The tirucallane-type triterpenoids, composed of six isoprene units, belong to a group of tetracyclic triterpenoids. Although the naturally-derived tirucallane-type triterpenoids were found in a small amount, the kind of compounds showed various structures, which consist of apo-type, linear said-chain-type and cyclolike said-chain-type and broad bioactivities, such as cytotoxicity, anti-inflammation, antioxidation and anti-plasmin, etc. This paper summarized origins, structures and bioactivities of tirucallane-type triterpenoids in recent ten years. The future research and exploration of tirucallane-type triterpenoids were discussed and prospected.
Antineoplastic Agents, Phytogenic ; Molecular Structure ; Triterpenes

*Alkaloids ; *Antineoplastic Agents, Phytogenic ; Chemistry ; *Harringtonines

Paclitaxel, a tetracyclic diterpenoid compounds, was firstly isolated from the bark of the Pacific yew trees. Currently, as a low toxicity, high efficiency, and broad-spectrum natural anti-cancer drug, paclitaxel has been widely used against ovarian cancer, breast cancer, uterine cancer, and other cancers. As the matter of fact, natural paclitaxel from Taxus species has been proved to be environmentally unsustainable and economically unfeasible. For this reason, researchers from all over the world are devoted to searching for new ways of obtaining paclitaxel. At present, other methods, including artificial cultivation of Taxus plants, microbial fermentation, chemical synthesis, tissue and cell culture have been sought and developed subsequently. Meanwhile, the biosynthesis of paclitaxel is also an extremely attractive method. Unlike other anti-cancer drugs, paclitaxel has its unique anti-cancer mechanisms. Here, the source, production, and anti-cancer mechanisms of paclitaxel were summarized and reviewed, which can provide theoretical basis and reference for further research on the production, anti-cancer mechanisms and utilization of paclitaxel.
Antineoplastic Agents, Phytogenic/pharmacology* ; Humans ; Neoplasms/drug therapy* ; Paclitaxel/pharmacology*

Alkaloids ; Antineoplastic Agents, Phytogenic ; Chemical Phenomena ; Chemistry ; Harringtonines

Steroidal saponins have a wide range of pharmacological effects and biological activities, such as anti-tumor, antifungal, hypoglycemic, immune regulation, insecticides, etc. In the last ten years, some new structures of steroidal saponins compounds were found from natural plants, they have some new and different activities. In order to accelerate the research on the drug innovation of steroidal saponins, we summarized the new progress of the research on such compounds.
Animals ; Anti-Inflammatory Agents ; pharmacology ; Antifungal Agents ; pharmacology ; Antineoplastic Agents, Phytogenic ; pharmacology ; Humans ; Hypoglycemic Agents ; pharmacology ; Saponins ; pharmacology ; Steroids ; pharmacology

OBJECTIVE: The current difficulties in the treatment of tumor include repeated administration and high recurrence rate after tumor resection. In order to reduce the number of doses, avoid side effects of chemotherapeutic drugs, suppress tumor growth and delay tumor recurrence after surgery, a temperature-sensitive in situ gel with paclitaxel microspheres (PTX/M gel) was prepared. PTX/M gel was administered by intratumoral injection once a month. METHODS: First of all, paclitaxel microspheres (PTX/M) were prepared by emulsion solvent evaporation method. A laser particle size distribution analyzer was used to investigate the size, distribution, specific surface area of microspheres. Paclitaxel content was determined by high performance liquid chromatography (HPLC). Then encapsulation efficiency of paclitaxel was calculated and in vitro release characteristics were studied. Secondly, PTX/M gel was prepared by cold dissolution method. The phase transition temperature, elastic modulus, dissolution curve, correlation between dissolution and release were measured. Finally, U87 MG and 4T1 subcutaneous tumor models were established respectively to study the efficacy of PTX/M gel in suppressing tumor growth and delaying tumor recurrence after surgery. RESULTS: The median diameter of the selected PTX/M was (32.24±1.09) μm, the specific surface area was (206.61±10.23) m²/kg, the encapsulation efficiency was 85.29%±1.34%, and the cumulative release percentage of paclitaxel from PTX/M was 33.56%±3.33% in one month. Phase transition temperature of PTX/M gel was 33 °C. The elastic modulus of PTX/M gel at 25 °C and 37 °C were 4.2×103 Pa and 18×103 Pa, respectively. The gel could stay in the body for up to 48 hours. It could be seen from the results of animal experiments that were compared with the saline group and the Taxol group, and the tumor-bearing mice of the PTX/M gel group had the slowest tumor growth (P<0.05). Similarly, in the tumor recurrence experiments, the mice of PTX/M gel group had the latest tumor recurrence after surgery. CONCLUSION As a local sustained-release preparation, PTX/M gel can effectively suppress tumor growth and delay postoperative recurrence of tumors. It has potential advantages in tumor treatment.
Animals ; Antineoplastic Agents, Phytogenic ; Cell Line, Tumor ; Delayed-Action Preparations ; Mice ; Microspheres ; Paclitaxel

OBJECTIVETo develop a fluorescence imaging-based novel system for quick screening of antitumor compounds in vitro.

METHODSThe antitumor activity of 26 components from Lindera aggregate were determined by relative number of viable cell labelled with fluorescein diacetate (FDA) in multiwell plates after exposure to these 26 different components. Then, the linearity and precision of this method were validated. The structures of active compounds in components with strong antitumor activity were deduced by LC/MS.

RESULTSThe linearity of this method for cells stained with FDA was validated (r² = 0.9858) in the range of 0-10⁴ cells per well, and the in-plate precision was 9.41 %. Two of 26 components from Lindera aggregate showed significant inhibition effect on proliferation of HepG2 cells (inhibition rate >90%).

CONCLUSIONThis proposed rapid and reliable approach can be used for screening compounds with antitumor activity from Traditional Chinese Medicine in vitro. The major active compound of Lindera aggregate was putatively identified as norboldine by LC/MS analysis.

OBJECTIVETo extract and isolate the component from myrsinane-type diterpenes of Euphorbia prolifera.

METHODSPetroleum extraction and chromatography on the silica gel were used to extract and isolate the diterpenes of Euphorbia prolifera.

RESULTSEight components of myrsinol diterpenes were isolated, namely: Proliferin A(1), Proliferin B (2), Proliferin C(3), Proliferin D(4), Euphorprolitherin B(5), Euphorprolitherin D(6), SPr5(7) and 14-desoxo-3-O-prorionyl-5, 15-di-O-acetyl-7-O-nicotinoyl-myrsinol-14β-acetate(8). Their structures were identified with mass-spectroscopic methods and NMR techniques. The cytotoxicity of compounds 1, 2, and 4 against cancer cells was evaluated, with compound 1 being active against A2780 cancer cells (IC(50) 7.7 μmol/L).

CONCLUSIONMyrsinane-type diterpene Proliferin A from Euphorbia prolifera shows cytotoxic effect against human ovarian cancer cell line A2780.

OBJECTIVETo isolate and purify components from polysaccharides of purple sweet potato (PPSP) and to test their anti-tumor activity.

METHODSDEAE-Cellulose and CM-Cellulose exchange chromatography were applied to separate components of PPSP. The anti-tumor activities of each component were measured by MTT assay on Hela and HepG(2) cells and their monosaccharide composition were analyzed by TLC chromatography, followed by infrared spectroscopy studies.

RESULTSThrough weak anion exchange chromatography and gradient elution by sodium chloride solution, four components were separated and named as PPSP, PPSPII, PPSPIII and PPSPIV, respectively. MTT tests showed that PPSP II and PPSPIII inhibited Hela and HepG2 tumor cells in a certain extent. The structural analysis revealed that PPSPI was mainly composed of glucose and galactose, PPSP II was composed of glucose and had a typical absorption peak of β-D-glucose chitosan pyranose, PPSP III was a glycoprotein showing a protein absorption peak.

CONCLUSIONFour components were separated from PPSP successfully, among which PPSP II and PPSP III shows anti-tumor activities on Hela and HepG(2) cells in vitro.

Produced by and purified from Taxus brevifolia, Taxol (paclitaxel) has become a widely used cancer drug in clinic. Due to the rapid growing market, current industrial production of taxol by semi-synthesis that consumes large amount of Taxus trees cannot meet the requirement of the market. The discovery of taxol-producing fungus Taxomyces andeanae, an endophyte of T. brevifolia, by Stierle et al (1993), paves a new way to the production of the drug, i.e. employing large-scale fungal fermentation to make Taxol at lower cost and yet higher yield. This review discusses the present problems in taxol production in pharmaceutical industry, the finding and research progress on taxol-producing fungi, and the potential application of fungal fermentation to manufacture this important drug.
Antineoplastic Agents, Phytogenic ; biosynthesis ; Fermentation ; Mitosporic Fungi ; metabolism ; Paclitaxel ; biosynthesis ; Taxus ; microbiology ; Technology, Pharmaceutical ; methods