Chong Ock Lee

Antitumor activity of some phenolic components in plants

The activity-guided fractionation of some medicinal plants led to yield five kinds of natural stilbene compounds namely 3,5-dihydroxy-4′-methoxystillbene(I), rhapontigenin(II), resveratrol (III), rhaponticin(IV) and piceid(V) and two common flavonoids, apigenin(VI) and luteolin(VII) as active principles of the antitumor property, in vitro, against five kinds of human tumor cell lines, A-549, SK-OV-3, SK-MEL-2, XF-498 and HCT15.

Synthesis andin vitro cytotoxicity of cinnamaldehydes to human solid tumor cells

Cinnamaldehydes and related compounds were synthesized from various cinnamic acids based on the 2′-hydroxycinnamaldehyde isolated from the bark ofCinnamomum cassia Blume. The cytotoxicity to human solid tumor cells such as A549, SK-OV-3, SK-MEL-2, XF498 and HCT15 were measured. Cinnamic acid, cinnamates and cinnamyl alcohols did not show any cytotoxicity against the human tumor cells. Cinnamaldehydes and realted compounds were resistant to A549 cell line up to 15 μg/ml. In contrast, HCT15 and SK-MEL-2 cells were much sensitive to these cinnamaldehyde analogues which showed ED50 values 0.63-8.1 μg/ml. Cytotoxicity of the saturated aldehydes was much weak compared to their unsaturated aldehydes. From these studies, it was found that the key functional group of the cinnamaldehyde-related compounds in the antitumor activity is the propenal group.

Antitumor activity ofPsoralea corylifolia

The activity-oriented fractionation ofPsoralea corylifolia led to an isolation of a (+)-bakuchiol1 as an active principle of its antitumoral propertyin vitro.1 was observed to exhibit a mild cytotoxicity against five kinds of cultured human cancer cell lines,i.e. the A549, SK-OV-3, SK-MEL-2, XF498 and HCT15. The synthesized 2,3-epoxide of (+)-bakuchiol3 showed the similar activity as the (+)-bakuchiol1, whereas the other oxidation derivatives4 and5 including the acetyl-(+)-bakuchiol2 showed a decreased activity.

Hydrolysable tannins and related compound having cytotoxic activity from the fruits ofTerminalia chebula

The cytotoxicity-directed fractionation of MeOH extract ofTerminalia chebula fruits led to the isolation of three hydrolyzed tannins and a related compound, gallic acid(I), 1,2,3,4,6-penta-O-galloyl-β-d-glucopyranose(II), chebulagic acid(III) and chebulinic acid(IV), as active principles. They were shown to exhibit moderate cytotoxicity against cultured human tumor cell lines including A-549, SK-OV-3, SK-MEL-2, XF-498 and HCT-15in vitro.

Antitumor triterpenes from medicinal plants

Thirteen kinds of naturally occurring or derivatised triterpenes, reported to have an antitumoral property, were reinvestigated on the basis of their direct cytotoxicity or the inhibitory activity on cell growth against five kinds of cultured human tumor cells,i. e., A-549, SK-OV-3, SK-MEL-2, XF498 and HCT15,in vitro. Ursonic acidIII, betulinic acidVIII, betulonic acidX and glycyrrhetinic acidXI were exhibited a marked inhibition on cell growth.

Antiviral triterpenes fromPrunella vulgaris

Two triterpenes 1 and 2 with antiviral activity againstHerpes simplex virus type 1in vitro were isolated fromPrunella vulgaris. Each compound caused a significant reduction in viral cytopathic effect whenvero cells were exposed to them for 72 hours after viral challenge. They were identified asbetulinic acid(1) and 2α, 3α-dihydroxyurs-12-en-28-oic acid(2) on the basis of their spectroscopic properties. The antiviral activity of them was estimated as EC50=30 μg/ml(1) and 8 μg/ml(2), respectively by plaque reduction assay.

In vitro antitumour activity of flavonoids from Sophora flavescens

The cytotoxicity‐guided fractionation of the roots of Sophora flavescens (Leguminosae) extracts led to the isolation of 15 active principles 1–15, responsible for cytotoxicity against five kinds of cultured human tumour cell lines, i.e. A549 (non small cell lung), SK‐OV‐3 (ovary), SK‐MEL‐2 (skin), XF498 (central nerve system) and HCT‐15 (colon), evaluated by SRB method in vitro. Compounds 2–14 were classified as unusual flavonoids occurring exclusively in this species and the proliferation of each of the examined tumour cells were significantly inhibited during continuous exposure to compounds 1–15 for 48u2009h, respectively.

Antitumor activity ofTrichosanthes kirilowii

The activity-directed fractionation upon the MeOH extract of the root ofTrichosanthes kirilowii led to the isolation of eight cucurbitane triterpenes namely cucurbitacin B (I), isocucurbitacin B (II), cucurbitacin D (III), isocucurbitacin D (IV), 3-epi-isocucurbitacin B (V), dihydrocucurbitacin B (VI), dihydroisocucurbitacin B (VII) and dihydrocucurbitacin E (VIII), as active principles. All isolates were shown to exhibit significant cytotoxicity against cultured human tumor cells, including A-549, SK-OV-3, SK-MEL-2, XF-498 and HCT 15, with an exceptionally high potency.

A new cytotoxic acyclic diterpene from Carpesium divaricatum.

A new acyclic diterpene (1) and a known acyclic diterpene, 12(S)-hydroxygeranylgeraniol (2) were isolated from the aerial parts ofCarpesium divaricatum. The structure of1 was determined to be (2E, 10E)-1, 12-dihydroxy-18-acetoxy-3,7,15-trimethylhexadeca-2,10,14-triene (1) on the basis of spectroscopic studies. Compounds1 and2 exhibited cytotoxicity against cultured human tumor cell lines, A549, SK-OV-3, SK-MEL-2, XF498, and HCT15, with ED50 values ranging from 4.3–10.2 μg/ml and 4.1–8.3 μg/ml, respectively.

Synthesis and biological activities of truncated acridone: Structure-activity relationship studies of cytotoxic 5-hydroxy-4-quinolone

Abstract A series of 5-hydroxy-4-quinolone ( 3 ) and 5-methoxy-4-quinolone ( 4 ) derivatives were synthesized as truncated acridone analogues and evaluated for antitumor and antiherpes activities. Among them 5-hydroxy-8-methoxy-quinolone showed potent antitumor activity (IC 50 = 17.7 μM for HL60) which was greater than that of acronycine.