Biomedical subjects
Publications and source records attributed to D Q Yu.
Two new acetogenins, gardnerilins A and B, have been isolated from the roots of Goniothalamus gardneri. Both are C35 acetogenins containing non-tetrahydrofuran rings. Their structures have been established on the basis of spectral evidence.
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Two new cytotoxic annonaceous acetogenins, named uvarigrin(1) and uvarigrandin A(3), were obtained from the roots of Uvaria grandiflora Roxb(Annonaceae). Based on X-ray analysis and Mosher's methodology, the overall absolute configuration of 1 was established as 15S, 17R, 18R, 21R, 22R, 36S. The absolute configuration of 3 was also resolved by Mosher's methodology. The relative configuration of the previously reported uvarigranin (2) was revised. Compound 1 showed cytotoxicity against HCT-8, Bel7402 and A2780 human tumor cell lines at ED50 levels of 0.15, 0.21 and 0.41 microgram.ml-1, respectively.
The root of Sarcococca vagans Stapt (Buxaceae) is well-known Chinese folk drug called as "Jie Gu Mu", distributed in southern of China. They are used in treatment of traumatic injury. Four new steroidal alkaloids, named sarcovagine A, B, C and D, were isolated from the root of Sarcococca vagans. Their structures were established on the basis of spectral evidence.
The total synthesis of cimicifugamide, a new natural compound isolated from the roots of Cimicifuga dahurica, was accomplished by a reaction sequence of seven steps in an overall yield of 31%. Trifluoroacetoxy was used as leaving group at the anomeric carbon. The target product was characterized by IR, MS, 1HNMR, 13CNMR and elemental analysis. In addition, seven analogues were synthesized and their preliminary pharmacological activities were tested.
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.
S-( -- )-Ligustiphenol is a new sesquiterpene with anti-inflammatory and immunosuppressive activities. In order to study its pharmacological activities, the total synthesis of its racemat was carried out by a six-step reaction sequence including bromination of aldehyde, iodination of m - cresol, protection of phenolic hydroxyl, Grignard reaction, Aldol condensation, etc. The target compound was characterized by comparing its 1(H)-NMR, MS and IR spectra with natural ( -- )-ligustiphenol. In order to study the structure-activity relationships of ligustiphenol, it five analogues were designed and synthesized. The pharmacological screening of these analogues has been performed.
A novel bioactive monotetrahydrofuran acetogenin named tonkinecin (1) and two known compounds, uvariamicins I and II, have been isolated from the roots of Uvaria tonkinesis. The structure of 1 was elucidated using spectral methods and its absolute stereochemistry established by 1H-NMR experiments utilizing Mosher ester methodology.
Further studies on the root bark of Uvaria tonkinensis Finet et Gagnep. (Annonacease) led to the isolation of a new Annonaceous acetogenin, tonkinelin (1). The structure of 1 was elucidated on the basis of spectral data and chemical evidence. This compound represents an unusual type of C37 Annonaceous acetogenin, having neither tetrahydrofuran (THF) nor epoxide rings and possessing only a vicinal diol in the hydrocarbon chain. Preliminary pharmacological tests showed that tonkinelin (1) inhibits human leukemia (HL-60) and human colon adenocarcinoma (HCT-8) cell lines in vitro.
Three new triterpenoid saponins were isolated from the alcoholic extract of the bark of Nothopanax davidii. Their structures have been determined on the basis of spectral and chemical data as 3-O-alpha-(4'-O-acetyl)-L-arabinopyranosyl-3 beta-hydroxyolean-12-ene- 28,29-dioic acid-28-O-[alpha-L-rhamnopyranosyl(1-->4)-beta-D-glucopyranosyl (1-->6)-beta-D-glucopyranosyl]ester, named yiyeliangwanoside IX; 3-O-alpha-(2'-O-acetyl)-L-arabinopyranosyl-3 beta-hydroxyolean-12-ene-28,29- dioic acid-28-O-[alpha-L-rhamnopyranosyl(1-->4)-beta-D-glucopyranosyl(1-->6)- beta-D-glucopyranosyl] ester, named yiyeliangwanoside X; and 3-O-beta-d-xylopyranosyl-3 beta-hydroxyolean-12-ene-28,29-dioic acid-28-O-[alpha-L-rhamnopyranosyl(1-->4)-beta-D-glucopyranosyl(1-->6)-b eta-D - glucopyranosyl] ester, named yiyeliangwanoside XI.
Two new triterpenoid saponins named aralosides H[1] and J [2], along with four known triterpenoid saponins 3-6 were isolated from the roots of Aralia spinifolia. Their structures were determined as 3-O-beta-D-xylopyranosyl-(1-->2)-[beta-D-glucuronopyranosyl (1-->3)]-beta-D-glucopyranosyl-oleanolic acid [1], 3-O-alpha-L-arabinofuranosyl-(1-->4)-beta-D-glucuronopyranosyl- oleanolic acid 28-O-beta-D-galactopyranosyl ester [2], araloside A methyl ester [3], chikusetusaponin Ib [4], chikusetusaponin IV [5], and araloside A [6] on the basis of spectral and chemical data.
Six compounds were isolated from leaves of Lantana camara. On the basis of chemical and spectral (UV, IR, EI-MS, 1HNMR 13CNMR) analysis, they were identified as oleanonic acid (I), lantadene A (II), lantadene B (III), lantanilic acid (IV), icterogenin (V) and 4',5-dihydroxy-3,7-dimethoxyflavone-4'-O-beta-D-glucopyranoside (VI). VI is a new compound named camaroside.
Eight triterpenoids were isolated from the roots of Lantana camara. On the basis of their chemical properties and spectral data (UV, IR, MS, 1HNMR, 13CNMR), they were identified as lantanolic acid (I), 22 beta-O-angeloyl-lantanolic acid (II), oleanolic acid (III), 22 beta-O-angeloyl-oleanolic acid (IV), 22 beta-O-senecioyl-oleanolic acid (V), 22 beta-hydroxy-oleanolic acid (VI), 19 alpha-hydroxy-ursolic acid (VII) and 3 beta-isovaleroyl-19 alpha-hydroxy-ursolic acid (VIII). II was obtained for the first time from plant. VIII is a new compound named lantaiursolic acid.
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.
In this paper, the structure modification of triptolide was studied and nine triptolide derivatives were synthesized. A preliminary test for the immunosuppression activity in vitro showed that tripchlorolide (2) and tripbromolide (3) have strong activity similar to triptolide, while their toxicity are much lower. The activity of other compounds was decreased significantly. A simple method for the preparation of tripchlorolide from triptolide in 92% yield was found by reacting triptolide with HCl in acetone under mild condition.
Chrysanthemum indicum L. is a Chinese traditional drug used for antifebrile, detoxication and hypotensive purposes. In continuation of our efforts to search for the active principles of this species, a new sesquiterpene compound, named chrysanthetriol was isolated from the more polar fraction of the title plant. Chrysanthetriol is a colorless oil, [alpha]D20-31.8 degrees (c 0.3, MeOH). HRMS showed the molecular formula to be C15H26O3. The structure and stereochemistry of chrysanthtriol was elucidated as I by the use of 1H-1H COSY, 1H-13C COSY, 1H-13C COLOC 2D NMR spectroscopy.
A reversed phase high performance liquid chromatographic method for the assay of tripchlorolide (T4) in pharmaceutical preparation was developed. The method used a Nucleosil 5 C18 column and a mobile phase of methanol-water (1:1). The column effluent was monitored at 218 nm. T4, triptolide (T0) and 1,4-dimethoxybenzene (IS) could be separated in less than 25 min. The retention times of T0, T4 and IS are 11, 17 and 23 min respectively. The method is very simple and rapid.
Two novel protoilludane norsesquiterpenoid esters, named armillasin and armillatin, have been isolated from the artificially cultured mycelium of ARMILLARIA MELLEA (Tricholomataceae). Their structures have been assigned on the basis of a detailed study of their spectral data. Their relative configurations were established from the nuclear Overhauser effects.