Exceptional contact elasticity of human enamel in nanoindentation test.

Objective: Tooth enamel has unsurpassed hardness and stiffness among mammalian tissue structures. Such stiff materials are usually brittle, yet mature enamel can survive for a lifetime. Understanding the nanoscale origin of enamel durability is important for developing advanced load-bearing biomaterials.

Six New Lanostane Triterpenoids from the Fruiting Body of Tyromyces sambuceus and Antiproliferative Activity.

During the search for secondary metabolites with antiproliferative activity, six new lanostane triterpenoids, tyrosamic acids A-F (1-6) together with ten known compounds (7-16), were isolated from the fruiting body of Tyromyces sambuceus. Their structures were elucidated using MS analyses, extensive 2D-heteronuclear NMR data interpretation and the structure of 3 was further confirmed by single-crystal X-ray data analyses. All lanostane triterpenoids (1-16) possesses a carboxy group at C-20 position and their strength of antiproliferative activity was affected by the presence or absence of a hydroxy group at C-15 position and at the side chain.

Phenanthrene and phenylpropanoid constituents from the roots of Cymbidium Great Flower 'Marylaurencin' and their antimicrobial activity.

Two new phenanthrenes, and one new phenylpropanoid, named ephemeranthoquinone C (1), and marylaurencinols C (2) and D (3), were isolated from the roots of Cymbidium Great Flower 'Marylaurencin', respectively. These structures were determined on the basis of 2D NMR experiments. The compounds were tested for antimicrobial activity against Bacillus subtilis, Klebsiella pneumoniae, and Trichophyton rubrum.

Two novel aromatic glucosides, marylaurencinosides D and E, from the fresh flowers of Cymbidium Great Flower 'Marylaurencin'.

Two novel aromatic glucosides, named marylaurencinosides D (1) and E (2), were isolated from the fresh flowers of Cymbidium Great Flower 'Marylaurencin'. In addition, eight known aromatic compounds (3-10) were isolated. These structures were determined on the basis of NMR experiments as well as chemical evidence.

Phenylpropanoid, sapnol A, lignan and neolignan sophorosides, saposides A and B, isolated from Canadian sugar maple sap.

One new phenolic compound, sapnol A (1), and two new aromatic sophorosides, named saposides A (2) and B (3) were isolated from sugar maple sap. In addition, seven known phenolic compounds 4-10 were isolated. These structures were determined on the basis of NMR experiments as well as chemical evidence.

Constituents of Caryopteris incana and their antibacterial activity.

Two new compounds named caryocanolide (1), and caryocanoside A (2), together with nine known compounds (3-11) were isolated from the whole plant of Caryopteris incana. These structures were determined mainly on the basis of 2D nuclear magnetic resonance and high resolution fast atom bombardment mass spectroscopy data. Furthermore, the isolated compounds (1, 2, 4-11) were tested for their antibacterial activity.

Yellow pigments, fomitellanols A and B, and drimane sesquiterpenoids, cryptoporic acids P and Q, from Fomitella fraxinea and their inhibitory activity against COX and 5-LO.

Yellow pigments, fomitellanols A (1a) and B (2a), and drimane-type sesquiterpenoid ethers of isocitric acid, cryptoporic acids P (3) and Q (4), have been isolated from the fruiting bodies of Fomitella fraxinea (Polyporaceae). Their structures were established by a combination of extensive NMR spectroscopy and/or X-ray crystallographic analyses, and their biological activity against COX-1, COX-2, and 5-LO was investigated.

Phenanthrene derivatives from Cymbidium Great Flower Marie Laurencin and their biological activities.

A new phenanthrendione, ephemeranthoquinone B (1), two phenanthrenes, marylaurencinols A (2) and B (3), and a phenanthrene glucoside, marylaurencinoside A (4), were isolated from the roots of Cymbidium Great Flower Marie Laurencin, along with six known phenanthrenes, 5-10. The structures of these compounds were established by a combination of extensive NMR spectroscopy and/or X-ray crystallographic analysis and chemical degradation. The compounds were tested for antibacterial activities against Bacillus subtilis and Klebsiella pneumoniae and for cytotoxic activity against the human promyelocytic leukemia (HL-60) cell line.

Aromatic constituents of Cymbidium Great Flower Marie Laurencin and their antioxidative activity.

Two novel aromatic glucosides, named marylaurecinosides B (1) and C (2), were isolated from Cymbidium Great Flower Marie Laurencin, together with six known aromatic compounds (3-8). These structures were determined on the basis of NMR experiments as well as chemical evidence. All of the isolated compounds (1-8) were tested for antioxidative activity using a superoxide dismutase-like assay.

Ipomotaosides A-D, resin glycosides from the aerial parts of Ipomoea batatas and their inhibitory activity against COX-1 and COX-2.

Four new resin glycosides, namely, ipomotaosides A-D (1-4), were isolated from the dried aerial parts of Ipomoea batatas. The structures of 1-4 were elucidated by analysis of their spectroscopic data and by chemical derivatization and were tested for their anti-inflammatory activity against cyclooxygenase (COX)-1 and -2.

Aromatic compounds and their antioxidant activity of Acer saccharum.

A new lignan glycoside, 5-(3″,4″-dimethoxy-phenyl)-3-hydroxy-3-(4'-hydroxy-3'-methoxybenzyl)-4-hydroxymethyl-dihydrofuran-2-one 4'-O-α-L: -rhamnopyranoside (1), with seven known compounds, compound 2, koaburside, icariside E(4), cleomiscosin C, cleomiscosin D, scopoletin, and 5'-demethylaquillochin, were isolated from the EtOH extract of the wood of Acer saccharum (Aceraceae). Their structures were determined by 1D and 2D nuclear magnetic resonance (NMR) and mass spectroscopy analysis. All of the isolated compounds, 1-8, were tested for their antioxidant activity in superoxide dismutase (SOD)-like assay.

Novel phthalide compounds from Sparassis crispa (Hanabiratake), Hanabiratakelide A-C, exhibiting anti-cancer related activity.

Sparassis crispa (SC), known as Hanabiratake in Japanese, is an edible mushroom with various medicinal properties. We isolated 3 novel phthalides, designated hanabiratakelide A (1), B (2), and C (3), from the SC fruit body. In this investigation, 3 known phthalides (4-6), ubiquinone-9, and 2 known unsaturated fatty acids were also isolated.

Constituents of the lichen Peltigera dolichorrhiza.

A new aromatic derivative, 5-(3,4-dihydroxyphenyl)-3-methylcyclohex-2-enone (1), and three known compounds, peltigerine, solorinine, and phenyl butanoid, were isolated from the MeOH extract of the lichen Peltigera dolichorrhiza (Peltigeraceae). Their structures were determined by 1D and 2D nuclear magnetic resonance and mass spectroscopy analysis.

Russujaponols G-L, illudoid sesquiterpenes, and their neurite outgrowth promoting activity from the fruit body of Russula japonica.

Six new illudoid sesquiterpene, russujaponols G-L (1-6) were isolated from the fruit bodies of Russula japonica. Their structures were established primarily by 2D NMR experiments. Furthermore, russujaponols I-K showed neurite outgrowth promoting activity in the primary cultured rat cortical neurons.

Novel abietane diterpenoids and aromatic compounds from Cladonia rangiferina and their antimicrobial activity against antibiotics resistant bacteria.

From Cladonia rangiferina were isolated two novel abietane diterpenoids, hanagokenols A (1) and B (2). Also in this investigation, four known abitetane diterpenoids (3-6), four known labdane diterpenoids (7-10), one known isopimarane diterpenoid (11), and six known aromatic compounds were isolated. These structures were elucidated primarily through extensive NMR experiments.

Flavonoids from Acacia pennata and their cyclooxygenase (COX-1 and COX-2) inhibitory activities.

Two new flavonoids quercetin 4'-O-alpha-L-rhamnopyranosyl-3-O-beta-D-allopyranoside (1) and apigenin 6-C-[2''-O-(E)-feruloyl- beta-D-glucopyranosyl]-8-C-beta-glucopyranoside (2), along with the known isorhamnetin 3-O-alpha-L-rhamnopyranoside (3), kaempferol 3-O-alpha-L-rhamnopyranosyl-(1-->4)-beta-D-glucopyranoside (4), and isovitexin (5) were isolated from the leaves of Acacia pennata Willd. (Mimosaceae) and tested for their anti-inflammatory activity. Their structures were determined by 1D and 2D NMR and mass spectrometry.

Russujaponols A-F, illudoid sesquiterpenes from the fruiting body of Russula japonica.

Six new illudoid sesquiterpenes, russujaponols A-F (1-6), were isolated from the fruiting bodies of Russula japonica Hongo. Their structures were established primarily by 2D NMR experiments, and the structure of the main compound, russujaponol A (1), was confirmed by X-ray crystallographic analysis of its benzoate (1a). Russujaponol A (1) suppressed invasion of human fibrosarcoma (HT1080) cells into Matrigel in a concentration-dependent manner and caused 63% inhibition at 3.

Abietane diterpenoids from the barks of Cryptomeria japonica.

From the bark of Cryptomeria japonica were isolated sugikurojins I (1) and J (2), and an abietane derivative (3) was obtained for the first time as a natural product. These structures were elucidated primarily through extensive NMR experiments. Sugikurojin I (1) has a unique skeleton incorporating an abietane diterpene and a 1,10-secocadinane sesquiterpene.

Three abietane diterpenes and two diterpenes incorporated sesquiterpenes from the bark of Cryptomeria japonica.

Three new abietane diterpenes, sugikurojins D (1), E (2), and F (3), and two new abietanes which incorporate cadinane, sugikurojins G (4) and H (5) were isolated from the bark of Cryptomeria japonica. These structures were elucidated primarily by extensive NMR experiments. The structure of sugikurojin D (1) was deduced to be 6alpha-acetoxy-7beta,11-dihydroxy-12-methoxy-8,11,13-abietatriene.

Cytotoxic constituents of the fruit body of Daedalea dickisii.

Three new lanostane triterpenoids (1, 7, 8) and five new lanostane triterpene glucosides (2-6) have been isolated from the fruit bodies of Daedalea dickinsii. Their structures were established primarily by NMR experiments, and their biological activity against HL-60 and HCT-15 cell lines was investigated. Compounds 3-6 induced internucleosomal DNA fragmentation characteristic of apoptotic cell death in the HL-60 cell line.

Lanostane triterpenoids and triterpene glycosides from the fruit body of Fomitopsis pinicola and their inhibitory activity against COX-1 and COX-2.

Two new lanostane triterpenoids (1, 2) and 10 new lanostane triterpene glycosides (3-12) have been isolated from the fruit bodies of Fomitopsis pinicola. Their structures were established primarily by NMR experiments and chemical methods, and their biological activity against COX-1 and COX-2 was investigated.

Three novel crustulinol esters, saponaceols A-C, from Tricholoma saponaceum.

Three novel triterpene esters, saponaceols A (1), B (2), and C (3) were isolated from the fruiting body of the fungus Tricholoma saponaceum, and their structures were elucidated on the basis of extensive NMR experiments. Saponaceol A (1) exhibited moderate inhibitory activity against HL-60 cells.

Three new sesquiterpenes from the black heartwood of Cryptomeria japonica.

Three new sesquiterpenes, (4S)-2,6,10-bisaboratrien-4-ol-1-one (1), 1,8-epoxy-1(6),2,4,7,10-bisaborapenta-en-4-ol (2), and 1-methoxy-4-cadinene (3) have been isolated from the black heartwood of Cryptomeria japonica. Compounds 1 and 2 were designated sugikurojinols A and B, respectively, and the structures of compounds 1-3 were established by extensive NMR experiments. Compounds 1 and 2 were also examined for antibacterial activity against Staphylococcus aureus and Escherichia coli, and for termiticidal activity against Coptotermes formosanus SHIRAKI.

A new abietane and two dimeric abietane diterpenes from the black heartwood of Cryptomeria japonica.

Three new diterpenes, sugikurojins A-C (1-3) were isolated from the black heartwood of Cryptomeria japonica. The structure of sugikurojin A was deduced to be 19-hydroxy-6,7-dehydroferruginol on the basis of extensive NMR experiments. Sugikurojin B was a dimer of 6,7-dihydroxyferruginol and 6,7-dehydroferruginol with a 6-O-11' linkage.

New triterpenoids from Tricholoma saponaceum.

Six new triterpenes, saponaceolides E (1), F (2), and G (3), and saponaceoic acids I (4), II (5), and III (6) were isolated from the fruiting body of the fungus Tricholoma saponaceum, and their structures were elucidated on the base of extensive NMR experiments. Compounds 1 and 2 exhibited inhibitor activity against B16 and L929 cells.