Six new monacolin analogs from red yeast rice.

Six novel monacolin analogs, monacolins V1-V6 (1-6), together with seven known ones (7-13), were isolated from the ethyl acetate extract of red yeast rice. Their structures and absolute configurations were determined by spectroscopic methods, especially 2D NMR (1H-1HCOSY, HSQC, HMBC, and NOESY/ROESY) and CD spectroscopic analyses as well as chemical derivation. Monacolins V2 (2) and V3 (3) represent the first examples of monacolins with 3-hydroxybutyrate substitute. The anti-inflammatory inhibitory activities against the lipopolysaccharide (LPS) induced NO production in BV-2 cells as well as antioxidant activities against rat liver microsomal lipid peroxidation were evaluated.

[Trace phenolic compounds from Red Yeast Rice].

Trace chemical constituents from the ethyl acetate extract of Red Yeast Rice were investigated. Four phenolic compounds were isolated by various column chromatographies, and their structures were identified on the basis of spectroscopic analysis including UV, MS, IR and NMR. The four compounds were identified as 2-methyl-5-(2'R-methyl-4'-hydroxy-butyl)-cinnamic acid(1), 5-(2'-hydroxy-6'-methyl phenyl)-3-methylfuran-2-carboxylic acid(2), daidzein(3), and genistein(4). Compound 1 was new and 2 was firstly discovered from the genus Monascus, while 3-4 were obtained from Red Yeast Rice for the first time.

Bysspectin A, an unusual octaketide dimer and the precursor derivatives from the endophytic fungus Byssochlamys spectabilis IMM0002 and their biological activities.

Bysspectin A (1), a polyketide-derived octaketide dimer with a novel carbon skeleton, and two new precursor derivatives, bysspectins B and C (2 and 3), were obtained from an organic extract of the endophytic fungus Byssochlamys spectabilis that had been isolated from a leaf tissue of the traditional Chinese medicinal plant Edgeworthia chrysantha, together with a known octaketide, paecilocin A (4). Their structures were determined by HRMS, 1D and 2D NMR spectroscopic analysis. A plausible route for their biosynthetic pathway is proposed. Compounds 1-3 were tested for their antimicrobial activities. Only compound 3 was weakly active against Escherichia coli and Staphyloccocus aureus with MIC values of 32 and 64 µg/mL, respectively. Further, the inhibitory effects on human carboxylesterases (hCE1, hCE2) of compounds 1 and 4 were evaluated. The results demonstrated that bysspectin A (1) was a novel and highly selective inhibitor against hCE2 with the IC50 value of 2.01 µM. Docking simulation also demonstrated that active compound 1 created interaction with the Ser-288 (the catalytic amino-acid in the catalytic cavity) of hCE2 via hydrogen bonding, revealing its highly selective inhibition toward hCE2.

Prenylated C6-C3 compounds with molecular diversity from the roots of Illicium oligandrum.

Eleven prenylated C(6)-C(3) compounds, illioliganpyranone A (1), illioliganfunone A-D (2-5), and illioliganone D-I (6-11), together with five known prenylated C(6)-C(3) compounds (12-16), were isolated from roots of Illicium oligandrum. The structures of 1-11 were elucidated by spectroscopic methods including 1D and 2D NMR, HRESIMS, and CD experiments. Possible biosynthetic pathways to compounds 1-16 derived from a common precursor of 5-allylbenzene-1,2,4-triol were postulated. All compounds were evaluated for cytotoxic activities against five human cancer cell lines (HCT-8, Bel-7402, BGC-823, A549 and A2780). Compound 15 exhibited significant cytotoxicity against HCT-8, BGC-823, A549, and A2780 cell lines with IC(50) values of 0.30-2.57 µM. Compound 16 showed moderate selective cytotoxicity against sensitive A2780 cells with IC(50) value of 1.38 µM.

Phenolic glycosides isolated from the bark of Lysidice brevicalyx Wei.

Two new compounds, lysidiside S (1) and 7-O-(+)-peltogynol-beta-d-glucopyranoside (2), together with six known phenolic glycosides (3-8) were isolated from the bark of Lysidice brevicalyx Wei. The structures of these compounds were characterized by chemical and spectroscopic methods. The antioxidant activities of compounds 1-8 were evaluated, and compound 3 exhibited remarkable antioxidant activity at concentrations of 10(-4), 10(-5), and 10(-6) mol/l.

Structural characterization of constituents with molecular diversity in fractions from Lysidice brevicalyx by liquid chromatography/diode-array detection/electrospray ionization tandem mass spectrometry and liquid chromatography/nuclear magnetic resonance.

A combination of electrospray ionization tandem mass spectrometry with high-performance liquid chromatography (HPLC/ESI-MSn), and hyphenation of liquid chromatography to nuclear magnetic resonance spectroscopy (HPLC/NMR), have been extensively utilized for on-line analysis of natural products, analyzing metabolite and drug impurity. In our last paper, we reported an on-line analytical method for structural identification of trace alkaloids in the same class. However, the structural types of the constituents in plants were various, such as flavanoids, terpenoids and steroids. It is important to establish an effective analytical method for on-line structural identification of constituents with molecular diversity in extracts of plants. So, in the present study, the fragmentation patterns of some isolated stilbenes, phloroglucinols and flavanoids from Lysidice rhodostegia were investigated by ESI-MSn. Their fragmentation rules and UV characteristics are summarized, and the relationship between the spectral characteristics, rules and the structures is described. According to the fragmentation rules, NMR and UV spectral characteristics, 24 constituents of different types in the fractions from L. brevicalyx of the same genus were structurally characterized on the basis of HPLC/HRMS, HPLC-UV/ESI-MSn, HPLC/1H NMR and HPLC/1H-1H COSY rapidly. Of these, six (10, 13, 14, 16, 17 and 23) are new compounds and all of them are reported from L. brevicalyx for the first time. The aim is to develop an effective analytical method for on-line structural identification of natural products with molecular diversity in plants, and to guide the rapid and direct isolation of novel compounds by chemical screening.

Cytotoxic triterpenoid saponins acylated with monoterpenic acid from Pithecellobium lucidum.

Three new oleanane-type triterpene saponins, named pithelucosides A-C (1-3), together with two known saponins (4, 5) were isolated from the roots of Pithecellobium lucidum. The structures of the new saponins were established on the basis of extensive 1D and 2D NMR experiments and mass spectrometry and confirmed by acid and alkaline hydrolysis. Compounds 1-5 and 7 (pro-sapogenin obtained from the mild alkaline hydrolysate of 1) were evaluated for cytotoxic activity on five human tumoral cell lines (HCT-8, Bel-7402, BGC-823, A549, and A2780) and for hemolytic property against rabbit erythrocytes. Compounds 2-5 showed significant cytotoxic activities with IC50 values of 0.61-7.56 microM. All tested compounds did not exhibit any hemolytic activity in the concentration range 0.01-100 microM.

[Studies on chemical constituents from roots of Craibiodendron henryi].

OBJECTIVE: To study the chemical constituents from the roots of Craibiodendron henryi. METHOD: Various chromatographic techniques were used to isolate and purify the constituents. The structures were elucidated by chemical evidence and spectral methods. RESULT: Twelve compounds were isolated from the ethyl acetate soluble fraction of the 95% ethanolic extract and their struc- tures were elucidated as quercetin (1), quercetin-3-O-rhamnicoside (2), quercetin-3-O-arabinofuranoside (3), (-)-epicatechin (4), proanthocyanidin A-2 (5), procyanidin B-2 (6), (-)-isolariciresinol-2a-O-beta-D-xylopyranoside (7), lyoniside (8), sitoster-yl-3beta-glucoside-6'-O-palmitate (9), beta-sitosterol (10), daucosterol (11) and octacosanoic acid (12). CONCLUSION: Compounds 1-12 were isolated from this plant for the first time.

[Studies on chemical constituents of Cynanchum forrestii].

OBJECTIVE: To study the chemical constituents of Cynanchum forrestii. METHOD: Chromatographic techniques were applied to isolated chemical constituents. The structures were identified on the basis of physico-chemical constants and spectroscopic data. RESULT: Eight compounds were isolated from the 95% ethanol extract of the roots of C. forrestii and elucidated as ( + ) -5'-methoxyisolariciresinol 3a-O-beta-D-glucopyranoside (1), hexahydroxycholest-7-en-6-one (2), tylophorinidine (3), sucrose (4), palmitic acid (5), beta-sitosterol (6), daucosterol (7), nonanedioic acid (8). CONCLUSION: Compounds 1-3 from this genus, and compounds 4-8 from the plant were obtained for the first time.

Resveratrol/phloroglucinol glycosides from the roots of Lysidice rhodostegia.

Two new phloroglucinol glycosides, lysidisides C (1) and D (2), together with two new resveratrol glycosides, lysidisides E (3) and F (4), were isolated from the n-BuOH extract of the roots of Lysidice rhodostegia. The structures were elucidated on the basis of spectroscopic and chemical evidence. The antioxidant activity of the isolates was also investigated

Novel phloroglucinol derivatives from the roots of Lysidice rhodostegia.

[structure: see text] Three novel phloroglucinol derivatives of lysidicins A-C (1-3) have been isolated from the roots of Lysidice rhodostegia and structures were elucidated by comprehensive NMR and MS spectroscopic analysis. 1 and 2 possess spirocyclic benzodihydrofuran skeleton. Their relative stereochemistries were assigned by NOE or NOESY experiment. A plausible pathway for the biosynthesis of 1-3 from 4 and a ketose derivative was postulated.

New cassaine diterpenoid amides with cytotoxic activities from the bark of Erythrophleum fordii.

A phytochemical investigation of the bark of Erythrophleum fordii led to six new cassaine diterpenoid amides (2, 4-8), together with two known compounds of the same skeleton, nor-cassamide ( 1) and nor-erythrosuamide (3). The structures were mainly established on the basis of 1D, 2D NMR and HR-MS analysis. The compounds 1, 2, 4, 6-8 exhibited selective cytotoxic activities (IC50 values < 10 microM) against A2780, KB, Bel-7402, BGC-823, MCF-7, HCT-8, Hela, PC-3M, A549 and Ketr3 human cancer cell lines in the MTT test.

Iridoid glycosides and grayanane diterpenoids from the roots of Craibiodendron henryi.

Four new iridoid glycosides, 10-O-trans-p-coumaroylscandoside (1), 10-O-cis-p-coumaroylscandoside (2), 10-O-trans-p-coumaroyldesacetyl asperulosidic acid (3), and 10-O-cis-p-coumaroyldesacetyl asperulosidic acid (4), and two new grayanane diterpenoids, 14beta-O-(2S,3S-nilyl)-2alpha,3beta,5beta,6beta,16alpha-pentahydroxygrayanane (5) and 14beta-O-(2S,3S-nilyl)-2alpha,3beta,5beta,6beta,16alpha-pentahydroxygrayan-10(20)-ene (6), have been isolated from Craibiodendron henryi. The structures of these compounds were determined by chemical and spectroscopic methods including 1H-1H COSY, HMQC, HMBC, and NOESY experiments. Antioxidant activities and vasodilator effects of these compounds were assessed.