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Three new iridoids, valeriandoids A-C (1-3), together with three known analogues (4-6), were isolated from the roots of Valeriana jatamansi. Their structures and relative configurations were elucidated by spectroscopic methods (IR, ESIMS, HRESIMS, 1D and 2D NMR) and by comparison of their NMR data with those of related compounds. All the isolated compounds were evaluated for their neuroprotective effects and compounds 1, 3, 4 and 6 showed moderate neuroprotective effects.

A novel amino-oligosaccharide, named SF638-1, was isolated from the culture filtrate of the Streptomyces strain PW638. Its chemical structure was determined by electrospray ionization tandem mass spectrometry (ESI-MS/MS) and two-dimensional nuclear magnetic resonance spectroscopy. The novel compound was a mixed inhibitor of human pancreatic α-amylase, with a Ki value in the same order of magnitude as that of the α-amylase inhibitor, acarbose. SF638-1 inhibited starch hydrolysis and glucose transfer in vitro, and suppressed postprandial blood glucose elevation in vivo. These results suggest that SF638-1 may be a potent antidiabetic agent.

Three new (1-3) and three known (4-6) neo-clerodane diterpenes have been isolated from the whole plants of Ajuga ciliata Bunge. The structures of the new compounds were elucidated as (12S)-1β,6α,19-triacetoxy-18-chloro-4α,12-dihydroxy-neo-clerod-13-en-15,16-olide (1), (12S,2'S)-12,19-diacetoxy-18-chloro-4α,6α-dihydroxy-1β-(2-methylbutanoyloxy)-neo-clerod-13-en-15,16-olide (2), and (12S)-6α,18,19-triacetoxy-4α,12-dihydroxy-1β-tigloyloxy-neo-clerod-13-en-15,16-olide (3), on the basis of spectroscopic data analysis. All the diterpenes were evaluated for the neuroprotective effects against MPP(+)-induced neuronal cell death in dopaminergic neuroblastoma SH-SY5Y cells and compounds 2-5 exhibited moderate neuroprotective effects.

Two new bakkenolides, valerilactones A (1), and B (2), and two known analogues, bakkenolide-H (3) and bakkenolide-B (4), were isolated from the roots of Valeriana jatamansi. Their structures and relative configurations were elucidated by spectroscopic methods (IR, ESIMS, HRESIMS, 1D and 2D NMR) and by comparison of their NMR data with those of related compounds. Compounds 1, 2, and 3 exhibited potent neuroprotective effects against MPP(+)-induced neuronal cell death in human dopaminergic neuroblastoma SH-SY5Y cells.

By bioactivity-guided isolation, two labdane diterpenes (1 and 2) have been isolated from the bulbs of Fritillaria ebeiensis. Their structures were elucidated as 6α,7β-dihydroxy-labda-8(17),12(E),14-triene (1) and 6-oxo-2α-hydroxy-labda-7,12(E), 14-triene (2), on the basis of spectroscopic data analysis (IR, ESI-MS, HR-ESI-MS, 1D and 2D NMR). Both of the isolates showed neuroprotective effects against MPP(+)-induced neuronal cell death in human dopaminergic neuroblastoma SH-SY5Y cells.

As a part of our ongoing search for plant-derived compounds that inhibit nitric oxide production, the methanol extract of the roots of Vladimiria souliei was found to show significant inhibitory effects on INF-γ-induced nitric oxide production in murine macrophage RAW264.7 cells. Bioactivity-guided isolation of the extract yielded two most active sesquiterpenes, including a new compound, named souliene A (1) and alismol (2). Their structures were elucidated by spectroscopic methods (IR, ESIMS, HRESIMS, 1D and 2D NMR). Two isolates showed promising inhibitory effects on INF-γ-induced nitric oxide production in murine macrophage RAW264.7 cells.

To study the chemical constituents from Centipeda minima.The constituents were isolated by column chromatography on silica gel, Sephadex LH-20 and HPLC-ODS, and identified by spectroscopic methods.Ten compounds, (-)-cis-chrysanthenol-O-beta-D-glucopyranoside (1), methy 3,5-dicaffeoylquinate (2), 3,5-di-O-caffeoyl quinicacid (3), tricin (4), 2-amino-4-methyl-pentanoicacid (5), 2-amino-3-phenyl-propionic acid (6), 4-amino-4-carboxychroman-2-one (7), brevilin-A (8), arnicolide C (9), arnicolide D (10) were isolated and identified.Compounds 1-7 were isolated from the plant for the first time.

A new clerodane diterpene, 15-hydroxy-16-acetoxy-ent-clerod-3-en-18-oic acid (1), together with three known clerodane diterpenes (2-4) and three known flavones (5-7), were isolated from the aerial parts of Baccharis gaudichaudiana. Their structures were elucidated on the basis of spectroscopic analysis. Compounds 2, 3, and 5 showed enhancing activity of nerve growth factor (NGF)-induced neurite outgrowth in PC 12D cells.

A new iridoid glycoside, 10-isovaleryl kanokoside C (1), and a new sesquiterpene (2) together with two known compounds (3, 4) were isolated from the rhizomes and roots of Valeriana fauriei. Their structures were elucidated on the basis of spectroscopic analysis. Compounds 2 and 4 showed enhancing activity of nerve growth factor (NGF)-induced neurite outgrowth in PC 12D cells.

Two new β-dihydroagarofuran sesquiterpene esters, 1β,2β,6α-triacetoxy-9α-cinnamoyloxy-β-dihydroagarofuran (1) and 1β,8β-diacetoxy-9β-cinnamoyloxy-2β-hexanoyloxy-β-dihydroagarofuran (2), and four kn...

Three novel three-membered ring sesquiterpenoids, named kissoone A (1), kissoone B (2), and its acetylated product, kissoone C (3), were isolated from the roots of Valeriana fauriei. Their structures were elucidated on the basis of spectroscopic analysis. Compounds 2 and 3 showed enhancing activity on nerve growth factor (NGF)-mediated neurite outgrowth in PC 12D cells.