共查询到20条相似文献,搜索用时 31 毫秒
1.
Previous studies on the lipase-mediated acylation of 6-azauridine with vinyl stearate in organic solvents revealed that while
preparing a potential prodrug, 3′-O-stearoyl-6-azauridine, a lipase from Burkholderia cepacia showed high regioselectivity toward the second hydroxyl group. The most suitable reaction solvent, molar ratio of vinyl stearate
to 6-azauridine, and reaction temperature were anhydrous acetone, 15:1, and 45°C, respectively. Under these conditions, the
initial reaction rate, 3′-regioselectivity, and maximum substrate conversion were as high as 10.4 mM/h, 86.0, and 99.0%, respectively. 相似文献
2.
Kalinovskaya NI Dmitrenok AS Kuznetsova TA Frolova GM Christen R Laatsch H Alexeeva YV Ivanova EP 《Current microbiology》2008,56(3):199-207
The marine bacterium “Pseudoalteromonas
januaria” SUT 11 isolated from a seawater sample produced the rare cell-bound cyclic lipodepsipeptides A/A′, B/B′, and C/C′. The matrix-assisted
laser desorption/ionization mass spectra indicated that one bromine atom presented in the peptides B/B′ and C/C′, whereas
the component A/A′ contained no bromine atom. The acyldepsipeptides A/A′–C/C′ have an identical amino acid sequence, Thr-Val-Asn-Asn-Leu/allo-Ile, but differed in C-terminal amino acid and acyl moieties. Peptides A–C have Leu as a C-terminal amino acid, whereas peptides
A′-C′ have allo-Ile. Acyl moieties in peptides A/A′, B/B′, and C/C′ have been found to consist of 11-(4′-hydroxyphenyl)-undeca-2,4,6,8,10-pentaenic
acid, 9-(3′-bromo-4′-hydroxyphenyl)-nona-2,4,6,8-tetraenic acid, and 11-(3′-bromo-4′-hydroxyphenyl)-undeca-2,4,6,8,10-pentaenic
acid, respectively. The structure of a main pair of peptides B/B′ with molecular masses 843/845 Da has been determined by
means of ultraviolet, infrared, and two-dimensional nuclear magnetic resonance spectroscopy. We have demonstrated that tandem
nano-electrospray ionization mass spectrometry is a very efficient way for the fast and sensitive investigation of lipopeptides
A/A′ and C/C′ with molecular masses 791 and 869/871 Da, respectively, which have been isolated in small amounts. 相似文献
3.
Paczkowski C Musial A Wlodkowski L Kalinowska M Wojciechowski ZA 《Biotechnology letters》2007,29(9):1403-1408
The regioselective acylation of cholesteryl β-d-glucoside, at the C-6 of the glucose moiety, was achieved using microbial lipases in organic solvents. With palmitic acid
as an acyl donor 81 or 63% conversions of cholesteryl glucoside to its 6′-O-palmitoyl derivative were obtained using Candida antarctica or Rhizomucor miehei enzymes, respectively. High yields (64–92%) were also obtained with fatty acids 6:0–22:0 and 16:1 (n-7). The synthesis of
cholesteryl (6′-O-palmitoyl)glucoside was also achieved via transesterification, using mono-, di- and tri-palmitoylglycerols or methyl and ethyl palmitate as acyl sources. With R. miehei lipase transesterification between methyl palmitate (80 mM) and cholesteryl glucoside (1 mM) proceeded after 24 h with a
nearly quantitative yield (97%). 相似文献
4.
A novel gene (IgASE2) encoding a C18-Δ9 polyunsaturated fatty acids specific (C18-Δ9-PUFAs-specific) elongase was isolated and characterized from
DHA-rich microalga, Isochrysis galbana H29. The IgASE2 gene was 1,653 bp in length, contained a 786 bp ORF encoding a protein of 261 amino acids that shared 87% identity with Δ9
elongase, IgASE1, and possessed a 44 bp 5′-untranslated region (5′-UTR) and a 823 bp 3′-untranslated region (3′-UTR). IgASE2,
by its heterologous expression in Saccharomyces cerevisiae, elongated linoleic acid (LA, 18:2n−6) and α-linolenic (ALA, 18:3n−3) to eicosadienoic acid (EDA, 20:2n−6) and eicosatrienoic acid (ETrA, 20:3n−3), respectively. The conversions of LA to EDA and ALA to ETrA were 57.6 and 56.1%, respectively. Co-expression of this elongase
with Δ8 desaturase required for the synthesis of C20-polyunsaturated fatty acids resulted in the accumulation of dihomo-γ-linolenic
acid (20:3n−6) from LA and eicosatetraenoic acid (20:4n−6) from ALA. These results demonstrated that IgASE2 exhibited C18-Δ9-PUFAs-specific elongase activity and the alternative
Δ8 pathway was reconstituted. 相似文献
5.
Manipulation of product heterogeneity was attempted by using yeast extract as nitrogen source in Alternaria alternata S-f6 transformation process of 4′-demethylepipodophyllotoxin. When the nitrogen source of NaNO3 was replaced by yeast extract, the heterogeneity of biotransformation products was significantly varied from a single product
(i.e., 4′-demethylpodophyllotoxone) to four podophyllum derivates. According to the kinetics of 4′-demethylepipodophyllotoxin
biotransformation process by A. alternata S-f6, the starting substrate of 4′-demethylepipodophyllotoxin was preferentially transformed to produce 4′-demethylpodophyllotoxone
(1) with an oxidation reaction. By the further comparison of products configuration, 4β-caprinoyl-4′-demethylepipodophyllotoxin
(3) was produced from 4′-demethylpodophyllotoxone (1) instead of 4′-demethylisopicropodophyllone (2), which might be produced from 4′-demethylpodophyllotoxone (1) with the isomerization of lactone. Finally, 4′-demethylisopicropodophyllone (2) was hydrolyzed to produce 3α-hydroxymethyl-(6, 7)-dioxol-4-one-naphthalene (4). This work shows new information on the 4′-demethylepipodophyllotoxin biotransformation process by A. alternata S-f6 and provides a foundation for further studies on the structural diversification of a bioactive natural lead compound. 相似文献
6.
S. Takaichi Zheng-Yu Wang Mitsuo Umetsu Tsunenori Nozawa Keizo Shimada Michael T. Madigan 《Archives of microbiology》1997,168(4):270-276
The complete carotenoid composition of the thermophilic green sulfur bacterium Chlorobium tepidum strain TNO was determined by spectroscopic methods. Major carotenoids were four kinds of carotenes: γ-carotene, chlorobactene,
and their 1′,2′-dihydro derivatives (1′,2′-dihydro-γ-carotene and 1′,2′-dihydrochlorobactene). In lesser amounts, hydroxyl
γ-carotene, hydroxyl chlorobactene, and their glucoside fatty acid esters were found. The only esterified fatty acid present
was laurate, and OH-chlorobactene glucoside laurate is a novel carotenoid. In other strains of C. tepidum, the same carotenoids were found, but the composition varied from strain to strain. The overall pigment composition in cells
of strain TNO was 4 mol carotenoids and 40 mol bacteriochlorophyll c per mol bacteriochlorophyll a. The effects of nicotine on carotenoid biosynthesis in C. tepidum differed from those in the thermophilic green nonsulfur bacterium Chloroflexus aurantiacus.
Received: 3 February 1997 / Accepted: 6 June 1997 相似文献
7.
A UDP-glucose: anthocyanin 3′,5′-O-glucosyltransferase (UA3′5′GT) (EC 2.4.1.-) was purified from the petals of Clitoria ternatea L. (Phaseoleae), which accumulate polyacylated anthocyanins named ternatins. In the biosynthesis of ternatins, delphinidin
3-O-(6″-O-malonyl)-β-glucoside (1) is first converted to delphinidin 3-O-(6″-O-malonyl)-β-glucoside-3′-O-β-glucoside (2). Then 2 is converted to ternatin C5 (3), which is delphinidin 3-O-(6″-O-malonyl)-β-glucoside-3′,5′-di-O-β-glucoside. UA3′5′GT is responsible for these two steps by transferring two glucosyl groups in a stepwise manner. Its substrate
specificity revealed the regioselectivity to the anthocyanin′s 3′- or 5′-OH groups. Its kinetic properties showed comparable
k
cat values for 1 and 2, suggesting the subequality of these anthocyanins as substrates. However, the apparent K
m value for 1 (3.89 × 10−5 M), which is lower than that for 2 (1.38 × 10−4 M), renders the k
cat/K
m value for 1 smaller, making 1 catalytically more efficient than 2. Although the apparent K
m value for UDP-glucose (6.18 × 10−3 M) with saturated 2 is larger than that for UDP-glucose (1.49 × 10−3 M) with saturated 1, the k
cat values are almost the same, suggesting the UDP-glucose binding inhibition by 2 as a product. UA3′5′GT turns the product 2 into a substrate possibly by reversing the B-ring of 2 along the C2-C1′ single bond axis so that the 5′-OH group of 2 can point toward the catalytic center.
K. Kogawa, N. Kato, K. Kazuma, and N. Noda contributed equally to this work. 相似文献
8.
Selective isotopic labeling provides an unparalleled window within which to study the structure and dynamics of RNAs by high
resolution NMR spectroscopy. Unlike commonly used carbon sources, the asymmetry of 13C-labeled pyruvate provides selective labeling in both the ribose and base moieties of nucleotides using E. coli variants, that until now were not feasible. Here we show that an E. coli mutant strain that lacks succinate and malate dehydrogenases (DL323) and grown on [3-13C]-pyruvate affords ribonucleotides with site specific labeling at C5′ (~95%) and C1′ (~42%) and minimal enrichment elsewhere
in the ribose ring. Enrichment is also achieved at purine C2 and C8 (~95%) and pyrimidine C5 (~100%) positions with minimal
labeling at pyrimidine C6 and purine C5 positions. These labeling patterns contrast with those obtained with DL323 E. coli grown on [1, 3-13C]-glycerol for which the ribose ring is labeled in all but the C4′ carbon position, leading to multiplet splitting of the
C1′, C2′ and C3′ carbon atoms. The usefulness of these labeling patterns is demonstrated with a 27-nt RNA fragment derived
from the 30S ribosomal subunit. Removal of the strong magnetic coupling within the ribose and base leads to increased sensitivity,
substantial simplification of NMR spectra, and more precise and accurate dynamic parameters derived from NMR relaxation measurements.
Thus these new labels offer valuable probes for characterizing the structure and dynamics of RNA that were previously limited
by the constraint of uniformly labeled nucleotides. 相似文献
9.
10.
Unexpected inversion of the 3′:5′-regioselectivity was observed in the enzymatic methacryloylation, crotonylation and cinnamoylation
of floxuridine (1.5:1, 2.3:1 and 4.4:1, respectively), where Thermomyces lanuginosus lipase preferentially catalyzed the acylation of 3′-hydroxyl rather than that of 5′-hydroxyl group. The possible reason might
be the presence of a remote interaction between the unsaturated bond in the acyl group and the aromatic ring of amino acid
residue Trp89 in the lid of the lipase.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
11.
Escherichia coli (E. coli) is a versatile organism for making nucleotides labeled with stable isotopes (13C, 15N, and/or 2H) for structural and molecular dynamics characterizations. Growth of a mutant E. coli strain deficient in the pentose phosphate pathway enzyme glucose-6-phosphate dehydrogenase (K10-1516) on 2-13C-glycerol and 15N-ammonium sulfate in Studier minimal medium enables labeling at sites useful for NMR spectroscopy. However, 13C-sodium formate combined with 13C-2-glycerol in the growth media adds labels to new positions. In the absence of labeled formate, both C5 and C6 positions
of the pyrimidine rings are labeled with minimal multiplet splitting due to 1JC5C6 scalar coupling. However, the C2/C8 sites within purine rings and the C1′/C3′/C5′ positions within the ribose rings have
reduced labeling. Addition of 13C-labeled formate leads to increased labeling at the base C2/C8 and the ribose C1′/C3′/C5′ positions; these new specific labels
result in two- to three-fold increase in the number of resolved resonances. This use of formate and 15N-ammonium sulfate promises to extend further the utility of these alternate site specific labels to make labeled RNA for
downstream biophysical applications such as structural, dynamics and functional studies of interesting biologically relevant
RNAs. 相似文献
12.
Selective isotopic labeling provides an unparalleled window within which to study the structure and dynamics of RNAs by high
resolution NMR spectroscopy. Unlike commonly used carbon sources, the asymmetry of 13C-labeled pyruvate provides selective labeling in both the ribose and base moieties of nucleotides using Escherichia coli variants, that until now were not feasible. Here we show that an E. coli mutant strain that lacks succinate and malate dehydrogenases (DL323) and grown on [3-13C]-pyruvate affords ribonucleotides with site specific labeling at C5′ (~95%) and C1′ (~42%) and minimal enrichment elsewhere
in the ribose ring. Enrichment is also achieved at purine C2 and C8 (~95%) and pyrimidine C5 (~100%) positions with minimal
labeling at pyrimidine C6 and purine C5 positions. These labeling patterns contrast with those obtained with DL323 E. coli grown on [1, 3-13C]-glycerol for which the ribose ring is labeled in all but the C4′ carbon position, leading to multiplet splitting of the
C1′, C2′ and C3′ carbon atoms. The usefulness of these labeling patterns is demonstrated with a 27-nt RNA fragment derived
from the 30S ribosomal subunit. Removal of the strong magnetic coupling within the ribose and base leads to increased sensitivity,
substantial simplification of NMR spectra, and more precise and accurate dynamic parameters derived from NMR relaxation measurements.
Thus these new labels offer valuable probes for characterizing the structure and dynamics of RNA that were previously limited
by the constraint of uniformly labeled nucleotides. 相似文献
13.
Anastassia Kanavarioti David H. White 《Origins of life and evolution of the biosphere》1987,17(3-4):333-349
We have undertaken a complete kinetic analysis of the template-directed oligoguanylate synthesis originated in Orgel's laboratory
(Inoue and Orgel, 1982). The reaction of guanosine 5′-phospho-2-methylimidazolide, 2-MelmpG, with ribooligoguanylates all
3′–5′ linked, designatedn
3 withn=7−12, was studied in the presence/absence of the complementary template polycytidylic acid, poly(C). Conditions were chosen
where poly(C) and 2-MelmpG are in large excess over the oligoguanylate. In the absence of the template at 37 °C the reaction
leads to three isomeric oligomers that are elongated by one monomer unit. They are the 3′–5′ linked, (n+1)3, the 2′–5′ linked, (n+1)2, and the pyrophosphate product, (n+1)
p
, formed in an approximate ratio 1:2:5. In the presence of the template the reaction is 20-fold faster and yields productsn+1,n+2,n+3 etc. as long as 2-MelmpG is available. Most importantly the formation of the natural, 3′–5′ linked isomer, is enhanced
selectively by 140-fold at 37 °C. Qualitative observations allow the conclusion that this enhancement is temperature dependent
and increases with decreasing temperature. For example, at 1 °C only the 3′–5′ linked isomers were detected. Initial rates
for the disappearance of then
3 oligoguanylate were determined at 1, 23, and 37 °C. It was found that the pseudo-first order rate constant for oligoguanylate
elongation was linearly proportional to the 2-MelmpG concentration. This implies that the reaction complex poly(C)·n
3·2-MelmpG does not accumulate under the reaction conditions, a conclusion which is also supported by infrared data (Miles
and Frazier, 1982). The implication of the above results with respect to chemical evolution is that lower temperatures, i.e.,
close to freezing, enhance the regioselectivity of these template-directed reactions and that one way to improve replication
models may be sought in finding conditions that favor stable reaction complexes.
NASA — National Research Council Research Fellow. 相似文献
14.
S.-y. Xu J.-p. Xiao L. Ettwiller M. Holden J. Aliotta C. L. Poh M. Dalton D. P. Robinson T. R. Petronzio L. Moran M. Ganatra J. Ware B. Slatko J. Benner 《Molecular & general genetics : MGG》1998,260(2-3):226-231
The genes encoding the ApaLI (5′-G^TGCAC-3′), NspI (5′-RCATG^Y-3′), NspHI (5′-RCATG^Y-3′), SacI (5′-GAGCT^C-3′), SapI (5′-GCTCTTCN1^-3′, 5′-^N4GAAGAGC-3′) and ScaI (5′-AGT^ACT-3′) restriction-modification systems have been cloned in E.␣coli. Amino acid sequence comparison of M.ApaLI, M.NspI, M.NspHI, and M.SacI with known methylases indicated that they contain the ten conserved motifs characteristic of C5 cytosine methylases. NspI and NspHI restriction-modification systems are highly homologous in amino acid sequence. The C-termini of the NspI and NlaIII (5′-CATG-3′) restriction endonucleases share significant similarity. 5mC modification of the internal C in a SacI site renders it resistant to SacI digestion. External 5mC modification of a SacI site has no effect on SacI digestion. N4mC modification of the second base in the sequence 5′-GCTCTTC-3′ blocks SapI digestion. N4mC modification of the other cytosines in the SapI site does not affect SapI digestion. N4mC modification of ScaI site blocks ScaI digetion. A DNA invertase homolog was found adjacent to the ApaLI restriction-modification system. A DNA transposase subunit homolog was found upstream of the SapI restriction endonuclease gene.
Received: 15 April 1998 / Accepted: 3 August 1998 相似文献
15.
A. M. Varizhuk S. V. Kochetkova N. A. Kolganova E. N. Timofeev V. L. Florent’ev 《Russian Journal of Bioorganic Chemistry》2010,36(2):199-206
A dinucleotide containing a C3′-NH-C(O)-CH2-C5′ amide internucleotide bond was synthesized by the interaction of 3′-deoxy-3′-amino-5′-O-(tert-butyldimethylsilyl)thymidine with 3′-O-benzyl-2′-O-tert-butyldimethylsilyl-5′-deoxy-5′-carboxymethylribosylthymine, which was obtained from 2′-O-acetyl-3′-O-benzyl-5′-deoxy-5′-ethoxycarbonylmethylribosylthymine through the methanolysis of the acetyl group followed by silylation
of liberated hydroxyl and ester saponification. After standard manipulation with protecting groups, the dinucleotide was converted
into 3′-O(2-cyanoethyl-N,N-diisopropylphosphoramidite), which was used for the synthesis of modified oligonucleotides on an automated synthesizer. The
melting curves of the duplexes formed by modified and complementary natural oligonucleotides were registered, and the melting
temperatures and thermodynamic parameters of the duplex formation were calculated. The introduction of a single modified bond
into the oligonucleotide led to an insignificant decrease in the melting temperature of these duplexes as compared to unmodified
ones. 相似文献
16.
Praveen Bawankar Philip J. Shaw Richa Sardana Prasad H. Babar Swati Patankar 《Molecular biology reports》2010,37(4):2125-2133
5′ caps provide recognition sequences for the nuclear import of snRNAs. The 5′ and 3′ ends of snRNAs were studied in Plasmodium falciparum with a modified adapter ligation method, which showed that 5′ ends of U1, U2, U4, U5 and U6 snRNAs are capped. In P. falciparum, the 3′ ends of U1, U2, U4 and U5 snRNAs have free hydroxyl groups whereas U6 snRNA has a blocked 3′ end. An immunoprecipitation
assay for trimethyl guanosine caps shows that the cap structures of parasite U1-U5 snRNAs are hypermethylated while U6 snRNA
may be γ-mono-methylated. Bioinformatics analysis of proteins involved in hypermethylation and trafficking of snRNAs indicates
that the methyltransferase TGS1 is present in the P. falciparum genome. PfTGS1 is larger than its orthologs and may have transmembrane domains in the C-terminus. Surprisingly, the snRNA
trafficking protein Snurportin is absent from the P. falciparum genome suggesting that reminiscent of yeast, parasite snRNAs may be retained in the nucleus. 相似文献
17.
M. A. Ivanov G. S. Ludva A. V. Mukovnya S. N. Kochetkov V. L. Tunitskaya L. A. Alexandrova 《Russian Journal of Bioorganic Chemistry》2010,36(4):488-496
4′-Fluoro-2′,3′-O-isopropylidenecytidine was synthesized by the treatment of 5′-O-acetyl-4′-fluoro-2′,3′-O-isopropylideneuridine with triazole and 4-chlorophenyl dichlorophosphate followed by ammonolysis. The interaction of 4′-fluoro-2′,3′-O-isopropylidenecytidine with hydroxylamine resulted in 4′-fluoro-2′,3′-O-isopropylidene-5′-O-acetyl-N
4-hydroxycytidine. The removal of the 2′,3′-O-isopropylidene groups led to acetyl derivatives of 4′-fluorouridine, 4′-fluorocytidine, and 4′-fluoro-N
4-hydroxycytidine. 4′-Fluorouridine 5′-O-triphosphate was obtained in three steps starting from 4′-fluoro-2′,3′-O-isopropylideneuridine. 4′-Fluorouridine 5′-O-triphosphate was shown to be an effective inhibitor of HCV RNA-dependent RNA polymerase and a substrate for the NTPase reaction
catalyzed by the HCV NS3 protein, the hydrolysis rate being similar to that of ATP. It could also activate a helicase reaction
with an efficacy of only threefold lower than that for ATP. 相似文献
18.
Inhibitor studies and mutant analysis revealed a C30 pathway via 4,4′-diapophytoene and 4,4′-diaponeurosporene to 4,4′-diaponeursoporene-4-oic acid esters related to staphyloxanthin
in Halobacillus halophilus. Six genes may be involved in this biosynthetic pathway and could be found in two adjacent gene clusters. Two genes of this
pathway could be functionally assigned by functional pathway complementation as a 4,4′-diapophytoene synthase and a 4,4′-diapophytoene
desaturase gene. These genes were organized in two operons together with two putative oxidase genes, a glycosylase and an
acyl transferase ortholog. Pigment mutants were obtained by chemical mutagenesis. Carotenoid analysis showed that a white
mutant accumulated 4,4′-diapophytoene due to a block in desaturation. In a yellow mutant carotenogenesis was blocked at the
stage of 4,4′-diaponeurosporene and in an orange mutant at the stage of 4,4′-diaponeurosporene-4-oic acid. The protective
function of these pigments could be demonstrated for H. halophilus after inhibition of carotenoid synthesis by initiation of oxidative stress. A degree of oxidative stress which still allowed
50% growth of carotenogenic cells resulted in the death of the cells devoid of colored carotenoids. 相似文献
19.
Seidel V Windhövel J Eaton G Alfermann AW Arroo RR Medarde M Petersen M Woolley JG 《Planta》2002,215(6):1031-1039
Cell cultures of Linum album Kotschy ex Boiss. (Linaceae) showing high accumulation of the lignan podophyllotoxin (PTOX) were established. Enzymological
studies revealed highest activities of phenylalanine ammonia-lyase, cinnamyl alcohol dehydrogenase, 4-hydroxycinnamate:CoA
ligase and cinnamoyl-CoA:NADP oxidoreductase immediately prior to PTOX accumulation. To investigate PTOX biosynthesis, feeding
experiments were performed with [2-13C]3′,4′-dimethoxycinnamic acid, [2-13C]3′,4′-methylenedioxycinnamic acid (MDCA), [2-13C]3′,4′,5′-trimethoxycinnamic acid, [2-13C]sinapic acid, [2-13C]- and [2,3-13C2]ferulic acid. Analysis of the metabolites by HPLC coupled to tandem mass spectrometry revealed incorporation of label from
ferulic acid into PTOX and deoxypodophyllotoxin (DOP). In addition, MDCA was also unambiguously incorporated intact into PTOX.
These observations suggest that in L. album both ferulic acid and methylenedioxy-substituted cinnamic acid can be incorporated into lignans. Furthermore, it appears
that, in this species, the hydroxylation of DOP is a rate-limiting point in the pathway leading to PTOX.
Electronic supplementary material to this article is available at and is accessible for authorized users.
Electronic Publication 相似文献
20.
The enzymes flavonoid 3′-hydroxylase (F3′H) and flavonoid 3′,5′-hydroxylase (F3′5′H) play an important role in flower color
by determining the B-ring hydroxylation pattern of anthocyanins, the major floral pigments. F3′5′H is necessary for biosynthesis
of the delphinidin-based anthocyanins that confer a violet or blue color to most plants. Antirrhinum majus does not produce delphinidin and lacks violet flower colour while A. kelloggii produces violet flowers containing delphinidin. To understand the cause of this inter-specific difference in the Antirrhinum genus, we isolated one F3′H and two F3′5′H homologues from the A. kelloggii petal cDNA library. Their amino acid sequences showed high identities to F3′Hs and F3′5′Hs of closely related species. Transgenic
petunia expressing these genes had elevated amounts of cyanidin and delphinidin respectively, and flower color changes in
the transgenics reflected the type of accumulated anthocyanidins. The results indicate that the homologs encode F3′H and F3′5′H,
respectively, and that the ancestor of A. majus lost F3′5′H activity after its speciation from the ancestor of A. kelloggii. 相似文献