Ten cyclopentanoid monoterpenes from the whole plant of Rehmannia piasezkii maxim.

Ten new cyclopentanoid monoterpenes (1-10) were isolated from the whole plant of Rehmannia piasezkii. The structures of these compounds were elucidated based on spectroscopic data analysis. In in-vitro assays, compounds 3, 7, and 9 exhibited weak hepatoprotective activities against APAP-induced HepG2 cell damage. Compound 9 exhibited protective effect on hapassocin carbon tetrachloride model.

New iridal-type triterpenoid analogues with 6/5/6-fused carbon skeleton from the rhizomes of Belamcanda chinensis.

Five new iridal-type triterpenoid derivatives with 6/5/6 tricyclic ring skeleton (1-5) were obtained from the rhizomes of Belamcanda chinensis. Their structures were determined on the basis of detailed spectroscopic data and ECD calculation. Compounds 1-5 possessed the same 6/5/6-fused carbon skeleton as Belamchinenin A, which further enriched this kind of iridals. In vitro bioassay, compounds 2 and 3 exhibited 51.95 and 54.52% inhibitory activities, respectively, against Fe2+/cysteine-induced liver microsomal lipid peroxidation at a concentration of 10 µM. A putative biogenetic pathway for compounds 1-5 was proposed.

Aporphine and phenanthrene alkaloids with antioxidant activity from the roots of Stephania tetrandra.

Five new alkaloids (1-5), including three new aporphine alkaloids and two new phenanthrene alkaloids, together with 10 known compounds (6-15) were obtained from the roots of Stephania tetrandra. Their structures were elucidated by spectroscopic methods, single-crystal X-ray diffraction, and electronic circular dichroism analyses. Compounds 7-10, and 13 showed antioxidant activities with malondialdehyde (MDA) inhibitory rates of 62.50 ± 1.91 to 98.44 ± 0.34% at the concentration of 10 µM.

Rearranged iridal-type triterpenoids from Iris tectorum.

Three new iridal-type triterpenoids (1-3) featuring a rearranged homofarnesylside chain were isolated from the rhizomes of Iris tectorum. Compounds 2 and 3 were found to be a pair of epimers. Their structures were elucidated on the basis of comprehensive spectroscopic analysis. A possible biosynthetic pathway for them was postulated. Moreover, the mixture of compounds 2 and 3 exhibited moderate neuroprotective activity against serum deprivation-induced PC12 cell death.

Schekwanglupaside C, a new lupane saponin from Schefflera kwangsiensis, is a potent activator of sarcoplasmic reticulum Ca2+-ATPase.

Schefflera kwangsiensis Merr. ex H.L. Li (Araliaceae) is a widely used traditional Chinese medicine for pain management in the clinic. In the present study, we isolated a previously undescribed lupane saponin, designated as schekwanglupaside C (Sch C) from the ethanolic extract of S. kwangsiensis. The structure of Sch C was determined by comprehensive spectroscopic and spectrometric analyses and chemical degradation. In primary cultured cortical neurons, Sch C altered the pattern of spontaneous Ca2+ oscillation (SCO) with a slight increase in the frequency of SCO right after addition and a gradual decrease in the frequency and amplitude of SCO, that dynamic change mimicked by an activator of sarcoplasmic reticulum Ca2+-ATPase (SERCA). The IC50 values for Sch C suppression of the frequency and amplitude of SCO were 1.75 and 2.51 µM, respectively. Furthermore, we demonstrated that Sch C is a potent SERCA activator (EC50 = 1.20 µM). Given the pivotal role of SERCA in the progression of neuropathic pain and neurodegenerative diseases, Sch C represents a new drug lead compound to develop the treatment of neuropathic pain and Alzheimer's disease.

A Chemical Investigation of the Leaves of Morus alba L.

The leaves of Morus alba L. are an important herbal medicine in Asia. The systematic isolation of the metabolites of the leaves of Morus alba L. was achieved using a combination of liquid chromatography techniques. The structures were elucidated by spectroscopic data analysis and the absolute configuration was determined based on electronic circular dichroism (ECD) spectroscopic data and hydrolysis experiments. Their biological activity was evaluated using different biological assays, such as the assessment of their capacity to inhibit the aldose reductase enzyme; the determination of their cytotoxic activity and the evaluation of their neuroprotective effects against the deprivation of serum or against the presence of nicouline. Chemical investigation of the leaves of Morus alba L. resulted in four new structures 1⁻4 and a known molecule 5. Compounds 2 and 5 inhibited aldose reductase with IC50 values of 4.33 µM and 6.0 µM compared with the potent AR inhibitor epalrestat (IC50 1.88 × 10−3 µM). Pretreatment with compound 3 decreased PC12 cell apoptosis subsequent serum deprivation condition and pretreatment with compound 5 decreased nicouline-induced PC12 cell apoptosis as compared with control cells (p < 0.001).

Iritectol G, a novel iridal-type triterpenoid from Iris tectorum displays anti-epileptic activity in vitro through inhibition of sodium channels.

Iritectol G, a novel iridal-type triterpenoid containing an uncommon tetrahydrofuran moiety, was isolated from the rhizomes of Iris tectorum. The structure was elucidated by comprehensive spectroscopic analysis. Iritectol G inhibited spontaneous and 4-aminopyridine-evoked calcium oscillations in primary cultured neocortical neurons with IC50 values of 8.2µM and 12.5µM, respectively. Further electrophysiological study demonstrated that iritectol G preferred to interact with inactivated state of voltage-gated sodium channel with an IC50 value of 7.0µM. These data demonstrated that iritectol G was a novel sodium channel inhibitor.

Heliosterpenoids A and B, two Novel Jatrophane-Derived Diterpenoids with a 5/6/4/6 Ring System from Euphorbia helioscopia.

Heliosterpenoids A and B (1 and 2), two unprecedented jatrophane-derived diterpenoid esters with a novel 5/6/4/6-fused tetracyclic ring skeleton, were isolated from the whole plants of Euphorbia helioscopia. The structures of 1 and 2 were elucidated by extensive spectroscopic methods and electronic circular dichroism (ECD) analyses. The plausible biogenetic pathways of 1 and 2 were postulated. 1 and 2 were found to be potent inhibitors of P-glycoprotein (ABCB1) and 1 also exhibited cytotoxicity against MDA-MB-231 cell lines.

Three new triterpenoids from Ganoderma theaecolum.

Three new triterpenoids (1-3), together with four known triterpenoids (4-7), were isolated from the fruiting bodies of Ganoderma theaecolum. Their structures were elucidated on the basis of their spectroscopic data and chemical evidence. Compounds 4 and 6 exhibited antitumor activities against H460 cells with IC50 values of 22.4 and 43.1 µM, respectively. And the cytotoxic activities of compounds 4 and 5 against MDA-MB-231 cancer cell lines were assayed with IC50 values of 49.1 and 75.8 µM, respectively.

Aristolochic acid derivatives from the rhizome of Arisolochia championii.

Four new aristolochic acid derivatives aristchamic A (1), aristchamic B (2), aristochamic C (3a), aristchamic D (3b) and one new aristolactam aristolactam-CV (4), together with 10 known compounds (5-14), were isolated from the rhizomes of Aristolochia championii. Their structures were assigned by detailed analysis of MS and NMR spectroscopic data. All of the isolated compounds were evaluated for their cytotoxic activities against HCT-116, HepG2, BGC-823, NCI-H1650, and A2780 cell. Compound 1 exhibited significant cytotoxic activity against HCT-116, HepG2, BGC-823, and NCI-H1650, with IC50 values of 0.50, 7.37, 2.66, and 0.75µM, respectively.

Apocynin derivatives from Iris tectorum.

Phytochemical investigation of the rhizomes of Iris tectorum resulted in the isolation and characterization of three new apocynin derivatives, apocynin-4-O-ß-D-(6'-O-syringyl)glucopyranoside (1), scrophenoside C-7-ethyl ether (2, 3), together with a new naturally occurring compound but known by synthesis, apocynin-4-O-ß-D-xylopyranoside (4), and five known ones (5-9). Their structures were elucidated on the basis of spectroscopic data interpretation.

Four new compounds from the rhizome of Aristolochia championii.

Three new flavonoid glycosides (1-3) and one new aristololactam N-glycoside (4) were isolated from the rhizome of Aristolochia championii. The structures of compounds 1-4 were elucidated on the basis of their spectroscopic data and chemical evidence (UV, IR, HR-ESI-MS, 1D and 2D NMR). Their structures were determined as 8-(5-formyl-2-furanmethyl)-isorhamentin 3-O-robinobioside (1), 8-(5-methyl-2-furanoyl)-isorhamentin 3-O-robinobioside (2), 8-formylisorhamentin 3-O-robinobioside (3), and N-ß-D-glucopyranosylaristololactam V (4), respectively.

Polycycloiridals with a Cyclopentane Ring from Iris tectorum.

Six new iridal-type triterpenoids containing an unprecedented cyclopentane ring, polycycloiridals E-J (1-6), were isolated from a large-scale re-extraction of Iris tectorum. A possible biosynthesis pathway is postulated. The known spirioiridotectal D (7) was also obtained in the current investigation, and its structure was unequivocally defined using X-ray diffraction data. Compound 7 suppressed LPS-activated NO production in the BV2 cell line with an IC50 value of 0.54 µM.

Aromatic glycosides from the whole plants of Iris japonica.

Phytochemical investigation on the whole plants of Iris japonica led to the isolation of four new aromatic glycosides. Their structures including the absolute configurations were determined by spectroscopic and chemical methods as (-)-4-hydroxy-3-methoxy acetophenone 4-O-ß-d-{6-O-[4-O-(7R,8S)-(4-hydroxy-3-methoxyphenylglycerol-8-yl)-3-methoxybenzoyl]}-glucopyranoside (1), (-)-4-hydroxy-3-methoxy acetophenone 4-O-ß-d-{6-O-[4-O-(7S,8R)-(4-hydroxy-3-methoxyphenylglycerol-8-yl)-3-methoxybenzoyl]}-glucopyranoside (2), (-)-4-hydroxy-3-methoxy acetophenone 4-O-ß-d-{6-O-[4-O-(7R,8R)-(4-hydroxy-3-methoxyphenylglycerol-8-yl)-3-methoxybenzoyl]}-glucopyranoside (3), (-)-4-hydroxy-3-methoxy acetophenone 4-O-ß-d-{6-O-[4-O-(7S,8S)-(4-hydroxy-3-methoxyphenylglycerol-8-yl)-3-methoxybenzoyl]}-glucopyranoside (4), respectively.

Nine new compounds from the whole plants of Rehmannia chingii.

Nine new compounds, together with 16 known analogs, were isolated from the whole plants of Rehmannia chingii. The structures of compounds 1-9 were elucidated on the basis of their spectroscopic data and chemical evidence. In addition, the new compounds were tested for their hepatoprotective activities against APAP-induced HepG2 cell damage and their ability to inhibit LPS-induced nitric oxide production in the murine microglia BV2 cell line. Compounds 2 and 5 exhibited pronounced hepatoprotective activities against APAP-induced HepG2 cell damage at a concentration of 10 µM, and compounds 4 and 9 showed moderate inhibitory activity against microglial inflammation factor with IC50 values of 3.51 and 7.11 µM, respectively.

Cytotoxic Lignans and Sesquiterpenoids from the Rhizomes of Acorus tatarinowii.

Five new compounds, including a rare phenyldihydronaphthalene lignanamide (1), an unusual hybrid-norlignan derivative (2), a rare cycloheptenone oxide derivative (3), one new acorane-type sesquiterpenoid (4), and one new guaiane-type sesquiterpenoid (5), together with seven known compounds (6-12), have been isolated from the rhizomes of Acorus tatarinowii. The structures of compounds 1-5 were determined by means of extensive spectroscopic methods. To the best of our knowledge, this is first report of a phenyldihydronaphthalene lignanamide and hybrid-norlignan and cycloheptenone oxide derivatives from the genus Acorus. In addition, compound 5 represents the first guaiane-type sesquiterpenoid with an epoxy group located between C-6 and C-9 from natural sources. Compounds 1-12 were evaluated for their in vitro cytotoxicity against five tumor cell lines. Among them, 2, 3, 5, and 10 exhibited moderate cytotoxicity with IC50 values of 2.11-9.23 µM.

Bioactive Iridoid Glycosides from the Whole Plants of Rehmannia chingii.

Nine new iridoid glycosides, rehmachingiiosides A-I (1-9), together with 16 known analogues, were isolated from the whole plants of Rehmannia chingii. The structures of compounds 1-9 were elucidated on the basis of spectroscopic data analysis and from chemical evidence. Furthermore, in two vitro assays, compounds 5 and 10 showed an inhibitory effect on LPS-induced NO production with IC50 values of 2.5 and 7.3 µM, and compounds 4, 6, and 10-12 (when evaluated at 10 µM) exhibited evidence of hepatoprotective effects against APAP-induced HepG2 cell damage.

Lignans from the rhizomes of Iris tectorum.

Chemical examination of the ethanol extract of rhizomes of Iris tectorum led to the isolation and characterization of three new lignans, (7R,7'R,8S,8'S)-5'-methoxy-neo-olivil (1a), (7S,7'S,8R,8'R) -5'-methoxy-neo-olivil (1b), (7S,7'R,8S,8'S)-neo-olivil (2a), (7R,7'S,8R,8'R)-neo-olivil (2b), (7R,7'R,8S,8'S,7''S,8''S)-threo-neo-olivil-4'-O-8-guaiacylglycerol ether (3), together with six known ones (4-9). Among them, compounds 1 and 2 were found to be racemic mixtures, respectively, which were verified by chiral HPLC analysis, compound 3 was a new sesquineolignan. The structures were elucidated on the basis of extensive spectroscopic analysis. To our knowledge, this is the first report of lignan constituents isolated from I. tectorum. All compounds were evaluated for their cytotoxicity against five human tumor cell lines and none of them displayed significant toxicity in tested cell lines at a concentration of 10 µM.

[Chemical constituents from Morus notabilis and their cytotoxic effect].

Une new flavonoids named as notabilisin K (1), together with four known compounds, morusin (2), mulberrofuran A (3), neocyclomorusin (4) and mornigrol F (5) are separated from 95% ethanol extracts of the twigs of Morus notabilis. Compounds 2-5 are separated from this plant for the first time. Notabilisin I, notabilisin J exhibits certain effect against cells of HCT-116, HepG2 and A2780 with IC50 values ranging from 1.47 µmol x L(-1) to 5.46 µmol x L(-1). Morusin exhibits strong effect against five kinds of human cancer cells (BGC823, A2780, HCT-116, HepG2 and NCI-H1650) with IC50 values ranging from 0.74 µmol x L(-1) to 1.58 µmol x L(-1).

An unusual dihydrobenzofuroisocoumarin and ent-kaurane diterpenoids from Pteris multifida.

An unusual 5-C-methylated-dihydrobenzofuroisocoumarin, named multifidarin A (1), and two new ent-kaurane diterpenoids, named multikauranes A (2) and B (3), together with three known ent-kaurane diterpenoids, were isolated from the whole plants of Pteris multifida. The structures of 1-3 were elucidated by spectroscopic methods. The cytotoxic activities of all new compounds were evaluated against five human tumor cell lines. A possible biosynthetic process for the formation of 1 is proposed.