Osteogenic activity of diphenyl ether-type cyclic diarylheptanoids derived from Acer nikoense

Osteogenic activity of six diarylheptanoids, acerogenin A (1), (R)-acerogenin B (2), aceroside I (3), aceroside B₁ (4), aceroside III (5) and (−)-centrolobol (6) and two phenolic compounds; (+)-rhododendrol (7) and (+)-cathechin (8), isolated from the stem bark of Acer nikoense (Nikko maple) was evaluated using alkaline phosphatase (ALP) activity as a marker for early osteoblast differentiation. We found that the diphenyl ether-type cyclic diarylheptanoids 1-5 promoted ALP activity in mouse preosteoblastic MC3T3-E1 cells without affecting cell proliferation, but linear-type diarylheptanoid 6 and phenolic compounds 7 and 8 did not. Diphenyl ether-type cyclic diarylheptanoids 1-4 also increased protein production of osteocalcin, a late stage maker for osteoblast differentiation, and induced osteoblastic mineralization. Structure-activity relationships of these compounds demonstrated that the stimulative efficacy of aglycones was higher than that of its glycosides. Taken together, diphenyl ether-type cyclic diarylheptanoids promote early- and late-stage osteoblastogenesis, which may open the possibility for the development of novel osteogenic agents.     

Diarylheptanoids from Curcuma comosa

Three new diarylheptanoids, designated 1-(3,4-dihydroxyphenyl)-7-(4-hydroxyphenyl)-(6E)-6-hepten-3-ol (1), 1-(3-hydroxyphenyl)-7-(3,4-dihydroxyphenyl)-3-methoxy-(6E)-6-heptene (2), (3R, 5R)-1-(3,4-dihydroxyphenyl)-7-phenyl-heptane-3,5-diol (3) and three known compounds, were isolated from rhizomes of Curcuma comosa. Structures of the compounds were determined by spectroscopic data analysis.     

Secondary metabolites from the leaves of Juglans regia L.

One new diarylheptanoid (1) and one previously unknown ascorbic acid derivative (2) along with 48 known compounds including three ascorbic acid derivatives (3-5), three diarylheptanoids (6-8), three juglone derivates (9-11), six racemic α-tetralones (12a/b-17a/b), four anthraquinones (18-21), eight flavonoids (22-29), nine oligomeric proanthocyanidins (30-38), one phenolic aldehyde (39), one aromatic ketone (40), one pyrrole alkaloid (41), one steroid (42), six terpenes (43-48) and two fatty acids (49-50) were isolated from the leaves of Juglans regia. Their chemical structures were elucidated on basis of 1D and 2D NMR techniques, HRESIMS, polarimetry and CD spectroscopy as well as chiral HPLC and literature data. Furthermore, the chemotaxonomic significance is discussed.     

Phenolic compounds isolated from Dioscorea zingiberensis protect against pancreatic acinar cells necrosis induced by sodium taurocholate

One new bibenzyl (1) and one new phenanthrene (2), together with two known bibenzyls (3–4) and four known diarylheptanoids (5–8) were isolated from the rhizomes of Dioscorea zingiberensis. The structures of 1–2 were elucidated by spectroscopic methods including 1D and 2D NMR. Phenols 1–8 were evaluated for their anti-pancreatitic activities on sodium taurocholate (NaT)-induced pancreatic acinars necrosis. Notably, 0.5 mM of compound 6 exhibited comparable inhibitory effect with 5 mM of caffeine. Furthermore, compound 6 prevented the ATP depletion and excessive ROS production which could be also involved in mitochondria-mediated injuries in acute pancreatitis. As a result, compound 6 has been demonstrated to be a potential candidate for mediating mitochondrial dysfunction to prevent pancreatic necrosis. This study is also the first report on the isolation of bibenzyls and diarylheptanoids from this plant.     

Secondary metabolites from the stems of Engelhardia roxburghiana and their antitubercular activities

Bioassay-guided fractionation of stems of Engelhardia roxburghiana led to isolation of: four diarylheptanoids, engelheptanoxides A–D (1–4); two cyclic diarylheptanoids, engelhardiols A (5) and B (6); one naphthoquinone dimer, engelharquinonol (7); and one 1-tetralone, (4S)-4,6-dihydroxy-1-tetralone (8), along with 24 known compounds (9–32). The structures of 1–8 were by spectroscopic analysis. Compounds 5, 6, 13, 22, and 23 showed antitubercular activity against Mycobacterium tuberculosis H₃₇Rv with MIC values of 72.7, 62.1, 9.1, 15.3, and 70.1 μM, respectively.     

Anti-influenza diarylheptanoids from the bark of Alnus japonica

This study to investigate anti-influenza components from the bark of Alnus japonica resulted in the isolation of two rare acylated diarylheptanoids, named oregonoyl A (5) and oregonoyl B (6), along with nine known compounds (1–4 and 7–11). Their structures were elucidated on the basis of extensive spectroscopic and chemical methods. Antiviral testing of compounds 1–11 against KBNP-0028 (H9N2) avian influenza virus showed that platyphyllone (10) was strongly active, and platyphyllonol-5-xylopyranoside (9) was moderately active against KBNP-0028 as compared with the positive control, zanamivir, respectively.     

Phytochemical investigation on the roots of Juglans mandshurica and their chemotaxonomic significance

Phytochemical research of the roots of Juglans mandshurica Maxim. (Juglandaceae) verified 37 secondary metabolites, including thirteen diarylheptanoids (1–13), five naphthoquinones (14–18), five tetralones (19–23), three lignans (24–26), three phenols (27–29), two anthraquinones (30–31), two triterpenoids (32–33), two secoiridoids (34–35), one naphthalenyl glycoside (36), and one flavonoid (37). The chemical structures of these constituents were elucidated by NMR spectroscopy and compared with data from the literature. This is the first confirmation of the presence of ten compounds (6, 12, 16, 18, 24–26, 30, 32–33) isolated from the family Juglandaceae, two compounds (1 and 8) from the genus Juglans, and four compounds (27, 31, 34–35) from J. mandshurica. The isolation and chemotaxonomic significance of the metabolites from the roots of J. mandshurica were described in this study.     

Anti-neuroinflammatory diarylheptanoids from the rhizomes of Dioscorea nipponica

In a continuing search for bioactive constituents from Dioscoreaceae medicinal plants, two new cyclic diarylheptanoids, diosniponol A (1) and B (2), together with 10 known compounds (3–12) were isolated from the rhizomes of Dioscorea nipponica. The structures of these new compounds were determined by spectroscopic analyses, including extensive two-dimensional nuclear magnetic resonance, high-resolution mass spectrometry, and optical rotation. All isolated compounds 1–12 were evaluated for their effects on nitric oxide (NO) production in murine microglia cell line BV-2. Compounds 8 and 11 showed potent inhibitory activities on NO production (IC₅₀ 13.36 and 14.36 μM, respectively) without cell toxicity in lipopolysaccharide-activated BV-2 cells.     

Diarylheptanoids from the fruits of Amomum kravanh and their inhibitory activities of nitric oxide production

Two new diarylheptanoids with a tetrahydropyran ring, kravanhol A (1) and kravanhol B (2), along with one known diarylheptanoid renealtin A (3) were isolated from the fruits of Amomum kravanh. The structures of compounds 1 and 2 were established by analysis of spectroscopic data and their absolute configurations were determined by Mosher's method and CD experiments. Compound 2 showed inhibitory effect on nitric oxide production in lipopolysaccharide-activated RAW264.7 macrophages with an IC₅₀ value of 38.9 ± 1.8 μM.     

Anti-adipogenic diarylheptanoids from Alnus hirsuta f. sibirica on 3T3-L1 cells

A new diarylheptanoid, (5S)-hydroxy-1-(3,4-dihydroxyphenyl)-7-(4-hydroxyphenyl)-hepta-1E-en-3-one (1), was isolated along with seventeen known diarylheptanoids (2–18) from the methanol extract of Alnus hirsuta f. sibirica leaves using bioactivity-guided fractionation. Among the isolated compounds, compounds 1 and 2 and 4–12 reduced lipid accumulation dose-dependently in 3T3-L1 preadipocytes. Of the compounds active in the present assay system, the most potent compound 7, platyphyllonol-5-O-β-d-xylopyranoside, significantly suppressed the induction of peroxisome proliferator activated receptor γ (PPARγ and CCAAT/enhancer binding protein α (C/EBPα) protein expression, and inhibited adipocyte differentiation induced by troglitazone, a PPARγ agonist. It was demonstrated that compound 7 has anti-adipogenic activity mediated by the regulation of PPARγ dependent pathways.     

Cyclic diarylheptanoids as Na+-glucose cotransporter (SGLT) inhibitors from Acer nikoense

Two cyclic diarylheptanoids, acerogenins A (1) and B (2) have been isolated from the bark of Acer nikoense as inhibitors of Na⁺-glucose cotransporter (SGLT). Acerogenins A (1) and B (2) inhibited both isoforms, SGLT1 and SGLT2. Structure–activity relationship of acerogenin derivatives on inhibitory activity of SGLT as well as conformational analysis of 1 and 2 on the basis of J-resolved HMBC spectra and X-ray analysis were discussed.     

Flavonoid glycosides from the aerial parts of Curcuma comosa

Four new flavonoid glycosides, curcucomosides A–D (1–4), three known flavonoid glycosides, 5–7, and four known diarylheptanoids, 8–11, were isolated from the ethanol extract of the aerial parts of Curcuma comosa. The structures of the new compounds were established as rhamnazin 3-O-α-l-arabinopyranoside (1), rhamnocitrin 3-O-α-l-arabinopyranoside (2), rhamnazin 3-O-α-l-rhamnopyranosyl-(1→2)-O-α-l-arabinopyranoside (3), and rhamnocitrin 3-O-α-l-rhamnopyranosyl-(1→2)-O-α-l-arabinopyranoside (4) by spectroscopic analysis and chemical reactions whereas those of the known compounds were identified by spectral comparison with those of the reported values.     

Isopimarane diterpenes and flavan derivatives from the twigs of Caesalpinia furfuracea

The first phytochemical investigation of Caesalpinia furfuracea twigs led to the isolation and identification of four new compounds including two isopimarane diterpenes, caesalfurfuric acids A (1) and B (2), and two flavans, (2R)-caesalflavans A (5) and B (6), together with four known compounds, 4-epi-isopimaric acid (3), methyl (E)-3-(3,4-dihydroxyphenyl)acrylate (4), (E)-resveratrol (7) and oxyresveratrol (8). Their structures were elucidated by intensive spectroscopic analysis. Compound 1 was found to exhibit antibacterial activity against MRSA SK1 with an MIC value of 16 μg/mL.     

A new flavanone sulfonate and other phenolic compounds from Fumana montana

The phytochemical study of ethyl acetate and n-butanol extracts of Fumana montana Pomel yielded a new flavanone sulfonate named naringenin-8-sulfonate (1), in addition to nine known compounds including two flavonols; tellimoside (2) and isoquercetrin (3), two flavanols; (−)-gallocatechin (4) and (−)-epigallocatechin (5), one benzophenone glucoside; iriflophenone-2-O-β-glucoside (6), one phenolic glucoside; (−)-rhododendrin (7) and three benzoic acid derivatives; p-hydroxybenzoic acid (8), gallic acid (9) and methyl gallate (10). It should be noted that this is the first report of compounds (2) and (6) in Cistaceae family. The structures of the isolated compounds were determined by comprehensive 1D and 2D NMR analysis, mass spectrometry, IR and by comparison with literature data.     

Phytochemical and chemotaxonomic studies on Pteris wallichiana J. Agardh

A systematic phytochemical investigation of Pteris wallichiana J. Agardh resulted in the isolation of twenty compounds, including five sesquiterpenes (1–5), six flavonoids (6–11), seven phenolic acids (12–18) and two fatty acids (19 and 20). Their structures were deduced from MS, NMR and ORD data. This is the first report of compounds dehydropterosin B (2), (2R,3S)-pterosin C (4), (2R,3R)-pterosin L (5), apigenin (6), luteolin (7), luteolin-7-O-glucoside (10), caffeic acid (13), vanillin (14), 3,4-dihydroxybenzaldehyde (15), chlorogenic acid (17), 3,5-dicaffeoylquinic acid (18), suberic acid (19) and azelaic acid (20) from P. wallichiana and of compounds 15, 19 and 20 from the family Pteridaceae. Furthermore, a chemotaxonomic study of the isolates was performed.     

Chemical constituents from Mentha canadensis

Phytochemical investigation on Mentha canadensis led to the isolation of two new compounds, 3,4-dihydro-3,6,7-trihydroxy-2(1H)-quinolinone (1), (E)-2-methoxy-2- oxethyl-3-(4-hydroxyphenyl) acrylate (2), along with nine known phenolic compounds, syringic acid (3), p-coumaric acid (4), esculetin (5), methyl rosmarinate (6), nepetoidin B (7), syringaresinol (8), methyl ester of caffeoyl glycollic acid (9), 2″,3″-diacetylmartynoside (10) and bracteanolide A (12). Additionally, cis-3-[2-[1-(3,4-dihydroxyphenyl)-1-hydroxymethyl]-1,3-benzodioxol-5-yl]-(E)-2-propenoic acid (11), which was isolated as a natural product for the first time. All these compounds were reported for the first time from this species, and their structures were elucidated by spectroscopic techniques. Compound 11 may be a useful chemotaxonomic marker for M. canadensis. The p-coumaric acid derivatives identified in the present investigation may have chemotaxonomic significance at the generic level.     

Phytochemical and chemotaxonomic study on Berchemiella wilsonii (Schneid.) Nakai

Phytochemical investigation of the aerial parts of Berchemiella wilsonii (Schneid.) Nakai (Rhamnaceae) led to the isolation of four flavonoids (1–4), three phenolic acids (5–7), two megastigmane derivatives (8–9) and one triterpene (10). The structures of these compounds were elucidated as taxifolin (1), (−)-epicatechin (2), quercetin 3-O-a-l-arabinopyranoside (3), vitexin (4), methyl p-hydroxycinnamat (5), 3,4-dihydroxybenzoic acid (6), 2-hydroxy-4-methoxy-3,6-dimethyl benzoic acid (7), (3S,5R,6R,7E,9S)-3,5,6,9-tetrahydroxy-7-en-megastigmane (8), (6S,9R)-roseoside (9) and lupeol (10) on the basis of NMR spectral data and comparison with literature values. These results are the first chemical constituent data of the genus Berchemiella, and the chemotaxonomic significance of these compounds is discussed.     

Chemical constituents from the fresh flower buds of Musa nana and their chemotaxonomic significance

Phytochemical study on the fresh flower of Musa nana Lour. provided seventeen known compounds including two alkaloids, 3-(hydroxyacetyl)-indole (1), bi-indol-3-yl (2), two terpenoids, 5-[(1R)-1-hydroxy-2,6,6-trimethyl-4-oxo-2-cyclohexen-1-yl]-3-methyl-, (2Z, 4E) −2, 4-pentadienoic acid (Valdes), 5, 6(S), 7, 7a(R)-tetrahydro-6-hydroxy-4,4-dimethyl-2(4H)-benzofuranone (4), seven phenols (5–11), three phenylphenalenones, 2-hydroxy-4-(4-methoxyphenyl)-1H-phenalen-1-one (12), 2-methoxy-9-phenyl-1H-phenalen-1-one (13), 2-methoxy-9-(4-methoxyphenyl)-1H-phenalen-1-one (14), and three lipids (15–17). In the present study, all the compounds were isolated for the first time from the species M. nana. Ten compounds including 1-8 and 15-16 have never been previously encountered in the Musaceae family. Furthermore, the chemotaxonomic significance of these isolates was also discussed.     

Chevalierinoside B and C: Two new isoflavonoid glycosides from the stem bark of Antidesma laciniatum Muell. Arg (syn. Antidesma chevalieri Beille)

Chevalierinosides B (1) and C (2), two new isoflavonoid glycosides, characterized as biochanin A 7-O-[β-d-apiofuranosyl-(1→2)-β-d-glucopyranoside] and genistein 7-O-[β-d-apiofuranosyl-(1→2)-β-d-glucopyranoside], together with the known isoflavonoids, chevalierinoside A (3) and genistein 7-O-β-d-glucopyranoside (4), kaempferol 3-O-β-d-glucopyranoside (5) and triterpenes, friedelin (6), betulinic acid (7), 30-oxobetulinic acid (8), 30-hydroxybetulinic acid (9), were isolated from the stem bark of Antidesma laciniatum Muell. Arg. (syn. Antidesma chevalieri Beille). Their structures were established by direct interpretation of their spectral data, mainly HR-TOFESIMS, 1D-NMR (¹H, ¹³C and DEPT) and 2D-NMR (COSY, NOESY, TOCSY, HSQC and HMBC), and by comparison with the literature.     

The isolation of two new lanostane triterpenoid derivatives from the edible mushroom Astraeus asiaticus

Two lanostane triterpenoid derivatives, astrasiaone (2), (22S, 25R, 26R)-26-methoxy-22-26-epoxylanost-8-en-3-one, and astrasiate (3), (3α, 22S, 25R)-3, 22-dihydroxylanost-8-en-26 -oate, together with six known compounds, astraodorol (1), artabotryol B (4), artabotryol C1 (5), 6-dehydrocerevisterol (6), ergosterol (7) and hypaphorine (8) were isolated from the edible mushroom Astraeus asiaticus. 3 and 4 exhibited weak cytotoxicity against KB and NCI-H187 cancer cell lines. A comparison of the structures of 2 and 3 to that of 1, 4 and 5 suggest that these two new compounds could be the intermediate form that occurs during biogenesis.