正交试验法优选超声提取知母皂甙的研究

用正交实验法对知母(Anemarrhena asphodeloides Bge.)中总皂甙的超声提取工艺进行了研究,采用正交表L9(34),以提取剂的体积分数、料液比(mA∶VB)、提取时间以及提取次数为因素,以知母总皂甙元的含量为指标,用紫外分光光度计法进行检测,所得提取液经大孔树脂纯化,得到的最佳提取参数和结果为:以φ(乙醇)=75%的水溶液为提取剂、提取料液比mA∶VB=1∶8、提取次数2次、每次30min,提取率92.8%,纯度91.0%。结果证明了对知母而言,超声提取法是一种提取效率高、操作简便、省时的方法。     

Isolation and anti-oomycete activity of nyasol from Anemarrhena asphodeloides rhizomes

The methanol extract of Anemarrhena asphodeloides rhizomes exhibited strong antifungal activity against the plant pathogenic fungi Magnaphothe grisea, Rhizoctonia solani, and the plant pathogenic oomycete Phytophthora capsici. The antifungal substance isolated from the rhizomes of A. asphodeloides was identified to be nyasol, (Z)-1,3-bis(4-hydroxyphenyl)-1,4-pentadiene by NMR and mass spectral analysis. Nyasol effectively inhibited the mycelial growth of Colletotrichum orbiculare, P. capsici, Pythium ultimum, R. solani, and Cladosporium cucumerinum in a range of 1-50 mug/ml, but did not affect the growth of bacteria and yeast. In a greenhouse test, treatment with the antifungal compound nyasol was significantly effective in suppressing the Phytophthora blight on pepper plants.     

Neolignans and phenylpropanoids from the roots of Piper taiwanense and their antiplatelet and antitubercular activities

Bioassay-guided fractionation of roots from Piper taiwanense led to isolation of three neolignans, diallylcatechol (1) and neotaiwanensols A, B (2, 3), two diphenylpropanoid ethers, taiwandimerols A, B (4, 5), with one phenylpropanoid, 2,3-diacetoxy-1-methoxy-5-allylbenzene (6), previously unknown in nature, together with 18 known compounds (7–24). Their structures were elucidated by spectroscopic evidence. Among the isolates, hydroxychavicol acetate (7), and 4-allylcatechol (8) showed potent inhibitory activities against platelet aggregation induced by collagen, with IC₅₀ values of 2.1, and 5.3 μM, respectively. Hydroxychavicol acetate (7), 4-allylcatechol (8), and trans-caffeicaldehyde (9) showed antitubercular activities against Mycobacterium tuberculosis H₃₇Rv, with MIC values of 30.3, 27.6, and 25.5 μg/mL, respectively.     

Steroidal saponins with cytotoxic activities from the rhizomes of Anemarrhena asphodeloids Bge.

Two new steroidal saponins, named timosaponin R (1) and S (2), together with seven known compounds (3-9) were isolated from the rhizomes of Anemarrhena asphodeloides Bge. Their structures were elucidated on the basis of NMR spectroscopy and mass spectrometry. All the compounds were evaluated for cytotoxic activities against the four human cancer cell lines MCF7, SW480, HepG2 and SGC7901 in vitro. Compounds 7-9 showed moderate activities against all the cell lines.     

Molecular and functional characterization of a new non-hemorrhagic metalloprotease from Bothrops jararacussu snake venom with antiplatelet activity

BjussuMP-II is an acidic low molecular weight metalloprotease (Mr  24,000 and pI  6.5), isolated from Bothrops jararacussu snake venom. The chromatographic profile in RP-HPLC and its N-terminal sequence confirmed its high purity level. Its complete cDNA was obtained by RT-PCR and the 615 bp codified for a mature protein of 205 amino acid residues. The multiple alignment of its deduced amino acid sequence and those of other snake venom metalloproteases showed a high structural similarity, mainly among class P-I proteases. The molecular modeling analysis of BjussuMP-II showed also conserved structural features with other SVMPs. BjussuMP-II did not induce hemorrhage, myotoxicity and lethality, but displayed dose-dependent proteolytic activity on fibrinogen, collagen, fibrin, casein and gelatin, keeping stable at different pHs, temperatures and presence of several divalent ions. BjussuMP-II did not show any clotting or anticoagulant activity on human citrated plasma, in contrast to its inhibitory effects on platelet aggregation. The aspects broached, in this work, provide data on the relationship between structure and function, in order to better understand the effects elicited by snake venom metalloproteases.     

Two new cycloartane-type triterpenoids and one new flavanone from the leaves of Dasymaschalon dasymaschalum and their biological activity

Two new cycloartane-type triterpenoids, 3β-hydroxy-21-O-acetyl-24-methylenecycloartane (3) and 3β,21-dihydroxy-24,31-epoxy-24-methylenecycloartane (4), one new flavanone, 7-hydroxy-6,8-dimethoxyflavanone (5), two new natural products, 2-hydroxybenzyl benzoate (7) and 2-phenyl-2-acetoxyethyl benzoate (8), and ten known compounds, 3β-hydroxy-24-methylenecycloartane (1), 3β,21-dihydroxy-24-methylenecycloartane (2), desmosdumotin B (6), artabotrene (9), (?)-senepoxide (10), (+)-crotepoxide (11), (?)-1,6-desoxypipoxide (12), rotundol (13), cassipourol (14) and (+)-spathulenol (15) were isolated from the leaves of Dasymaschalon dasymaschalum. The structures of the new compounds were elucidated by spectroscopic analysis and of the known compounds by comparison of their physical, UV, IR, ¹H and ¹³C NMR data with those of published compounds. Antimycobacterial, antiplasmodial and cytotoxic activities of the isolates, except 8 and 10 were evaluated. Compounds 1, 4, 5, 11, 12 and 15 exhibited potent cytotoxic activities against human lung cancer cell lines (NCI-H187) with respective IC₅₀ values of 4.67, 7.82, 1.85, 6.33, 3.07 and 6.68 μg/mL.     

Two new alkaloids from Pachysandra terminalis and their antibacterial activity assessment

Phytochemical investigation of a 90 % ethanol extract of Pachysandra terminalis Sieb. Et Zucc led to the isolation of a novel alkaloid, terminamine T (1); a new pregnane-type alkaloid, terminamine U (2); and four known pregnane-type alkaloids (3-6). The structures of these compounds were elucidated on the basis of nuclear magnetic resonance spectra, mass spectrometry data, single-crystal X-ray diffraction, and by a comparison with data from the literature. All compounds were evaluated for their antibacterial activities against gram-positive (S. aureus, ATCC 29213) and gram-negative (E. coli, ATCC 25922) bacteria. Compounds 2-6 exhibited generally modest to poor antibiotic properties. Furthermore, compound 2 showed antibacterial activity against methicillin-resistant Staphylococcus epidermidis (MRSE), methicillin-resistant Staphylococcus aureus (MRSA), and methicillin-resistant Staphylococcus aureus USA300 (LAC) with a minimal inhibitory concentration (MIC) value of 32 μg/mL (75 μM) and minimum bactericidal concentration (MBC) values of 64, 128, and 128 μg/mL (150, 300, and 300 μM), respectively.     

Desmiflavasides A and B: Two new bioactive pregnane glycosides from the sap of Desmidorchis flava

The sap from the succulent, Desmidorchis flava (N.E.Br) Meve & Liede (Apocyanaceae), provided two new pregnane glycosides named desmiflavasides A (1) and B (2) whose structures were established from 1D and 2D NMR spectroscopic techniques and mass spectromentry (ESIMS) measurements. Desmiflavaside B (2) was tested for anticancer activity and induced a 27.4% and 33.1% growth inhibition of the breast cancer cell line (MDA MB231) at a concentration of 75 μg/ml and 100 μg/ml, respectively. Desmiflavasides A (1) and B (2) were additionally evaluated for: DPPH antioxidant activity, urease enzyme inhibition as well as for xanthine oxidase enzyme, α-glucosidase enzyme and acetylcholinesterase inhibition activities. They displayed weak antioxidant and urease enzyme inhibition activities with 15% inhibition.     

Two new metabolites from Portulaca oleracea and their anti-inflammatory activities

Two new metabolites, identified as 6-phenylbenzofuran-4-ol, named olerabenzofuran (1), and 2-(furan-2-yl)− 6-hydroxy-1 H-inden-1-one, named oleraindenone (2), together with eight furan compounds obtained for the first time, (+)-pinoresinol (3), (-)-syringaresinol (4), (+)-diasyringaresinol (5), (+)-episyringaresinol (6), (2 S)− 1-[2-(furan-2-yl)− 2-oxoethyl]− 5-oxopyrrolidine-2-carboxylic acid (7), methyl (2 S)− 1[2-(furan-2-yl)− 2-oxoethyl]− 5-oxopyrrolidine-2-carboxylate (8), drynaran (9), and 2-furoic acid (10), were isolated from Portulaca oleracea L., and spectroscopic methods, including 1D and ²D NMR and UHPLC-ESI-QTOF/MS spectrometry techniques, were employed to determine their structures. It was suggested that both olerabenzofuran (1) and oleraindenone (2) could significantly inhibit inflammatory factor interleukin-1β (IL-1β) in RAW 264.7 cells induced by LPS.     

Two tirucallane derivatives from Paramignya scandens and their cytotoxic activity

Various chromatographic separations of the methanolic extract of Paramignya scandens stem and leaves resulted in the isolation of two new tirucallane derivatives, paramignyols A and B (1 and 2). Their structures were established by HR-ESI-MS, 1D and 2D NMR experiments, as well as, comparison with literature data. Compounds 1 and 2 showed significant cytotoxic activity (IC₅₀s ∼ 3.55–10.50 μM) on four tested human cancer cell lines: KB (epidermoid carcinoma), SK-Mel-2 (melanoma), LU-1 (lung adenocarcinoma), and MCF7 (breast cancer). This is the first report on chemical constituents and biological activities of P. scandens.     

Two new xanthones from Hypericum japonicum and their lipid-lowering activities

Phytochemical investigation of the aerial part of Hypericum japonicum afforded two new xanthones (1-2), together with twelve known compounds (3-14). Their structures with absolute configurations were elucidated by analysis of MS NMR and their experimental and calculated electronic circular dichroism spectra. All of the isolated compounds were tested for their lipid-lowering activities. Compounds 10, 11, 13 exhibited potent lipid-lowering activities (with LDL-Uptake rates 3.02, 2.68 and 1.99, respectively, compared with vehicle control, which was designated as 1.00) and compounds 2-5 showed moderate activities (with LDL-Uptake rates 1.46, 1.41, 1.31 and 1.51, respectively).     

民族药四数九里香的化学成分及其细胞毒活性研究

为了阐明民族药四数九里香Murraya tetramera Huang的药效物质基础,课题组使用色谱技术从其醇提取物中分离得14个化合物;运用~1H NMR、¹³C NMR波谱方法和文献数据对比鉴定为正24烷酸(1)、9,13,17,21-tetramethyl-5-docosenoic acid(2)、3-O-β-D-吡喃葡萄糖基-山奈酚甙(3)、补骨脂素(4)、紫苏醛(5)、槲皮素(6)、methyl salicylate glucoside(7)、(9S,10R,11E,13R,15Z)-9,10,13-trihydroxyoctadeca-11,15-dienoic Acid(8)、2-isopropyl-5-methylphenol(9)、β-胡萝卜甘(10)、7-羟基香豆素(11)、七叶内酯(12)、β-谷甾醇醋酸酯(13)、山奈酚(14)。除了化合物4、6外,其他化合物为首次从该植物中分离得到。同时,研究各化合物对5株肿瘤细胞的体外生长抑制作用。与阳性对照组比较,结果表明:化合物3、4、5、6、7、8、10、11、12、13、14对白血病HL60显现良好的细胞毒活性;化合物1～14对肺腺癌A549的的细胞毒活性低于阳性对照组;化合物6、13、14对肝癌SMMC7721显现良好的细胞毒活性;化合物1、2、3、6、7、9、11、12对乳腺癌MCF7显现良好的细胞毒活性;化合物1～14对结肠癌SW480的细胞毒活性低于阳性对照组。     

四数九里香中的咔唑类生物碱成分及其细胞毒活性研究

为阐明民族药四数九里香Murraya tetramera Huang的药效物质基础,本研究使用色谱分离技术从其醇提取物中分离纯化得7个咔唑类生物碱和1个甾体类化合物,运用波谱方法鉴定为β-谷甾醇(1)、1-甲基-3-丙酰基咔唑(2)、1-甲氧基-3-乙基咔唑(3)、1-甲氧基-3-甲酰基咔唑(4)、1-甲氧基-3-甲基咔唑(5)、1-羧基甲酯-3-甲基咔唑(6)、1-羧基甲酯-3-乙基咔唑(7)、mananimbine(8)。除了化合物1,其他化合物为首次从该植物中分离得到;化合物2～5、7对SMMC-7721的IC50分别为40. 93±0. 66、46. 03±2. 05、114. 21±5. 67、15. 79±0. 99、185. 1±0. 44。结果表明化合物2～5、7对SMMC-7721显现很好的细胞毒活性。     

Two new flavonol derivatives from the whole plants of Centella asiatica and their cytotoxic activities

Centella asiatica is well known as an important medicinal plant because of its various pharmacological effects. However, most investigations on C. asiatica focused on the pharmacological activity of its extract or asiatic acid. In the present work, we aimed to explore the bioactive compounds of the whole plants of C. asiatica. As a result, seven compounds including two new flavonol derivates named 4′-hydroxyl-7-methoxyl-6-prenyl-3-O-trans-p-coumaroyl-flavonol (1) and (2R,3R,2″S)-3-furanoyl-brosimacutin E (2), and five known compounds (3-7) were isolated. Their chemical structures were elucidated on the basis of spectroscopic analyses. All the isolates were evaluated for in vitro cytotoxic effects on four human cancer cells including A549, HepG2, SGC-7901 and MCF-7. Among them, compounds 1 and 2 exhibited higher cytotoxic activities on HepG2 and SGC-7901 cells compared with 3-7. And compound 2 showed potential cytotoxic activities on HepG2 and SGC-7901 cells with IC₅₀ values of 4.52 and 7.03 μM, respectively.     

Two new lignans with their biological activities in Portulaca oleracea L.

Two new lignans, identified as 6,7-dihydroxy-4-(4′’-hydroxy-3′’-methoxyphenyl)-2-naphthoic acid, named Oleralignan C (1), and 4-(3,4-dihydroxyphenyl)-6-hydroxy-7-methoxy-2-naphthoic acid, named Oleralignan D (2), were obtained from Portulaca oleracea L. The structures were determined by spectroscopic methods, including UHPLC-ESI-QTOFMS, ¹D and ²D NMR. Both Oleralignan C (1) and Oleralignan D (2) inhibited the inflammatory factors, IL-1β and TNF-α in RAW 264.7 cells induced by lipopolysaccharide (LPS). Both compounds also could clear 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radicals indicating their antioxidant potential.     

飞机草地上部分化学成分及其抑菌活性研究

为探究飞机草地上部分化学成分及其抑菌作用.采用正相硅胶、Sephadex LH-20等色谱方法,从飞机草乙酸乙酯提取物中得到10个化合物,根据1H NMR、13C NMR、MS波谱数据,分别鉴定为:5,6,7,4'-四甲氧基黄烷酮(1)、圣草素-7,4'-二甲醚(2)、5,7-二羟基-6,4'-二甲氧基黄酮(3)、二氢...     

虎杖根茎中蒽醌类成分的体外抗氧化活性

采用超声波提取法用体积分数80%乙醇对虎杖(Reynoutriajaponica Houtt.)根茎中的蒽醌类成分进行粗提,并利用D101大孔吸附树脂对粗提液进行纯化.以Vc为阳性对照,采用体外动物实验研究了虎杖根茎中蒽醌类成分对小白鼠肝组织匀浆中谷胱甘肽过氧化物酶(GSH-px)活力及对H2O2诱导的MDA含量和红细胞氧化溶血的影响,并采用化学模拟体系分析了其对DPPH·自由基的清除能力、对Fe3+的还原能力以及与Fe2+的螯合能力.结果表明:虎杖根茎中蒽醌类成分含量丰富,粗提物含量达到55.86 mg·g-1,纯化后含量达到44.77 mg·g-1.质量浓度l0、20、30和40μg·mL-1的蒽醌类成分可显著增强GSH-px活力、降低由H2O2诱导产生的MDA含量,并对H2O2诱导产生的红细胞氧化溶血有较强的抑制作用;质量浓度2、4、6和8μg·mL-1的蒽醌类成分对DPPH·自由基具有良好的清除能力,质量浓度6、8、12和16μg·mL-1蒽醌类成分对Fe3+具有较强的还原能力,而质量浓度5、10、15和20μg·mL-1蒽醌类成分对Fe2+则具有很强的螯合能力.随质量浓度的提高,虎杖蒽醌类成分及阳性对照Vc的各项抗氧化活性指标均逐渐增强,呈现出明显的量效关系,且虎杖根茎中蒽醌类成分的各项抗氧化指标均优于相同质量浓度的Vc.研究结果显示:虎杖根茎中的蒽醌类成分具有较强的抗氧化活性,不仅能够直接清除过量的自由基,也可以通过增强体内的抗氧化系统以抑制自由基的产生.结合他人研究结果,对虎杖资源的开发利用提出了一些建议.     

Preparation of a glucan from the roots of Rubus crataegifolius Bge. and its immunological activity

A water-soluble glucan (RCP-1) was prepared from the roots of Rubus crataegifolius Bge. by extraction with hot-water, deproteination by Sevag reagent, α-amylase treatment and ultrafiltration. RCP-1 consisted of only glucose, and its molecular weight was determined to be ∼7 KD by high performance gel permeation chromatography (HPGPC). Fourier transform infra-red spectroscopy (FT-IR), nuclear magnetic resonance spectroscopy (NMR), methylation and periodate oxidation analyses indicated that RCP-1 was an α-d-glucan. Its main chains were composed of (1→4)- and (1→6)-linked α-glucopyranosyls, and side chains were single α-glucopyranosyl residues attached to the O-6 of glucosyls in the main chains. RCP-1 could increase both cytotoxic activity against B16 melanoma cells and the production of nitric oxide (NO) of macrophages in vitro. Furthermore, in vivo bioassay tests indicated that RCP-1 could remarkably enhance T and B lymphocyte proliferations, augment the phagocytosis of macrophages and increase the tumour necrosis factor-alpha (TNF-α) levels in serum.     

Three new prenylated xanthones from Comastoma pedunculatum and their anti-tobacco mosaic virus activity

Comastomaxanthones A–C (1–3), three new xanthones with a rare 2-oxoprenyl substituent, along with three known ones (4–6) were isolated from the aerial parts of Comastoma pedunculatum. Their structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques. In addition, compounds 1–6 were tested for their anti-tobacco mosaic virus activity. The results showed that all isolated compounds exhibited weak anti-TMV activity with IC₅₀ values ranging from 122.7 to 242.9 μM.     

Antiplatelet effects of acidamides isolated from the fruits of Piper longum L.

The inhibitory effects of four acidamides, piperine, pipernonaline, piperoctadecalidine, and piperlongumine, isolated from the fruits of Piper longum L. on washed rabbit platelet aggregation were examined. All of the four tested acidamides showed dose-dependent inhibitory activities on washed rabbit platelet aggregation induced by collagen, arachidonic acid (AA), and platelet-activating factor (PAF), except for that induced by thrombin. Piperlongumine, in particular, showed stronger inhibitory effects than other acidamides to rabbit platelet aggregation induced by collagen, AA and PAF.