Biotransformation of (+)-(1R,2S)-fenchol by the larvae of common cutworm (Spodoptera litura)

Biotransformation of (+)-(1R,2S)-fenchol by the larvae of Spodoptera litura was carried out. Substrate was converted to three new terpenoids, (+)-(1R,2S)-10-hydroxyfenchol, (+)-(1R,2R,3S)-8-hydroxyfenchol and (−)-(1S,2S,6S)-6-exo-hydroxyfenchol, and one known terpenoid, (−)-(1R,2R,3R)-9-hydroxyfenchol. These structures were established by NMR, IR, specific rotation and mass spectral studies.     

Toxicity and influences of the alkaloids from Cynanchum komarovii AL. Iljinski (Asclepiadaceae) on growth and cuticle components of Spodoptera litura Fabricius (Noctuidae) larvae

The acute lethal toxicity of the extracted and purified gross alkaloids from Cynanchum komarovii has been demonstrated on the insect pest, Spodoptera litura. The toxic regression equation of the gross alkaloids for S. litura larvae was Y?=?-2.69701?+?0.78711X and the LC(50) value 2669.88?mg?L(-1). The growth disruptions of S. litura caused by the alkaloids from C. komarovii were also evaluated. The rates of growth inhibition, malformation, developmental duration (from third instar to pupation), pupation and emergence inhibition of S. litura caused by the gross alkaloids at dose rates between 50 and 800?mg?L(-1) were 30.13-91.71%, 0.00-20.00%, 12-72?h, 16.66-36.66% and 16.66-50.00%, respectively. The alkaloids caused the modification of the cuticular components of S. litura. The relative contents of cuticular lipids, proteins and chitins showed a 3.02-17.11% rise before exposure, followed by 2.29-12.96% and 0.75-4.13% declines 72?h after treatment with gross alkaloids with concentrations between 50 and 800?mg?L(-1). Initial studies on the insecticidal properties of C. komarovii gross alkaloids indicate these to be very potent insect growth inhibitors.     

斜纹夜蛾性信息素的合成及其田间诱捕效果

以1,9-壬二醇为起始原料,经溴代、Wittig及Diels-Alder等反应合成了斜纹夜蛾性信息素主要组分——(Z,E)-9,11-十四碳二烯-1-醇乙酸酯(6),纯度99.2%,其结构经1H NMR,13C NMR和MS确证。田间试验结果表明,该方法合成的6,与市场上同类产品相比,对斜纹夜蛾雄虫具有明显诱捕效果。     

Biological studies of azadirachtin and its derivatives against polyphagous pest, Spodoptera litura

Azadirachtin-A (Aza-A, figure 1) was subjected to a variety of synthetic transformations and the antifeedant activity and toxicity of the azadirachtin derivatives were assessed against second instar larvae Spodoptera litura on castor leaves in comparison with the crude material containing 9.14% Aza-A, as well as relatively pure 91% Aza-A. A probable mechanism for the base initiated fragmentation of the diketocarbonate into a decalin fragment and a spiroketal moiety has been proposed. The present study indicates that the combination of insect toxicity and antifeedancy of azadirachtin provides good crop protection.     

Biotransformation of (-)-guaiol by Eurotium rubrum as a biocatalyst

The biotransformation of (-)-guaiol (1) has been investigated by using plant parasite fungus, Eurotium rubrum. Compound 1 was oxidized at the C-2 position, and transformed to pancherione.     

Biotransformation of 20(R)-panaxatriol by the fungus Aspergillus flavus Link AS 3.3950

Microbial transformation of 20(R)-panaxatriol by the fungus Aspergillus flavus Link AS 3.3950 was performed. Four new (1–4), along with two previously reported metabolites (5 and 6), were obtained. Their chemical structures were elucidated on the basis of extensive spectroscopic analyses. Furthermore, the inhibitory effects of those compounds on K562/ADR, Du-145, Hela, MCF-7 and HepG2 cell lines were evaluated by MTT assay. Among them, compound 15β-hydroxy-20(R)-panaxatriol (4) exhibited selective inhibitory effects on human leukaemic progenitor cells K562/ADR through arresting cell cycle, which was associated with obvious decrease of cyclin B1, cyclin D1 and cyclin-dependent kinase (CDK) 1/2/4/6 protein expression.     

Phenotypic and genetic diversity of Bacillus thuringiensis strains isolated in India active against Spodoptera litura

Bacillus thuringiensis strains isolated from different agroclimatic regions of India were found to harbor cry1 family genes. Of 831 strains 18 that were found to produce 130- and 68-kDa mol wt proteins in sodium dodecyl sulfate polyacrylamide gel electrophoresis were subjected to bioassay against second instar larvae of Spodoptera litura. According to the time response curve, while the highest toxic activity against S. litura was observed in PBT-782 with an LT₅₀ of 25.46 h, strains PBT-372, PBT-574, PBT-801, and PBT-716 in descending order of merit had LT₅₀ values of 36.81, 48.18, 50.35, and 73.53 h. The results of the field experiment testing the efficacy of different B. thuringiensis strains in controlling S. litura larvae infecting peanut plants showed that the chemical insecticide chlorpyriphos was the most effective in controlling S. litura throughout the study period. However, among B. thuringiensis strains, PBT-372 was superior. All the B. thuringiensis strains except PBT-689 were found to contain cry1Ac1-type gene. However, only nine strains contained cry1Aa1 gene. While cry1Ab1 was present only in PBT-372 and PBT-689, cry1Ca1 was present in PBT-574, PBT-688, PBT-689, and PBT-695. cry1Da1 was detected only in PBT-688 and PBT-692. None of the strains contained cry1Ba1 and cry1Ea1 genes. When polymerase chain reaction analysis using cry1Ca1 primer was performed, PBT-695 produced an unexpected 739-bp product, which showed 33% homology with cry1Ca1 gene between nucleotides 1819 and 2107. Our results indicated that among the field-collected B. thuringiensis strains, PBT-372 harbors multiple cry-type genes and could be employed for biological control of insects.     

Biotransformation from geraniol to nerol by immobilized grapevine cells (V. vinifera)

The abilities of two grapevine cell suspensions (Vitis vinifera L. cv. Gamay Fréaux andVitis vinifera L. cv. Monastrell) to biotransform geraniol into nerol in a biphasic system based on the culture medium and Miglyol 812 were compared. The Gamay grape cell suspension was able to transform higher concentrations of geraniol into nerol than the Monastrell one. Gamay grape cells were immobilized in both calcium alginate beads and polyurethane foams. The cytotoxic effect of increasing concentrations of geraniol, as well as the ability of the immobilized cells to biotransform geraniol into nerol, was checked. Immobilization proved to be advantageous in protecting cells against the toxicity of the substrate. Furthermore, immobilization also seemed to have an effect on the secondary metabolism, the cells immobilized in polyurethane foams being more efficient at performing the isomerization process (40% conversion of geraniol into nerol) than both the freely suspended and calcium alginate immobilized cells (20% conversion).     

Enantioselective epoxidation of isoflavones by Jacobsen's Mn(III)salen catalysts and dimethyldioxirane oxygen-atom source

The catalytic enantioselective epoxidation of the isoflavones 1a–f has been performed by the Mn(III)salen complexes (R,R)-3 and (S,S)-3 as catalysts and dimethyldioxirane as the oxygen-atom source to afford optically active isoflavone epoxides 2a–f. The absolute configuration of the nonracemic epoxides 2 have been determined by X-ray diffraction analysis. Our present results constitute the first examples of the preparation of optically active isoflavone epoxides.     

天然单萜柠檬烯的微生物转化

天然单萜柠檬烯资源丰富,价格便宜,在日用化工和医药行业已得到重要的应用。近几十年来,以柠檬烯为起始原料的新产品的研究与开发一直受到关注。大量文献报道了微生物能够对柠檬烯进行生物转化,得到系列在化妆品、食品、医药、有机合成等领域有重要应用价值的含氧衍生物。本文系统地综述了柠檬烯的微生物转化菌株和所得到转化产物的结构,分析了微生物对柠檬烯的主要转化途径以及影响微生物转化效率的主要因素。柠檬烯经微生物转化所得到的产物具有区域和立体选择性,并且难以通过人工合成方法得到。对生物转化过程进行系统优化,将有可能实现有用化合物的工业化生产。此外,在转化过程中诱导的高活性酶,尤其是单加氧酶和羟化酶的研究与应用也展现了诱人的前景。     

Bioactivity of Carica papaya (Caricaceae) against Spodoptera frugiperda (Lepidoptera: Noctuidae)

The composition of a chloroform seed extract of C. papaya was determined by GC-MS. Nineteen compounds were identified, with oleic (45.97%), palmitic (24.1%) and stearic (8.52%) acids being the main components. The insecticidal and insectistatic activities of the extract and the three main constituents were tested. Larval duration increased by 3.4 d and 2.5 d when the extract was used at 16,000 and 9,600 ppm, respectively, whereas the pupal period increased by 2.2 d and 1.1 d at the same concentrations. Larval viability values were 0%, 29.2%, and 50% when the extract was applied at 24,000, 16,000, and 9,600 ppm, respectively; pupal viability was 42.9% and 66.7% at 16,000 and 9,600 ppm; and pupal weight decreased by 25.4% and 11.5% at 16,000 and 9,600 ppm. The larval viability of the main compounds was 33.3%, 48.5%, and 62.5% when exposed to 1,600 ppm of palmitic acid, oleic acid, or stearic acid, respectively.     

Biotransformation of (1S)-2-carene and (1S)-3-carene by Picea abies suspension culture

Biotransformation of (1S)-2-carene and (1S)-3-carene by Picea abies suspension culture led to the formation of oxygenated products. (1S)-2-Carene was transformed slowly and the final product was identified as (1S)-2-caren-4-one. On the other hand, the transformation of (1S)-3-carene was rapid and finally led to the formation of (1S)-3-caren-5-one and (1S)-2-caren-4-one as equally abundant major products. The time-course of the reaction indicates that some products abundant at the beginning of the reaction (e.g. (1S, 3S, 4R)-3,4-epoxycarane and (1R)-p-mentha-1(7),2-dien-8-ol) were consumed by a subsequent transformations. Thus, a precise selection of the biotransformation time may be used for a production of specific compounds.     

Practical and efficient entry to isoflavones by Pd(0)/C-mediated Suzuki-Miyaura reaction. Total synthesis of geranylated isoflavones

A scalable synthesis of isoflavones taking advantage of the Suzuki-Miyaura reaction catalyzed by Pd(0)/C is described. The approach developed has been extended to the total synthesis of 7-O-geranylformononetin, griffonianone D, and conrauinone D, which did not display cytotoxicity against human HeLa carcinoma cells. In addition, this study established unambiguously the absolute configuration of natural griffonianone D.     

Toxicity of Bioactive Molecule Andrographolide against Spodoptera litura Fab and Its Binding Potential with Detoxifying Enzyme Cytochrome P450

Spodoptera litura Fab. is a polyphagous pest causing damage to many agriculture crops leading to yield loss. Recurrent usage of synthetic pesticides to control this pest has resulted in resistance development. Plant-derived diterpenoid compound andrographolide was isolated from the leaves of Andrographis paniculata. It was analysed by gas chromatography-mass spectroscopy and quantified by HPLC. Nutritional indices and digestive enzymatic profile were evaluated. Third, fourth and fifth instar larvae were treated with different concentrations of andrographolide. At 3, 6 and 9 ppm-treated concentrations the larvae showed decreased RGR, RCR, ECI, ECD values with adverse increase in AD. The digestive enzymes were significantly inhibited when compared with control. Conspicuously, andrographolide showed pronounced mortality of S. litura by inhibition of enzyme secretion and intake of food. The binding ability of andrographolide with CYTP450 showed high affinity with low binding energy. Andrographolide has the potential to be exploited as a biocontrol agent against S. litura as an eco-friendly pesticide.     

Biotransformation of Jervine by Cunninghamella echinulata

Biotransformation of jervine ( 1 ) by Cunninghamella echinulata (ACCC 30369) was carried out. Four biotransformation products were obtained, and three of them, 3 – 5 , were identified as new compounds. On the basis of their NMR and mass‐spectral data, their structures were characterized as jervinone ( 2 ), 7α‐hydroxyjervine ( 3 ), 14α‐hydroxyjervine ( 4 ), and 1β,7α‐dihydroxyjervine ( 5 ). The X‐ray diffraction structure of 1 is also reported for the first time.     

Biotransformation of daidzein ditiglate by microorganisms

Biotransformation of the daidzein ditiglate (2) by fungi, Aspergillus niger and Glomerella cingulata was investigated. Compound 2 was transformed to daidzein (1) by A. niger and G. cingulata. This suggested that compound 2 was converted to compound 1 by hydrolysis at both of the C-7 and C-4' positions.     

Biotransformation of Vermitaline by Cunninghamella echinulata

Biotransformation of vermitaline ( 1 ) by Cunninghamella echinulata (ACCC 30369) was carried out. Four biotransformation products were obtained and three of them were characterized as new compounds. On the basis of their NMR and mass‐spectral data, their structures were characterized as 7α‐hydroxyrubijervine ( 2 ), 7α‐hydroxyrubijervine‐7‐O‐β‐D ‐galactofuranoside ( 3 ), 7α‐hydroxyvermitaline ( 4 ), and 7α‐hydroxyvermitaline‐7‐O‐β‐D ‐galactofuranoside ( 5 ).     

海洋细菌对柠檬烯的生物转化及萜类产物鉴定

从南海大亚湾的海洋微生物中筛选出3株对单萜D-柠檬烯有显著生物催化转化作用的海洋细菌(Vibrio cholerae、Listonella dam sela和Vibrio alginolyticus)。以2216E为培养基,添加200mg/L的柠檬烯,在28℃,以120 r/m in摇瓶培养5 d,用乙酸乙酯提取培养液,经GC-MS分析其转化产物,结果显示,这些细菌能在柠檬烯的不同位置进行羟基化、羰基化等,并伴随有还原、水解、酯化、开环等反应,但转化能力和转化程度不同;在产物中,还检测到系列结构不同的其它萜类:包括倍半萜、二萜以及三萜等,这些萜类化合物的产生跟柠檬烯的加入有关,说明柠檬烯能影响细菌代谢产物的产生。单萜微生物转化反应操作简单、条件温和、高效率和高选择性、无毒、环境友好,能够分离发现系列新的在医药、有机合成、精细化工等领域有用的化合物,为丰富的天然单萜资源的开发与利用提供新的途径和方法。     

Biotransformation of tetrahydro-alpha-santonins by Absidia coerulea

The fungus, Absidia coerulea was employed to bioconvert tetrahydro-alpha-santonins, 1,2,4alpha,5alpha-tetrahydro-alpha-santonin (1), and its 4-epimer (2), from which 10 products (3-12) were obtained. Furthermore, their structures were determined, based on their chemical and spectroscopic data analyses. Among them, 3-5, 7, 9, 11 and 12 were observed to be seven new compounds. The reactions mainly involved in these bio-process included hydroxylation(s) (C-4, C-11, and C-1), reduction (C-3 ketone to alcohol).