Berkeleylactones S-T, novel 16-membered macrolides isolated from the endophytic fungus .

The fungus has been reported as a producer of the 16-membered macrolide antibiotic A26771B. In this study, two new berkeleylactone analogues, berkeleylactones S-T (-), were isolated from . Their structures were determined by the analyses of 1D- and 2D-NMR data, HRESIMS, and chemical derivatization.

Two pairs of 2-pyrone enantiomers and a benzophenone analogue from the endophytic fungus .

Four new 2-pyrone derivatives, two pairs of enantiomers, (±)-egypyrone A [(±)-] and (±)-egypyrone B [(±)-], together with a new benzophenone analogue, orbiophenone B (), were isolated from the endophytic fungus . The enantiomeric mixtures (±)- and (±)- were separated through chiral HPLC, respectively. Their structures were elucidated by extensive analysis of spectroscopic data and the absolute configuration was determined by comparing the optical rotation of structurally similar molecule.

Six new monacolin analogs from red yeast rice.

Six novel monacolin analogs, monacolins V-V (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 (H-HCOSY, HSQC, HMBC, and NOESY/ROESY) and CD spectroscopic analyses as well as chemical derivation. Monacolins V (2) and V (3) represent the first examples of monacolins with 3-hydroxybutyrate substitute.

Diphenyl Ethers from a Marine-Derived .

Six new diphenyl ethers (⁻) along with eleven known analogs were isolated from the ethyl acetate extract of a marine-derived guided by LC-UV-MS. Their structures were unambiguously characterized by HRESIMS, NMR, as well as chemical derivatization. Compounds and are rare diphenyl ether glycosides containing d-ribose.

[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).

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.

Phloroglucinols with Antioxidant Activities Isolated from Lysidice rhodostegia.

Two new phloroglucinols, lysidisides X and Y ( and ), and two known compounds, 2-(2-methylbutyryl)phloroglucinol 1--β-d-glucopyranoside () and ()-resveratrol 3-(6″-galloyl)--β-d-glucopyranoside (), have been isolated from the roots of . The structures of and were elucidated primarily by NMR experiments. Their absolute configurations were deduced via circular dichroism (CD) data and electronic circular dichroism (ECD) calculations.

Cytotoxic cardenolides from the stems of Periploca forrestii.

Six new cardenolides, periforosides D-E (1-2), periforgenin C (3) and periforosides F-H (4-6), as well as 10 previously identified cardenolides (7-16) were isolated from the ethanol extract of the stems of Periploca forrestii. The structures of the new compounds were determined using extensive spectroscopic analyses including HRESI-MS, 1D and 2D NMR data. Evaluation of the cytotoxic activity of all the isolated compounds in five different human cancer cell lines indicated that compounds 2-6, 8, 9 and 12-16 have potent activity.

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.

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.

Lysidicins F-H, three new phloroglucinols from Lysidice rhodostegia.

Three new phloroglucinols, named lysidicins F-H (1-3), were isolated from the roots of Lysidice rhodostegia. These compounds have a unprecedented benzyl benzo[b]furo[3,2-d]furan skeleton, and lysidicin F (1) is the first example of natural product with trans-fused furan rings. Their structures were established on the basis of extensive spectroscopic analysis, and the absolute configurations of them were determined by computational methods.

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.

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.

Glucosides from the roots of Capparis tenera.

Two new lignan glucosides, compounds 2 and 3, two new 1H-indole-alkaloid glucosides, 5 and 6, as well as two new phenolic glucosides, 7 and 10, were isolated from the roots of Capparis tenera, together with five known compounds. Their structures were characterized by chemical and spectroscopic methods. Most of these isolates were obtained for the first time from Capparidaceae.

Two new compounds from the roots of Lysidice rhodostegia.

Two new compounds, lysidicin D (1) and lysidicin E (2), were isolated from the roots of Lysidice rhodostegia. Their structures were elucidated by means of spectroscopic methods. Among them compound 1 showed potent anti-oxidant activity on in vitro.

[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.

[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.

Structure-activity studies of phenanthroindolizidine alkaloids as potential antitumor agents.

Five phenanthroindolizidine alkaloids (PA) were chemically synthesized and seven were isolated from Tylophora atrofolliculata. To facilitate future drug design of phenanthroindolizidine alkaloids as potential antitumor agents, we have explored the structure-activity relationships (SAR) of this class of compounds. We demonstrated that DCB-3503 and tylophorinidine (PA-7) were among the most active compounds against tumor growth both in vitro and in vivo.

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

Seven new steroidal glycosides from the roots of Cynanchum forrestii.

Seven new steroidal glycosides, cynaforrosides K (1), L (2), M (3), N (4), and Q (7), based on a 13,14:14,15-disecopregnane-type aglycone, and cynaforrosides O (5) and P (6) with a 14,15-secopregnane-type aglycone, were isolated from the 95% ethanol extract of the roots of Cynanchum forrestii Schlechter. The structures of new compounds were determined on the basis of spectroscopic and chemical evidence. The sugar units of cynaforrosides K-P contained two moieties of glucoses with the mode of 1-->4 linkage and those of cynaforrosides K-O contained six moieties of sugars.

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.

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.