Antineoplastic agents 430. Isolation and structure of cribrostatins 3, 4, and 5 from the republic of maldives cribrochalina species

Continued investigation of cancer-cell growth-inhibitory constituents of the blue marine sponge Cribrochalina sp. has led to discovery of cribrostatins 3 (4a), 4 (5), and 5 (4b) in 10(-5) to 10(-7) % of the wet weight. The structure of cribrostatin 3 (4a) was determined by results of high field (500 MHz) (1)H and (13)C NMR and HRMS interpretations. The same general approach to the structures of cribrostatins 4 (5) and 5 (4b) was completed by X-ray crystal structure determinations. Cribrostatins 3, 4, and 5 provided significant cancer cell line inhibitory activities. Cribrostatins 1 and 2(2) and the newly isolated cribrostatins 3-5 displayed antibacterial and/or antifungal activities.     

当归芍药散通过调控NF-κB炎性通路改善H2O2诱导的SH-SY5Y细胞氧化损伤的作用

目的:研究当归芍药散(Danggui Shaoyaosan,DSS)含药血清对过氧化氢(H2O2)诱导人神经母细胞瘤细胞(SHSY5Y)氧化应激和炎症反应的调控作用。方法:采用噻唑蓝(MTT)比色法测定SH-SY5Y细胞存活率构建最佳时间和最佳剂量的H2O2诱导的细胞损伤模型。实验设空白组,模型组,当归芍药散含药血清高、中、低剂量组(2.5%,5%,10%)。采用MTT比色法检测DSS干预后细胞活率,分光光度法测定抗氧化指标丙二醛(MDA),过氧化氢酶(CAT),超氧化物歧化酶(SOD)和谷胱甘肽(GSH),采用实时荧光定量聚合酶链式反应(Real-time PCR)检测肿瘤坏死因子-α(TNF-α),白细胞介素-1β(IL-1β)和白细胞介素-6(IL-6)mRNA表达水平,采用免疫荧光检测核转录因子-κB(NF-κB)p65的核移位情况。结果:H2O2浓度为250μmol·L-1干预24 h后SH-SY5Y细胞存活率约55%为最佳造模条件,DSS高、中、低剂量干预后,与模型组比较,细胞活率呈剂量依赖性上升(P<0.05),MDA明显下调(P<0.05),抗氧化指标CAT,SOD和GSH明显上升(P<0.05);H2O2能显著上调SH-SY5Y细胞炎性因子TNF-α,IL-1β和IL-6 mRNA表达水平,并介导胞质NF-κB的激活和向核移位,当归芍药散含药血清能呈剂量依赖性抑制NF-κB p65的入核并降低IL-1β,IL-6和TNF-α等细胞炎性因子的mRNA表达水平。结论:当归芍药散含药血清可以显著降低H2O2诱导的SH-SY5Y细胞的氧化损伤通过改善其抗氧化状态,同时也能降低炎症反应通过抑制NF-κB信号通路。     

5-hydroxytryptamine-derived alkaloids from two marine sponges of the genus Hyrtios

Indonesian specimens of the marine sponges Hyrtios erectus and H. reticulatus were found to contain 5-hydroxytryptamine-derived alkaloids. Their structures were determined on the basis of their spectral properties. H. erectus contained hyrtiosulawesine (4), a new beta-carboline alkaloid, together with the already known alkaloids 5-hydroxyindole-3-carbaldehyde (1), hyrtiosin B (2), and 5-hydroxy-3-(2-hydroxyethyl)indole (3). H. reticulatus contained the novel derivative 1,6-dihydroxy-1,2,3,4-tetrahydro-beta-carboline (11) together with serotonin (5), 6-hydroxy-1-methyl-1,2,3,4-tetrahydro-beta-carboline (7), and 6-hydroxy-3,4-dihydro-1-oxo-beta-carboline (9).     

Synthesis of the marine sponge cycloheptapeptide phakellistatin 5(1)

Phakellistatin 5 (1), a constituent of The Federated States of Micronesia (Chuuk) marine sponge Phakellia costada, was synthesized by solution-phase and solid-phase techniques. Because the linear peptide bearing (R)-Asn resisted cyclization, the synthesis of this peptide was repeated using the PAL resin attachment proceeding from N-Fmoc-D-Asp-alpha-OCH(2)CH=CH(2). After addition of the final unit (Ala), the allyl ester was removed under neutral conditions with Pd(o) [P(C(6)H(5))(3)](4). Removal of the final Fmoc-protecting group and cyclization with PyAOP provided (R)-Asn-phakellistatin 5 (2) in 28% overall yield. The same synthetic route from (S)-Asp led to natural phakellistatin 5 (1) in 15% overall recovery. The solution-phase and solid-phase synthetic products derived from (S)-Asp were found to be chemically but not biologically identical with natural phakellistatin 5 (1). This important fact suggested that a trace, albeit highly cancer-cell growth inhibitory, constituent accompanied the natural product or that there is a subtle conformational difference between the synthetic and natural cyclic peptides.     

Inhibition of [3H]-LSD binding to 5-HT7 receptors by flavonoids from Scutellaria lateriflora

The hot water and 70% ethanol extracts of dried mad-dog skullcap (Scutellaria lateriflora) both bound to the 5-HT(7) receptor, with 87.2 +/- 6.2% and 56.7 +/- 1.3% inhibition of [(3)H]-LSD binding to the receptor at 100 microg/mL, respectively. The on-line analysis of a 70% ethanol extract by HPLC-UV/MS resulted in the identification of five flavones (1-5). Fractionation of the ethanol extract resulted in the isolation of three flavone-glucuronides (6-8) and a flavanone-glucuronide (9), including one new compound, lateriflorin (5,6,-dihydroxy-7-glucuronyloxy-2'-methoxyflavone) (8). The structure of 8 was determined by NMR ((1)H NMR, (13)C NMR, and NOESY experiments) and MS analysis. From the results obtained in the testing of the pure compounds, it is evident that the activity on the 5-HT(7) receptor is at least partly due to the presence of flavonoids. Scutellarin and ikonnikoside I showed the highest inhibition of [(3)H]-LSD binding with IC(50) values of 63.4 and 135.1 microM, respectively.     

A novel (5E,9Z)-dialkylindolizidine from the ant Monomorium smithii

The alkaloidal venom of Monomorium smithii was found to contain (5E,9Z)-3-butyl-5-(4-penten-1-yl)indolizidine [1b], a novel indolizidine, its monocyclic analogue trans-2-butyl-5-(8-nonen-1-yl)pyrrolidine [2], (5E,8Z)-3,5-di(5-hexen-1-yl)pyrrolizidine [3], and trans-2-(5-hexen-1-yl)-5-(8-nonen-1-yl)pyrrolidine [4]. The structure of 1b was based on the results of two independent syntheses. Reductive amination of the appropriate triketone confirmed the carbon-nitrogen skeleton of 1b and suggested its stereochemistry, which was verified by the results of a stereoselective synthesis based on pyrrole hydrogenation. The chemotaxonomic implications of this first report of the concomitance of a 3,5-dialkylindolizidine and a 3,5-dialkylpyrrolizidine in an ant venom are discussed.     

Antihyperglycemic sesquiterpenes from Psacalium decompositum.

Psacalium decompositum was investigated for antihyperglycemic compounds using diabetic ob/ob mice as a model for type 2 diabetes. In vivo bioassay-guided fractionation of an aqueous extract from the roots of P. decompositum led to the isolation of two new eremophilanolides, 3-hydroxycacalolide (1a) and epi-3-hydroxycacalolide (1b). A 1:1 mixture of 1a/1b exhibited antihyperglycemic activity when tested at 1.09 mmol/kg in ob/ob mice. The known furanoeremophilanes, cacalone (2a) and epicacalone (2b), were also isolated from the aqueous extract and were inactive. The known furanoeremophilane, cacalol (3), was isolated from a CH2Cl2 extract of P. decompositum roots and possessed antihyperglycemic activity. The relative stereochemistry in 1a and 1b was assigned 3R,5S and 3S,5S, respectively, based on ROESY data, 3J H-H values, and molecular mechanics calculations. Complete 13C and 1H NMR chemical shifts were assigned for 1a, 1b, 2a, 2b, and 3, and several revisions in 13C NMR assignments for 2a and 3 were made. Results from the conformational analysis of 1a, 1b, 2a, and 2b indicate that each compound exists in one major conformation in solution with H3-12 in a pseudoaxial position.     

高效液相色谱法测定人血浆中氟尿嘧啶浓度

 目的测定人血浆中氟尿嘧啶的浓度。方法高效液相色谱法，测量氟尿嘧啶的波长λ_max=254nm，流动相为水-甲醇 冰醋酸(96.95∶3.0∶0.05),pH=3.5。结果回归方程为Y=11.82X+0.078(r=0.999 2)，其线性范围为0.66～42.00μg·mL^-1，最低检测浓度为0.154 9 μg·mL^-1(S/N=3)。结论该法简单、快速、结果准确，适用于临床氟尿嘧啶的药物浓度监测     

5-deoxyflavones with cytotoxic activity from Mimosa diplotricha

Bioassay-guided isolation of Mimosa diplotricha led to the isolation of four new 5-deoxyflavones, diplotrins A-C (1-3) and diplotasin (4), together with 12 known flavonoids, flavonolignans, and triterpenoids. On the basis of spectroscopic evidence, compounds 1-4 were characterized as 2',5'-dihydroxy-3,7,8,4'-tetramethoxyflavone (1), 3'-hydroxy-3,7,8,4'-tetramethoxyflavone (2), 2'-hydroxy-7,4',5'-trimethoxyflavone (3), and 4-hydroxy-3,10,11-trimethoxyisochromeno-[4,3-b]-chromen-7(5H)-one (4). The cytotoxic effects of these isolated compounds were evaluated against the A549, AGS, HT-29, and PC3 human cancer cell lines. Compounds 2 and 5″-methoxyhydnocarpin-D (5) showed the most potent antiproliferative activity.     

A vibrational circular dichroism approach to the determination of the absolute configurations of flavorous 5-substituted-2(5H)-furanones

Sotolon (1) and maple furanone (2) are naturally occurring chiral furanones. These 5-substituted-2(5H)-furanones are industrially significant aroma compounds due to their characteristic organoleptic properties and extraordinarily low odor thresholds. Each enantiomer of 1 and 2 was successfully obtained by preparative enantioselective supercritical fluid chromatography. The absolute configuration of 1 was confirmed as (R)-(-)-1 and (S)-(+)-1 by adopting the vibrational circular dichroism (VCD) approach. The absolute configuration of 2, which has remained ambiguous since its discovery in 1957, was determined as (R)-(+)-2 and (S)-(-)-2 for the first time by the VCD technique. Surprisingly, the signs of the optical rotation of 2 are opposite of those of 1 regardless of their identical absolute configurations. This observation emphasizes the risk in absolute configurational assignments based on comparison of optical rotation signs of similar structures. Odor evaluation of the enantiomers of 2 revealed different odor intensities.