Three flavonoid glycosides containing acetylated allose from stachys recta

By means of ¹³C and ¹H NMR spectroscopy three flavone glycosides, obtained from Stachys recta, were identified as 7-O-(2″-O-6″′-O-acetyl-β-D-allopyranosyl-β-D-glucopyranosides) of 4′-O-methylisoscutellarein, isoscutellarein and 3′-hydroxy-4′-O-methylisoscutellarein. The latter two compounds are isolated for the first time. Only mannose and glucose have been reported previously as sugar components of flavonoids of the genus Stachys.     

Flavonoid constituents of Ephedra alata

Two new flavonol glucosides have been identified in Ephedra alata, namely, herbacetin 8-methyl ether 3-O- glucoside-7-O-rutinoside and herbacetin 7-O-(6″-quinylglucoside). The known flavonoids vicenin II, lucenin III, kaempferol 3-rhamnoside, quercetin 3-rhamnoside and herbacetin 7-glucoside were also found. The structure of the isolated compounds was determined mostly by FABMS and ¹H NMR spectroscopy. The final structure of the new compounds and of herbacetin 7-glucoside was confirmed by ¹³C NMR spectroscopy.     

Phenolic Glycosides with antiproteasomal activity from Centaurea urvillei DC. subsp. urvillei

A new flavanone glycoside, naringenin-7-O-β-d-glucuronopyranoside, and a new flavonol glycoside, 6-hydroxykaempferol-7-O-β-d-glucuronopyranoside were isolated together with 12 known compounds, 5 flavone glycoside; hispidulin-7-O-β-d-glucuronopyranoside, apigenin-7-O-β-d-methylglucuronopyranoside, hispidulin-7-O-β-d-methylglucuronopyranoside, hispidulin-7-O-β-d-glucopyranoside, apigenin-7-O-β-d-glucopyranoside, a flavonol; kaempferol, two flavone; apigenin, and luteolin, a flavanone glycoside; eriodictyol-7-O-β-d-glucuronopyranoside, and three phenol glycoside; arbutin, salidroside, and 3,5-dihydroxyphenethyl alcohol-3-O-β-d-glucopyranoside from Centaurea urvillei subsp. urvillei. The structure elucidation of the new compounds was achieved by a combination of one- (¹H and ¹³C) and two-dimensional NMR techniques (G-COSY, G-HMQC, and G-HMBC) and LC-ESI-MS. The isolated compounds were tested for their antiproteasomal activity. The results indicated that kaempferol, a well known and widely distributed flavonoid in the plant kingdom, was the most active antiproteasomal agent, followed by apigenin, eriodictyol-7-O-β-d-glucuronopyranoside, 3,5-dihydroxyphenethyl alcohol-3-O-β-d-glucopyranoside, and salidroside, respectively.     

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.     

Metabolomics-oriented isolation and structure elucidation of 37 compounds including two anthocyanins from Arabidopsis thaliana

In order to conduct metabolomic studies in a model plant for genome research, such as Arabidopsis thaliana (Arabidopsis), it is a prerequisite to obtain structural information for the isolated metabolites from the plant of interest. In this study, we isolated metabolites of Arabidopsis in a relatively non-targeted way, aiming at the construction of metabolite standards and chemotaxonomic comparison. Anthocyanins (5 and 7) called A8 and A10 were isolated and their structures were elucidated as cyanidin 3-O-[2-O-(β-d-xylopyranosyl)-6-O-(4-O-(β-d-glucopyranosyl)-E-p-coumaroyl)-β-d-glucopyranoside]-5-O-[6-O-(malonyl)-β-d-glucopyranoside] and cyanidin 3-O-[2-O-(2-O-(E-sinapoyl)-β-d-xylopyranosyl)-6-O-(4-O-(β-d-glucopyranosyl)-E-p-coumaroyl)-β-d-glucopyranoside]-5-O-[β-d-glucopyranoside] from analyses of 1D NMR, 2D NMR (¹H NMR, NOE, ¹³C NMR, HMBC and HMQC), HRFABMS, FT-ESI-MS and GC-TOF-MS data. In addition, 35 known compounds, including six anthocyanins, eight flavonols, one nucleoside, one indole glucosinolate, four phenylpropanoids and a derivative, together with three indoles, one carotenoid, one apocarotenoid, three galactolipids, two chlorophyll derivatives, one steroid, one hydrocarbon, and two dicarboxylic acids, were also isolated and identified from their spectroscopic data.     

Chemical constituents from Ficus natalensis hochst (Moraceae) and their chemophenetic significance

Phytochemical investigation of the stem bark of Ficus natalensis afforded eleven compounds including one ceramide (1), two anthraquinones (2, 3), four triterpenes (4–7), two polyols (8, 9) and two steroids (10, 11). The structures of the compounds were determined by spectroscopic analyses including IR, UV, MS, 1D- and 2D- NMR (¹H, ¹³C, ¹H–¹H COSY, HMQC, HMBC and NOESY), as well as by comparison with literature data. The antibacterial activity and the cytotoxicity of the extract, fractions and some isolated compounds (3, 5, 8 and 9) were evaluated. Some fractions and sub-fractions from various column chromatography displayed moderate antibacterial activity with diameter zone of inhibition (DZI) ranging from 7 to 10 mm. None of the compounds tested had activity. In the present study, all the compounds are isolated for the first time from the species F. natalensis. Compounds 2, 4–7, 10 and 11 were previously reported from the genus Ficus. The chemophenetic significance of the isolated compounds is discussed.     

PHYSIOLOGICAL EFFECT OF LICHEN SECONDARY METABOLITES ON THE LICHEN PARASITE MARCHANDIOMYCES CORALLINUS

It has been suggested that the host specificity exhibited by some lichenicolous fungi depends on their ability to tolerate the secondary chemistry of potential host lichens. For example, the lichen parasite Marchandiomyces corallinus is able to degrade the tissues of the lichen Flavoparmelia baltimorensis irrespective of the presence or absence of endogenous phenolic compounds. In contrast, the degradation of tissues from the lichen Lasallia papulosa is suppressed when endogenous phenolics are not removed. We have investigated the physiological basis of this inhibition in order to understand more about how lichen chemistry influences host preference in lichenicolous fungi. Results showed that the secondary compounds from L. papulosa inhibit the overall growth of M. corallinus , but not the catalytic activity of its tissue-degrading polysaccharidases. This effect is different from that shown by another lichen parasite, Nectria parmeliae , where lichen compounds specifically inhibited polysaccharidase activity. Compared with the compounds of L. papulosa , the endogenous phenolics of F. baltimorensis inhibited the growth of M. corallinus substantially less and exhibited little or no inhibition of polysaccharidases. For M. corallinus , host preference appears to be associated with physiological adaptation to the chemistry of F. baltimorensis .     

Anti-inflammatory iridoid glycosides from fruits of Cornus officinalis

Three undescribed iridoid glycosides, cyc(7β-O-6′)-morroniside (1), 6′-methyl succinate-7β-O-methylmorroniside (2), and 7β-O-methyl phenyllactate morroniside (3) were isolated from 50% ethanol extract of Cornus officinalis fruits. The structures of the isolated compounds were determined by HRESIMS, ¹D NMR, ²D NMR, UV and IR spectroscopic methods. Compounds 1-3 exhibited moderate anti-inflammatory activities in vivo in a CuSO₄-induced zebrafish inflammation model (when evaluated at 50 μM).     

Three new compounds isolated from the bulbs of Fritillaria pallidiflora Schrenk and their anti-inflammatory activity

Three new compounds, 17β-cevanin-6-oxo-5α,20β-diol yibeinine (1), 2-(tetrahydro-5-(2-hydroxyphenyl)-2H-pyran-3-yl) phenol (2), 1,3-O-diferuloyl-2-methoxypropane diol (3), as well as four known compounds (4–7), have been isolated from the ethanol extract of dried bulbs of Fritillaria pallidiflora Schrenk. All structures were determined based on their spectroscopic data (1D and 2D NMR (including ¹H NMR, ¹³C NMR, ¹H-¹H COSY, HMBC, HSQC, HSQC-TOCSY, and NOESY experiments), and MS). Biological evaluation showed that compounds 1–4 inhibited the production of nitric oxide (NO) in LPS-stimulated RAW 264.7 cells with IC₅₀ values of 18.0, 38.7, 29.5, and 47.1 μM, respectively. These results indicated that compound 1 has potential anti-inflammatory activity.     

Novel metabolites from the roots of Cadaba natalensis

From an extract of the roots of Cadaba natalensis Sond. the novel macrocyclic dibenzo-diazacyclododecanedione 1 was isolated together with (S)-2-ethyl-2-methyloxazolidin-5-one (2a). In addition, the five known compounds were obtained. Of these, (R)-5-ethyl-5-methyloxazolidin-2-one (3) is reported as a natural product for the first time. The structures of the isolated compounds were elucidated by analysis of the spectral data, 1D NMR (¹H, ¹³C, and DEPT), 2D NMR (COSY, HMQC, HMBC, and NOESY), and HRESIMS, as well as by the comparison with previously reported data.     

Anthraquinones and other constituents from the roots of Eremomastax speciosa (Hochst.) Cufod

The chemical investigation of the roots of Eremomastax speciosa (Hochst.) Cufod (Acanthaceae). led to the isolation of thirteen compounds including five anthraquinones 1,8-dihydroxy-3-methylanthraquinone (1), 1,8-dihydroxy-3-methoxy-6-methylanthraquinone (2), emodin (3), aloe emodin (4) and 8-O-D-glucopyranosideemodin (5); one phenylethanoid glucoside acteoside (6); one benzophenone 2,6-dimethoxybenzophenone (7); two pentacyclic triterpenoids lupeol (8) and betulinic acid (9); three phytosterols stigmasterol (10), β-sitosterol (11), and β-sitosterol-3-O-β-D-glucopyranoside (12) and one fatty acid hexadecanoid acid (13). All these compounds are firstly reported from the roots of E. speciosa. Emodin and acteoside were modified chemically through allylation reaction to afford 3-O-allylated emodin (3a) and a new perallylated acteoside derivative (6a), respectively. The structure of the isolated compounds as well as those of the allylated derivatives were established by means of spectroscopic methods: NMR analysis (¹H and ¹³C NMR, ¹H–¹H–COSY, HSQC and HMBC), high-resolution mass spectrometry (HR-ESI-MS) and by comparison with previously reported data. All those compounds were tested for their cytotoxic activity against the human cervix carcinoma KB-3-1 cells and their antioxidant activity, the allylated acteoside derivative and 2,6-dimethoxybenzophenone showed weak cytotoxicity while acteoside showed a good antioxidant activity. In addition, the chemotaxonomic significance of the isolated compound is discussed.     

A naphthalene glycoside from callus cultures of Diospyros kaki

Calli of Diospyros kaki Thunb. were induced on half-strength Murashige–Skoog solid medium supplemented with 1.0 mg l⁻¹ IAA and 0.1 mg l⁻¹ BA in the dark and successfully subcultured on the same medium. A new phenolic metabolite, 7-methyl-1, 4, 5-trihydroxy-naphthalene 4-O-(6′-O-β-xylopyranosyl)-β-glucopyranoside, was isolated from MeOH extract of the callus cultures and its chemical structure was elucidated by NMR spectroscopic analysis.     

Synthesis and characterization of some new quinoline based derivatives endowed with broad spectrum antimicrobial potency

The synthesis of a novel series of 2-(5-(2-chloro-6-fluoroquinolin-3-yl)-3-(aryl)-4,5-dihydro-1H-pyrazol-1-yl)thiazol-4(5H)-ones (4a–l) and N-(4-(2-chloro-6-fluoroquinolin-3-yl)-6-(aryl)pyrimidin-2-yl)-2-morpholinoacetamides (7a–l) are described in the present paper. The chemical structures of compounds have been elucidated by IR, ¹H NMR, ¹³C NMR and mass spectral data. Antimicrobial activity was measured against Escherichia coli (MTCC 443), Pseudomonas aeruginosa (MTCC 1688), Staphylococcus aureus (MTCC 96), Streptococcus pyogenes (MTCC 442), Candida albicans (MTCC 227), Aspergillus niger (MTCC 282) and Aspergillus clavatus (MTCC 1323) by serial broth dilution. Evaluation of antimicrobial activity showed that several compounds exhibited greater activity than reference drugs and thus could be promising new lead molecules.     

Acetylated allose-containing flavonoid glucosides from Stachys anisochila

In continuation of our chemosystematic study of Stachys (Labiatae) we have isolated the previously reported isoscutellarein 7-O-[6″'-O-acetyl-β-D-allopyranosyl-(1 → 2)-β-D-glucopyranoside] (1) and 3′-hydroxy-4′-O-methylisoscutellarein 7-O-[6″'-O-acetyl-β-D-allopyranosyl-(1 → 2)-β-D-glucopyranoside] (4) and four new allose-containing flavonoid glycosides from S. anisochila. The new glycosides are hypolaetin 7-O-[6″'-O-acetyl-β-D-allopyranosyl-(1 → 2)-β-D-glucopyranside] (6) as well as the three corresponding diacetyl analogues of 1, 4 and 6, isoscutellarein 7-O-[6″'-O-acetyl-β-D-allopyranosyl-(1 → 2)-6″-O-acetyl-β-D-glucopyranoside], 3′-hydroxy-4′-O-methylisoscutellarein 7-O-[6″'-O-acetyl-β-D-allopyranosyl-(1 → 2)-6″-O-acetyl-β-D-glucopyranoside] and hypolaetin 7-O-[6″'-O-acetyl-β-D-allopyranosyl-(1 → 2)-6″-O-acetyl-β-D-glucopyranoside]. Extensive two-dimensional NMR studies (proton-carbon correlations, COSY experiments) allowed assignment of all ¹H NMR sugar signals and a correction of the ¹³C NMR signal assignments for C-2 and C-3 of the allose.     

Sulphated flavonoid glycosides from leaves of Atriplex hortensis

Two flavonoid sulphates, i.e. quercetin 3-O-sulphate-7-O-α-arabinopyranoside and kaempferol 3-O-sulphate-7-O-α-arabinopyranoside, were isolated from leaves of Atriplex hortensis L. The structures of these compounds were established by UV, ¹H and ¹³C NMR, 2D NMR and MS spectra. The compounds were isolated for the first time from plant material.     

Three flavone glycosides from citrus sudachi

Three flavone glycosides, sudachiins B, C and D, were isolated from the green peel of Citrus sudachi. On the basis of UV, ¹H NMR and ¹³C NMR spectral data sudachiins B and C were identified as sudachiin A 6″- (3-hydroxy-3-methyl)glutarateand 7-O-β-D-glucosyl sudachitin 6″-(3-hydroxy-3-methyl)glutarate, respectively. Sudachiin D was found to be a unique glycoside in which sudachiin A and 7-O-β-D-glucosylsudachitin were esterified at their 6″-positions with 3-hydroxy-3-methylglutaric acid.     

Flavonoid glycosides and triterpenoids from Atractylis flava

Two new flavonoid glycosides, together with twelve known compounds including seven flavonoids and five triterpenoids were isolated from the whole plant Atractylis flava Desf. The structures of new compounds have been elucidated as 6-hydroxykaempferol 6-methyl ether 7-O-β-glucopyranuronoside (1) and isorhamnetin 3-O-[(6″′-O-E-feruloyl)-β-d-glucopyranosyl-(1 → 2)]-β-d-galactopyranoside (2) named Atraflavoside A and B successively, on the basis of physical and spectroscopic analysis, including 1D and 2D NMR (¹H, ¹³C, COSY, TOCSY, HSQC, HMBC and NOESY) and mass spectrometry (HRESIMS) whereas those of the known compounds (3–14) were established by spectral comparison with those published in the literature.     

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.     

Methylated anthocyanidin glycosides from flowers of Canna indica

Methylated anthocyanin glycosides were isolated from red Canna indica flower and identified as malvidin 3-O-(6-O-acetyl-β-d-glucopyranoside)-5-O-β-d-glucopyranoside (1), malvidin 3,5-O-β-d-diglucopyranoside (2), cyanidin-3-O-(6″-O-α-rhamnopyranosyl-β-glucopyranoside (3), cyanidin-3-O-(6″-O-α-rhamnopyranosyl)-β-galactopyranoside (4), cyanidin-3-O-β-glucopyranoside (5) and cyanidin-O-β-galactopyranoside (6) by HPLC-PDA. Their structures were subsequently determined on the basis of spectroscopic analyses, that is, ¹H NMR, ¹³C NMR, HMQC, HMBC, ESI-MS, and UV-vis. Compounds (1-4) were found to be in major quantity while compounds (5-6) were in minor quantity.     

Canna indica flower: New source of anthocyanins

In this study the red flowers of Canna indica (Cannaceae) were extracted by using sonicator and isolation of anthocyanins have been carried out. Four anthocyanin pigments have been isolated apart from quercetin and lycopene. They are Cyanidin-3-O-(6′′-O-α-rhamnopyranosyl)-β-glucopyranoside (1), Cyanidin-3-O-(6′′-O-α-rhamnopyranosyl)-β-galactopyranoside (2), Cyanidin-3-O-β-glucopyranoside (3) and Cyanidin-O-β-galactopyranoside (4). These compounds were isolated by using HPLC and their structures were subsequently determined on the basis of spectroscopic analyses, i.e., ¹H NMR, ¹³C NMR, HMQC, HMBC, ESI-MS, FTIR, UV–Visible etc. The isolated compounds showed good antioxidant activity thus makes it suitable for use in food coloration and as a nutraceutical. Thus it is a promising pigment source for food applications.