The electronic structure of a Lindqvist type [Mo7O24]6- anion with 5 different types of counterion (K+, Na+, NH4+, [NH3Pr]+ and [NH3Pri]+) was calculated by using the Discrete Variational Method coupled with Density Functional Theory (DFT-DVM). It could be concluded through variance analysis to the calculated results that the type of counterion does not influence remarkably the electronic structure of [Mo7O24]6- anions. Perhaps it can be used to explain the experiment fact that the polyoxomolybdate structure of the Mo7O24 framework is apparently of critical significance to antitumor action. On these grounds we forecast that two other lindqvist type heptamolybadates(their counterions are Na+ and [NH3Pr]+ respectively) may also exhibit antitumor activities.
Antineoplastic Agents ; chemistry ; Ions ; chemistry ; Molybdenum ; chemistry

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

To elucidate further sequence selectivity and nature of the binding of anticancer drugs to DNA, the interaction between anticancer drugs, which are minor groove ligands (distamycin A, DM and netropsin, NP) and intercalator (mitoxantrone, MT), and DNA were studied by electrospray ionization mass spectrometry. The 2 : 1 specific complex of DM and AT-rich DNA were observed principally, while only 1 : 1 specific complex of NP and AT-rich DNA were observed. MT specifically binds to GC-rich DNA. In addition, DM binds to DNA containing 5 A/T bases minor groove almost in a 2 : 1 mode and does not bind to DNA containing 3 A/T bases minor groove. NP binds most strongly to DNA containing 4 A/T bases minor groove. The 1 : 1 specific complex of MT and 6-mer DNA was also observed. The result of competitive binding experiment shows that DM binds more strongly to AT-rich DNA than NP does. These results provide bases for investigating the mechanism of interaction between the drugs and DNA and for improving the structure of target drug.
Antineoplastic Agents ; chemistry ; DNA ; chemistry ; Spectrometry, Mass, Electrospray Ionization ; methods

Two new polyketides, lasobutone A(1) and lasobutone B(2), along with three known compounds, guignardianone C(3), guignardic acid(4), and 4-hydroxy-17R-methylincisterol(5), were isolated from the endophytic fungi Xylaria sp. by silica gel, MCI, and preparative HPLC, which was separated from the Chinese medicinal material Coptis chinensis and cultivated through solid fermentation with rice. Their structures were elucidated on the basis of spectroscopic methods, such as MS, NMR, IR, UV, and ECD. Compounds 2 and 4 showed inhibitory activities against the nitric oxide(NO) production in the LPS-induced macrophage RAW264.7 with IC_(50) values of 58.7 and 42.5 μmol·L~(-1) respectively, while compound 5 exhibited cytotoxic activities against HT-29 with IC_(50) value of 14.3 μmol·L~(-1).
Antineoplastic Agents ; Coptis chinensis ; Endophytes/chemistry* ; Fungi ; Polyketides/chemistry*

AIMThe interactions between diorganotin (IV) complexes of 1,3-dimethyl-4-acetyl-5-pyrazolone (HL1) and mono-nucleotides together with DNA near physiological condition were investigated.

METHODSThe mode of action of the diorganotin (IV) complexes with mononucleotides and DNA under different conditions and different times were investigated by high resolution NMR technology and UV spectra.

RESULTSThe interaction of [(L1)2SnEt2] with AMP was shown to result in significant change of chemical shift of H(8), H(2) and 31P of AMP. Hyperchromic effect of DNA could be observed due to the interaction of; [(L1)2SnEt2] with DNA, while interaction of [(L1)2SnMe2] with AMP and DNA could only cause obvious change of chemical shift of 31P and lead to hypochromic effect of DNA.

CONCLUSIONThe results indicate that [(L1)2SnEt2] can selectively bind to the N1 atom of the base and the phosphate oxygen atom of AMP and may further destroy the helical structure of DNA, while the dimethyltin (IV) compound of 1,3-dimethyl-4-acetyl-5-pyrazolone [(L1)2SnMe2] merely binds to the the phosphate oxygen atom of AMP and causes the contraction of DNA helical structure.

Antineoplastic Agents ; chemistry ; DNA ; chemistry ; Nucleotides ; chemistry ; Organotin Compounds ; chemistry ; Porphyrins ; chemistry

5-fluorouracil was combined with peanut agglutinin by a water-soluble carbodiimide to prepare the tumor target conjugate of 5-fluorouracil-peanut agglutinin and the ratio of drug to conjugate was determined by the modified trinitrobenzenesulfonic acid method (TNBS). The ratio of drug to conjugate was 76.33%. The result showed that 5-fluorouracil could link to the peanut agglutinin by EDC/NHS crosslinking with high drug ratio.
Antineoplastic Agents ; chemistry ; Cross-Linking Reagents ; chemistry ; Fluorouracil ; chemistry ; Peanut Agglutinin ; chemistry

Polyethylene glycol (PEG) is extensively used to increasing the in vivo and in vitro stability of liposomes. However, PEGylated liposomes also produce some negative effects with further research, such as low cellular uptake, poor "endosomal escape" of pH sensitive liposome (PSL) and accelerated blood clearance (ABC) phenomenon, and this situation is referred as the "PEG dilemma". "PEG dilemma" posed severe challenges for the targeted delivery of PEGylated liposomes-loaded anticancer drugs, effective intracellular release of PEGylated PSL-encapsulated gene and protein drugs, and repeated administration of PEGylated liposomes. Therefore, it is urgent to solve the "PEG dilemma". This review focused on the definition, classification of "PEG dilemma", and discussed several possible approaches to overcome "PEG dilemma".
Antineoplastic Agents ; chemistry ; Drug Carriers ; chemistry ; Liposomes ; chemistry ; Polyethylene Glycols ; chemistry

Small-molecule compounds with rich sources have diverse structures and activities. The active ingredients in traditional Chinese medicine(TCM) provide new sources for the discovery of new antitumor drugs. Aconitum plants as Chinese medicinal plants have the effects of dispelling wind, removing dampness, warming meridian, and relieving pain. They are mainly used to treat inflammation, pain, rheumatism, and tumors, improve heart function, and dilate blood vessels in clinical practice. Diterpenoid alkaloids are the main active components of Aconitum plants, including C20-, C19-, C18-diterpenoid alkaloids and bis-diterpenoid alkaloids. Stu-dies have demonstrated that diterpenoid alkaloids can effectively treat lung cancer, liver cancer, breast cancer, colon cancer and other cancers. Diterpenoid alkaloids are considered as the most promising natural compounds against cancers. In this review, we summarized the chemical structures and antitumor activities of C20-, C19-, C18-diterpenoid alkaloids and bis-diterpenoid alkaloids extracted from plants of Aconitum, aiming to provide reference for further development of diterpenoid alkaloids from Aconitum as antitumor drugs.
Humans ; Aconitum/chemistry* ; Molecular Structure ; Alkaloids/analysis* ; Diterpenes/chemistry* ; Antineoplastic Agents/chemistry* ; Plant Roots/chemistry*

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

By various chromatographic techniques and extensive spectroscopic methods, 17 abietane diterpenoids were isolated from the dichloromethane fraction of the 95% ethanol cold-soak extracts of the seeds of Pseudolarix amabilis, namely pseudoamaol A(1), 12α-hydroxyabietic acid(2), 12-methoxy-7,13-abietadien-18-oic acid(3), 13-hydroxy-8,11,13-podocarpatrien-18-oic acid(4), 15-hydroxy-7,13-abietadien-12-on-18-oic acid(5), 8(14)-podocarpen-13-on-18-oic acid(6), holophyllin K(7), metaglyptin B(8), 7α-hydroxydehydroabietinsaure-methylester(9), 7-oxodehydroabietic acid(10), 15-hydroxy-7-oxodehydroabietinsaure-methy-lester(11), 15-methoxydidehydroabietic acid(12), 7-oxo-15-hydroxy-dehydroabietic acid(13), 15-hydroxydehydroabietic acid(14), 8,11,13-abietatriene-15,18-diol(15), 8,11,13-abietatriene-15-hydroxy-18-succinic acid(16), and 7β-hydroxydehydroabie-tic acid(17). Compound 1 was a new compound. The isolated compounds were evaluated for their antitumor activities(HepG2, SH-SY5Y, K562), and compounds 8 and 17 showed potential cytotoxic activity against K562 cells, with IC_(50) values of 26.77 and 37.35 μmol·L~(-1), respectively.
Humans ; Molecular Structure ; Neuroblastoma ; Diterpenes/chemistry* ; Antineoplastic Agents