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Arnequinol A (1), featuring an unprecedented 6/6/3 tricyclic carbon skeleton fused with a heptatomic oxo-bridge, together with arnequinone A (2) bearing a highly conjugated methyl-shifting benzogeijerene skeleton, were isolated from Arnebia euchroma. Their structures were elucidated by extensive spectroscopic methods and quantum chemical calculations of the 13C nuclear magnetic resonance (NMR) data and electronic circular dichroism (ECD) spectra. The plausible biosynthetic pathways for 1 and 2 were presented. In an in vitro test, compound 2 showed potent neuroprotective activity against serum-deprivation induced PC12 cell damage at a concentration of 10 μmol/L.

One pair of new amides enantiomers (1a and 1b) and two known amides were isolated from the rhizomes of Polygonum cuspidatum. Their structures were established using UV, IR, HRESIMS, and NMR data. Notably, compound 1 possesses unique C-C connection between feruloyltyramine and resveratrol. Their absolute configurations were determined by the ECD method. All compounds were evaluated for their α-glucosidase inhibitory activity and compounds 2 and 3 showed significant inhibitory activity with IC50 values of 2.82 and 13.06 μmol/L, respectively (positive control acarbose, IC50 385 μmol/L).

New phloroglucinol glycosides, aglycones, and oxidative dearomatized products of aglycones were discovered from Agrimonia pilosa, and the mechanism of the auto oxidative dearomatization was disclosed as a free radical chain reaction with 3O2.

Three new monocyclic monoterpenoid containing β-D-apiofuranosyl-(1→2)-O-β-D-glucopyranosyl moieties, together with three other known monocyclic monoterpenoid O-glycosides, were obtained from the roots of Glycyrrhiza uralensis for the first time. Their structures were determined by UV, IR, HRESIMS, and 1D and 2D NMR data.

One new tanshinone derivative, which possesses an unusual 6/6/5/6 fused-ring skeleton system (1), together with four new five-membered lactone benzohexa-membered ring compounds (2, 3, 4A and 4B), and three new carboxyl substituted 5,5-spiroketal compounds (5–7), were isolated from the dried rhizomes of Salvia miltiorrhiza. The structures of these compounds were determined by multiple spectral analyses (UV, IR, NMR, and HR-ESI-MS). In addition, the absolute configurations were established by X-ray diffraction experiments, calculated and experimental circular dichroism spectra. Evaluation of antitumor activity showed that 1 had strong cytotoxicity to tumor-repopulating cells (TRCs) with an IC50 value of 2.83 μM. In the evaluation of neuroprotective activity, 4A and 6 showed a strong improvement in the survival rates of SK-N-SH cell injury induced by oxygen glucose deprivation (OGD).

Eight new geranylquinol derivatives (1-8) were purified from the roots of Arnebia euchroma. Compounds 1-6 possess an unprecedented dearomatic benzocogeijerene skeleton with a rare trans-fused hydronaphthalene moiety. Their structures and absolute configurations were elucidated by HRESIMS, NMR, ECD, and X-ray diffraction. A convenient strategy for rapid determination of the relative configuration of H-1/H-7/Me-16 and the absolute configuration at C-1 for 1-6 was summarized. Compound 2 exhibited cytotoxicity against all the tested cell lines, namely PC9, BGC823, HCT116, HepG2, HeLa, and U87-MG, with IC50 values ranging from 13.7 to 29.3 μM.

Saffloneoside (1), a structurally unusual p-hydroxycinnamylcyclopentenone C-glucoside obtained from the florets of Carthamus tinctorius, was synthesized on a gram scale in seven steps. A stereospecific acyloin ring contraction controlled by the chirality of glucose moiety at the C5 position of highly substituted cyclohexadienones was discovered. The possible β-orientation hydrogen migration mechanism in the transformation of C5(sp2) into C5(sp3) was proposed.

Thirteen undescribed diterpenoid quinones were isolated from the dried roots of Salvia miltiorrhiza. Their structures were determined by extensive analysis, including NMR, HRESIMS, and IR. Their absolute configurations were determined by X-ray diffraction, calculated and experimental circular dichroism spectroscopy, and optical rotation. In the evaluation of bioactivities, salviadionether obviously inhibited the proliferation of HCT-116 cells. R-(+)-salmiltiorin E and R-(+)-grandifolia D both showed inhibitory activities on a variety of tumor cells. Salvianone ester A showed strong cytotoxicity to tumor-repopulating cells (TRCs) with an IC50 value of 2.19 μM.

Four new compounds including two new phenylpropanoid esters of sucrose, polygonusucroside A (1) and B (2); two new anthraquinones, 8-O-β- d -(6′-galloyl)-glucopyranoside (3) and polyanthraquinoside A (4), together with six known compounds were isolated from Polygonum cuspidatum. Their structures were established using UV, IR, HRESIMS, and NMR data. All compounds were evaluated for their α-glucosidase inhibitory activities and neuroprotective effects. Compounds 5, 7 and 9 showed significant α-glucosidase inhibitory activities with IC50 values of 27.30, 5.51, and 1.09 μmol/L, respectively (acarbose as positive control, IC50 = 6.17 μmol/L). In addition, the assessment of neuroprotective effect showed that compound 3 exhibited remarkable effect against PC12 cells injured by serum-deprivation and compounds 2, 7, and 9 exhibited moderate effects against PC12 cells injured by rotenone.

Three new thionic compounds, (S)-2-(2-carboxyl-2-hydroxyethylthio)-ferulic acid (1), (E)-2-methoxy-4-(3-(methylsulfonyl)prop-1-en-1-yl)phenol (2), and thiosenkyunolide C (3), together with two new aromatic glycosides (4 and 5) were isolated from the rhizome of Ligusticum chuanxiong Hort. Two known compounds (6 and 7) were also obtained. Their structures were elucidated based on extensive spectroscopic data (UV, IR, 1D and 2D NMR, and HR-ESI-MS). Furthermore the absolute configurations were established by comparison of their calculated and experimental circular dichroism spectra and by a dimolybdenum tetraacetate [Mo2(AcO)4]-induced circular dichroism procedure. All compounds were evaluated against lipopolysaccharide (LPS)-induced NO production in BV2 cells, and compounds 4 and 5 showed strong inhibitory activities with IC50 values of 2.03 and 3.09 µmol/L, respectively (positive control curcumin, IC50 = 6.17 µmol/L). In addition, compound 1 showed weak proteintyrosine phosphatase-1B (PTP1B) inhibitory activity. KEY WORDS: Ligusticum chuanxiong Hort., Thionic compounds, Aromatic glycosides, Anti-inflammatory, Natural products

In our ongoing investigation of the bioactive compounds from the extract of the roots of Sophora flavescens, two novel prenylated flavanones, named sophoflavanones A (1) and B (2), each with an unusual pyran ring were isolated. Their structures, as well as their absolute configurations, were elucidated based on spectroscopic data including a comparison of their experimental and calculated electronic circular dichroism (ECD) spectra. Additionally, compounds 1 and 2 showed moderate antioxidant activities against Fe2+/cysteine-induced toxicity at a concentration of 0.1 µM (inhibition values of 71.65% and 72.49%, respectively, using vitamin C as a positive control (87.83%)).

Four new sesquiterpene compounds, (5R,7R,10S)-3-O-β- d -glucopyranosylisopterocarpolone-11-O-β- d -apiofuranosyl-(1 → 6)-β- d -glucopyranoside (1), (5R,7R,10S)-14-carboxylisopterocarpolone-11-O-β- d -glucopyranoside (2), (1R,7R,10R)-1-hydroxylcarissone-11-O-β- d -glucopyranoside (3), and (1R,7R,10S)-10,11-dihydroxy-4-guaien-3-one 11-O-β- d - glucopyranoside (4), were isolated from the Atractylodes lancea by high-performance liquid chromatography. The compounds’ structures were elucidated through detailed spectroscopic methods.

Four new ferulic acid derivatives ligusticumacid A-C (1-3) and ligusticumaldehyde A (4), one new dimer ligusticumacid D (5), and two novel 8-8' lignans ligusticumacid E-F (6-7) were isolated from the rhizome of Ligusticum chuanxiong Hort. In particular, compounds 1-2, 5 were rarely phenylpropanoid phenolic acid dimers through different polymerization action in natural products. Their structures were established using UV, IR, HRESIMS, NMR data. The absolute configurations of 3 was determined by quantum ECD calculation and 4, 6-7 were determined by the ECD exciton chirality method. In addition, all compounds were evaluated for their neuroprotective effects on human neuroblastoma SH-SY5Y cell injury induced by H2O2. Compound 2 had a moderate neuroprotective activity and 7 had a weak neuroprotective activity on human neuroblastoma SH-SY5Y cell injury induced by H2O2 respectively.

Eight new amino acid derivatives (1–8) and two known compounds (9–10) were isolated from the rhizome of Ligusticum chuanxiong Hort. Their structures were established using UV, IR, HRESIMS, and NMR data. Notably, phenylpropanoid–amino acid adducts 1–6 are the first reported natural products, which possess a unique adduct structure. In addition, their analogues (1–5) were successfully synthesized by nucleophilic substitution and hydrolysis. The absolute configurations of 1–5 were determined by comparison of the specific rotations with those of their analogues and the natural amino acid methyl ester hydrochloride in acetic acid. In addition, these compounds were all evaluated for their neuroprotective effects, and compound 9 showed a moderate protective effect towards human neuroblastoma SH-SY5Y cell injury induced by H2O2.

Five new dimeric phloroglucinol derivatives, agrimones A − E (1–5), were isolated from the whole plant of Agrimonia pilosa. Their structures including absolute configurations were determined by a series of spectroscopic data (UV, IR, HR-ESI-MS, 1D and 2D NMR), complemented with the comparison of the experimental and calculated ECD spectra, and gauge-independent atomic orbital (GIAO) NMR calculations. Notably, compounds 1 and 2 represent a highly oxidized 6/6/6 tricyclic ring skeleton based on the cis-fused paraquinone and chroman. Compounds 1a, 4, and 5 exhibited moderate hepatoprotective activities against APAP-induced HepG2 cell injury at 10 μM.

Six new phenylethanoid glycosides possessing dioxane moieties, named forsyoxasides A−F ( 1–6 ), together with four known such compounds ( 7–10 ) were isolated from the fruits of Forsythia suspensa . These structures were illustrated by extensive NMR spectroscopic techniques and by comparing their NMR data with the related literatures. Notably, forsyoxaside A ( 1 ) is a novel dioxane phenylethanoid glycoside with an axial aromatic ring, which is rare in the natural sources. Compounds 1 , 4 , 7 and 8 showed remarkable bioactivities against rotenone induced PC12 cell damage. Furthermore, 1 and 7 displayed strong activities against serum deprivation induced damage on the same cells.

Five new heterocyclic compounds, 5-α-d-fructofuranosylmethyl-furfural (1), 5-β-d-fructofuranosylmethyl-furfural (2), 5-β-d-fructopyranosylmethyl-furfural (3), 4-(2-((2S-2,3-dihydroxypropoxy)methyl)-5-formyl-1H-pyrrol-1-yl)butanoic acid (4), and 3S,4S-4,5,8-trihydroxy-3-(prop-1-en-2-yl)isochroman-1-one (5), were obtained from the root of Ranunculus ternatus Thunb., which is a traditional Chinese anti-tuberculosis medicine. Their structures were elucidated by UV, IR, HRESIMS, NMR data, and the comparison of experimental and calculated electronic circular dichroism (ECD) spectra. Notably, compounds 1-3 are rarely occurring furfural fructosides in natural sources. These heterocyclic compounds could be further studied for the synthetic chemists and pharmacologists due to the source and structural properties.

Four new and rare iridoid glucosides, cornusfuroside A-D (1-4), containing the furan ring were identified from water extract of the fruit of Cornus officinalis. These new chemical structures were determined through extensive spectroscopic analysis, including 1D and 2D NMR, IR, HRESIMS, experimental and calculated electronic circular dichroism (ECD). Notably, this study is the first report on the isolation of four iridoid glucoside structures with acetal functions in the sugar moiety. The neuroprotective effects of these compounds were also evaluated in vitro.

Three new caffeoylquinic acid derivatives, chrysanthemorimic acids A-C (1-3), and 11 known compounds (4-14) were isolated and characterized from the flowers of Chrysanthemum morifolium. Their structures were confirmed by spectroscopic data as well as by comparison of the experimental and calculated electronic circular dichroism spectra. Chrysanthemorimic acids A-C possess a rare 8-oxa-bicyclo[3.2.1]oct-3-en-2-one ring that is formed through a [5+2] cycloaddition of caffeoylquinic acid with a d-glucose derivative. Compounds 1-3, 6-8, 12, and 13 displayed significant effects against hydrogen peroxide-induced neurotoxicity in SH-SY5Y cells at 10 μM.

Four new glycosides including a eudesmane-type sesquiterpenoid (1), a guaiane-type sesquiterpenoid (2), and two C14-polyacetylenes (3, 4) were isolated from the rhizomes of Atractylodes lancea. Their structures were elucidated by means of spectroscopic and spectrometric analyses (UV, IR, 1D and 2D NMR, and HR-ESIMS). The absolute configurations of their aglycones were established based on the experimental and calculated electronic circular dichroism (ECD), whereas those of monosaccharide moieties were determined by the GC method after chiral derivatization. Compound 4 showed weak anti-inflammatory effects on the LPS-induced NO production in microglia BV2 cells at a concentration of 10 μmol L−1.

An approach for discriminating the threo and erythro configurations of polyacetylene glycosides by 1H NMR spectroscopy was developed. Using acetic acid-d4/D2O as the solvent, a relatively larger 3JHH value (7.0 Hz) for the acyclic vicinal diol group was unambiguously assigned to the threo configuration, whereas the smaller value (3.5 Hz) was assigned to the erythro configuration. This convenient method requires no hydrolysis or derivatization and is suitable for micromolar concentrations of polyacetylene glycosides. The underlying mechanism is discussed via visualized conformations.

Lycium chinense Mill. is a deciduous shrub in the Solanaceae family that is known for its fruits (Lycii fructus) and root bark (Lycii cortex). In our ongoing search for α-glucosidase inhibitors from the root bark of L. chinense, lyciumflavane A, one new flavane with an unusual benzofuran unit, one new amide possessing a naphthalene skeleton, one new sesquiterpene, three new lignan glucosides, and three new phenolic glucosides were isolated along with eight known compounds. Their structures were elucidated using NMR, HRESIMS, UV, ECD, and IR spectroscopic data. Their α-glucosidase inhibitory activity was screened using acarbose as a positive control (IC50 = 385 μM). Compound 1 showed strong inhibitory activity against α-glucosidase (IC50 = 20.89 μM).

Eleven new phthalide derivatives (1–11) have been isolated from the rhizome of Ligusticum chuanxiong. In particular, 1 and 2 contain a mercaptopropionic acid moiety in the phthalide derivatives. All the structures, including their absolute configurations, were determined by UV, IR, HRESIMS, 1D and 2D NMR spectroscopic measurements, and by a comparison of the experimental and calculated electronic circular dichroism (ECD) spectra. Results of a bioassay showed that compound 4 has a moderate neuroprotective activity on human neuroblastoma SH-SY5Y cell injury induced by H2O2 and oxygen glucose deprivation (OGD).

Forsythenethosides A (1) and B (2), two new phenylethanoid glycosides with an unprecedented 15-membered carbon scaffold ring, were isolated from the fruits of Forsythia suspensa. Their structures, including their geometric configurations, were determined via extensive NMR spectroscopy techniques, especially using 2D NMR data combined with systematic conformational analysis. Forsythenethosides A and B showed strong neuroprotective activities against serum-deprivation-induced PC12 cell damage. Furthermore, they were active on rotenone-induced PC12 cell damage.

During our continuing study on the fruits of Forsythia suspensa, one new heterodimer (forsythoneoside E) containing a flavonoid and a phenethanoid glycoside formed through a pyran ring, one new phenylethanoid glycoside dimer (forsythoneoside F) with a C–O bond, along with a pair of flavonoid glycoside dimers (forsythobiflavone A and B) possessing different axial chirality, were obtained. Their chemical structures, including absolute configurations, were established by NMR, HRESIMS, UV, IR, and ECD spectroscopic data and comparison of experimental and calculated electronic circular dichroism (ECD) spectra. All of the compounds were evaluated for their neuroprotective effects against rotenone-induced neurotoxicity in PC12 cells at 1 μM.

One new epoxydon ester (1) and a new benzolactone derivative (2), along with four known compounds (3−6), were isolated from the insect-associated fungus Phoma sp. Their structures were confirmed by extensive MS and NMR spectroscopic analysis and their absolute configurations were determined by a combination of modified Mosher method and Mo2(OCOCH3)4-induced electronic circular dichroism (ECD) experiments. Compounds 1 and 5 were revealed to have potent antioxidant activities, which were approximate to the potency of the positive control trolox. In addition, 1 also exhibited moderate cytotoxic effect against human MGC-803 tumor cell line.

Two new isobenzofuranone derivatives, polyphthaliside A (1) and polyphthaliside B (2), and a new isocoumarin derivative, polyisocoumarin (3), were isolated from Polygonum cuspidatum. Their structures were elucidated by detailed spectroscopic analysis and chemical methods. The cytotoxicity activity and PTP1B inhibitory activity of compounds 1–3 were estimated and none of them exhibited activities at a concentration of 10 μM.

In the course of studying the components from the roots of Sophora flavescens, eight new unusual biflavonoids consisting of a flavanone fused with a dihydrochalcone skeleton were isolated. These new chemical structures were elucidated by means of UV, IR, HRESIMS, NMR and ECD spectroscopic data and a comparison of experimental ECD spectra with calculated ECD spectra. Some compounds were subjected to an antidiabetic bioassay on human recombinant PTP1B inhibition, and showed strong inhibitory activity.

An ongoing phytochemical investigation of the rhizomes of Atractylodes lancea resulted in the isolation of four new C10-type polyacetylene glycosides (1-4). Their structures were elucidated on the basis of extensive spectroscopic data (UV, IR, 1D and 2D NMR, and HRESIMS). The absolute configurations of compounds 2-4 were determined by comparing the specific rotations of their aglycones. Notably, compounds 2 and 3 exhibited significant hepatoprotective activities against APAP-induced HepG2 cell injury at a concentration of 10 μM. Compounds 2 and 3 showed weak anti-inflammatory effects on LPS-induced NO production in microglia BV2 cells at a concentration of 10 μM.

Three new compounds, 4-{erythro-2-[3-(4-hydroxyl-3-methoxyphenyl)-3-O-β- d -glucopyranosyl-propan-1-ol]}-O-medioresinol (1), (7⿳E,9⿳E,1⿳R*,3⿳S*,5⿳R*,6⿳S*)-5-O-caffeoyl-3-O-dihydrophaseicoylquinic acid (2), and (7⿳E,9⿳E,1⿳R*,3⿳S*,5⿳R*,6⿳S*)-5-O-caffeoyl-4-O-dihydrophaseicoylquinic acid (3), were isolated from Chinese folk herb Erycibe obtusifolia together with six known compounds (4⿿9). Their structures were elucidated on the basis of comparisons of literatures and extensive spectroscopic analysis, including UV, IR, HRMS, and 1D and 2D NMR techniques. Further, the cytotoxicities of these compounds were evaluated against five cell lines (HCT-8, Bel-7402, BGC-823, A549, and A2780), but they were inactive against these tumor cell lines (IC50 > 10 μmol/L).

Lyciumsterols A-K (1-11), 11 new octahydroxylated C21 steroids, were isolated from the root bark of Lycium chinense, along with 15 known compounds. Characterization of these C21 steroids showed the presence of eight hydroxy groups on the C21 steroid skeleton with a (2E,4E)-5-phenyl-2,4-pentadienoate group at C-12 or C-20 and various 2,6-deoxy sugar residues at C-3. The structures of these compounds were elucidated using spectroscopic data interpretation. Compounds 2, 3, and 7 exhibited dose-dependent protective effects on pancreatic islet cells and may help to improve cell viability. In addition, it was found that compounds 7, 8, 9, and 11 exhibited autophagy activation.

Polyflavanostilbene B (1), an unusual adduct of epicatechin-3-O-gallate fused to piceid through a carbon–carbon bond, four new dimeric stilbene glycosides (2–5), three new stilbene glucosides (6–8), one new flavan glucoside (9), and six known compounds were isolated from the rhizome of Polygonum cuspidatum. The structures of these compounds were elucidated using spectroscopic data, including electronic circular dichroism (ECD) and Rh2(OCOCF3)4-induced CD spectra. All of the compounds were screened for their inhibitory activity against α-glucosidase using acarbose as a positive control (IC50 = 385 μM), and strong inhibitory activity against α-glucosidase was observed for compound 8 (IC50 = 3.04 μM).

Three new triacetic acid lactone (TAL) glycosides, forsyphensides A-C (1-3) were isolated from the fruits of Forsythia suspensa. Their structures were elucidated by comprehensive spectroscopic techniques. The absolute configurations of their monosaccharides were determined by GC analysis. Notably, forsyphensides A-C were relatively rare TAL glycosides identified from plants. Compound 1 exhibited inhibitory activity against the lipopolysaccharide (LPS)-induced nitric oxide (NO) production in microglia BV2 cells with the inhibition rate of 69.40%.

Seven new butylphthalide derivatives, ligusticumolide A-G (1–7), together with two known butylphthalide derivatives (8–9) were isolated from an ethanol extract of Ligusticum chuanxiong Hort. The structures of these derivatives were elucidated from analysis of 1D/2D NMR, UV, IR and HRESIMS data. The absolute configurations of these derivatives were determined by electronic circular dichroism (ECD) calculations and Mosher′s method. Ligusticumolide A (1) and ligusticumolide B (2) are enantiomers that were obtained by chiral separation. Ligusticumolide C (3) and ligusticumolide D (4) are diastereomers. All of the compounds were evaluated for their hepatoprotective activity against N-acetyl-p-aminophenol-induced HepG2 cell injury. Compounds 4, 5, and 7–9 showed more significant hepatoprotective activity than that of the positive control drug (bicyclol) at a concentration of 10 μM (p

The first synthesis of polyflavanostilbene B (1), which has seven contiguous stereocenters including two quaternary carbon centers, from abundant polymeric (-)-epicatechin gallate on a gram scale in three steps without the use of protecting groups is reported. The key transformations of this strategy include a regioselective and stereoselective substitution of resveratrol to give the 4-derivative of (-)-epicatechin 3-gallate and an iron-catalyzed cyclization reaction. The possible radical cyclization mechanism in the formation of the hexahydrocyclopenta[c]furan core is also discussed.

Forsythoneosides A-D (1-4), four unusual adducts of a flavonoid unit fused to a phenylethanoid glycoside through a pyran ring or carbon-carbon bond, and four new phenylethanoid glycosides (5-8) were isolated from the fruits of Forsythia suspensa, together with nine known compounds. The structures of 1-8, including their absolute configurations, were elucidated by spectroscopic data as well as experimental and calculated electronic circular dichroism analysis. Compounds 2 and 4 inhibited PC12 cell damage induced by rotenone, and increased cell viability from 53.9 ± 7.1% to 70.1 ± 4.0% and 67.9 ± 5.2% at 0.1 μM, respectively.

Arctiidilactone (1), a novel rare butyrolactone lignan with a 6-carboxyl-2-pyrone moiety, and 11 new butyrolactone lignans (2-12) were isolated from the fruits of Arctium lappa L., together with 5 known compounds (13-17). Their structures were elucidated by interpretation of their spectroscopic data (1D and 2D NMR, UV, IR, ORD, and HRESIMS) and comparison to literature data. The absolute configurations of compounds 1-12 were determined by a combination of rotating-frame nuclear Overhauser effect spectroscopy (ROESY), circular dichroism (CD) spectroscopy, and Rh2(OCOCF3)4-induced CD spectroscopy. All of the compounds were tested for their anti-inflammatory properties in terms of suppressing the production of NO in lipopolysaccharide-induced BV2 cells. Compounds 1, 6, 8, and 10 exhibited stronger anti-inflammatory effects than the positive control curcumin, particularly 1, which exhibited 75.51, 70.72, and 61.17% inhibition at 10, 1, and 0.1 μM, respectively.

In recent years, certain "new" naturally occurring compounds (1-28) with 3,5-dioxygenated aromatic rings have been reported. A comparison of the NMR data of these compounds with the data of four model compounds (A-D) indicated that the structures of these "new" compounds were erroneous. The reason for the incorrect elucidation of the structures of 1-28 was attributed to "deceptively simple" (1)H NMR spectra, which displayed two broad singlets with integrations of 1:2 for H-2 and H-5, H-6, respectively. To expose the misleading results from the spectra, serial (1)H NMR experiments on compounds A-D were performed using various deuterated solvents and temperatures. The results revealed separated proton signals for the ABX system in certain deuterated solvents. Additionally, the characteristic differences between 3,4- and 3,5-dioxygenated aromatic rings in their (13)C NMR spectra are summarized based on our experiment and data reported. This approach is useful for analyzing the patterns of dioxygenated aromatic rings in natural products, especially when "deceptively simple" (1)H NMR spectra are displayed.

Ten naphthalene derivatives including two unusual glycosides possessing a naphthalene-fused piceid via a [C8'-O-C6-C5-C7']-trans-dihydrofuran ring, two flavan derivatives, as well as sixteen known phenolic compounds, were isolated from Polygonum cuspidatum. The structures were determined by extensive NMR, MS, CD data, and chemical evidence. In the in vitro neuroprotective assays, at the concentration of 10 μM, five of these compounds exhibited significant effects against PC12 cells injured by rotenone.

In our study to investigate components with hepatoprotective activities, eight new phenylethanoid glycoside derivatives (1-8) were isolated from the 75% EtOH-H2O extract of the fruits of Forsythia suspensa along with six known compounds (9-14). These new structures were elucidated through HRESIMS and extensive NMR spectroscopic techniques. The absolute configurations of their sugars were determined by GC analysis. The pharmacological assay showed that compounds 2, 3, and 9-11 displayed remarkable hepatoprotective activities against N-acetyl-p-aminophenol (APAP)-induced HepG2 cell damage at the concentration of 10μM (Bicyclol as positive contrast).

Sophopterocarpan A (1), with a novel benzotetrahydrofuran-fused bicyclo [3.3.1] nonane ring, was isolated from the roots of Sophora flavescens Ait. Its unusual structure, including its stereochemistry, was determined on the basis of a comprehensive spectroscopic data analysis. A plausible biogenetic pathway for 1 is presented. Sophopterocarpan A was identified as a potential autophagy activator. Additionally, it was found that 1 exhibited cytotoxic activity in MCF-7 cells with an IC50 of 29.36 μM.

Twelve new dibenzoyl derivatives sophodibenzoside A-L (1-12) and five new isoflavone glycosides (13-17) have been isolated from the roots of Sophora flavescens together with eight known compounds (18-25). Notably, the use of acetic acid-d4 was required to enable identification of the dibenzoyl glycoside structures. Compounds 1, 2, 13, 14, and 19 exhibited weak inhibition of the cytotoxic effect of d-galactosamine on the human hepatic cell line HL-7702.

Ternatusine A (1), a novel alkaloid with an unprecedented epoxyoxepino[4,5-c] pyrrole ring, was isolated from the roots of Ranunculus ternatus Thunb. Its unusual structure, including its absolute stereochemistry, was determined using UV, IR, HRESIMS, and 1D and 2D NMR data and through comparison of the experimental and calculated electronic circular dichroism (ECD) spectra. A possible biosynthetic pathway for ternatusine A was postulated.

Hydroxysafflor yellow A (HSYA), a representative component of Carthamus tinctorius, has attracted much attention because of its remarkable cardiovascular activities. Its structure was originally reported in 1993 and has been widely cited to date. In our experiments, its solution structure was studied using NMR techniques in different solvents, including DMSO-d(6), pyridine-d(5), and CD(3)OH. The results indicate that the structure of HSYA is different than the previously described 1b, with 3-enol-1,7-diketo form. The structure has two keto-enol tautomers (2a and 2b), and 2a, with the 1-enol-3,7-diketo form, is the preferred tautomer. On the basis of this finding, other published quinochalcone C-glycoside structures were revised. Furthermore, a trend in the (13)C NMR data of the (E)-olefinic carbons of quinochalcone C-glycosides is summarized, and a hypothesis is proposed for the relationship between the features of the molecular structure and the preferred keto-enol tautomer.

Polyflavanostilbene A, a new flavanol-fused stilbene glycoside, was isolated from the rhizome of Polygonum cuspidatum. Its unusual structure, including its absolute stereochemistry, was determined by UV, IR, HRESIMS, and 1D and 2D NMR data and by the comparison of experimental and calculated electronic circular dichroism (ECD) spectra. Polyflavanostilbene A has an unprecedented rearranged flavanol skeleton fused to stilbene via a hexahydrocyclopenta[c]furan moiety. Polyflavanostilbene A showed strong inhibitory activity against α-glucosidase with an IC(50) value of 17.7 μM.

Two new phenolic glycosides with a rare β- d -glucopyranosyl-(1 → 3)-α- l -rhamnopyranosyl moiety ( 1 , 2 ), one new dihydrobenzofuran derivative ( 3 ), one new pyrazine derivative ( 4 ), two new furofuran lignan glycosides ( 5 , 6 ), and six known compounds ( 7 – 12 ) were isolated from the rhizomes of Atractylodes lancea . The structures of these compounds were elucidated by extensive spectroscopic analyses combined with the experimental and calculated electronic circular dichroism and the Rh 2 (OCOCF 3 ) 4 -induced circular dichroism for configurational assignments. Notably, compounds 1 – 3 showed significant hepatoprotective activities against N -acetyl- p -aminophenol-induced HepG2 cell injury. This study is also the first Letter on the isolation of furofuran lignans and pyrazine derivatives ( 4 – 7 ) from the genus Atractylodes .

Ligubenzocycloheptanone A (1), a novel tricyclic butenolide with a 6/7/5-membered ring skeleton, was isolated from the rhizome of Ligusticum chuanxiong. Its unusual structure was determined using UV, IR, HRESIMS, 1D and 2D NMR data, X-ray diffraction crystallography and by the comparison of experimental and calculated electronic circular dichroism (ECD) spectra. 1 possessed a benzocycloheptanone core featuring butyrolactone, which is rarely observed in nature. A possible biosynthetic pathway was proposed. Ligubenzocycloheptanone A showed strong radical scavenging activity with an IC50 value of 2.3 μM.

Phytochemical and pharmacological study on the rhizomes of Atractylodes lancea led to the identification of twenty-one compounds: six new eudesmane-type sesquiterpenoids ( 1 – 6 ), two new eremophilane-type sesquiterpenoids ( 7 , 8 ), and thirteen known compounds ( 9 – 21 ). These new compounds were elucidated using extensive spectroscopic analyses with experimental and calculated electronic circular dichroism (ECD) for the configurational assignments. Notably, this study was the first report on the isolation of two eremophilane-type sesquiterpenoids ( 7 , 8 ) from the genus Atractylodes . Compounds 5 , 7 , and 16 showed potent hepatoprotective activities against N -acetyl- p -aminophenol (APAP)-induced HepG2 cell injury at a concentration of 10 μM (bicyclol as the positive drug).

Nine new sesquiterpenoids (1–9), five new polyacetylenes (10–14), and six known compounds were isolated from the rhizomes of Atractylodes lancea. These new chemical structures were established using NMR, MS, and ECD data. Notably, compounds 3–5, the aglycone of which possesses two stereogenic centers (C-5 and C-7), exhibited similar ECD spectra to compounds 1 and 2, the aglycone of which possesses one stereogenic center (C-7). Such a difference was supported by the experimental and calculated ECD data and single-crystallographic analyses of 3a. In addition, compound 3 inhibited lipopolysaccharide-induced NO production in BV2 cells with an IC50 value of 11.39 μM (positive control curcumin, IC50 = 4.77 μM); compound 4 showed better hepatoprotective activity against N-acetyl-p-aminophenol-induced HepG2 cell injury than the positive drug (bicyclol) at a concentration of 10 μM (p < 0.001).

The basic substances of life include various amino acids and sugars. To search such molecules is the precondition to understand the essential nature. Here we reported four unprecedented hybrids of γ-amino acids and sugars from the roots of Ranunculus ternatus, which possess potential tail to tail ether-connected (6,6-ether-connected) modes in the sugar moiety. The structures of these hybrids were elucidated by extensive analyses of spectra and calculated electronic circular dichroism (ECD) method.