Antiviral Activities of Hibiscus sabdariffa L. Tea Extract Against Human Influenza A Virus Rely Largely on Acidic pH but Partially on a Low-pH-Independent Mechanism.

Influenza A virus (IAV) infection is perennially one of the leading causes of death worldwide. Effective therapy and vaccination are needed to control viral expansion. However, current anti-IAV drugs risk inducing drug-resistant virus emergence.

Structure Revision of (22E)-24-Methylcholesta-8(14),22-diene- 3β,5α,6β,7α-tetraol from the Marine-Derived Fungus Penicillium sp.

Careful reexamination of the published ¹H- and ¹³C-NMR spectral data of (22E)-24-methylcholesta-8(14),22-diene-3β,5α,6β,7α-tetraol (1), isolated from the marine-derived fungus Penicillium sp., indicates that, in reality, the compound is 5α,6α-epoxy-(22E,24R)-24-methylcholesta-8(14),22-diene-3β,7α-diol (5).

Structure Revision of (22E)-Ergosta-7,22-diene-3β,5α,6β,9α,14α- pentol from the Spores of the Medicinal Mushroom Ganoderma lucidum.

Careful reexamination of the published ¹H and ¹³C NMR spectral data of (22E)-ergosta-7,22-diene-3β,5α,6β,9α,14α-pentol (1), isolated from the spores of the medicinal mushroom Ganoderma lucidum, indicates that, in reality, the compound is (22E)-ergosta-7,22-diene-3β,5α,6β,9α,14β-pentol (5).

Structure Revision of Two Polyoxygenated Sterols from the Marine Sponge Neofibularia nolitangere.

Careful reexamination of the published 1H- and 13C-NMR spectral data of (24S)-24-ethylcholest-8-ene-3β,5α,6β,7α-tetraol (1) and (24S)-24-ethylcholest-8(14)-ene-3β,5α,6β,7α-tetraol (2), isolated from the marine sponge Neofibularia nolitangere, indicates that, in reality, compounds 1 and 2 are (24S)-5α,6α- epoxy-24-ethylcholest-8-ene-3β,7α-diol (9) and (24S)-5α,6α-epoxy-24-ethylcholest-(14)-ene-3β,7α-dio (10), respectively.

Terpenoids and sterols from some Japanese mushrooms.

Over the past twenty years, our research group has been studying the chemical constituents of mushrooms. From nineteen species, namely, Amanita virgineoides Bas (Amanitaceae), Daedaleopsis tricolor (Bull.: Fr.

Three new lactarane sesquiterpenoids from the mushroom Russula sanguinea.

The family Russulaceae is one of the largest in the subdivision Basidiomycotina in Whittaker's Kingdom of Fungi [1] and comprises hundreds of species, worldwide distributed, belonging to the genera Lactarius and Russula. While secondary metabolites occurring in the fruiting bodies of Lactarius species have been well investigated [2], the Russula mushrooms have received less attention, notwithstanding the larger number of existing species [3]. In a previous paper, we reported the isolation and structural elucidation of sterols from the fruiting bodies of Russula sanguinea (Bull.

[New sesquiterpenoids from the rhizomes of Petasites japonicus MAXIM. and the roots of Ligularia dentata HARA].

Over the past twenty years, our research group has been involved in the phytochemical study of terpenoids from Compositae plants. From seven species, namely, Erigeron annuus (L.) PERS.

Terpenoids and related compounds from plants of the family Compositae (Asteraceae).

This review will summarize the authors' studies on the structures of terpenoids and related compounds from plants of the family Compositae (Asteraceae). Eighty three new compounds have been obtained and characterized from seven species of the plants, namely, Erigeron annuus (L.) Pers.

A new geranylated aromatic compound from the mushroom Hericium erinaceum.

A new geranylated aromatic compound, 5-[(2'E)-3',7'-dimethyl-2',6'-octadienyl]-4-hydroxy-6-methoxy-1-isoindolinone (1), was isolated from the fruiting bodies of the mushroom Hericium erinaceum (Bull.: Fr.) Pers.

Two new phenolic glycosides from Viburnum plicatum var. plicatum f. plicatum.

Two new glycosides, named dideoxyplicatumoside A (1) and erythro-syringylglycerol-beta-O-4'-(+)-isoeucommin A 4'''-O-beta-D-glucopyranoside (2), together with seven known compounds, were isolated from the leaves of Viburnum plicatum Thunb. ex Murray var. plicatum f.

Six new secoiridoids from the dried fruits of Ligustrum lucidum.

Six new secoiridoid constituents, named isoligustrosidic acid (1), 6'-O-trans-cinnamoyl 8-epikingisidic acid (2), 6'-O-cis-cinnamoyl 8-epikingisidic acid (3), oleopolynuzhenide A (4), nuzhenals A (5) and B (6) were isolated from the dried fruits of Ligustrum lucidum AIT. Their structures were established on the basis of spectral and chemical data.

Structure and cytotoxic activity of enzymatic hydrolysis products of secoiridoid glucosides, isoligustroside and isooleuropein.

Hydrolysis of isoligustroside (1) and isooleuropein (2), secoiridoid glucosides, in the presence of β-glucosidase provided 2-(4-hydroxyphenyl)methyl (2R,3S,4S)-3-formyl-3,4-dihydro-4-(2-methoxy-2-oxoethyl)-2-methyl-2H-pyran-5-carboxylate (3) and 2-(3,4-dihydroxyphenyl)methyl (2R,3S,4S)-3-formyl-3,4-dihydro-4-(2-methoxy-2-oxoethyl)-2-methyl-2H-pyran-5-carboxylate (4), respectively. The structures of 3 and 4 were elucidated on the basis of extensive spectral analyses, including 2D-NMR experiments. Compounds 3 and 4 were found to be new rearrangement products of the aglycones of 1 and 2.

Two new glycosides from Viburnum plicatum Thunb. ex Murray var. plicatum f. plicatum.

Two new glycosides, named plicatumoside A (1) and (+)-neomedioresinol 4,4'-di-O-β-D: -glucopyranoside (2), together with 13 known compounds, were isolated from the leaves of Viburnum plicatum Thunb. ex Murray var. plicatum f.

Glycosides from whole plants of Glechoma hederacea L.

From dried whole plants of Glechoma hederacea L. (Labiatae), seven known glycosides were isolated and identified: (6R,7E,9R)-megastigma-4,7-dien-3-one 9-O-beta-D-glucopyranoside (1), apigenin 7-O-neohesperidoside (2), chrysoeriol 7-O-neohesperidoside (3), (+)-pinoresinol 4,4'-bis-O-beta-D-glucopyranoside (4), (+)-syringaresinol 4,4'-bis-O-beta-D-glucopyranoside (5), (+)-lariciresinol 4,4'-bis-O-beta-D-glucopyranoside (6), and (7R,8R)-threo-7,9,9'-trihydroxy-3,3'-dimethoxy-8-O-4'-neolignan 4-O-beta-D-glucopyranoside (7).

Three new glycosides from the leaves of Hydrangea macrophylla subsp. serrata (THUNB.) MAKINO.

Three new glycosides, 7-deoxyloganic acid beta-D-glucopyranosyl ester (1), (3R)-hydrangenol 8,4'-di-O-beta-D-glucopyranoside (2), and (6R,7E,9R)-megastigma-4,7-dien-3-one 9,13-di-O-beta-D-glucopyranoside (3), have been isolated from the leaves of Hydrangea macrophylla subsp. serrata (THUNB.) MAKINO (Saxifragaceae).

Two new glycosides from the whole plants of Glechoma hederacea L.

Two new glycosides, 7S,7'S,8R,8'R-icariol A(2)-9-O-beta-D-glucopyranoside (1) and 4-allyl-2-hydroxyphenyl 1-O-beta-D-apiosyl-(1-->6)-beta-D-glucopyranoside (2), were isolated from the dried whole plants of Glechoma hederacea L. (Labiatae) together with four known compounds, cistanoside E (3), dihydrodehydrodiconiferyl alcohol 4-O-beta-D-glucopyranoside (4), apigenin 7-O-beta-D-glucuronopyranoside (5) and luteolin 7-O-beta-D-glucopyranoside (6). The structures of the new compounds were elucidated on the basis of chemical and spectral analysis.

Five new phenylethanoid glycosides from the whole plants of Lamium purpureum L.

Five new phenylethanoid glycosides, lamiusides A (1), B (2), C (3), D (4) and E (5), were isolated from the whole plants of Lamium purpureum L. (Labiatae) together with seven known compounds (6-12). On the basis of chemical and spectral analyses, the structures of the new compounds were elucidated to be 2-(3,4-dihydroxyphenyl)ethyl-O-beta-D-galactopyranosyl-(1-->2)-alpha-L-rhamnopyranosyl-(1-->3)-(4-O-trans-caffeoyl)-beta-D-glucopyranoside (1), 2-(3,4-dihydroxyphenyl)ethyl-O-beta-D-galactopyranosyl-(1-->2)-alpha-L-rhamnopyranosyl-(1-->3)-(4-O-trans-feruloyl)-beta-D-glucopyranoside (2), 2-(3,4-dihydroxyphenyl)ethyl-O-beta-D-galactopyranosyl-(1-->2)-alpha-L-rhamnopyranosyl-(1-->3)-(6-O-trans-caffeoyl)-beta-D-glucopyranoside (3), 2-(3,4-dihydroxyphenyl)-R,S-methoxy-ethyl-O-beta-D-galactopyranosyl-(1-->2)-alpha-L-rhamnopyranosyl-(1-->3)-(4-O-trans-caffeoyl)-beta-D-glucopyranoside (4) and 2-(3-hydroxy-4-methoxyphenyl)ethyl-O-alpha-L-rhamnopyranosyl-(1-->3)-beta-D-glucopyranosyl-(1-->6)-(4-O-cis-feruloyl)-beta-D-glucopyranoside (5).

Three new dimeric benzofuran derivatives from the roots of Ligularia stenocephala MATSUM. et KOIDZ.

Three new dimeric benzofuran derivatives, ligulacephalins A (1), B (2) and C (3), were isolated from the roots of Ligularia stenocephala MATSUM. ET KOIDZ. (Compositae) together with three known compounds, 5,6-dimethoxy-2-isopropenylbenzofuran (4), euparin (5) and (R)-(-)-hydroxytremetone (6).

Two new aromatic compounds from Hericium erinaceum (BULL.: FR.) PERS(1).

Two new aromatic compounds, erinacerins A (1) and B (2), were isolated from the fruiting bodies of Hericium erinaceum (BULL.: FR.) PERS.

Secoiridoid glycosides from Gentiana scabra.

Six new secoiridoid glycosides, gentiascabraside A (1), 6beta-hydroxyswertiajaposide A (2), 1-O-beta-d-glucopyranosyl-4-epiamplexine (3), and scabrans G3 (4), G4 (5), and G5 (6), have been isolated from the rhizomes and roots of Gentiana scabra together with a known compound, swertiajaposide A (7). The structures of the new compounds were determined by spectroscopic (NMR, MS) and chemical means.

A new norsesquiterpenoid from Russula delica Fr.

Russulanorol (1), a new norsesquiterpenoid with a novel carbon skeleton, was isolated from the fruiting bodies of Russula delica FR. (Russulaceae) together with three known sesquiterpenoids. The structure of 1 was elucidated on the basis of spectral data and chemical transformation.

Two new cyclopentenone derivatives and a new cyclooctadienone derivative from Erigeron annuus (L.) PERS., Erigeron philadelphicus L., and Erigeron sumatrensis RETZ.

Two new cyclopentenone derivatives, erigerenones A (1) and B (2), and a new cyclooctadienone derivative, erigerenone C (3), were isolated from the aerial parts of Erigeron philadelphicus L. Compound 2 was also isolated from the aerial parts of Erigeron annuus (L.) PERS.

Studies on the constituents of Gentiana species. II. A new triterpenoid, and (S)-(+)- and (R)-(-)-gentiolactones from Gentiana lutea.

A new triterpenoid, 12-ursene-3beta, 11alpha-diol 3-O-palmitate (1), has been isolated from the rhizomes and roots of Gentiana lutea, together with the artificial diene derivative, 9 (11), 12-ursadien-3beta-ol 3-O-palmitate (1a) and five known compounds (3-7). Their structures were established on the basis of spectral analysis. In addition, (+/-)-gentiolactone [(+/-)-2], isolated from this plant, was successfully separated into its enantiomers [(+)-2, (-)-2] for the first time, and the absolute configurations at C-9 of (+)-2, (-)-2 were assigned as S and R, respectively, from the optical rotations and the circular dichroism (CD) spectral data.

Five new sesquiterpenoids and a new diterpenoid from Erigeron annuus (L.) PERS., Erigeron philadelphicus L. and Erigeron sumatrensis RETZ.

The aerial parts of Erigeron annuus (L.) PERS., E.

New triterpenoids from Gentiana lutea.

Three new triterpenoids, 2,3-seco-3-oxours-12-en-2-oic acid, 2,3-seco-3-oxoolean-12-en-2-oic acid, and betulin 3-O-palmitate, have been isolated from the rhizomes and roots of Gentiana lutea, together with five known ones. The structures of the new compounds were determined by spectral and chemical methods.