香荚兰酶促生香的研究

采用ＨＰＬＣ分析监测不同生香阶段和陈化期的香荚兰豆荚中香兰素等４个糖甙水解成分的含量变化。用β－葡糖甙酶处理香荚兰青荚,处理后之豆保,香兰素等４个糖甙水解成分的含量均远高于对照。对加酶量,酶促反应时间,反应温度,ｐＨ值４个关键因素进行条件筛选研究,并在所选最佳反应条件下,对不同生香阶段的豆荚进行酶处理。     

不同季节中香荚兰叶片的光合作用特征

通过对生长于人工阴蔽下香荚兰(Vanilla planifolia)不同部位叶片的气体交换、可滴定酸度和叶绿素含量等四个不同季节的观测,较为详细地研究了叶龄和光合作用类型之间的关系及其季节性的变化规律。成熟叶片在四个季节中表现为稳定的景天酸代谢(CAM),且光期有较长时间的CO_2吸收,几乎无CO_2向外释放,有显著的昼夜酸度波动。幼叶以C_3代谢为主,但在较高昼夜温差和较低空气相对湿度的条件下也能进行CAM代谢,且不同季节中表现了不同程度的酸积累。我们认为,香荚兰叶片随叶龄的增长有一个从C_3代谢到CAM代谢的光合作用途径的转移,幼叶在对环境因子变动的反应中也有一个类似的转移现象。叶片的光合作用能力也表现了季节性的差异,尤其对温度反应敏感,低温季节(日均温<20℃),CO_2的固定作用大大减弱。     

香荚兰的快速繁殖

香荚兰是生长在热带地区的攀援性兰科植物。原产墨西哥,现广泛栽植在热带多雨地区。它的果实(荚)发酵后,是一种天然食品香料(主香成份是香草醛)的来源。 香荚兰可以用种子繁殖,但从出芽到结实约需7—9年。因此,通常用扦插法繁殖。用长为30—50厘米的插条扦插,3—4年后即可开花结实。因所用的插条较长,国     

香荚兰种子的无菌萌发试验

香荚兰(Vanilla planifolia)是兰科、香荚兰属植物,主产于湿热地区。香荚兰的果实是国际上重要的食用香料的原料。大约在1960年,我国引入香荚兰试栽。生产上,通常用扦插法繁殖;但如用种子繁殖,虽然结实较晚(约7至8年开始结实,较扦插苗晚4—5年),但结实期长,盛产期可维持约15年。而且,在杂交育种过程中,一定要用种子繁殖。     

香荚兰的快速繁殖

研究了香荚兰组织培养中植物激素、椰乳、糖分以及光和温度对器官形成的影响。结果表明,１．５ｍｇ／ＬＢＡ或０．２ｍｇ／ＬＢＡ附加１２．５％椰乳或１ｍｇ／ＬＮＡＡ有利于芽的增殖和长高;诱导生根用０．５ｍｇ／ＬＩＡＡ和３％蔗糖。适宜光照强度８０００１ｘ、温度２８℃,光照以１８小时为好。     

香荚兰细胞悬浮培养产生香兰素条件的研究

该文报道了碳源、氮源及吸附剂对香荚兰细胞悬浮培养产生香兰素的影响,结果表明,蔗糖比葡萄糖及果糖更适合作香荚兰细胞生长及产生香兰素的碳源,最佳蔗糖浓度为５％;当培养基中仅含ＫＮＯ３,则有利于细胞的生长和香兰素的形成,培养液中去掉ＫＮＯ３仅含ＮＨ４ＮＯ３时,细胞生长和香兰素形成均被抑制;培养基添加吸附剂后,香美兰细胞产生的香兰素含量明显增加,活性炭的效果优于ＸＡＤ-２,而且活性炭用量增加,香兰素的产量亦增加。     

不同加工处理条件下香荚兰荚果中二种内源酶的活性变化

香荚兰(VanillaplanifoliaAndr.)成熟荚果经过不同的杀青与烘烤条件处理后,分析其内部的β-葡萄糖甙酶与过氧化物酶的活性的变化,结果表明:经不同的杀青温度与时间处理后,β-葡萄糖甙酶活性都比对照高,而过氧化物酶的活性较对照低;经过不同的烘烤时间与温度处理后,β-葡萄糖甙酶活性与过氧化物酶的活性都比未经任何处理的有显著性地增高。     

Hydroxyester disaccharides from fruits of cape gooseberry (Physalis peruviana)

The 3-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranoside of ethyl 3-hydroxyoctanoate and the diastereomeric 3-O-alpha-L-arabinopyranosyl-(1-->6)-beta-D-glucopyranosides of (3R) and (3S)-butyl 3-hydroxybutanoate, respectively, were isolated by chromatographic methods from fruits of cape gooseberry (Physalis peruviana) harvested in Colombia. Their structures were identified by ESI-MS/MS and NMR spectroscopy. The three glycoconjugates can be considered as immediate precursors of ethyl 3-hydroxyoctanoate and butyl 3-hydroxybutanoate, which are important aroma volatiles found in the fruit.     

几种玫瑰油的化学成分及香气比较

用ＧＣ及ＧＣ／ＳＭ方法,定性定量地分析了法国玫瑰油、摩洛哥玫瑰油、我国甘肃苦水玫瑰油及山东平阴玫瑰油及山东阴玫瑰油的化学成分,各鉴定了７９,７４,４５和５４个成分。它们的主要化学成分均为得茅醇（玫瑰醇）、香叶醇、苯乙醇、金合欢醇及其酯类、芳樟醇、玫瑰醚、丁香酚、甲基丁香酚。由于它们含量上的多少及其化学成分上的差异,使这几种一般说来玫瑰油的香气产生了微妙的新鲜的玫瑰花香;而苦水玫瑰油、平阴玫瑰油成分     

GC-MS and GC-olfactometry analysis of aroma compounds extracted from culture fluids of <Emphasis Type="Italic">Antrodia camphorata</Emphasis>

A comprehensive inventory of the organic components and aroma-active compounds produced by Antrodia camphorata during growth in submerged culture has been established by extracting culture fluids using three different organic solvent systems and subjecting the extracts to gas chromatography-mass spectrometry (GC–MS) and gas chromatography–olfactometry (GC-O). Forty-two organic components, of which esters, alcohols, acids and ketones were the most prevalent, were identified in pentane/ether (1/1, v/v) extracts. The most representative of A. camphorata aroma-active compounds were detected in pentane/ether and ether extracts (eleven and nine aroma-active compounds, respectively) by GC-O. Of these, ethyl acetate, γ-undecalactone, linaloöl and 3-hydroxy-2-butanone were assessed to be present at the highest intensity.     

Purification and characterization of α-l-rhamnosidase from Penicillium corylopholum MTCC-2011

An extracellular α-l-rhamnosidase has been purified to electrophoretic homogeneity from the culture filtrate of Penicillium corylopholum MTCC-2011 using a simple procedure consisting of concentration by ultrafiltration and cation exchange column chromatography on carboxymethyl cellulose. The sodium dodesyl sulphate polyacrylamide gel electrophoresis analysis of the purified enzyme gave a single protein band corresponding to the molecular mass of 67.0 kDa. The native – polyacrylamide gel electrophoresis analysis also gave a single protein band confirming the purity of the enzyme and also showing that the enzyme is a monomer in the native state. The K_m and k_cat values of the enzyme were 0.42 mM and 35.7 s^?1, respectively, using p-nitrophenyl α-l-rhamnopyranoside as the substrate. The pH and temperature optima of the enzyme were 6.5 and 57.0 °C, respectively. The purified enzyme preparation successfully hydrolyzed naringin and rutin to prunin and quercetin glucoside, respectively. Thus it can be used for the preparation of these pharmaceutically important compounds.     

Synthesis and Antimicrobial Activity of Some S-β-D-Glucosides of 4-Mercaptopyrimidine

5-Acetyl-2-aryl-6-methyl-4-(2,3,4,6-tetra- O -acetyl-β-D-glucopyranosylmercapto)pyramidines 3a–c were obtained by the reaction of 5-acetyl-2-aryl-6-methyl-pyrimidine thiol 1a–c with 2,3,4,6-tetra- O -acetyl-α-D-glucopyranosyl bromide (2) in aq. KOH/acetone. The reaction of 1a–c with peracetylated galactose 5 and peracetylated ribose 8 under MW irradiation gave 5-acetyl-2-aryl-6-methyl-4-(2,3,4,6-tetra- O -acetyl-β-D-galactopyranosylmercapto)pyrimidine 6a–c and 5-acetyl-2-aryl-6-methyl-4-(2,3,5-tri- O -acetyl-β-D-ribofuranosylmercapto)pyrimidines 9a–c. The deprotection of 3a–c, 6a–c, and 9a–c in the presence of methanol and TEA/H₂O yielded the deprotected products 4a–c, 7a–c, and 10a–c. The structures of the compounds were confirmed by using IR, ¹H, ¹³C spectra and microanalysis. Selected members of these compounds were screened for antimicrobial activity.