Flavonoids and polyacetylenes from the aerial parts of Bidens tripartita

Fourteen flavonoids (1–14) and two polyacetylenes (15 and 16) were isolated from the aerial parts of Bidens tripartita. Thirteen compounds (1–7, 9, 11, 12, and 14–16) were isolated from this species for the first time, of which a flavonoid (11) was obtained for the first time from the genus Bidens. The chemotaxonomic significance of these compounds was summarized.     

A new flavonoid from the stem bark of Acer tegmentosum

A new flavonoid, 6-carboxyl-(−)-catechin methyl ester (1) was isolated from the stem bark of Acer tegmentosum, along with six known flavonoids (2–7). The structure of compound 1 was determined by spectral analyses, including HR-ESI-MS, 1D and 2D NMR (COSY, HMQC and HMBC) experiments. From present investigation, compound 7 was isolated for the first time from the Aceraceae family.     

A new flavonoid from the bark of Ulmus pumila L

A new flavonoid (6), together with eight (1–5 and 7–9) known flavonoids, were isolated from the n-butyl alcohol soluble portion of the EtOH extract of Ulmus pumila L. The chemical structures of the compounds were determined by using spectroscopic methods and further supported by comparison with previously literature values. Among them, flavonoids 4, 6 and 9 were isolated for the first time from the family Ulmaceae. Furthermore, the chemotaxonomic significance of the isolates was also discussed.     

Two new labdane diterpenoids and one new β-lactam from the aerial parts of Roylea cinerea

Two new labdane diterpenoids cinereanoid C (1), cinereanoid D (2), a new β-lactam, cinerealactam E (3) as well as six known flavonoid glycosides (4–9) were isolated from the aerial parts of Roylea cinerea (Lamiaceae). The structures of (1–9) were all determined by MS, IR and NMR spectroscopy. The structure of cinereanoid D (2) was further proven by single crystal X-ray diffraction. Six known flavonoid glycosides (4–9) were also isolated for the first time from this plant. 2, 5, 6 and 7 were found to significantly inhibit the ATP binding of a tumour growth-promoting heat shock protein, Hsp90.     

Chromone acyl glucosides and an ayanin glucoside from Dasiphora parvifolia

Two new chromone acyl glucosides, 5-hydroxy-7-O-(6-O-p-cis-coumaroyl-β-D-glucopyranosyl)-chromone (1) and 5-hydroxy-7-O-(6-O-p-trans-coumaroyl-β-D-glucopyranosyl)-chromone (2), and a new flavonoid glucoside, ayanin 3′-O-β-D-glucopyranoside (3) were isolated from aerial parts of Dasiphora parvifolia, together with flavonoid glycosides (4–10), catechins (11, 12), and hydrolysable tannins (13, 14). The chemical structures of these compounds were elucidated on the basis of spectroscopic data. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and the hyaluronidase inhibitory activity of these compounds were evaluated.     

Triterpene saponins from Fagonia scabra Forssk and other Fagonia species

This article reports on the structure of triterpenoids saponins (1–49) isolated from Fagonia species. In addition, it describes one known flavonoid (50) with luteolin as aglycone and seven known triterpenoid saponins (26, 51–56) isolated from the aerial parts of Fagonia scabra Forssk. Compounds 50–56, were isolated for the first time from the genus Fagonia, while compounds 50–53, 55–56 have never been encountered in the Zygophyllaceae family. The chemotaxonomic relationship between F. scabra and other Fagonia species was also discussed.     

Chemical constituents from the roots of Zizyphus jujuba Mill. var. spinosa

One new flavonoid, named (R)-2-hydroxynaringenin (1), along with fifteen known compounds, including six flavonoids (2–7), six lignans (8–13), two phenolic glycosides (14–15) and one alkaloid (16) were isolated from the roots of Zizyphus jujuba Mill. var. spinosa (Bunge) Hu ex H. F. Chou. Their structures were established on the basis of spectroscopic evidence, including 1D and 2D NMR, circular dichroism (CD) curve analysis, and by comparison with literature data. Compounds 2, 3 and 8–16 were found in Z. jujuba Mill. var. spinosa for the first time, while compounds 8, 10 and 13–15 were new to the Rhamnaceae family. In addition, the chemotaxonomic significance of the isolates was discussed in this paper.     

Phenolics from Tanacetum sinaicum (Fresen.) Delile ex Bremer & Humphries (Asteraceae)

The phytochemical investigation on Tanacetum sinaicum (Fresen.) Delile ex Bremer & Humphries led to the isolation of eight flavonoid aglycones (apigenin 1, acacetin 2, luteolin 3, chrysoeriol 4, cirsilineol 5, jaceidin 6, chrysosplenetin 7 and vitexicarpin; casticin 8), four flavonoid glycosides (apigenin 7-O-β-glucopyranoside 9, apigenin 7-O-β-glucuronide 10, luteolin 7-O-β-glucopyranoside 11 and luteolin 7-O-β-glucuronide 12) and three phenolics (4-hydroxy-3-methoxy benzoic acid 13, 3,4-dimethoxy benzoic acid 14 and 4-hydroxy acetophenone 15). Their structures were determined by chemical and spectroscopic analysis. Among them, compounds 1–3, 9, 11, 13 and 14 were reported for the first time from T. sinaicum. The chemotaxonomic significance of the isolated flavonoids was also summarized.     

Anthocyanins and flavonols from the blue flowers of six Meconopsis species in Bhutan

Blue flowers of six Bhutani Meconopsis species, M. bhutanica, M. bella, M. horridula, M. simplicifolia, M. primulina and M. polygonoides, were surveyed for anthocyanins and other flavonoids. Four anthocyanins were isolated and identified as cyanidin 3-O-sambubioside-7-O-glucoside (1), cyanidin 3-O-[xylosyl-(1 → 2)-(6″-malonylglucoside)]-7-O-glucoside (2), cyanidin 3-O-sambubioside (4) and cyanidin 3-O-[xylosyl-(1 → 2)-(6″-malonylglucoside)] (5). On the other hand, 12 flavonols were isolated from their Meconopsis species with various combination and characterized as kaempferol 3-O-glycosides (8–12), kaempferol 3,7-O-glycosides (13–16), quercetin 3-O-glycosides (17 and 18) and isorhamnetin 3-O-glycoside (19). Of six Meconopsis species which were surveyed in this experiment, anthocyanin and flavonol composition of five species except for M. horridula was clarified for the first time. Their Meconopsis species showed the different flavonoid profiles, respectively, and flavonoid diversity within the glycosylation level of Meconopsis flowers were indicated.     

Chemical constituents of Peperomia tetraphylla (Forst. F.) Hooker et Arnott

Sixteen compounds were isolated from the whole herbs of Peperomia tetraphylla (Forst. F.) Hooker et Arnott by phytochemical methods, including eight flavonoids (1–3, 6, 7, 14–16), three lignans (8–10), three beta sitosterols (4, 5, 11), and two phenolic acids (12, 13). Their structures were identified by the analysis of NMR and MS, as well as the comparisons to the reported data. Among them, 2″-O-xylosylisoswertisin (14) was firstly isolated from the Piperaceae family, as well as ten compounds (1–4, 7, 10–11, 13, 15–16) were isolated from P. tytraphylla for the first time. Moreover, the chemotaxonomic significance of constituents isolated from P. tytraphylla was also discussed.     

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 the pericarps of Zanthoxylum bungeanum and their chemotaxonomic significance

The phytochemical study of the pericarps of Zanthoxylum bungeanum Maxim under the guidance of bioactivity led to the isolation of 18 compounds, including a new isobutylhydroxyamide (1) and 17 known compounds, i.e. six alkylamides (2–7), five coumarins (8–12), one benzene derivative (13), three flavonoids (14–16), and two sterols (17–18). Their structures were elucidated based on extensive spectroscopic methods (HRESIMS, 1D and 2D NMR experiments) and by comparison with literature data. New compound (1) and known compound (2) are cis-trans isomeric isobutylhydroxyamides. Among them, compounds 9, 10, and 12 were isolated for the first time from Z. bungeanum, compound 11 was firstly recovered from the genus Zanthoxylum, and compound 14 was reported for the first time from the Rutaceae family. The chemotaxonomic significance of isolated compounds from Z. bungeanum is discussed.     

Neuraminidase inhibitory activities of flavonols isolated from Rhodiola rosea roots and their in vitro anti-influenza viral activities

Five flavonols (3, 5, and 9–11) were isolated from Rhodiola rosea, and compared with commercially available flavonoids (1, 2, 4, 6–8, and 12–14) to facilitate analysis of their structure–activity relationship (SAR). All compounds (1–14) showed neuraminidase inhibitory activities with IC₅₀ values ranging from 0.8 to 56.9 μM. The in vitro anti-influenza virus activities of flavonoids 1–6, 8–12, and 14 were evaluated using two influenza viral strains, H1N1 (A/PR/8/34) and H9N2 (A/Chicken/Korea/MS96/96), testing their ability to reduce virus-induced cytopathic effect (CPE) in MDCK cells. We found that the activity of these compounds ranged from 30.2 to 99.1 μM against H1N1- and 18.5 to 133.6 μM against H9N2-induced CPE. Of compounds 1–14, gossypetin (6) exhibited the most potent inhibitory activity, with IC₅₀ values of 0.8 and 2.6 μM on neuraminidases from Clostridium perfringens and recombinant influenza virus A (rvH1N1), respectively. In contrast, kaempferol (3) exhibited the highest activity against two influenza viruses, H1N1 and H9N2 with EC₅₀ values of 30.2 and 18.5 μM, respectively. Activity depended on the position and number of hydroxy groups on the flavonoids backbone. In kinetic studies, all isolated compounds behaved as noncompetitive inhibitors.     

Chemical constituents from the fruits of Vitex trifolia L. (Verbenaceae) and their chemotaxonomic significance

One new labdane-type diterpenoid (1) named viterotulin D, along with twenty-three known compounds, including fourteen diterpenoids (2–15), one monoterpenoid (16), three steroids (17–19), one flavonoid (20), and four phenols (21–24) were isolated from the fruits of Vitex trifolia L. The structures of these compounds were identified based on spectroscopic data interpretation and comparison with previously reported values in the literature. This is the first report on the isolation of compounds (1, 6, 14, 15, 17, and 22) and (2, 9, and 10) from the family Verbenaceae and Vitex trifolia, respectively. The chemotaxonomic significant of the isolates was also discussed.     

A new flavone glycoside from the leaves of Agastache rugosa (Fisch. & C.A.Mey.) Kuntze

Agastache rugosa (Fisch. & C.A.Mey.) Kuntze has been widely used as a food spice and a remedy for colds in Korea, China and Japan. In this study, one new flavone glycoside (1) along with six flavonoids (2–7), nine phenyl glycosides (8–16) and three megastigmane glycosides (17–19) were isolated from the leaves of A. rugosa. By extensive spectroscopic methods including 1D and 2D NMR, and MS data, the structure of the new compound (1) was elucidated as acacetin 7-O-β-(6″-(E)-crotonylglucopyranoside). From present investigation, compound 1 and 7–19 were isolated for the first time from the genus Agastache and 1, 16, 18 and 19 in the Lamiaceae family.     

Chemical constituents from Orobanche cernua Loefling

Phytochemical study of Orobanche cernua Loefling afforded 17 compounds, including eleven phenylpropanoid glycosides (1–11), two flavonoids (12, 13), one lignan (14), and three phenolic acids (15–17) were isolated from the fresh whole plant of O. cernua. Their structures were identified by spectroscopic analyses and by comparison of their spectral data with those reported in the literature. This is the first report of isolation of compounds (6, 8, 9, 11, 14–16) from O. cernua and compounds (14, 15) from the family Orobanchaceae, respectively. Compound 14 was obtained from natural source for the first time, the chemotaxonomic significance of these compounds was summarized.     

Phytochemical study of Capraria biflora L. aerial parts (Scrophulariaceae) from Martinique island (French West Indies)

Aerial parts of Capraria biflora L. were collected in Martinique (French West Indies) and extracted by methanol. Two original chlorinated iridoids, 3-hydroxymyopochlorin (1) and 5-hydroxyglutinoside (2) were isolated by CPC (centrifugal partition chromatography) and characterized from the extract together with five known iridoid glycosides (3–7), two flavonoid glucuronides (8–9) and the phenylethanoid glycoside verbascoside (10). The structure of these compounds together with their relative configuration was established by spectroscopic data including in particular 1D and 2D NMR experiments (HSQC, HMBC, NOESY) and HRESIMS. Preliminary antibacterial evaluation of 1, 2 and 3 against a panel of Gram-positive and Gram-negative strains has been performed.     

Flavonoids,megastigmanes and other constituents from Ardisia incarnata

Phytochemical investigation of the leaves and twigs of Ardisia incarnata Pit. (syn. Ardisia hanceana Mez, Primulaceae) led to the isolation of one bicyclic monoterpene (1), five phenolic compounds (2–5, 8), two megastigmanes (6–7) and one glyceroglycolipid (9). Their structures were established based on analysis of their spectroscopic data and comparison with literature. The compounds 1 and 6–9, isolated for the first time from Ardisia genus, may constitute chemomarkers of A. incarnata within Primulaceae family. Moreover, the flavonoid fingerprint may also be of chemotaxonomic significance.     

Flavonol glycosides with lipid accumulation inhibitory activity from Sedum sarmentosum

Three new flavonol glycosides, sarmenosides V–VII (1–3), were isolated from the whole plant of Sedum sarmentosum (Crassulaseae). The structures of 1–3 were determined on the basis of spectroscopic analysis. Among the flavonoid constituents from S. sarmentosum, 1 and 3 were found to show oleic acid–albumin-induced lipid accumulation inhibitory activity.     

New antioxidant C-geranylated flavonoids from the fruit peels of Paulownia catalpifolia T. Gong ex D.Y. Hong

Three new geranylated flavonoids, including two geranylflavones (1, 2) and one geranylflavonol (3), named as paucatalinone C–E, were isolated from the fruit peel of P. catalpifolia T. Gong ex D.Y. Hong. Their structures were determined by means of UV, IR, MS, and NMR techniques. To our known, geranylflavone or geranylflavonol was the first isolation from the genus Paulownia. These isolated geranylated flavonoids displayed good antioxidant effects on DPPH and the senescent human embryonic lung diploid fibroblasts cells (2BS cells) induced by H₂O₂. The geranyl substituent may be an important factor for the cellular radical-scavenging effect because of its lipophilic character.