Prenylated C6-C3 compounds from the roots of Illicium henryi

Eleven prenylated C(6)-C(3) compounds, illihenryifunones A, B (1, 2), illihenryifunol A (3), illihenryipyranol A (4), illihenryiones A-G (5-11), and three known prenylated C(6)-C(3) compounds (12-14), were isolated from the roots of Illicium henryi. Structures of 1-11 were elucidated by spectroscopic methods including NMR, HRESIMS, and CD. The absolute configuration of the 11,12-diol moiety in 5 was determined by observing its induced circular dichroism after addition of Mo(2)(OAc)(4) in DMSO. The absolute configuration of C-11 in 4 was determined as S based on the Rh(2)(OCOCF(3))(4)-induced CD data; the absolute configuration of 3 was determined as R by comparison of its experimental and calculated electronic circular dichroism (ECD). The antioxidant activities of compounds 1-14 were also evaluated. Compound 4 exhibited strong antioxidant activity with an IC(50) value of 2.97±1.30 μM, whereas compounds 3 and 8 showed antioxidant activities with IC(50) values of 44.36±0.30 and 48.00±2.01 μM, respectively.

Chiroptical properties of ajugol investigated by quantum chemical calculation using time-dependent density functional theory

The chiroptical properties of an iridoid glycoside ajugol were fully investigated by quantum chemical calculations of specific optical rotation at the sodium D line ([α]D value), optical rotatory dispersion (ORD), and electronic circular dichroism (ECD) using time-dependent density functional theory (TDDFT). TDDFT calculations of the [α]D value and ORD of ajugol over the range of 365-633 nm were in good agreement with the experimental data. The predicted ECD spectrum of ajugol was also consistent with the experiment, showing a strong negative Cotton effect (CE) at around 190 nm and a weak positive CE at around 220 nm. Our results unambiguously determined the absolute configuration (AC) of the aglycone part of ajugol as (1S, 5R, 6R, 8S, 9S) and supported the generally accepted AC assignments of iridoid glycosides. Semi-empirical rule for the enol ether chromophore, basis set selection, and effect of glucose group on ECD spectra were also discussed in the case of ajugol.

Bioactive sesquiterpenoids from the rhizomes of Acorus calamus

Eight new sesquiterpenes (1-8) and one new norsesquiterpene (9) named calamusins A-I were isolated from the ethanol extract of Acorus calamus rhizomes. The absolute configuration of compound 8 was determined by comparing its experimental and calculated ECD spectra. The absolute configurations of the other compounds were determined from their CD spectra. Furthermore, in in vitro assays, compounds 3, 4, 7, and 9 (10 μM) exhibited weak hepatoprotective activities against APAP-induced HepG2 cell damage.

Neolignans and sesquiterpenes from cell cultures of Stellera chamaejasme

Two new neolignans (1, 2) and six sesquiterpenes (3- 8) were isolated from the cell cultures of Stellera chamaejasme. Their structures and absolute configurations were elucidated by extensive spectroscopic and computational methods. Compound 4 exhibited significant protective effects against CCl (4)-induced hepatotoxicity in HepG2 cells, reducing aspartate aminotransferase release by 29.49 % at 10 µM. These compounds have not been isolated from plant material, which implies that in vitro plant cell cultures may offer alternative and effective sources of bioactive natural compounds.

Carbazole alkaloids from the stems of Clausena lansium

Ten new carbazole alkaloids, claulansines A-J (1-10), and seven known analogues (11-17) were isolated from the stems of Clausena lansium. Their structures were established on the basis of extensive spectroscopic analyses, and their absolute configurations were determined by CD experiments and computational methods. Screening results indicated that compounds 1, 6, 8-10, 13, 14, and 17 showed selective neuroprotective effects at the concentration of 10 μM.

Two new terpenoids from endophytic fungus Periconia sp. F-31

Two new terpenoids, (+)-(3S,6S,7R,8S)-periconone A (1) and (-)-(1R,4R,6S,7S)-2-caren-4,8-olide (2), have been isolated from an endophytic fungus Periconia sp., which was collected from the plant Annona muricata. Their structures were elucidated on the basis of extensive spectroscopic analyses. In the in vitro assays, the two compounds showed low cytotoxic activities against six human tumor cell lines (HCT-8, Bel-7402, BGC-823, A549, A2780 and MCF-7) with IC(50)>10(-5) M.

Indole alkaloids and quassinoids from the stems of Brucea mollis

Seven new indole alkaloids, bruceollines H-N (1-7), three new quassinoids, yadanziolides T-V (10-12), and four known analogues, bruceolline E (8), bruceolline F (9), bruceine D (13), and yadanziolide B (14), were isolated from an ethanol extract of the stems of Brucea mollis. The absolute configurations of compounds 2 and 5 were determined by comparison of their experimental and calculated ECD spectra. The absolute configuration of the known compound 9 was determined by using Mo2(OAc)4-induced CD analysis for the first time. Compounds 10, 13, and 14 exhibited cytotoxic activities with IC50 values of 3.00-5.81 μM.

Anticancer effect and neurotoxicity of S-(+)-deoxytylophorinidine, a new phenanthroindolizidine alkaloid that interacts with nucleic acids

Phenanthroindolizidine alkaloids are a family of plant-derived compounds with significant antineoplastic activity as well as other effects like antiamebicidal, antiviral, and anti-inflammatory activities. The specific biomolecular targets of these compounds have not yet been clearly identified. S-(+)-Deoxytylophorinidine (CAT) is a new phenanthroindolizidine alkaloid, originally extracted from the roots of Tylophora atrofolliculata and Tylophora ovata. Potent anticancer activity was observed in vitro and in vivo. Neurotoxicity of CAT was also studied and it was far less serious than that of vinblastine. Interactions between this compound and DNA had been studied in detail in our laboratory previously, and we further studied its interactions with RNA.

Neolignans and glycosides from the stem bark of Illicium difengpi

Five new neolignans (1-4 and 9), two pairs of neolignan epimers (5-8), and two new aromatic glycosides (10 and 11) have been isolated from the stem bark of Illicium difengpi. Their structures were determined by spectroscopic methods, including 1D and 2D NMR, HRESIMS, CD experiments, and chemical methods. The absolute configurations of the 3,4-diol moiety in 1 and 1,3-diol moiety in 2 were confirmed by Snatzke's method, observing the induced circular dichroism after addition of dimolybdenum tetraacetate in DMSO. Compounds 3, 4, and 11 exhibited moderate anti-inflammatory activities with IC(50) values ranging from 1.62 to 24.4 microM, while compound 3 displayed antioxidant activity with an IC(50) value of 42.3 microM.

[Studies on chemical constituents in herb from Artemisia rupestris]

OBJECTIVE

To study the chemical constituents of Artemisia rupestris.

METHOD

The chemical constituents were isolated by column chromatography on silical gel and sephadex LH - 20. Their structures were elucidated on the basis of spectral analysis.

RESULT

8 compounds have isolated from this plant, and the structures of them have identified as rupestonic acid (1), chrysosplenetin B (2), artemetin (3), herniarin (4), isokaempferide (5), vanillic acid (6), kaempferol 3, 3', 4'-trimethyl ether (7) and ermanine (8).

CONCLUSION

Compounds 2-8 have been isolated from this plant for the first time.

[Use of high-field nulear magnetic resonance spectroscopy for the analysis of stereoselective metabolites of ibuprofen (R)-enantiomer in rat urine]

AIM

To study the metabolic chiral inversion and chiral metabolites of R-(-)-ibuprofen.

METHODS

Following administration of R-(-)-ibuprofen (250 mg.kg-1), analysis was performed on rat urine purified extracts obtained by solid phase extraction onto C-18 bonded silica gel, then the metabolites of ibuprofen were detected and identified by 1HNMR spectroscopy.

RESULTS

Except for a little ibuprofen, there were 2'-hydroxy-ibuprofen and its glucuronide, 1'-carboxy-ibuprofen glucuronide and ibuprofen glucuronide in rat urine. 2'-hydroxy-ibuprofen is the main metabolite. 1'-carboxy-ibuprofen glucuronide and ibuprofen glucuronide were diastereoisomers.

CONCLUSION

There was the phenomenon of metabolic chiral inversion, whereby the R-enantiomer is transformed in vivo to its active S-antipode via an unusual process.

Absolute configuration of gossypol

The absolute configuration of the physiologically active (-)-gossypol has been suggested to be M by application of the coupled oscillator theory to its CD.