyl)flavanones (4a/4b) were isolated together with taraxerone, taraxerol, epitaraxerol, β-sitosterol, oleanolic acid, 1-O-docosanoyl glycerol, apigenin, and apigenin 7-O-β-D-glucopyranoside from the MeOH extract of the leaves of Mallotus mollissimus. The structures of the isolated compounds were determined on the basis of 1D/2D NMR and HR-MS spectroscopic data; the 2S configuration of the prenylflavanones 3, 4, and 6 was deduced from CD spectroscopic data. The presence of three taraxerane triterpenoids reinforces the inclusion of M. mollissimus (syn. Croton mollissimus) in Mallotus genus. Among species of Mallotus the occurrence of the (2S)-prenylflavanones 3, 4, and 6 is confined to M. mollissimus.