Antitrypanosomal activity of polycarpol from Piptostigma preussi (Annonaceae)

Polycarpol, sitosterol and sitosterol-3-O-β-D-glucoside isolated for the first time from Piptostigma preussi (Annonaceae) occur regularly in some Annonaceae such as Piptostigma genus. Polycarpol exhibits interesting antitrypanosomal activity with an ED₅₀ value of 5.11 µM on Trypanosoma brucei cells. Moreover, it inhibits T. brucei glycolytic enzymes GAPDH and PFK with IC₅₀ values of 650 and 180 µM respectively.     

Regeneration, in vitro glycoalkaloids production and evaluation of bioactivity of callus methanolic extract of Solanum tuberosum L.

Callus and differentiated shoots initiated from Solanum tuberosum L. on MS media containing BA, IAA, and Kin. Glycoalkaloids are produced in callus and shoots in concentrations higher than original tubers using HPLC. Callus methanolic extract had promising anticancer activity with low IC₅₀ values against human carcinoma cell lines of breast, lymphoplastic leukemia, larynx, liver, cervix, colon, and brain, IC₅₀ (µg/mL) were 2.7, 3.7, 6, 6.7, 10, 13.6, and 22.3 respectively. Antioxidant capacity of the extract (76.4%) performed using ESR. Preliminary screening showed that the extract exhibited in vitro virucidal activity against Herpes simplex. The extract possessed in vitro schistomicidal and fasciolicidal activity.     

Bioactive phenolics from the fruits of Livistona chinensis

This study investigated the antioxidant and cytotoxic activity of the phenolics isolated from the fruits of Livistona chinensis. Four new compounds, 1-{ω-isoferul[6- (4-hydroxybutyl)pentadecanoic acid]}-glycerol (1), E-[6′-(5″-hydroxypentyl)tricosyl]-4-hydroxy-3-methoxycinnamate (2), 2-(3′-hydroxy-5′-methoxyphenyl)-3-hydroxylmethyl-7-methoxy-2,3-dihydrobenzofuran-5- carboxylic acid (3), 7-hydroxy-5,4′-dimethoxy-2-arylbenzofuran (4), together with eleven known phenolics (5-15), were isolated and identified. Among these compounds, 1-4, 5-O-caffeoylshikimic acid (5), caffeic acid (7), and 3-O-caffeoylshikimic acid (8) showed potent antioxidant activity. 1-5, and 8 showed potent antiproliferative activities with IC₅₀ values among 5-150 μM against HepG2 human liver cancer, HL-60 human myeloid leukemia, K562 human myeloid leukemia, and CNE-1 human nasopharyngeal carcinoma cell lines. On the basis of these findings, it could be proposed that the fruits of L. chinensis may serve as attractive mines of powerful anticancer and antioxidant agents for various purposes.     

Novel indole C-glycosides from Isatis indigotica and their potential cytotoxic activity

Two novel indole C-glycosides, which were the first reported alkaloids C-glycosides from Isatis indigotica, together with five known alkaloids were isolated. The novel alkaloids were elucidated to be indole-3-acetonitrile-4-methoxy-2-C-β-D-glucopyranoside (1) and N-methoxy-indole-3-acetonitrile-2-C-β-D-glucopyranoside (2) on the basis of spectroscopic analysis. 1 exhibited significant cytotoxic activities against human myeloid leukemia HL-60 and human liver cancer HepG2 cells with the IC₅₀ of 1.3 ± 0.1 and 2.1 ± 0.3 μM, respectively. 2 showed potential cytotoxic activities against HL-60 and human myeloid leukemia Mata cells with the IC₅₀ of 5.1 ± 0.4 and 12.1 ± 0.8 μM, respectively.     

松墨天牛在云南松树干的垂直分布研究

松墨天牛(Monochamus alternatus Hope) (又名松褐天牛、松天牛)属鞘翅目,天牛科,墨天牛属,是松属树种如马尾松(Pinus massoniana Lamb.)、黑松(P.thunbergii Parl.)、云南松(Pinus yunnanensis Franch)和思茅松(P. kesiya var. langbianensis(A.chev.)Gaussen)等的重要蛀干害虫,主要危害生长衰弱的树木或新伐倒木,造成松树枯死,同时还传播松材线虫(Bursaphelenchus xylopilus (Steiner & Buhrer) Nickle)萎蔫病[1-2].松墨天牛在云南主要危害云南松,目前分布范围已经扩展到43县(市),并在部分地方成灾,加大了松材线虫病传入的可能性[3].松墨天牛在滇中地区1年1代,雌成虫在树干上咬出长椭圆刻槽,将卵产在刻槽中部的表皮层下,幼虫生长发育至一定阶段蛀入木质部, 在边材表面留下椭圆形的蛀入孔;蛀入木质部的幼虫在蛀道内取食,老熟幼虫在蛀道末端构筑蛹室化蛹,成虫从蛹室向外咬出近圆形的羽化孔爬出[4-5].松墨天牛是典型的钻蛀性害虫,调查和防治非常困难.前人曾经对松墨天牛在马尾松和思茅松上的分布规律进行了研究[6-8],但这些研究是某一时间段天牛的危害痕迹或幼虫在树干上的分布,对于天牛产卵刻槽、蛀入孔和羽化孔的数量关系,目前还没有相关报道.本文对松墨天牛的产卵刻槽、蛀入孔和羽化孔在云南松树干的垂直分布规律及其数量关系进行了调查分析,旨在为松墨天牛的林间调查和防治提供参考.     

黄牡丹花粉生活力测定方法的比较研究

以黄牡丹的新鲜花粉为试材,利用单因子试验比较了液体培养基中蔗糖浓度、硼、钙、镁、钾对黄牡丹花粉萌发的影响,在此基础上进行了正交试验,比较了蔗糖、H₃BO₃及CaCl₂对黄牡丹花粉萌发的影响;通过对醋酸洋红染色法、I-KI染色法和TTC染色法的比较,寻找快速测定黄牡丹花粉生活力的方法。试验结果表明:蔗糖及H₃BO₃对黄牡丹花粉萌发有极显著影响。在pH值为6.0时,蔗糖150 g·L^-1+H₃BO₃30 mg·L^-1+CaCl₂20 mg·L^-1适宜黄牡丹花粉培养,萌发率为68.7%;纯水培养没有造成花粉原生质体破裂,内含物外流,但萌发率极低,仅为3%;200 g·L^-1以上的高浓度蔗糖溶液和300 mg·L^-1以上的高浓度盐溶液会造成原生质体失水萎缩,质壁分离,这两种情况都抑制花粉萌发;TTC染色法测得的花粉活力率为64.9%,是快速测定黄牡丹花粉生活力的最适染色法。     

配方施肥对辣木生长效应及其初果期产量构成的影响

[目的]研究不同配方施肥对辣木生长效应及产量构件因素的影响,[方法]采用正交设计L9(34)3因素3水平进行施肥试验。[结果]施肥处理对各时期生长有显著的促进作用,且营养生长期N肥和K肥占主导作用。适合株高和地径生长的最优组合为N150P40K100,而适合冠幅和分枝数生长的最优组合为N85P85K100。生殖生长各指标较对照均有明显提高。低浓度的氮肥和高浓度的磷钾肥有助于辣木的开花和座果,同时提高果荚产量和种子产量,明显促进产量增加以及花序数、成熟果数、百粒质量和座果率的提高。[结论]合理的配比施肥显著促进辣木的生长效应以及提高产量,果荚产量和种子产量的最优组合为N_(40)P_(150)K_(100)。     

A new cytotoxic 1-azaanthraquinone from the stems of Goniothalamus laoticus

A new 1-azaanthraquinone, named laoticuzanone A (1), and a synthetically known 3-methyl-1H-1-azaanthracene-2,9,10-trione (2), together with four known compounds, Griffithazanone A (3), methyl sinapate (4), methyl p-coumarate (5), and p-hydroxyphenylethyl p-coumarate (6) were isolated from the stems of Goniothalamus laoticus. Their structures were established on the basis of spectroscopic data as well as comparisons with the previous literature data. Compound 1 showed the highest cytotoxicity against KB and HeLa cells with IC₅₀ values of 0.68 and 0.50 μg/ml, respectively.     

Cytotoxic effect of triterpenoids from the root bark of Hibiscus syriacus

In this study, 4 new triterpenoids—3β- acetoxy-olean-11-en,28,13β-olide (1), 3β- acetoxy-11α,12α-epoxy-olean-28,13β-olide (2), 19α-epi-betulin (3), and 20, 28-epoxy-17β,19β-lupan-3β-ol (4)—and 12 known compounds, were isolated from the root bark of Hibiscus syriacus L. by using acetone extraction. Their structures were characterized by extensive spectroscopic analysis. To investigate cytotoxicity, A549 human lung cancer cells were exposed to the extract and the compounds identified from it. Significantly reduced cell viability was observed with betulin-3-caffeate (12) (IC₅₀, 4.3 μM). The results of this study indicate that betulin-3-caffeate (12) identified from H. syriacus L. may warrant further investigation for potential as anticancer therapies.     

3-Prenyl luteolin,a new prenylated flavone with melanin biosynthesis inhibitory activity from wood of Artocarpus heterophyllus

In our efforts to find new whitening agent from natural resources, we focused on wood of Artocarpus heterophyllus which shows anti-melanogenesis activity. By activity-guided fractionation of A. heterophyllus wood extract, a new prenylated flavonoid, 3-prenyl luteolin (1) was isolated. The IC₅₀ of mushroom tyrosinase inhibitotry activity of 1 was 76.3 µM. The results of the comparison with that of luteolin showed the prenyl substituent at C-3 position of 1 play an important role for revealing tyrosinase inhibition. In melanin formation inhibition on B16 melanoma cells, IC₅₀ of 1 was 56.7 µM with less cytotoxicity.     

地涌金莲及红苞地涌金莲对光和CO2的响应

比较分析了地涌金莲原种及红苞地涌金莲变种的光响应和CO2响应特征以及叶绿素含量等指标.结果表明:(1)在Pn-PAR中,地涌金莲原种的最大光饱和净光合速率、光补偿点和暗呼吸速率分别较红苞变种高20.42％、34.88％、31.95％,而光饱和点却较红苞变种低4.95％;Pn-Ci响应的各参数中,原种的光呼吸速率、CO2饱和最大净光合速率以及羧化效率分别高于红苞变种2.73％、14.79％、21.35％,说明地涌金莲的光合能力要强于红苞地涌金莲;(2)地涌金莲具有典型的C3植物特征;(3)地涌金莲为阳性耐荫植物;(4)地涌金莲的叶绿素a、b以及a/b的含量分别高于红苞地涌金莲22.60％、32.46％、25.06％.     

水分胁迫对四倍体刺槐苗生长和光合作用的影响

刺槐是我国三北地区的主要防护造林树种,尤其是西北干旱、半干旱地区有广泛的种植;但由于当地气候条件的制约,刺槐难于获得生长所需的足够水分[1],生长受到严重抑制,在黄土高原出现了大面积的"小老树"和低劣残次林[2-4],其生态、经济效益都很低.     

Isolation, stability and bioactivity of Jatropha curcas phorbol esters

Jatropha curcas seed oil, which can be utilized for biodiesel production upon transesterification, is also rich in phorbol esters (PEs). In this study, PEs from J. curcas oil (Jatropha factors C₁ and C₂ (purified to homogeneity), Jatropha factors C₃ and (C₄ + C₅) (obtained as mixtures) and PE-rich extract (containing all the above stated Jatropha factors) were investigated. The concentrations of Jatropha PEs were expressed equivalent to Jatropha factor C₁. In the snail (Physa fontinalis) bioassay, the order of potency (EC₅₀, μg/L) was: PE-rich extract < factor C₃ mixture < factor C₂ < factor C₁ < factor (C₄ + C₅). In the Artemia salina bioassay, the order of potency (EC₅₀, mg/L) was: factor C₂ < factor C₃ mixture < factor C₁ < factor (C₄ + C₅) mixture. In addition, Jatropha PEs exhibited platelet aggregation (ED₅₀, μM, factor C₂ < factor C₃ mixture < factor C₁ < factor (C₄ + C₅) mixture. The stability of a PE-rich extract was evaluated and found to be low at room temperature but favourable in ethanol over a range of temperatures. By integrating the isolation methodology developed in this study in the Jatropha biodiesel industry, PEs could be obtained as value-added co-products.     

Stand-scale transpiration estimates in a Moso bamboo forest: (I) Applicability of sap flux measurements

The applicability of sap flux (F_d) measurements to bamboo forests has not been studied. This study was undertaken to establish an optimal and effective design for stand-scale transpiration (E) estimates in a Moso bamboo forest. To this aim, we validated F_d measurements in Moso bamboos in a cut bamboo experiment. In addition, we analyzed how sample sizes affect the reliability of E estimates calculated from F_d and conducting culm area (A_{S_b}). In the cut bamboo experiments, we found that F_d measurement using a 10 mm probe was a valid means of determining the water-use behavior of a Moso bamboo, although a specific correction was needed. Furthermore, we calculated E from stand A_{S_b} (A_{S_stand}) and mean stand F_d (J_S). Employing Monte Carlo analysis, we examined potential errors associated with sample size in E, A_{S_stand}, and J_S using an original dataset with A_{S_b} and F_d measured for 40 and 16 individuals, respectively. Consequently, we determined the optimal sample size for both A_{S_stand} and J_S estimates as 11. The optimal sample sizes for J_S were almost the same under different vapor pressure deficit and soil moisture conditions. The optimal sample size for J_S at the study site was less than that of a coniferous plantation in the same region probably owing to small individual-to-individual variations in sap flux in the Moso bamboo forest. Our study concludes that sap flux measurements are an applicable technique for assessing water use in Moso bamboo forests.     

O_3胁迫对三种楠木幼苗光合作用的影响及伤害症状

[目的]随着全球O_3浓度升高,O_3胁迫对植物影响的研究已成为研究的热点之一。我国的相关研究较少,主要以农作物为主,且大多局限在北方地区。本研究探讨O_3胁迫下,亚热带三种楠木幼苗光合作用的变化规律及其可见伤害症状,以期为后续研究提供理论依据。[方法]以一年生亚热带乡土树种桢楠、闽楠和刨花楠幼苗为材料,采用开顶式气室(OTCs),研究低浓度O_3、环境大气、100 n L·L-1O_3、150 n L·L-1O_3处理对光合作用的影响及伤害症状。[结果]研究表明:(1)O_3胁迫下,三种楠木幼苗的光合作用受到一定的抑制,气孔导度和净光合速率的相关性降低,对光合有效辐射的利用范围整体减小,出现了明显的光抑制现象。O_3浓度越高,对桢楠和刨花楠光合作用的抑制效果越明显,而100 n L·L-1O_3处理对闽楠光合作用的抑制效果较150 n L·L-1O_3处理明显。环境大气中的O_3浓度均值较低,但由于其较高的O_3浓度峰值,仍对三种楠木幼苗的光合作用产生了一定的抑制。与环境大气相比,低浓度O_3处理通过消除较高的O_3浓度峰值从而缓解了O_3对光合作用的不利影响。(2)O_3胁迫下,桢楠叶片出现褪绿、黄斑和坏死斑的症状,闽楠叶片出现褪绿、黄斑和水渍的症状,刨花楠叶片出现红褐色斑、水渍、坏死斑、卷曲皱缩、失水萎蔫的症状。三种楠木幼苗叶片的伤害症状随O_3浓度的增加而更明显。[结论]三种楠木幼苗叶片的光合作用均受到O_3的抑制,并出现了伤害症状,可作为O_3污染的指示树种。光合作用对O_3敏感性的关系为:刨花楠闽楠桢楠,其中刨花楠对O_3更敏感,伤害症状也较多样,因此指示O_3污染的效果更好。     

Chemical constituents of the Vietnamese liverwort Porella densifolia

From the ether extract of Porella densifolia, the first liverwort collected and chemically investigated in Vietnam, a kaurane diterpenoid, ent-kauren-15-one (1) and two sesquiterpene norpinguisone (2) and norpinguisone methyl ester (3) have been purified. Their structures were elucidated by spectroscopic analysis. In addition, an X-ray crystal structure of norpinguisone was obtained, allowing to determine its stereochemistry. Furthermore, the inhibitory activity of nitric oxide (NO) production in RAW 264.7 cells stimulated by lipopolysaccharide (LPS) of compounds 1–3 was examined with their IC₅₀ values of 69.4, 45.5 and 1.68 μM, respectively.     

盐胁迫下3个楸树无性系光合特征研究

以3个楸树无性系为材料进行盐胁迫试验,分析了叶片叶绿素含量、净光合速率(P_n)、气孔导度(G_s)、胞间CO₂浓度(C_i)等指标的变化规律。结果表明:随盐浓度增加,所有无性系的叶绿素a、叶绿素b及总叶绿素含量呈下降趋势;方差分析表明:处理间及无性系间差异显著(P＜0.05)。叶绿素a/叶绿素b值呈上升趋势,YQ₁无性系各盐处理与CK差异不显著,02-2-5和07-1无性系各盐处理与CK存在一定差异。从光合日变化看,3个无性系的P_n随盐浓度的升高明显降低,降幅为07-1〉YQ₁〉02-2-5,净光合速率最大值(P_max)都出现在8:00时,无性系间差异显著,且02-2-5〉YQ₁〉07-1。回归分析和通径分析表明:02-2-5和YQ₁无性系主要受胞间CO₂浓度(C_i)、叶温(T_l)、光合有效辐射(PAR)的影响,07-1无性系主要受G_s和C_i的影响。初步认为3个无性系的耐盐能力为02-2-5〉YQ₁〉07-1。     

版纳龙竹CONSTANS同源基因的克隆与序列分析

以版纳龙竹基因组DNA为模板,采用前人基于水稻CO同源基因Hd1序列的保守区所设计的特异引物COS1和COA1,运用PCR方法扩增出一条1 520 bp的DNA片段,并克隆到pGEM-T载体。测序和序列分析结果显示:该片段含有1个590 bp的内含子,编码区930 bp共编码310个氨基酸;该基因被命名为DxCO1,其DNA序列在G enB ank中的注册号为GQ358925。在G enB ank中进行同源性检索的结果显示:其核苷酸序列与其它禾本科植物CO同源基因的氨基酸序列同源性高达81%~91%;推测的DxCO1蛋白质序列与其它种子植物CO同源基因蛋白质序列的系统发育分析结果显示:DxCO1与小麦Hd1-like等5个基因聚成了一个强烈支持的分支;另外,在该片段推测的蛋白质序列的氨基端含有一个类似锌指蛋白的B-box(Cx2Cx8Cx7Cx2Cx4Hx8H)结构域,羧基端含有一个CCT(CO,CO-like,TOC1)结构域。序列和结构的高度同源性表明:DxCO1是版纳龙竹的1个CO-like基因,可能对其开花调控有着重要作用。     

Baicalein decreases side population proportion via inhibition of ABCG2 in multiple myeloma cell line RPMI 8226 in vitro

ObjectiveTo investigate the effect of baicalein on side population in human multiple myeloma cell line RPMI 8226 and the underlying molecular mechanisms in vitro and in silico.MethodsMTT assay was applied to detect the anti-proliferation effect of baicalein. The detection of side population cells is based on the Hoechst 33342 exclusion assay technique and flow cytometric analysis. Western blotting assay was used to explore the expression of ABCG2 protein. Homology modeling and molecular docking were performed with Discovery Studio 2.1.ResultsBaicalein decreased both cell viability with IC₅₀ = 168.5 μM and the proportion of SP cells in a dose-dependent manner. Correspondingly, it significantly decreased the expression level of ABCG2 protein. Baicalein also shared similar binding sites and modes with fumitremorgin C to the protein.ConclusionsBaicalein possessed novel anticancer properties, such as anti-proliferation and drug efflux inhibition in side population cells, which suggested its potential feature of targeting cancer stem cells of multiple myeloma.     

Stand level estimation of root respiration for two subtropical plantations based on in situ measurement of specific root respiration

In this study, the stand level root respiration was estimated for two monoculture plantations: Acacia crassicarpa and Eucalyptus urophylla, based on in situ measurement of specific root respiration using simplified root chamber method. The respiration rates of fine roots (<5 mm) were significantly higher than those of coarse roots (>5 mm) for both A. crassicarpa and E. urophylla species. The root respiration of A. crassicarpa showed a clear seasonal pattern with a higher value in the wet season. For E. urophylla, the seasonal pattern was observed for fine roots but not for coarse roots. After determining the biomass of fine roots and coarse roots and their specific rates of respiration at different time points, root respiration at the stand level (R_a) was estimated using a direct up-scaling model. We found that the R_a accounted for 14% and 19% of total soil respiration (R_s) for A. crassicarpa and E. urophylla, respectively. The fine (R_Tf) and coarse (R_Tc) root respiration at the stand level accounted for about 47% and 53% of the R_a for A. crassicarpa, and accounted for 58% and 42% for E. urophylla. This suggests that coarse root respiration cannot be ignored when estimating the root respiration at the stand level. Our results showed that the Q₁₀ values were more accurate in representing the temperature dependence when the confounding effect of soil moisture was considered. This study introduces an alternative approach to estimate stand level root respiration, but its reliability is largely dependent on the accuracy of root biomass quantification.