A new furofuran mono-lactone from Forsythia suspensa.

A new furofuran mono-lactone, named forsythenin, was isolated from the fruits of Forsythia suspensa, together with the known compounds, ocotillone, ocotillol monoacetate, (6'-O-palmitoyl)-sitosterol-3-O-beta-D-glucoside and palmitic acid. The structure of the new compound was elucidated on the basis of spectroscopic means and X-ray crystallography.

[The structural elucidation of new polyoxygenated cyclohexenes from Uvaria grandiflora].

Four new polyoxygenated cyclohexenes, named uvarigranol A(1), B(2), E(3) and F(4), along with the known zeylenol were obtained from the roots of Uvaria grandiflora Roxb (Annonaceae). Based on spectral and X-ray analysis as well as Mosher methodology, their structures and absolute configuration were established.

Rearranged taxoids from Taxus yunnanensis.

Two rearranged 2(3-->20)abeotaxanes were isolated from the leaves and stems of Taxus yunnanensis, and designated as taxin B and 2-deacetyltaxin B. The structure of taxin B with a unique 6/10/6 skeleton was deduced on the basis of 1H-NMR, 13C-NMR, 1H-1H COSY, DEPT, NOE, and mass spectra and confirmed by X-ray crystallographic analysis. The structure of 2-deacetyltaxin B is elucidated by analog.

[Studies on diterpenoids from leaves of Tripterygium wilfordii].

Tripterygium wilfordii Hook f. has been used as a medicinal herb in traditional Chinese medicine and as an insecticide by the Chinese for hundreds of years. Recently, this plant has been used to treat cancer, rheumatic arthritis and various skin diseases in some Chinese clinics. It is of interest to note that Tripterygium also showed significant antifertility activities. The active principles of the anti-inflammatory, immunosuppressive and antifertile actions in Tripterygium are diterpenoid containing triepoxides, but information on its chemistry is limited to the woody part of the root and the root bark. Recently, we have studies the leaves of Tripterygium (collected at Zhejiang province, China), and isolated two novel diterpenoids by chromatography named tripdioltonide (8) and 13,14-epoxide 9,11,12-trihydroxytriptolide (9), besides triptonide (1), triptolide (2), tripdiolide (3), triptolidenol (4), 16-hydroxyl-triptolide (5), tripchlorolide (6) and triptriolide (7). Their structures were established by chemical reactions, TLC, UV, MS, IR, 1H-1H COSY, 1H-13C COSY, DEPT spectrometric investigation. The structure of tripdioltonide was further confirmed by X-ray analysis.

[The structure and absolute configuration of isorupestonic acid from Artemisia rupestris L].

A new sesquiterpene compound named isorupestonic acid was isolated from Artemisia rupestris and its absolute stereostructure was elucidated as 3B by spectral and X-ray crystallographic methods. Interestingly, the isorupestonic acid is based upon an unusual 6, 7 membered ring skeleton differing from the 5, 7 membered ring rupestonic acid although both have the same absolute configuration at C-1. The biogenesis of isorupestonic acid most likely involves breaking the C4-C5 bond of rupestonic skeleton and forming the C5-C14 bond. The absolute configuration of rupestonic acid was also determined as 4C by X-ray analysis and CD data.

[Structure of pingbeimine C].

A new C-nor-D-homosteroid alkaloid, C27H43O6N, mp 171.5-173 degrees C, named pingbeimine C, was isolated from the bulb of Fritillaria ussuriensis Maxim. On the basis of IR, MS, 1HNMR and 13CNMR spectroscopic data, particularly X-ray crystallographic analysis, structure IV has been assigned to this alkaloid.

Isolation and structure elucidation of armillaricin1.

From the petroleum ether extracts of the artificially cultured mycelium of ARMILLARIA MELLEA, a novel sesquiterpenoid aromatic ester named armillaricin has been isolated by silica gel column chromatography. Its structure was deduced from spectral data and confirmed by single-crystal X-ray analysis.

[Chemical studies of flower buds of Tussilago farfara L].

We have studied the flower buds of Tussilago farfara L. collected from Yulin county Shaanxi Province and have isolated a new terpenoid compound I with the composition C23H34O5, M+ 390.2416, mp 100-101 degrees C. On basis of physical and chemical properties and spectroscopic analysis (UV, IR, 1HNMR, 13CNMR, 1H-1H-COSY, 13C-1H-COSY DEPT, EI-MS, FAB-MS, HR-MS) and X-ray, the structure of I has been elucidated as a novel sesquiterpenoid compound, which is named farfaratin.

[The structure of versicolactone D].

The extracts of Aristolochia versicolar S.M. Huang root afforded a new dimeric sesquiterpene lactone, versicolactone D, with a novel skeleton. Its structure was established by spectroscopic methods, mainly X-ray and 2D-NMR.

[The isolation and structure identification of triptotriterpenic acid C].

A new ursolic-type acid named triptotriterpenic acid C was obtained from the total glycosides extracted from the root of Tripterygium wilfordii Hook.f. Its structure was inferred from chemical reaction, IR, 1HNMR, 13CNMR and MS spectral data. The structure and stereochemistry of this compound was confirmed to be 3 beta,22 alpha-dihydroxy-delta 12-ursene-30-oic acid by X-ray crystallo-diffraction analysis of its methyl ester.

[Studies on the chemical constituents of Aquilaria sinensis (Lour) Gilg. III. Elucidation of the structure of isobaimuxinol and isolation and identification of the constituents of lower boiling fraction of the volatile oil].

A new sesquiterpenoid, named isobaimuxinol, C15H26O2, mp 73-75 degrees C, [a]D12-68(0) (c 0.10, CHCl3), was isolated from the volatile oil of Aquilaria sinensis (Lour), Gilg. (Thymeleaceae). Based on spectral (IR, 1H-NMR, 13C-NMR and 2D-NMR as well as MS) analysis its structure was identified as isobaimuxinol. The relative stereochemistry of isobaimuxinol was determined by X-ray crystallograhy. In addition, four known compounds, benzylacetone, p-methoxybenzylacetone, anisic acid and beta-agarofuran were isolated and identified from the lower boiling fraction of the volatile oil of this plant. These compounds were obtained for the first time from this plant.

[Studies on the chemical constituents of the root of Desmos cochinchinensis Lour].

Desmos cochinchinensis as a folk medicine is used for treatment of malaria in China. Pharmacological studies showed that the petroleum ether extract of the root of the plant exhibited anti-malarial activity. Three flavonoids were isolated from this extract, of which two were identified as lawinal and isounonal. Compound III is a new flavanol. On the basis of spectroscopic analyses (UV, IR, MS, 1HNMR, 13CNMR and X-RD) the structure was established as 4,7-dihydroxyl-5-methoxyl-6-methyl-8-formyl-flavan. I and II were found from this plant for the first time.

[Coetsoidin A, a new diterpenoid from Rabdosia coetsoides C. Y. Wu].

From the leaves of Rabdosia coetsoides C. Y. Wu, a new diterpenoid, coetsoidin A (I) was isolated and its structure was established by spectroscopic and X-ray diffraction analysis. It is the first instance of a kaurene type diterpenoid possessing alpha,beta-unsaturated ketone functionality in ring B.

[Studies on the chemical constituents of Curcuma kwangsiensis].

A new sesquiterpene lactone named gweicurculactone, along with beta-sitosterol, germacrone, daucosterin and palmitic acid, was isolated from Curcuma kwangsiensis. Its structure has been confirmed by means of spectral and X-ray diffraction analysis.