Liang Guo

Government of the People's Republic of China, Peping, Beijing, China

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Publications (9)27.41 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: A series of novel N(2)-alkylated quaternary β-carbolines was synthesized by modification of position-1, 2, 7 and 9 of β-carboline nucleus with various alkyl and arylated alkyl substituents, and their cytotoxic activities in vitro and antitumor potencies in mice were evaluated. Compound 3m was found to be the most potent antitumor agent. SARs analysis revealed that (1) the substituents in position-2 and 9 of β-carboline nucleus played a vital role in modulation of antitumor activity; (2) the benzyl and 3-phenylpropyl substituents in position-2 and 9 of β-carboline ring were the optimal substituents giving rise to significant antitumor agent. These compounds might be a novel promising class of antitumor agents with clinical development potential.
    European Journal of Medicinal Chemistry 04/2013; 65C:21-31. · 3.43 Impact Factor
  • Qin Ma, Liang Guo, Jie Sun, Wen-Xi Fan
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    ABSTRACT: The starting material L-tryptophan reacted with 4-chlorobenzaldehyde via Pictet-Spengler condensation and followed by oxidation and decarboxylation to afford the 1-(4-chlorophenyl)-beta-carboline. The intermediate was further reacted with alkyl halogenide by N(9)-alkylation and N2-quaternarization to obtain 12 novel 1-(4-chlorophenyl)-beta-carboline derivatives. The chemical structures of all target compounds were characterized by elemental analyses, MS and 1H NMR spectra. The antitumor activities of the target compounds were evaluated by MTT method. The results demonstrated that N2-quaternarized compounds enhanced the antitumor activity significantly. In particular, compound 15 was found to be the most potent compound with IC50 values lower than 5 micromol x L(-1) against 6 human tumor cells. These results confirmed that the N2-alkyl or aralkyl substituent on the beta-carboline ring played an important role in the modulation of the antitumor activities.
    Yao xue xue bao = Acta pharmaceutica Sinica 01/2013; 48(1):77-82.
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    ABSTRACT: Harmine, a naturally occurring β-carboline alkaloid, showed good antitumor activities together with remarkable neurotoxic effects in animal models. In order to search for novel leading compounds endowed with better antitumor activities and less neurotoxicities, a series of harmine derivatives were designed and synthesized by modification of position-2, 7 and 9 of β-carboline nucleus, and their cytotoxic activities against human tumor cell lines were investigated. Acute toxicities and antitumor activities of the selected compounds in mice were also evaluated. Structure-activity relationships studies confirmed that (1) the 7-methoxy structural moiety was the pharmacophore responsible for the neurotoxic effects of this class of compounds; (2) the substituents in position-2 and 9 played a vital role in modulation of their antitumor activities.
    European Journal of Medicinal Chemistry 12/2012; 60C:135-143. · 3.43 Impact Factor
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    ABSTRACT: A series of bivalent β-carbolines with a spacer of three to ten methylene units between the indole nitrogen was synthesized and evaluated as antitumor agents. The results demonstrated that compounds 18c, 21b, 25a and 31b exhibited strong cytotoxic activities with IC(50) value of lower than 20 μM against four tumor cell lines. Acute toxicities and antitumor efficacies of the selected compounds in mice were also evaluated, compounds 18b, 21b, 26a and 31b exhibited potent antitumor activities with tumor inhibition rate of over 40% in animal models. Preliminary structure-activity relationships analysis indicated that (1) the spacer length affected antitumor potencies, and four to six methylene units were more favorable; (2) the introduction of appropriate substituent into position-1 of β-carboline facilitated antitumor potencies.
    European Journal of Medicinal Chemistry 11/2012; 60C:10-22. · 3.43 Impact Factor
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    ABSTRACT: Polo-like kinases play an essential role in the ordered execution of mitotic events and 4 mammalian PLK family members have been identified. Accumulating evidence indicates that PLK1 is an attractive target for anticancer drugs. In this paper, a series of beta-carboline derivatives were synthesized and three compounds, DH281, DH285 and DH287, were identified as potent new PLK inhibitors. We employed various biochemical and cellular approaches to determine the effects of these compounds on the activity of PLK1 and other mitotic kinases and on cell cycle progression. We found that these three compounds could selectively inhibit the kinase activity of purified PLK1, PLK2 and PLK3 in vitro. They show strong antitumor activity against a number of cancer cell lines with relatively low micromolar IC(50)s, but are relatively less toxic to non-cancer cells (MRC5). Moreover, these compounds could induce obvious accumulation of HeLa cells in G(2)/M and S phases and trigger apoptosis. Although MRC5 cells show clear S-phase arrest after treatment with these compounds, the G2/M arrest and apoptosis are less insignificant, indicating the distinct sensitivity between normal and cancer cells. We also found that HeLa cells treated with these drugs exhibit monopolar spindles and increased Wee1 protein levels, the characteristics of cells treated with PLK1 inhibitors. Together, these results demonstrate that DH281, DH285 and DH287 beta-carboline compounds are new PLK inhibitors with potential for cancer treatment.
    PLoS ONE 01/2012; 7(10):e46546. · 3.53 Impact Factor
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    ABSTRACT: A series of novel 1,9-disubstituted β-carbolines was designed, synthesized and evaluated as cytotoxic and DNA intercalating agents. Compounds 7b, 7c, 8b and 8c exhibited the most potent cytotoxic activities with IC(50) values of lower than 20 μM against ten human tumor cell lines. The results indicated that (1) the 3-chlorobenzyl and 3-phenylpropyl substituents in position-9 of β-carboline nucleus were the suitable pharmacophoric group giving rise to significant antitumor agents; (2) the length of the alkylamino side chain moiety affected their cytotoxic potencies, and three CH(2) units were more favorable. In addition, these compounds were found to exhibit remarkable DNA intercalating effects.
    European Journal of Medicinal Chemistry 08/2011; 46(10):5127-37. · 3.43 Impact Factor
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    ABSTRACT: In a continuing effort to develop novel β-carbolines endowed with better pharmacological profile, a series of water-soluble β-carbolines bearing a flexible amino side chain was designed and synthesized, and the cytotoxic activities in vitro of these compounds were evaluated. The N(9)-arylated alkyl substituted β-carbolines represented the most interesting cytotoxic agents, and compounds 4c and 4d were found to be the most potent compounds with IC(50) values lower than 10 μM against ten human tumor cell lines. The results confirmed that the N(9)-arylated alkyl substituents of β-carboline played a very important role in the modulation of the cytotoxic potencies. In addition, the interaction with DNA of these compounds was also investigated, these compounds were found to exhibit significant DNA binding affinity.
    European Journal of Medicinal Chemistry 11/2010; 45(11):4740-5. · 3.43 Impact Factor
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    ABSTRACT: The condensation of alkylenediamine with ethyl β-carboline-1-carboxylate and 1-bromo-β-carboline gave β-carboline-1-carboxamides and 1-amino-β-carbolines, respectively. Some of these β-carbolines were active against a panel of human tumor cell lines, and 1-amino derivatives were more potent than their 1-carboxamide congeners. In particular, among the 1-amino-β-carbolines, the N(9)-arylated alkyl substituted β-carbolines exhibited the most interesting cytotoxic activities with IC(50) value of lower than 20 μM. The preliminary structure-activity relationships (SARs) analysis suggested that (1) 1-amino substituents were the advisable pharmacophoric group for enhanced cytotoxic activities; (2) the introduction of appropriate arylated alkyl groups into position-9 of β-carboline facilitated their cytotoxic potencies.
    European Journal of Medicinal Chemistry 11/2010; 45(11):5513-9. · 3.43 Impact Factor
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    ABSTRACT: A better way to treat complex diseases such as cancer is to aim for several targets at once. Beta-carboline derivatives have been shown to have anticancer activity, but these compounds may target several enzymes required for cell division. Polo-like kinases (PLKs) are well conserved serine/threonine kinases and PLK1 plays multiple roles in cell proliferation. Thus, PLK1 is one of the attractive mitotic targets for anticancer drugs. We found that DH166, a beta-carboline derivative, inhibits the growth of cdc5-2 temperature-sensitive mutant more profoundly than wild-type yeast cells. Because Cdc5 is the human PLK1 homologue in budding yeast, this observation indicates that DH166 might be a PLK1 inhibitor. Indeed, DH166 inhibits the kinase activity of purified PLK1 at low micromolar concentration in an ATP-competitive manner, which is consistent with the docking result based on the crystal structure of PLK1. In addition, DH166 blocks cancer cell proliferation, causes a mitotic arrest, increases cyclin B1 accumulation, induces aberrant mitotic spindles and apoptosis, presumably due to the downregulation of PLK1. Although beta-carboline derivatives have been demonstrated to show antitumor activities through multiple mechanisms, our data indicate for the first time that their cytotoxicity to tumor cells might be attributable to the inhibition of PLK1 as well.
    Cancer biology & therapy 12/2009; 8(24):2374-83. · 3.29 Impact Factor

Publication Stats

30 Citations
27.41 Total Impact Points

Institutions

  • 2012
    • Government of the People's Republic of China
      Peping, Beijing, China
  • 2010–2012
    • Sun Yat-Sen University
      • Department of Chemical Engineering
      Guangzhou, Guangdong Sheng, China