Oil secretion and the pollination of Colpias mollis (Scrophulariaceae)

 Colpias mollis is a perennial lithophyte that secretes non-volatile oil as a pollinator reward. Its white to yellow flowers bear two narrow pouches lined with glandular oil-secreting trichomes. The pollinating bee, Rediviva albifasciata (Melittidae), collects oil with its forelegs and midlegs by rubbing them against the gland patches within the flower. The presence of specialised hairs on these legs facilitates oil-collection. The strongly congruent geographic distributions of C. mollis and R. albifasciata and their close morphological fit suggest a long and close association between plant and pollinator. Although C. mollis appears dependent on R. albifasciata for pollination, R. albifasciata is not always dependent on C. mollis for oil. It can also obtain and utilise oil from flowers of the annual herb Hemimeris racemosa (Scrophulariaceae). At the main study site, fruit set of C. mollis was high (75.7%; N=202 flowers) in a dry year when H. racemosa was rare and relatively low (11.4%; N=184 flowers) in a wet year when H. racemosa was common. Received July 15, 2001; accepted June 17, 2002 Published online: November 20, 2002 Addresses of the authors: Kim E. Steiner (e-mail: ksteiner@calacademy.org), Compton Herbarium, National Botanical Institute, Kirstenbosch, South Africs; Current address: Department of Botany, Califormia Academy of Sciences, Golden Gate Park, San Francisco, CA 94118, USA. V. B. Whitehead, South African Museum, P.O. Box 61, Cape Town 8000, South Africa; Current address: 87 Bruke Street, Graaff-Reinet 6280, South Africa.     

A Simple Method for Resolution of Endo‐/Exo‐Monoesters of Trans‐Norborn‐5‐Ene‐2,3‐Dicarboxylic Acids Into Their Enantiomers

Separation of optical isomers obtainable from trans‐norborn‐5‐ene‐2,3‐dicarboxylic acid methyl and tert‐butyl monoesters was performed by crystallization of the respective salts prepared with (R)‐ and (S)‐1‐phenylethylamine. Starting from racemic endo‐monomethyl ester of trans‐norborn‐5‐ene‐2,3‐dicarboxylic acid, prepared by partial hydrolysis of the cyclopentadiene‐dimethyl fumarate adduct, the corresponding (2R,3R)‐endo‐monoester was isolated in 97% enantiomeric excess (ee) yield after seven repeated crystallizations from tetrachloromethane. Starting from exo‐mono‐tert‐butyl ester of the same acid, prepared by alcoholysis of the cyclopentadiene‐maleic anhydride adduct followed by isomerization, (2R,3R)‐exo‐monoester was isolated in >98% ee yield after four repeated crystallizations from ethanol. Crystallization of the acids from the mother liquor containing (S)‐1‐phenylethylamine yielded products with inverse stereochemical configuration. Chirality 27:151–155, 2015. © 2014 Wiley Periodicals, Inc.     

响应面分析法优化当归粗多糖提取工艺

选取岷县当归药材为原料,采用水提醇沉法进行多糖提取,以当归粗多糖得率为指标,探讨加水量、回流提取时间、水提液的浓缩比、醇沉后所达含醇比例对当归多糖得率的影响。在单因素分析的基础上,采用响应面分析法(RSM)确定了当归粗多糖最佳提取条件为:加水量837.6 mL/100 g,浓缩后溶液体积为228.12 mL,最终含乙醇浓度为65.80%,回流提取时间2 h,在此条件下预测当归粗多糖得率理论的最佳值为10.44%,实际验证值为10.40%,两者相符,说明RSM法分析的可靠性。     

海滨滨麦叶片和根对不同厚度沙埋的生理响应差异分析

以烟台海岸抗风沙植物滨麦为研究材料,通过对不同厚度沙埋下其叶片和根部抗氧化酶活力(超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT))、丙二醛(MDA)含量和渗透调节物含量变化的分析,探讨了叶片和根部对沙埋生理响应的差异。试验按滨麦成株株高(约40 cm)对其进行了轻度沙埋(在株高1/4处)、中度沙埋(2/4处)和重度沙埋(3/4处)。在沙埋第6天,分别测定了不同厚度沙埋处理下,植株各段叶片和根抗氧化酶活力、MDA和渗透调节物含量。结果表明,轻度和中度沙埋均加速植株生长。与对照相比,经轻度、中度沙埋处理6 d,叶片平均MDA含量增加,在重度沙埋下降低。不同厚度沙埋6 d,叶片平均SOD活力和脯氨酸含量增加,而CAT活力、可溶性糖和可溶性蛋白质含量下降。但不同厚度沙埋均使沙上叶片MDA、脯氨酸、可溶性蛋白质含量和SOD和CAT活力增加,尤其是叶片顶部增加最为明显,使沙下叶片MDA、可溶性糖、可溶性蛋白质含量和CAT活力下降,导致同株沙上和沙下叶片MDA、脯氨酸、可溶性糖、可溶性蛋白质含量和SOD和CAT活力差异显著(P0.05)。与叶片相比,根中MDA、可溶性蛋白质含量和SOD和CAT活力较低,而POD活力和可溶性糖含量较高并与叶片差异显著(P0.05)。不同厚度沙埋6 d,滨麦根中MDA和可溶性蛋白质含量变化较小,可溶性糖含量和CAT、POD、SOD活力略有降低。研究表明,滨麦根和叶片对不同厚度沙埋的生理响应不同。沙埋直接作用于叶片并诱发叶内氧自由基积累,但叶片通过快速激活的抗氧化酶保护系统(CAT、SOD)维持氧自由基代谢平衡,以及渗透调节物(脯氨酸、可溶性糖)的积累维护细胞水分代谢平衡,并满足能量的需求和快速生长。但在不同厚度沙埋下,由于根系不受沙埋直接影响而生理变化较小,并且还维持较低的膜脂过氧化水平,这可能是根能维持正常的吸水输水功能并在沙埋处理过程中和沙埋后地上叶片快速生长摆脱沙埋的重要物质基础。     

中华蚊母树染色体制片及核型分析

以中华蚊母树根尖为材料,采用常规压片法制片,比较材料的不同采集时间、预处理方法、固定剂、解离方法、解离时间及染色方法对中华蚊母树根尖染色体制片的影响.结果表明最佳的制片技术为:取材时间为上午9:00~11:00或下午13:00~15:00,以饱和对二氯苯预处理3 h,用1 mol?L-1盐酸60℃下解离8 min,卡诺固定剂固定,以改良石碳酸品红染色10 min.以该最佳制片方案对中华蚊母树进行体细胞染色体核型分析,首次揭示了中国特有植物———中华蚊母树体细胞染色体数目为2n=2x=24,染色体基数x=12,染色体核型公式为2n=2x=24=12m(2SAT)+10sm+2st,主要由中部和近中部着丝点染色体组成;染色体相对长度组成为2n=24=2L+8M2+12M1+2S,核型不对称指数为64.29%,属于2A型.结果显示中华蚊母树核型对称程度较高,在进化中属于比较原始的类型.     

国家二级保护植物翅果油树营养器官结构的研究

系统研究了国家二级保护植物翅果油树(Elaeagnus mollis Diels)营养器官的结构,结果表明:根表皮外有2.4～36.7μm的粘液质层,对着韧皮部的内皮层细胞含有黑色物质,与粘液质层的形成有关.茎的皮层中有一层排列整齐紧密的椭圆形细胞,类似于内皮层.髓细胞中含有大量的針晶.次生木质部为典型的环孔材,具有多列同型射线.栅栏组织发达,叶细胞含有大量針晶,栅栏组织与海绵组织之比为1.96,具有旱生结构特性.     

沙枣果总黄酮类化合物的富集研究

通过对9种型号大孔吸附树脂静态筛选,最终确定AB-8型大孔吸附树脂用于沙枣果总黄酮化合物的富集,并通过动态实验,确定沙枣果总黄酮最优富集条件为：样品浓度2.43 mg·mL^-1,上样速率2 BV·h^-1,乙醇浓度70%,洗脱速率2 BV·h^-1。在最优工艺条件下,沙枣果总黄酮浓度由9.73%增加到49.52%;其中金丝桃苷含量由0.53%增加到3.07%,提高5.79倍。本研究为沙枣果总黄酮的开发利用提供了理论依据。     

稀有濒危植物翅果油树种群黄酮类化合物多样性研究

以稀有濒危植物翅果油树叶中黄酮类化合物为标记,探索翅果油树种群与其生境的相互关系。通过对濒危植物翅果油树的主要分布区,山西省的乡宁、翼城、平陆等三种群及环境的调查,并采集三个种群的24个样品。用水提法、甲醇提法,经聚酰胺薄层层析法分离,并将层析结果作1/0的二元数据化处理,用于聚类分析和PCA排序。结果表明:1)翅果油树叶中黄酮类化合物的种类比较稳定,可以作为研究种群分化的标记物;2)聚类分析表明乡宁、翼城、平陆三个种群间所含的黄酮类化合物已有分化,乡宁种群与翼城种群之间的相异性较小,在截取值为20时,乡宁与翼城种群首先聚为一支,当截取值为25时,平陆种群归并,表明平陆种群与其他种群的相异性较大;3)各种群内个体间的共享率有明显的差异4)PCA分析表明:不同种群内的黄酮类化合物的差异与其地理位置、温度、地形地貌及土壤养分等因子有关。     

Synthesis of novel chromeno-annulated cis-fused pyrano[3,4-c]benzopyran and naphtho pyran derivatives via domino aldol-type/hetero Diels–Alder reaction and their cytotoxicity evaluation

New chromeno-annulated cis-fused pyrano[3,4-c]benzopyran and naphtho pyran derivatives have been synthesized by domino aldol-type reaction/hetero Diels–Alder reaction generated from o-quinone methide in situ from 7-O-prenyl derivatives of 8-formyl-2,3-disubstituted chromenones with resorcinols/naphthols in the presence of 20 mol % ethylenediamine diacetate (EDDA), triethylamine (2 mL) as co-catalyst in CH₃CN under reflux conditions in good yields. The structures were established based on spectroscopic data, and further confirmed by X-ray diffraction analysis. The results showed that compounds 4h and 4j exhibited very potent cytotoxicity against human cervical cancer cell line (HeLa). Compound 4h displayed good inhibitory activity against both breast cancer cell lines, MDA-MB-231 and MCF-7. Further, the compound 4i exhibited good cytotoxicity against only MDA-MB-231, and compound 4j showed promising activity against human lung cancer cell line, A549 with IC₅₀ value of 2.53 ± 0.07 μM, which was comparable to the standard doxorubicin (IC₅₀ = 1.21 ± 0.1 μM).