Identification of key gene networks controlling monoterpene biosynthesis during grape ripening by integrating transcriptome and metabolite profiling

Monoterpenes are typical aroma components of muscat grape cultivars,providing pleasant floral and fruity aromas to grapes and wines.However,the molecular mechanism of monoterpene biosynthesis between muscat and non-muscat grape remains unclear.Here,the muscat grape cultivar‘Jumeigui’and the non-muscat grape cultivar‘Kyoho’were chosen as plant materials for a comprehensive transcriptome and metabolite analysis.The gas chromatography-mass spectrometry(GC-MS)analysis demonstrated that a total of 27 and 23 monoterpene compounds were identified and quantified in the‘Jumeigui’and‘Kyoho’grape,respectively.‘Jumeigui’grape accumulated significantly higher concentrations of monoterpenes than‘Kyoho’grape.Furthermore,geraniol,linalool,geranic acid,and β-citronellol might be important odorants contributing to the floral character of the‘Jumeigui’grape due to the high levels odor activity values(OAVs).Transcriptome analysis demonstrated that the expression profiles of VvDXS,VvGGPPS.SSU1,Vv TPS-b/g showed a positive correlation with monoterpene accumulation in grapes.In addition,the expression patterns of the genes involved in jasmonic acid(JA)synthesis and signal were also positively correlated with monoterpene accumulation.All these results will help guide the functional verification of candidate genes related to monoterpene biosynthesis,as well as identify the master transcriptional and hormonal regulators of this pathway in grapes.

Highly Oxygenated Monoterpenes from Eupatorium fortunei

A pair of epimers of highly-oxygenated monoterpenes were isolated from the traditional Chinese medicine Eupatorium fortunei. Their structures were elucidated on the basis of the spectral analysis as （1R＊, 2S＊, 3R＊, 4R＊, 6S＊）-1, 2, 3, 6-tetrehydroxy-p-menthane （1） and （1S＊, 2S＊, 3S＊, 4R＊, 6R＊）-1, 2, 3, 6-tetrehydroxy-p-menthane （2）.

Larvicidal efficacy of monoterpenes against the larvae of Anopheles gambiae

Objective:To evaluate the larvicidal efficacy of eight volatile components of essential oils against 3rd instar larvae of Anopheles gambiae s.s.Methods:Larvicidal effects of each compound were evaluated in both laboratory and semi-field trials.Stock solution was prepared and serial dilutions were made in six concentrations for each compound.A total of 20 larvae were exposed to larvicides for each replicate and monitored at intervals of 12,24,48 and 72 h.Larvae monitoring was done on basis of dead and live larvae in all intervals.Results:All assayed compounds were larvicides and presented varying degrees of larval toxicity,with LC50 values ranging from 1.28 to 1 938.92 mg/L depending on the treatment time(12,24,48 or 72 h).(-)-Perillyl alcohol presented the strongest larvicidal activity towards Anopheles gambiae larvae,with LC_(50) values of 73.60,18.36,1.72 and1.28 mg/L after 12,24,48 and 72 h of exposure,respectively.The next strongest were(-)-isopulegol(LC_(50)= 135.10,49.39,34.39 and 20.22 mg/L) and(-)-carvone epoxide(LC_(50)= 168.86,124.74,80.84 and 23.46 mg/L).After 12,24 and 48 h of treatment,hydroxydihydrocarvone was the least toxic compound,with LC_(50) values of 1 938.92,1 172.18 and 401.03 mg/L,respectively.Conclusions:The data obtained in this study suggest that all evaluated monoterpenes,especially(-)-perillyl alcohol,have remarkable larvicidal effects and may be considered as potential sources for the development of suitable natural larvicides for mosquito management programs.Further small-scale field trials should be conducted.

落叶松八齿小蠹伴生长喙壳真菌致病性研究

[目的]通过分析落叶松八齿小蠹伴生长喙壳真菌对寄主的致病能力,探究其对落叶松的危害程度与潜在风险。[方法]利用人工接种的方法,将从落叶松八齿小蠹虫体及坑道中分离到的12种长喙壳真菌接种到长白落叶松上,60 d后观察和测量病斑大小。并对2种Endoconidiophora真菌(E.fujiensis和E.laricicola)诱导寄主抗性的能力进行测定。[结果]结果表明,5种长喙壳真菌E.laricicola、E.fujiensis、Ophiostoma hongxingense、O.peniculi和O.xinganense接种长白落叶松产生的病斑面积大于对照处理,其余7种Ophiostoma真菌产生的病斑面积与对照无显著差异。E.laricicola产生的平均病斑面积最大,为3.51 cm^(2),且诱导寄主萜类物质含量呈现先升高后降低的趋势,表现出对长白落叶松的较强致病力。而E.fujiensis产生的平均病斑面积为1.70 cm^(2),诱导寄主萜类物质含量呈现下降趋势,表现出较弱致病力。[结论]E.laricicola对长白落叶松具有强致病性,E.fujiensis、O.hongxingense、O.peniculi和O.xinganense对长白落叶松具有弱致病性,而另外7种Ophiostoma真菌对落叶松无明显致病性。

紫丁香花香成分鉴定及关键TPS基因的功能分析

萜烯合成酶(TPS,terpene synthase)基因是萜类化合物生物合成途径中的关键基因,其在植物萜烯代谢中起到重要的作用。本研究以紫丁香(Syringa oblata Lindl.ex Carr.)花瓣为材料,在优化固相微萃取花香化合物条件的基础上,对4个不同花发育时期(花蕾期、初开期、盛开期和衰败期)的花香化合物进行鉴定分析;结合基因组和转录组数据筛选到了SoTPS2和SoTPS3关键候选基因,并对其进行克隆和功能研究。结果表明:(1)最适的萃取条件为30℃萃取40 min;4个花发育时期的花香总释放量呈先升高后下降的趋势,盛花期达到最高;4个时期中萜烯类化合物的释放量占花香总释放量的比例均最高,其中以单萜罗勒烯的释放量最高。(2)SoTPS2和SoTPS3基因编码区长度分别为1731 bp和1779 bp,编码氨基酸分别为576个和592个,编码的蛋白具有Terpene_cyclase_plant_C1保守结构域,属于Isoprenoid_Biosyn_C1超家族;实时荧光定量表明2个基因均在花瓣中表达量最高,在不同花发育时期表达量均呈先升高后下降趋势,在盛开期表达量最高,与单萜罗勒烯的释放量呈正相关。(3)在金鱼草(Antirrhinum majus L.)花瓣中异源瞬时过表达SoTPS2和SoTPS3基因,发现罗勒烯释放量与对照组相比分别显著增加10.91倍和23.67倍。综上表明,紫丁香花香主要成分为单萜类化合物,SoTPS2和SoTPS3可以影响紫丁香单萜化合物,尤其是罗勒烯的合成。

保湿保水沟对采脂湿地松木材纸浆特性和松脂成分的影响

以16年生的湿地松林分为试验对象,设置3种处理方法进行对照分析,探讨不同处理下保湿保水沟对采脂湿地松木材纸浆特性及松脂成分的影响。结果表明:除木材基本密度外,管胞长度、管胞宽度、管胞长宽比、综纤维素、纤维素、木质素及松脂成分含量在不同处理之间均没有显著差异;随着保湿保水沟深度的增加,采脂湿地松植株的木材基本密度、管胞长度、管胞长宽比、综纤维素、纤维素含量逐渐增加,但木质素含量逐渐减少;保湿保水沟处理的湿地松松脂成分组成与对照完全一致,但湿地松松脂各种成分的含量随着保湿保水沟深度的增加,其变化趋势并不一致。

Cyclization mechanism of monoterpenes catalyzed by monoterpene synthases in dipterocarpaceae

Monoterpenoids are typically present in the secretory tissues of higher plants,and their biosynthesis is catalyzed by the action of monoterpene synthases(MTSs).However,the knowledge about these enzymes is restricted in a few plant species.MTSs are responsible for the complex cyclization of monoterpene precursors,resulting in the production of diverse monoterpene products.These enzymatic reactions are considered exceptionally complex in nature.Therefore,it is crucial to understand the catalytic mechanism of MTSs to elucidate their ability to produce diverse or specific monoterpenoid products.In our study,we analyzed thirteen genomes of Dipterocarpaceae and identified 38 MTSs that generate a variety of monoterpene products.By focusing on four MTSs with different product spectra and analyzing the formation mechanism of acyclic,monocyclic and bicyclic products in MTSs,we observed that even a single amino acid mutation can change the specificity and diversity of MTS products,which is due to the synergistic effect between the shape of the active cavity and the stabilization of carbon-positive intermediates that the mutation changing.Notably,residues N340,I448,and phosphoric acid groups were found to be significant contributors to the stabilization of intermediate terpinyl and pinene cations.Alterations in these residues,either directly or indirectly,can impact the synthesis of single monoterpenes or their mixtures.By revealing the role of key residues in the catalytic process and establishing the interaction model between specific residues and complex monoterpenes in MTSs,it will be possible to reasonably design and engineer different catalytic activities into existing MTSs,laying a foundation for the artificial design and industrial application of MTSs.

Itoside O,a new linear monoterpene glycoside from the bark and twigs of Itoa orientalis

To investigate the chemical components of the barks and twigs ofltoa orientalis. A new linear monoterpene glycoside named itoside O was isolated from the crude extract of Itoa orientalis together with 11 known compounds. The new compound was identified to be 3,7-dimethyl-1, 6-octadien-3, 10-dihydroxyl-10-O-α-L-arabinopyranosyl （1 -→6）-O-β-D-glucopyranoside by 1D and 2D NMR analysis, and all known compounds were isolated from this plant for the first time.

牡丹皮正丁醇部位化学成分研究

研究牡丹皮85%乙醇提取物正丁醇萃取部位化学成分及其抗炎、抗菌的活性。采用大孔树脂柱色谱、硅胶柱色谱、Sephadex LH-20凝胶柱色谱结合反相中压柱色谱和半制备色谱技术,分离纯化牡丹皮的正丁醇萃取部位,并利用核磁共振波谱、质谱数据与文献比对鉴定化合物的结构。从牡丹皮乙醇提取部位的正丁醇萃取物中得到16个化合物,分别为5-hydroxy-3 S-hydroxymethyl-6-methyl-2,3-dihydrobenzofuran(1)、(S)-(6-methyl-2,3-dihydrobenzofuran-3-yl)methanol(2)、4-thujone-7-hydroxyl-8-O-β-D-glucopyranoside(3)、resacetophenone(4)、acetoisovanillone(5)、2,5-二羟基-4-甲氧基-苯乙酮(6)、3-(4-hydroxy-3-methoxy phenyl)propan-1,2-diol(7)、erythro-1-(3-methoxy-4-hydroxy-phenyl)-propan-1,2-diol(8)、thero-1-(3-methoxy-4-hydroxy-phenyl)-propan-1,2-diol(9)、(+)-儿茶素(10)、(+)-儿茶素-7-O-β-D-吡喃葡萄糖苷(11)、对羟基苯甲酸-β-D-吡喃葡萄糖苷(12)、苯甲酸-β-D-吡喃葡萄糖苷(13)、没食子酸乙酯(14)、没食子酸甲酯(15)、香草酸(16)。化合物2、7~9和11~16均首次从芍药属中分离得到。活性筛选发现化合物1能够抑制脂多糖诱导的RAW 264.7细胞中的炎症因子水平(NO、TNF-α和IL-6),其IC 50值分别为15.67±1.20、18.59±1.27和15.79±1.20μmol/L。

两收栽培下‘瑞都红玉’葡萄单萜类物质积累差异解析

为探究两收栽培模式下‘瑞都红玉’葡萄单萜类物质积累的差异,本研究以6年生‘瑞都红玉’葡萄为试材,通过对比分析‘一’字形平棚架(简称棚架)和高宽垂‘V’形篱架(简称篱架)两种栽培夏果、冬果的理化指标及游离态单萜类物质含量,得出不同栽培方式下‘瑞都红玉’葡萄冬果和夏果的单萜类物质的积累差异。结果显示,夏果的果粒大小和质量均显著高于冬果;两种架式下冬果可滴定酸含量均高于夏果,但冬果篱架有利于可滴定酸含量的降低。此外,不同处理果实中均检测到24种游离态单萜类化合物,其中里哪醇含量最高,棚架下冬果含量最高达到了577.22 μg·L^(-1)。利用主成分分析可以将夏果棚架、夏果篱架、冬果棚架、冬果篱架很好的区分,也进一步说明广西地区‘瑞都红玉’葡萄利用棚架栽培条件下更有利于冬果单萜化合物的积累。本研究结果为该品种一年两收栽培的架式选择提供了重要的理论依据,为提升该品种葡萄的品质与产量奠定了基础。

Monoterpene Glycosides from the Roots of Paeonia lactiflora

A new monoterpene glycoside, together with nine known ones, 3-O-methylpaeoniflorin, mudanpioside J, paeoniflorin, benzoylpaeoniflorin, oxypaeoniflorin, benzoyloxypaeoniflorin, oxybenzoylpaeoniflorin, albiflorin and lactiflorin, was isolated from the roots of Paeonia lactiflora Pall.. The structure of the new compound was elucidated as galloylalbiflorin by the spectro- scopic evidence including ESI-MS, 1D- and 2D-NMR spectra.

Paeonivayin, A New Monoterpene Glycoside from Paeonia delavayi

A new monoterpene glycoside named paeonivayin with other seven known compounds were isolated from the roots of Paeonia delavayi Franch. and their structures were determined by means of spectroscopic studies.

Structural characterization of monoterpene indole alkaloids in ethanolic extracts of Rauwolfia species by liquid chromatography with quadrupole time-of-flight mass spectrometry

Rauwolfia species(Apocynaceae) are medicinal plants well known worldwide due to its potent bioactive monoterpene indole alkaloids(MIAs) such as reserpine,ajmalicine,ajmaline,serpentine and yohimbine.Reserpine,ajmalicine and ajmaline are powerful antihypertensive,tranquilizing agents used in hypertension.Yohimbine is an aphrodisiac used in dietary supplements.As there is no report on the comparative and comprehensive phytochemical investigation of the roots of Rauwolfia species,we have developed an efficient and reliable liquid chromatography-tandem mass spectrometry(LC–MS/MS) method for ethanolic root extract of Rauwolfia species to elucidate the fragmentation pathways for dereplication of bioactive MIAs using highperformance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry(HPLC–ESI–QTOF–MS/MS) in positive ion mode.We identified and established diagnostic fragment ions and fragmentation pathways using reserpine,ajmalicine,ajmaline,serpentine and yohimbine.The MS/MS spectra of reserpine,ajmalicine,and ajmaline showed C-ring-cleavage whereas E-ring cleavage was observed in serpentine via Retro Diels Alder(RDA).A total of 47 bioactive MIAs were identified and characterized on the basis of their molecular formula,exact mass measurements and MS/MS analysis.Reserpine,ajmalicine,ajmaline,serpentine and yohimbine were unambiguously identified by comparison with their authentic standards and other 42 MIAs were tentatively identified and characterized from the roots of Rauwolfia hookeri,Rauwolfia micrantha,Rauwolfia serpentina,Rauwolfia verticillata,Rauwolfia tetraphylla and Rauwolfia vomitoria.Application of LC–MS followed by principal component analysis(PCA) has been successfully used to discriminate among six Rauwolfia species.

Two New Monoterpene Diglycosides from Winchia calophylla A.DC

Two new monoterpene diglycosides, wincaloside A (1) and wincaloside B (2), along with loganin (3) were isolated from the stem barks of Winchia calophylla A. DC. The structures of 1 and 2 were established by spectroscopic and chemical methods.

A New Monoterpene Glycoside from Swertia punicea

A new monoterpene glycoside, 2,6-dimethyl-2E,6E-octadienoic acid 1,6'-lactone 8-beta-D-glucopyranoside, was isolated from Swertia punicea, accompanying with six known compounds 1-O-primeverosyl-3,7-dimethoxy-8-hydroxyxanthone, 1-O-primeverosyl-3,7,8-tri-methoxyxan-thone, epi-eustomoside, 1-hydroxy-3,7,8-trimethoxyxanthone, 1,8-dihydroxy-3,7-dimethoxy xanthone and isovitexine. Their structures were elucidated based on spectral evidence.

A New Monoterpene Glycoside from Paeonia veitchii

A new monoterpene glycoside, acetoxypaeoniflorin, was isolated from the root cortex of Paeonia veitchii Lynch.. The structure was elucidated by spectral methods.

A New Monoterpene Glucoside from the Leaves of Betula platyphylla Suk.

A new monoterpene glucoside. (2E,67.)-2.6-dimethyl-8-beta -D-glucosyloxy-2,6-octadienoic acid, was isolated from the leaves of Betula platyphylla Suk. The structure was established by spectroscopic data.

A Novel Monoterpene Glycoside from Swertia mileensis

A novel monoterpene glycoside, mileenside, was isolated from Swertia mileensis by repeated normal and reverse phase silica gel chromatography and its structure was elucidated mainly based on spectral evidence.

Two new monoterpene glycosides from Doellingeria scaber

Two new methane-type monoterpene glycosides were isolated from the roots of Doellingeria scaber. Their structures were identified as trans-p-menthane-1α,2β,8-triol 8-O-β-D-（3′,6′-diangeloyloxy）-glucopyranoside and trans-p-menthane-1α,2β,8-triol 8-O-β-D-（3′-angeloyloxy,6′-isobutyloxy）-glucopyranoside based on 1D and 2D NMR spectroscopy.

New monoterpene phenyl ethers from Illicium micranthum

Seven new monoterpene phenyl ethers,namely micranthumnins A-G(1-7),were isolated from the stem bark of Illicium micranthum(Illiciaceae).Their structures were elucidated by comprehensive spectroscopic analyses including MS,IR,1D and 2D NMR.All compounds were evaluated for their anti-AChE activities.