Synthesis and evaluation of antitumor activity of novel 2-[<Emphasis Type="Italic">N</Emphasis>-Methyl-<Emphasis Type="Italic">N</Emphasis>-(4-methyl-1,3-benzothiazol-2-yl)aminomethyl]-5,8-diacyloxy-1,4-naphthoquinones

A series of nine new compounds bridged by acyl groups at the 5,8-dihydroxyl group of DHNQ were synthesized and their cytotoxic activity against L1210 and P388 cancer cells was examined. Their antitumor action in mice bearing S-180 cells in the peritoneal cavity was also assessed. Increasing the size of the acyl group (compounds 7–9) up to propyl increased the antitumor activity (T/C value), whereas the cytotoxicity of these compounds was comparable against L1210 (lymphocytic leukemia) and P388 (lymphoid neoplasm) cancer cells. Further increasing in the chain length (compounds 11–15) decreased the potency. Thus, acyl group chains of three carbon atoms is optimal for antitumor activity. The most potent compound of this series was 2-[N-methyl-N-(4-methyl-1,3-benzothiazol-2-yl)aminomethyl]-5,8-dipropylcarbonyloxy-1,4-naphthoquinone (compound 9) with a T/C (%) value of 354.     

Anthracene-1,4,9,10-tetraone Derivatives: Synthesis and Antitumor Activity

A series of 2-alkylated anthracene-1,4,9,10-tetraone (ATO) derivatives were synthesized, and their antitumor action in ICR mice bearing S-180 cells and antiproliferative activity against L1210 cells were evaluated. Overall, the introduction of an alkyl group (C₁–C₈) at C-2 enhanced the antiproliferative activity. Among 2-(1-hydroxyalkyl)- or 2-(1-acetoxyalkyl)-ATO derivatives, four compounds possessing alkyl chain of an intermediate size (C₄–C₆) gave T/C values of > 300%. Acetylation at 1′-OH failed to cause an enhancement in the antitumor action, in contrast to a remarkable increase in antiproliferative activity. Although there was no direct relationship between antiproliferative activity and antitumor action, the compounds with lower antiproliferative activity tended to show higher antitumor activity. Further study shows that the antiproliferative activity of ATO derivatives may be explained properly neither by redox cycling nor arylating capacity.     

Anti-angiogenic effect of triterpenoidal saponins from Polygala senega

Senegasaponins [senegin II (1), senegin III (2), senegin IV (3), senegasaponin a (4), and senegasaponin b (5)] from Polygala senega were re-discovered as selective anti-proliferative substances against human umbilical vein endothelial cells (HUVECs). Senegasaponins (1–5) showed anti-proliferative activity against HUVECs with IC₅₀ values in the range 0.6–6.2 μM, and the selective index was 7–100-fold in comparison with those for several cancer cell lines, while the desacyl mixture of senegasaponins (6) and tenuifolin (7) lost anti-proliferative activity, indicating that the 28-O-glycoside moiety and methoxycinnamoyl group were essential for the HUVEC-selective growth inhibition of senegasaponins. Senegin III (2) inhibited the vascular endothelial growth factor (VEGF)-induced in vitro tubular formation of HUVECs and basic fibroblast growth factor (bFGF)-induced in vivo neovascularization in the mouse Matrigel plug assay. Moreover, senegin III (2) suppressed tumor growth in the ddY mice s.c.-inoculated murine sarcoma S180 cells. The analysis of the action mechanism of senegin III (2) suggested that the induction of pigment epithelium-derived factor (PEDF) would contribute to the anti-angiogenic effects of senegasaponins.     

Synthesis and cytotoxic activities of <Emphasis Type="Italic">C</Emphasis>-benzylated flavonoids

Some C-benzylated flavonoids based on gericudranin A were synthesized and evaluated their cytotoxic activities for the elucidation of structure-activity relationship. 2,4,6-Trihydroxyacetophenone was converted to target molecules in 6∼7 steps via sequential protection, aldol condensation, cyclization, regioselective C-benzylation, and deprotection. The cellular growth inhibition of the synthetic C-benzylated flavonoids was investigated against sixteen human cancer cell lines. Among these compounds, 5b showed the most potent cytotoxicities against several cell lines, especially as potent as adriamycin against SNB19 cell lines with an IC₅₀ value of 0.7 μM.     

Synthesis and evaluation of antitumor activity of 2- and 6-[(1,3-benzothiazol-2-yl)aminomethyl]-5,8-dimethoxy-1,4-naphthoquinone derivatives

2- or 6-substituted BZT-N derivatives were synthesized, and their cytotoxic activity against cancer L1210 and SNU-1 cells was examined. The antitumor action was also assessed in mice bearing S-180 cells in peritoneal cavity. In a comparison, it was found that 6-substituted BZT-N derivatives exhibited higher potencies in both bioactivities than 2-substituted BZT-N derivatives against L1210 cells in in vitro and S-180 in vitro tests exception of compound 36. Interestingly, it was observed that 2-substituted compound 36, which has methyl group at R1 position, exhibited a better antitumor activity than 6-substituted compounds against L1210 and SNU-1 in vitro. The ED50 value of 2-substituted compound 36 against L1210 was found to be comparable to the ED50 value of adriamycin and was even better against the solid cancer cell line SNU-1. It was also observed that 2-substituted compound 36 showed better antitumor activity in mice bearing S-180 cells in the peritoneal cavity. The T/C (%) value of 2-substituted compound 36 was similar to that of adriamycin. Quantitative structure-activity relationship (QSAR) tests reveal that the experimental ED50 values against SNU-1 closely correlate with both the calculated HOMO energies (E(HOMO)) and the measured 1H-NMR chemical shift of 3-H (deltaH). The results suggests that a compound having higher E(HOMO) and deltaH values usually should have a lower ED50 (SNU-1) value.     

山药提取物联合树突细胞-细胞因子诱导的杀伤细胞对荷MDA-MB-231乳腺癌干细胞瘤裸鼠的治疗作用研究

目的 研究山药Dioscorea opposita提取物联合树突细胞-细胞因子诱导的杀伤细胞（DC-CIK）对荷MDA-MB-231乳腺癌干细胞瘤裸鼠的治疗效果。方法 制备荷MDA-MB-231乳腺癌干细胞Balb/c裸鼠模型,随机分为4组,每组8只：对照组裸鼠尾iv生理盐水,0.2 mL/次,2次/周;DC-CIK组裸鼠在肿瘤干细胞接种4 d后尾iv 1×10⁶个DC-CIK细胞,2次/周,给药3周;山药提取物组裸鼠ig山药提取物125 mg/kg,0.2 mL/d,给药3周;山药提取物联合DC-CIK组裸鼠ig山药提取物125 mg/kg,0.2 mL/d,同时尾iv 1×10⁶个DC-CIK细胞,2次/周,给药3周。各组裸鼠在治疗3周期间每2天测量瘤体大小及裸鼠体质量,治疗结束后处死裸鼠,取出瘤体称质量;qRT-PCR法检测瘤组织中Akt信号通路中关键原癌基因c-Myc表达水平。结果 治疗结束后,各组裸鼠瘤体生长速率为山药提取物联合DC-CIK组结论 对荷MDA-MB-231乳腺癌干细胞瘤裸鼠治疗效果中,各给药组裸鼠肿瘤生长均受到明显抑制,其中以山药提取物联合DC-CIK组效果最佳。     

Naphthazarin derivatives: Synthesis, cytotoxic mechanism and evaluation of antitumor activity

The rate of the GSH conjugate formation, the inhibition of DNA topoisomerasel-1 and the cytotoxic activity against L1210 cells of the naphthoquinones showed the same order; 5,8-dimethoxy-1,4-naphthoquinone (DMNQ)>6-(1-hydroxyethyl)-DMNQ>2-(1-hydroxyethyl)-DMNQ; the steric hindrance of the substituents, particularly 2-substutuent, in reacting with cellular nucleophiles must be the main cause for lowering the bioactivities. Acetylation of 2-(1-hydroxyethyl)-DMNQ producing 2-(acetyloxyethyl)-DMNQ potentiated the bioactivities; 2-(1-hydroxyethyl)-DMNQ did not react with GSH and the enzyme, and showed ED₅₀ of 0.680 μg/ml, whereas the values of 2-(1-acetyloxyethyl)-DMNQ were the conjugate formation of 0.14 μM, IC₅₀ value of 81 μM for the enzyme inhibition and ED₅₀ of 0.146 μg/ml for the cytotoxcity. Furthermore, the acetylation 2-(1-hydroxyethyl)-DMNQ (T/C, 119%) enhaced the T/C values for the mice bearing S-180 tumor [T/C of 2-(1-acetyloxyethyl)-DMNQ, 276%]. It was assumed that the difference in bioactivities ensued by acetylation was based on the mechanism of the so-called bioreductive alkylation.     

大豆多糖对S180荷瘤小鼠免疫调节作用的研究

目的 从免疫学角度探讨大豆多糖对荷瘤小鼠抗肿瘤作用的机制。方法 采用分光光度计测定大豆多糖对S₁₈₀荷瘤小鼠巨噬细胞一氧化氮生成量的影响,利用酶标仪测定大豆多糖对S₁₈₀荷瘤小鼠腹腔巨噬细胞吞噬功能的影响,定量溶血分光光度法检测B细胞功能。结果 与对照组比较,大豆多糖各组均能显著提高小鼠巨噬细胞的吞噬活性,同时能明显提高荷瘤小鼠巨噬细胞产生一氧化氮的能力,并能使体内B淋巴细胞数量增加而提高抗体生成量。结论 大豆多糖通过调节荷瘤小鼠免疫功能发挥抗肿瘤作用。     

大豆多糖对S180荷瘤小鼠免疫调节作用的研究

目的 从免疫学角度探讨大豆多糖对荷瘤小鼠抗肿瘤作用的机制。方法 采用分光光度计测定大豆多糖对S₁₈₀荷瘤小鼠巨噬细胞一氧化氮生成量的影响,利用酶标仪测定大豆多糖对S₁₈₀荷瘤小鼠腹腔巨噬细胞吞噬功能的影响,定量溶血分光光度法检测B细胞功能。结果 与对照组比较,大豆多糖各组均能显著提高小鼠巨噬细胞的吞噬活性,同时能明显提高荷瘤小鼠巨噬细胞产生一氧化氮的能力,并能使体内B淋巴细胞数量增加而提高抗体生成量。结论 大豆多糖通过调节荷瘤小鼠免疫功能发挥抗肿瘤作用。     

Pharmacologically active compounds in the Anoectochilus and Goodyera species

The extract of Anoectochilus formosanus showed significant activity in decreasing the levels of the cytosolic enzymes LDH, GOT, and GPT, and the result demonstrated that A. formosanus possessed prominent hepatoprotective activity against CCl₄-induced hepatotoxicity. Moreover, in the results of the test using aurothioglucose-induced obese mice, the extract showed a significant antihyperliposis effect. A. formosanus grown in the wild and propagated by tissue culture contain ten compounds, including a major known component, (3R)-3-(β-d-glucopyranosyloxy)butanolide (kinsenoside; 1), and two new components, (3R)-3-(β-d-glucopyranosyloxy)-4-hydroxybutanoic acid (2) and 2-[(β-d-glucopyranosyloxy)methyl]-5-hydroxymethylfuran (3), along with the known compounds, isopropyl-β-d-glucopyranoside (4), (R)-3,4-dihydroxybutanoic acid γ-lactone (5), 4-(β-d-glucopyranosyloxy) benzyl alcohol (6), (6R,9S)-9-(β-d-glucopyranosyloxy)megastigma-4,7-dien-3-one (7), and (3R)-3-(β-d-glucopyranosyloxy)-4-hydroxybutanolide (8). Since a higher concentration of kinsenoside (1) was detected in the crude drugs A. formosanus and A. koshunensis by high-performance liquid chromatography (HPLC) analysis, we proved a simple purification system for kinsenoside (1), giving 180 mg of kinsenoside (1) from 1 g of dried samples for further pharmacological experiments. In an anti-hyperliposis assay using high-fat-diet rats, 1 significantly reduced the weights of the body and the liver, and also decreased the triglyceride level in the liver compared to those of control rats. On the other hand, the epimer of 1, (3S)-3-(β-d-glucopyranosyloxy)butanolide, goodyeroside A (9), which was isolated from the Goodyera species, had no effect for anti-hyperliposis. In aurothioglucose-induced obese mice, 1 suppressed the body and liver weight increase, significantly ameliorated the triglyceride level in the liver, and also reduced the deposition of uterine fat pads. The anti-hepatoxic activities of 9 and goodyerosides B (10) were studied on injury induced by CCl₄ in primary cultured rat hepatocytes by measuring the levels of LDH, GOT, and GPT. In the CCl₄-treated control group, there were marked increases in LDH, GOT, and GPT activities compared with the normal group. In contrast, these levels were suppressed in 9- and 10-treated groups. Goodyerin (11), a new typical flavone glycoside, exhibited a significant and dose-dependent sedative and anticonvulsant effect.     

Anti-HIV-1 activity of lignans from the fruits of <Emphasis Type="Italic">Schisandra rubriflora</Emphasis>

This study investigated the 70% aqueous acetone extract of the fruits of Schisandra rubriflora which led to the isolation of eight lignans, including a new isolate, rubrisandrin C (1), and seven known lignans (2–8). The structure of 1 was established by extensive 1D and 2D NMR spectroscopy and its absolute stereochemistry was determined by CD spectrum. Compounds 1–5 and 7–8 were evaluated for their anti-HIV-1 activity that showed inhibitory activity on HIV-1_IIIB induced syncytium formation with EC₅₀ values in the range of 2.26∼20.4 μg/mL. Compounds 1 and 7 exerted their obvious protection of HIV-1_IIIB inducted MT-4 host cells lytic effects with a selectivity index of 15.4 and 24.6, respectively.     

吉非替尼脂质体对S180荷瘤小鼠生存时间及生命质量的影响

目的 考察吉非替尼(GFB)脂质体对S180荷瘤小鼠生存时间及生命质量的影响。方法 30只小鼠制备S180荷瘤模型,随机分为5组:模型组,GFB低、高剂量溶液(GFB-S-20、GFB-S-40)组,GFB低、高剂量脂质体(GFB-L-20、GFB-L-40)组,低、高剂量为20、40 mg/kg。观察荷瘤小鼠的生存时间、体质量和肿瘤体积的增长情况,并以为自主活动次数为指标,评价小鼠的生命质量。结果 与模型组比较,GFB组的生存时间明显延长(P<0.05、0.01),GFB-L-40组生存时间显著长于GFB-S-40组(P<0.05);模型组小鼠体质量增长最快;肿瘤生长速度大小顺序为:模型组> GFB-S-20组> GFB-S-40组> GFB-L-20组> GFB-L-40组;GFB显著改善荷瘤小鼠自主活动次数下降,相同剂量的溶液和脂质体组之间存在显著性差异(P<0.05)。结论 GFB脂质体明显延长了S180荷瘤小鼠的生存时间,提高了生命质量,效果优于溶液组。     

Antitumor activity of arylacetylshikonin analogues

Twenty one phenylacetylshikonin analogues were synthesized from various substituted phenyl acetic acids and their cytotoxicity values against A549, K562 and L1210 cell lines and antitumor action in mice bearing S-180 cells were measured. All of phenylacetylshikonin analogues expressed a potent cytotoxicity (ED₅₀, 0.1–1.80 μg/ml) against L1210 and K562 cells. L 1210 cells were the most sensitive to shikonin analogues among these cells. Except 4-methoxyphenylacetylshikonin (0.098μg/ml) and α-acetoxyphenylacetylshikonin (0.10μg/ml), all other shikonin derivatives showed higher ED₅₀ values than phenylacetylshikonin (0.13μg/ml) in L 1210. In K562 cell, α-substitution of phenylacetylshikonin (0.1 μg/ml), while other substitutions increased it slightly; 4-methoxyphenylacetylshikonin (0.033 μg/ml) showed a exceptionally good cytotoxicity against K562 cell. 4-Halogenation tended to decrease the cytotoxic effect on L1210 cells, while it enhanced the effect on K562; 4-bromophenylacetyl [ED₅₀ (L1210)=1.76 μ/ml, ED₅₀ (K 562)=0.32 μg/ml] and 4-chlorophenylacetyl shikonin [ED₅₀ (L 1210)=1.64 μg/ml, ED₅₀ (K562)=0.32 μg/ml]. In contrast, A549 cells were much less sensitive to these shikonin analogues which showed ED₅₀ values of 1.5–13.5 μg/ml. Most of phenylacetylshikonin derivatives showed good antitumor activity in mice bearing S-180 cells. α-A-cetoxyphenylacetylshikonin and 4-dimethylaminophenylacetylshikonin showed highest T/C value (192–195%), implying that introduction of α-acetyl or of 4-dimethyl amino group gave a positive effect on the antitumor activity. Introduction of 4-dimethylamino group enhanced the antitumor activity as shown for 4-dimethylaminophenylacetylshikonin (T/C, 192%). It might be due to improvement of water solubility by dimethylamino group in the molecule.     

Inhibition of DNA topoisomerases I and II and cytotoxicity of compounds from <Emphasis Type="Italic">Ulmus davidiana</Emphasis> var. <Emphasis Type="Italic">japonica</Emphasis>

Twenty five compounds including ten triterpenes (1–3, 5–11), six flavonoids (12–15, 24, 25), five lignans (17, 18, 21–23), two butenyl clohexnone glycosides (19–20), one fructofuranoside (16) and one fatty acid (4) were isolated from the roots of Ulmus davidiana var. japonica. The structures of those compounds were identified by comparing their physicochemical and spectral data with those of published in literatures. All the compounds were evaluated for DNA topoisomerase inhibitory activities and cytotoxicities. Among the purified compounds, 4 and 19 showed more potent inhibitory acitivities (IC₅₀: 39 and 19 μM, respectively) than camptothecin, as the positive control (IC₅₀: 46 μM) against topoisomerase I. Compounds, 4, 10, 12, 19, 24 and 25 showed strong inhibitory activities toward DNA topoisomerase II (IC₅₀: 0.1, 0.52, 0.47, 0.42, 0.17 μM and 17 nM, respectively), which were more potent than that of etoposide as positive control (IC₅₀: 20 μM). In A549 cell line, 5 and 6 showed cytotoxicities (IC₅₀: 4 μM and 3 μM, respectively, with IC₅₀ of camptothecin as positive control: 10.3 μM). In the HepG2 cell line, 3, 5 and 7 showed cytotoxicity (IC₅₀: 4, 3 and 4 μM, respectively, with IC₅₀ of camptothecin: 0.3 μM). Compounds 6, 12 and 23 showed cytotoxicities in the HT-29 cell line (IC₅₀: 19, 19 and 15 μM, respectively, with IC₅₀ of camptothecin: 2 μM).     

2- or 6-(1-azidoalkyl)-5,8-dimethoxy-1,4-naphthoquinone: Synthesis, evaluation of cytotoxic activity; Antitumor activity and inhibitory effect on DNA topoisomerase-I

6-(1-azidoalkyl)-DMNQ derivatives compared to 2-(1-azidoalkyl)-DMNQ isomers, exhibited higher cytotoxic activity against L1210 mouse leukemia cells and stronger inhibition of DNA topoisomerase-I (TOPO-I), suggesting involvement of steric hindrance. However, similar antitumor activity against mice bearing S-180 cell was shown by 2- and 6-(1-azidoalkyl)-DMNQ derivatives.     

A new cytotoxic coumarin, 7-[(<Emphasis Type="Italic">E</Emphasis>)-3′,7′-dimethyl-6′-oxo-2′,7′-octadienyl] oxy Coumarin,from the leaves of <Emphasis Type="Italic">Zanthoxylum schinifolium</Emphasis>

A new coumarin, 7-[(E)-3′,7′-Dimethyl-6′-oxo-2′,7′-octadienyl]oxy coumarin (1), together with three known compounds, schinilenol (2), schinindiol (3) and 7-[(E)-7′-hydroxy-3′,7′-dimethylocta-2′,5′-dienyloxy]-coumarin (4) were isolated from the methylene chloride fraction of Z. schinifolium by normal and reverse phase column chromatographies. Their structures were determined on the basis of physical and spectroscopic evidences. Compound 1 (IC₅₀ 8.10 μM) showed potent cytotoxicity compared to auraptene (IC₅₀ 55.36 μM) against Jurkat T cells. The other isolated compounds 2 and 4 exhibited weak cytotoxicities.     

Potential antitumor α-methylene-ψ-butyrolactone-bearing nucleic acid bases. 2. Synthesis of 5′-methyl-5′-[2-(5-substituted uracil-1-yl)ethyl]-2′-oxo-3′-methylenetetrahydrofurans

Ten, heretofore unreported, 5′-methyl-5′-[2-(5-substituted uracil-1-yl)ethyl)]-2′-oxo-3′-methylenetetrahydrofurans (H, F, Cl, Br, I, CH₃, CH₃, CH₂CH₃, CH=CH₂, SePh) (7a-j) were synthesized and evaluated against four cell lines (K-562, FM-3A, P-388 and U-937). For the preparation of α-methylene-γ-butyrolactone-linked to 5-substituted uracils (7a-j), the convenient Reformasky type reaction was employed which involves the treatment of ethyl α-(bromomethyl)acrylate and zinc with the respective 1-(5-substituted uracil-1-yl)-3-butanone (6a-j). The 5-substituted uracil ketones (6a-j) were directly obtained by the respective Michael type reaction of vinyl methyl ketone with the K₂CO₃ (or NaH)-treated 5-substituted uracils (5a-j) in the presence of acetic acid in the DMF solvent. The α-methylene-γ-butyrolactone compounds showing the most significant antitumor activity are7e, 7f, 7h and7j (inhibitory concentration (IC₅₀) ranging from 0.69 to 2.9 μg/ml), while7b, 7g and7i have shown moderate to significant activity. The compounds7a, 7c and7d were found to be inactive. The synthetic intermediate compounds6a-j were also screened and found marginal to moderate activity where compounds6b and6g showed significant activity (IC₅₀:0.4∼2.8 μg/ml).     

Comparison of the cytotoxic effect of lapachol, α-lapachone and pentacyclic 1,4-naphthoquinones on human leukemic cells

The pentacyclic 1,4-naphthoquinones 1a–d were cytotoxic (IC₅₀ ∼ 2–7 μM) to human leukemic cell lines K562 (oxidative stress-resistant), Lucena-1 (MDR phenotype) and Daudi. Fresh leukemic cells obtained from patients, some with the MDR phenotype, were also sensitive to these compounds. The pentacyclic 1,4-naphthoquinones 1a and 1c induced apoptotic cell death in cells from leukemic patients as determined by flow cytometry. Conversely, the cell lines were highly insensitive to lapachol (2) and α-lapachone (3). Mitomycin-C inhibited cell proliferation at concentrations as low as 0.5 μM. The low toxicity against lymphocytes activated by phytohemagglutinin shows that these compounds are selective for the cancer cells studied. Previous data suggest that these compounds (1a–d) can be bioactivated in situ by reduction followed by rearrangement leading to enones, which are powerful alkylating agents. In contrast, lapachol (2) and β-lapachone (3), which cannot be bioactivated by reduction, showed little activity against the same cell lines.     

Immunosuppressive effects of new cyclolanostane triterpene diglycosides from the aerial part of <Emphasis Type="Italic">Cimicifuga foetida</Emphasis>

Two new cyclolanostane diglycosides, cimifoetiside A (1) and cimifoetiside B (2), were isolated from an 80% ethanolic extract of the aerial part of Cimicifuga foetida L. (Ranuculaceae). Using spectral data and chemical analysis, the structures of 1 and 2 were identified as (23R, 24S) cimicigenol 3-O-β-D-glucopyranosyl-(1″→3′)-β-D-xylopyranoside and (23R, 24S) cimicigenol 3-O-β-D-glucopyranosyl-(1″→2′)-β-D-xylopyranoside, respectively. The in vitro immunosuppressive effects of the two new compounds 1 and 2, as well as four other known cyclolanostane saponins 3–6 on T cells were evaluated. All the agents tested effectively inhibited the proliferation of murine splenocytes induced by Concanavalin A (ConA), with IC₅₀ values ranging from 12.7 nM to 33.3 nM.     

Promotion of IL-8 production in PMA-stimulated HL-60 cells by sesquiterpene quinones from a marine sponge, <Emphasis Type="Italic">Hippospongia</Emphasis> sp.

An extract of a marine sponge, Hippospongia sp., collected in Palau has inhibitory activity against colony formation by Chinese hamster V79 cells. Bioassay-guided isolation gave eleven sesquiterpene quinones. Compounds 1–8 inhibited colony formation by V79 cells with EC₅₀ values between 0.6 and 2.8 μmol L⁻¹. Their effects on the production of an inflammatory cytokine, IL-8, in tetradecanoyl phorbol acetate (PMA)-stimulated HL-60 cells were also investigated, because IL-8 production is sometimes correlated with inhibition of cell growth. Ilimaquinone (1) and its 5 epimer (2) had similar activity against V79 cells (EC₅₀ = 2.8 and 2.3 μmol L⁻¹, respectively) but did not modulate IL-8 production even at 10 μmol L⁻¹. Smenospongidine (3) and its 5 epimer (4), smenospongiarine (5) and its 5 epimer (6), and smenospongine (7) and its 5-epimer (8), at 10 μmol L⁻¹, promoted IL-8 production. Compounds 3, 5, and 7 had slightly stronger activity against V79 cells (EC₅₀ = 0.6, 1.7, and 0.8 μmol L⁻¹, respectively) than the corresponding 5 epimers 4, 6, and 8 (EC₅₀ = 0.8, 2.3, and 2.0 μmol L⁻¹, respectively). A similar structure–activity relationship was observed for promotion of IL-8 production. This is the first report of modulation of IL-8 production by these sesquiterpene quinones.