Artículos de revistas: "Biosynthèse in vitro"

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Roussel, J. P. "Implication des 3-déhydroecdystéroïdes dans la voie de biosynthèse de l'ecdysone chezLocusta migratoria, in vitro". Archives Internationales de Physiologie, de Biochimie et de Biophysique 100, n.º 1 (enero de 1992): 45–53. http://dx.doi.org/10.3109/13813459209035258.

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Arnould, J. M. "Mise en évidence in vitro de la biosynthèse d'histamine à partir de carnosine par le rein de souris gravide". Canadian Journal of Physiology and Pharmacology 65, n.º 1 (1 de enero de 1987): 70–74. http://dx.doi.org/10.1139/y87-013.

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Kidneys of pregnant mice synthesize histamine when incubated in the presence of carnosine, manganese, and pyridoxal phosphate. Intensity of biosynthesis increases linearly with the amount of enzyme and the incubation time. The reaction can only be catalysed by two enzymes that are located in kidneys and act in succession: carnosinase, which hydrolyzes carnosine into its two moieties, and histidine decarboxylase, which transforms histidine, a product of carnosine degradation, into histamine. The biosynthesis of histamine from carnosine seems to increase with the progress of pregnancy. In nonpregnant mice, kidneys do not effect this biosynthesis. The above results directly demonstrate that carnosine may be used for histamine synthesis when the activity of histidine decarboxylase is high, as in pregnant mouse kidney. Vertebrate carnosine, its role still enigmatic, might thus be mainly a potential histidine reservoir that would be mobilized any time there is a significant requirement for histidine, such as for histamine biosynthesis.

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3

De Angelis, Francesco, Rosario Nicoletti, Nicoletta Spreti y Franca Verì. "Ein neues In-vitro-Modell der Lignin-Biosynthese". Angewandte Chemie 111, n.º 9 (3 de mayo de 1999): 1364–67. http://dx.doi.org/10.1002/(sici)1521-3757(19990503)111:9<1364::aid-ange1364>3.0.co;2-y.

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Wagner, Hildebert, Michael Wierer y Rudolf Bauer. "In vitro-Hemmung der Prostaglandin-Biosynthese durch etherische Öle und phenolische Verbindungen". Planta Medica 52, n.º 03 (junio de 1986): 184–87. http://dx.doi.org/10.1055/s-2007-969117.

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Fischer, S., R. Lorenz, P. C. Weber y C. v. Schacky. "N-3 Fettsäuren, Eikosanoide und zelluläre Funktionen". Hämostaseologie 07, n.º 05 (septiembre de 1987): 101–8. http://dx.doi.org/10.1055/s-0038-1660538.

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ZusammenfassungIn geeigneten In-vitro-Modellen und beim Menschen verändern n-3 Fettsäuren das Eikosanoidsystem qualitativ und quantitativ in eine günstige Richtung. Zusätzlich zur unverminderten Bildung der stark vasodilatatorisch und antiaggregatorisch wirksamen Substanz PGI2 erscheint in größeren Mengen das biologisch beinahe ebenso wirksame PGI3. Die Biosynthese des physiologischen Gegenspielers von PGI, der starke Aggregator und Vasokonstriktor TXA2, wird gesenkt, in kleinen Mengen wird auch ein biologisch nicht oder nur gering wirksames TXA3 gebildet. EPA wird im Menschen in den Neutrophilen eingebaut und auf Stimulation hin das schwach chemotaktisch und chemokinetisch wirksame LTB5 in geringen Mengen gebildet. Ob die Biosynthese des biologisch viel stärker wirksamen LTB4 dabei zurückgeht, ist gegenwärtig unklar. Man nimmt an, daß die qualitative und quantitative Umstellung des Eikosanoidsystems bei den in vielen Untersuchungen festgestellten günstigen Veränderungen zellulärer Funktionen während der Anreicherung der Ernährung mit n-3 Fettsäuren eine Rolle spielt. Noch zu erklären bleibt, wie die Thrombozytenaggregationshemmung nach DCHA mediiert wird.Durch eine Anreicherung der Ernährung mit n-3 Fettsäuren lassen sich bei Gesunden wie bei Patienten auch unter unseren Zivilisationsbedingungen funktionelle und biochemische Veränderungen erzielen, wie sie bei Eskimos oder Japanern beobachtet werden: So sinkt die Thrombozytenaggregation ex vivo, als In-vivo-Korrelat wird die Blutungszeit verlängert. Auch scheinen sich günstige Veränderungen bei Zellen, die bei Entzündung und immunologischen Erkrankungen eine Rolle spielen, einzustellen. Da n-3 Fettsäuren außerdem Blutfette senken, Blutdruck und Blutdruckantwort auf Pressorhormone senken und rheologische Parameter günstig verändern, ist zu vermuten, daß n-3 Fettsäuren einen Platz in Therapie und Prophylaxe der Atherosklerose finden werden. Zuvor gilt es allerdings Ergebnisse laufender Studien abzuwarten, die Dosierungen und genaue Indikationen festlegen werden.

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Teramura, Misato, Jiro Harada y Hitoshi Tamiaki. "In vitro enzymatic assays of photosynthetic bacterial 3-vinyl hydratases for bacteriochlorophyll biosyntheses". Photosynthesis Research 135, n.º 1-3 (22 de junio de 2017): 319–28. http://dx.doi.org/10.1007/s11120-017-0415-6.

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Reichling, Jürgen y Rainer Stange. "Antivirale und viruzide Eigenschaften von ätherischen Ölen und ihren isolierten Verbindungen – Stand der präklinischen Forschung". Zeitschrift für Komplementärmedizin 16, n.º 01 (febrero de 2024): 16–25. http://dx.doi.org/10.1055/a-2239-4034.

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SummaryÄtherische Öle (ÄÖ) als Vielstoffgemische sowie einzelne chemisch charakterisierte Ätherisch-Öl-Verbindungen (ÄÖV) haben zahlreiche pharmakologische Wirkungen, wie antibakterielle, antimykotische, antivirale, entzündungshemmende, immunmodulatorische, antioxidative und wundheilungsfördernde. Auf der Grundlage ausgewählter wissenschaftlicher Arbeiten befasst sich die vorliegende Übersicht mit den potenziellen antiviralen und viruziden Aktivitäten von ÄÖ und ÄÖV gegen behüllte und unbehüllte Viren. Neuere In-vitro- und In-vivo-Studien haben gezeigt, dass verschiedene Arznei- und Aromapflanzen antiviral und viruzid wirkende ÄÖ und ÄÖV enthalten, die in der Lage sind, in verschiedenen Wirtszelllinien die Vermehrung von DNA- und RNA-Viren zu behindern, indem sie wichtige Schritte des viralen Infektions-/Replikationszyklus blockieren. In-vivo-Studien an Mäusen mit Viren als Atemwegserreger haben gezeigt, dass verschiedene ÄÖ und ÄÖV das Leben infizierter Tiere verlängern, Virustiter in Gehirn und Lungengewebe reduzieren und die Biosynthese von proinflammatorischen Zytokinen hemmen können. Neuere Arbeiten auf technologischem Gebiet konnten nachweisen, dass nanoverkapselte ÄÖ/ÄÖV eine vielversprechende Möglichkeit darstellen, um die chemische Stabilität, Wasserlöslichkeit, Bioverfügbarkeit und antivirale Wirkung von ÄÖ und ÄÖV zu verbessern.

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Müller, Wolfgang M, Timo Schmiederer, Paul Ensle y Roderich D Süssmuth. "In-vitro-Biosynthese des Typ-III-Lantibiotikums Prä-Labyrinthopeptin A2 unter C-C-Bindungsknüpfung als posttranslationaler Modifizierung". Angewandte Chemie 122, n.º 13 (28 de febrero de 2010): 2486–90. http://dx.doi.org/10.1002/ange.200905909.

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Ida-Yonemochi, Hiroko, Kazufumi Ohshiro, Wael Swelam, Hamdy Metwaly y Takashi Saku. "Perlecan, a Basement Membrane-type Heparan Sulfate Proteoglycan, in the Enamel Organ: Its Intraepithelial Localization in the Stellate Reticulum". Journal of Histochemistry & Cytochemistry 53, n.º 6 (junio de 2005): 763–72. http://dx.doi.org/10.1369/jhc.4a6479.2005.

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The localization and biosynthesis of perlecan, a basement membrane-type heparan sulfate proteoglycan, were studied in developing tooth germs by using murine molars in neonatal and postnatal stages and primary cultured cells of the enamel organ and dental papilla to demonstrate the role of perlecan in normal odontogenesis. Perlecan was immunolocalized mainly in the intercellular spaces of the enamel organ as well as in the dental papilla/pulp or in the dental follicle. By in situ hybridization, mRNA signals for perlecan core protein were intensely demonstrated in the cytoplasm of stellate reticulum cells and in dental papilla/pulp cells, including odontoblasts and fibroblastic cells in the dental follicle. Furthermore, the in vitro biosyntheses of perlecan core protein by the enamel organ and dental papilla/pulp cells were confirmed by immunofluorescence, immunoprecipitation, and reverse transcriptase-polymerase chain reaction. The results indicate that perlecan is synthesized by the dental epithelial cells and is accumulated in their intercellular spaces to form the characteristic stellate reticulum, whose function is still unknown.

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TSENG, Chen-Fang, Satoshi IWAKAMI, Akihiro MIKAJIRI, Masaaki SHIBUYA, Fumio HANAOKA, Yutaka EBIZUKA, Kosashi PADMAWINATA y Ushio SANKAWA. "Inhibition of in Vitro Prostaglandin and Leukotriene Biosyntheses by Cinnamoyl-.BETA.-phenethylamine and N-Acyldopamine Derivatives." CHEMICAL & PHARMACEUTICAL BULLETIN 40, n.º 2 (1992): 396–400. http://dx.doi.org/10.1248/cpb.40.396.

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11

Sou, Nga-Lai, Yu-Hsuan Huang, Der-Yuan Chen, Yi-Ming Chen, Feng-Yao Tang, Hsin-An Ko, Yi-Hsuan Fan et al. "Folinate Supplementation Ameliorates Methotrexate Induced Mitochondrial Formate Depletion In Vitro and In Vivo". International Journal of Molecular Sciences 22, n.º 3 (29 de enero de 2021): 1350. http://dx.doi.org/10.3390/ijms22031350.

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(1) Background: Antifolate methotrexate (MTX) is the most common disease-modifying antirheumatic drug (DMARD) for treating human rheumatoid arthritis (RA). The mitochondrial-produced formate is essential for folate-mediated one carbon (1C) metabolism. The impacts of MTX on formate homeostasis in unknown, and rigorously controlled kinetic studies can greatly help in this regard. (2) Methods: Combining animal model (8-week old female C57BL/6JNarl mice, n = 18), cell models, stable isotopic tracer studies with gas chromatography/mass spectrometry (GC/MS) platforms, we systematically investigated how MTX interferes with the partitioning of mitochondrial and cytosolic formate metabolism. (3) Results: MTX significantly reduced de novo deoxythymidylate (dTMP) and methionine biosyntheses from mitochondrial-derived formate in cells, mouse liver, and bone marrow, supporting our postulation that MTX depletes mitochondrial 1C supply. Furthermore, MTX inhibited formate generation from mitochondria glycine cleavage system (GCS) both in vitro and in vivo. Folinate selectively rescued 1C metabolic pathways in a tissue-, cellular compartment-, and pathway-specific manner: folinate effectively reversed the inhibition of mitochondrial formate-dependent 1C metabolism in mouse bone marrow (dTMP, methionine, and GCS) and cells (dTMP and GCS) but not methionine synthesis in liver/liver-derived cells. Folinate failed to fully recover hepatic mitochondrial-formate utilization for methionine synthesis, suggesting that the efficacy of clinical folinate rescue in MTX therapy on hepatic methionine metabolism is poor. (4) Conclusion: Conducting studies in mouse and cell models, we demonstrate novel findings that MTX specifically depletes mitochondrial 1C supply that can be ameliorated by folinate supplementation except for hepatic transmethylation. These results imply that clinical use of low-dose MTX may particularly impede 1C metabolism via depletion of mitochondrial formate. The MTX induced systematic and tissue-specific formate depletion needs to be addressed more carefully, and the efficacy of folinate with respect to protecting against such depletion deserves to be evaluated in medical practice.

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12

Henry, Joel y Eve Boucaud-Camou. "In vitro stimulation by progesterone of the main nidamental glands biosyntheses in the mollusc cephalopod Sepia officinalis L." Comparative Biochemistry and Physiology Part A: Physiology 108, n.º 1 (mayo de 1994): 25–30. http://dx.doi.org/10.1016/0300-9629(94)90049-3.

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13

Uthoff, Stefan, Tim Stöveken, Nikolaus Weber, Klaus Vosmann, Erika Klein, Rainer Kalscheuer y Alexander Steinbüchel. "Thio Wax Ester Biosynthesis Utilizing the Unspecific Bifunctional Wax Ester Synthase/Acyl Coenzyme A:Diacylglycerol Acyltransferase of Acinetobacter sp. Strain ADP1". Applied and Environmental Microbiology 71, n.º 2 (febrero de 2005): 790–96. http://dx.doi.org/10.1128/aem.71.2.790-796.2005.

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ABSTRACT The bifunctional wax ester synthase/acyl coenzyme A (acyl-CoA):diacylglycerol acyltransferase (WS/DGAT) from Acinetobacter sp. strain ADP1 (formerly Acinetobacter calcoaceticus ADP1) mediating the biosyntheses of wax esters and triacylglycerols was used for the in vivo and in vitro biosynthesis of thio wax esters and dithio wax esters. For in vitro biosynthesis, 5′His6WS/DGAT comprising an N-terminal His6 tag was purified from the soluble protein fraction of Escherichia coli Rosetta(DE3)pLysS (pET23a::5′His6 atf). By employing SP-Sepharose high-pressure and Ni-nitrilotriacetic acid fast-protein liquid chromatographies, a 19-fold enrichment with a final specific activity of 165.2 nmol mg of protein−1 min−1 was achieved by using 1-hexadecanol and palmitoyl-CoA as substrates. Incubation of purified 5′His6WS/DGAT with 1-hexadecanethiol and palmitoyl-CoA as substrates resulted in the formation of palmitic acid hexadecyl thio ester (10.4% relative specific activity of a 1-hexadecanol control). Utilization of 1,8-octanedithiol and palmitoyl-CoA as substrates led to the formation of 1-S-monopalmitoyloctanedithiol and minor amounts of 1,8-S-dipalmitoyloctanedithiol (59.3% relative specific activity of a 1-hexadecanol control). The latter dithio wax ester was efficiently produced when 1-S-monopalmitoyloctanedithiol and palmitoyl-CoA were used as substrates (13.4% specific activity relative to that of a 1-hexadecanol control). For the in vivo biosynthesis of thio wax esters, the knockout mutant Acinetobacter sp. strain ADP1acr1ΩKm, which is unable to produce fatty alcohols, was used. Cultivation of Acinetobacter sp. strain ADP1acr1ΩKm in the presence of gluconate, 1-hexadecanethiol, and oleic acid in nitrogen-limited mineral salts medium resulted in the accumulation of unusual thio wax esters that accounted for around 1.19% (wt/wt) of the cellular dry weight and consisted mainly of oleic acid hexadecyl thioester as revealed by gas chromatography-mass spectrometry.

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Araki, Yasuko, Takayoshi Awakawa, Motomichi Matsuzaki, Rihe Cho, Yudai Matsuda, Shotaro Hoshino, Yasutomo Shinohara et al. "Complete biosynthetic pathways of ascofuranone and ascochlorin inAcremonium egyptiacum". Proceedings of the National Academy of Sciences 116, n.º 17 (5 de abril de 2019): 8269–74. http://dx.doi.org/10.1073/pnas.1819254116.

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Ascofuranone (AF) and ascochlorin (AC) are meroterpenoids produced by various filamentous fungi, includingAcremonium egyptiacum(synonym:Acremonium sclerotigenum), and exhibit diverse physiological activities. In particular, AF is a promising drug candidate against African trypanosomiasis and a potential anticancer lead compound. These compounds are supposedly biosynthesized through farnesylation of orsellinic acid, but the details have not been established. In this study, we present all of the reactions and responsible genes for AF and AC biosyntheses inA. egyptiacum, identified by heterologous expression, in vitro reconstruction, and gene deletion experiments with the aid of a genome-wide differential expression analysis. Both pathways share the common precursor, ilicicolin A epoxide, which is processed by the membrane-bound terpene cyclase (TPC) AscF in AC biosynthesis. AF biosynthesis branches from the precursor by hydroxylation at C-16 by the P450 monooxygenase AscH, followed by cyclization by a membrane-bound TPC AscI. All genes required for AC biosynthesis (ascABCDEFG) and a transcriptional factor (ascR) form a functional gene cluster, whereas those involved in the late steps of AF biosynthesis (ascHIJ) are present in another distantly located cluster. AF is therefore a rare example of fungal secondary metabolites requiring multilocus biosynthetic clusters, which are likely to be controlled by the single regulator, AscR. Finally, we achieved the selective production of AF inA. egyptiacumby genetically blocking the AC biosynthetic pathway; further manipulation of the strain will lead to the cost-effective mass production required for the clinical use of AF.

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Vanage, G. R., M. A. Phadke, A. H. Bandivdekar y A. R. Sheth. "Hormonal modulation of Invitro Biosynthesis of Inhibin like Peptide by Human Prostate: Hormonelle Modulation der In-vitro-Biosynthese des Inhibin-ähnlichen Peptids durch die menschliche Prostata". Andrologia 22, n.º 1 (24 de abril de 2009): 7–11. http://dx.doi.org/10.1111/j.1439-0272.1990.tb01932.x.

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16

Chiu, Hsien-Tai, Yu-Chin Lin, Meng-Na Lee, Yi-Lin Chen, Mei-Sin Wang y Chia-Chun Lai. "Biochemical characterization and substrate specificity of the gene cluster for biosyntheses of K-252a and its analogs by in vitro heterologous expression system of Escherichia coli". Molecular BioSystems 5, n.º 10 (2009): 1192. http://dx.doi.org/10.1039/b912395b.

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17

Yu, Yue y Wilfred A. van der Donk. "Biosynthesis of 3-thia-α-amino acids on a carrier peptide". Proceedings of the National Academy of Sciences 119, n.º 29 (5 de julio de 2022). http://dx.doi.org/10.1073/pnas.2205285119.

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A subset of natural products, such as polyketides and nonribosomal peptides, is biosynthesized while tethered to a carrier peptide via a thioester linkage. Recently, we reported that the biosyntheses of 3-thiaglutamate and ammosamide, single amino acid–derived natural products, employ a very different type of carrier peptide to which the biosynthetic intermediates are bound via an amide linkage. During their biosyntheses, a peptide aminoacyl-transfer ribonucleic acid (tRNA) ligase (PEARL) first loads an amino acid to the C terminus of the carrier peptide for subsequent modification by other enzymes. Proteolytic removal of the modified C-terminal amino acid yields the mature product. We termed natural products that are biosynthesized using such pathways pearlins. To investigate the diversity of pearlins, in this study we experimentally characterized another PEARL-encoding biosynthetic gene cluster (BGC) from Tistrella mobilis ( tmo ). The enzymes encoded in the tmo BGC transformed cysteine into 3-thiahomoleucine both in vitro and in Escherichia coli . During this process, a cobalamin-dependent radical S- adenosylmethionine (SAM) enzyme catalyzes C -isopropylation. This work illustrates that the biosynthesis of amino acid–derived natural products on a carrier peptide is a widespread strategy in nature and expands the spectrum of thiahemiaminal analogs of amino acids that may serve a broader, currently unknown function.

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18

Matsuda, Kenichi, Kei Fujita y Toshiyuki Wakimoto. "PenA, a penicillin-binding protein-type thioesterase specialized for small peptide cyclization". Journal of Industrial Microbiology and Biotechnology 48, n.º 3-4 (13 de marzo de 2021). http://dx.doi.org/10.1093/jimb/kuab023.

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Abstract Penicillin-binding protein-type thioesterases (PBP-type TEs) are a recently identified group of peptide cyclases that catalyze head-to-tail macrolactamization of nonribosomal peptides. PenA, a new member of this group, is involved in the biosyntheses of cyclic pentapeptides. In this study, we demonstrated the enzymatic activity of PenA in vitro, and analyzed its substrate scope with a series of synthetic substrates. A comparison of the reaction profiles between PenA and SurE, a representative PBP-type TE, showed that PenA is more specialized for small peptide cyclization. A computational model provided a possible structural rationale for the altered specificity for substrate chain lengths.

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Fu, Chengzhang, Yunkun Liu, Christine Walt, Sari Rasheed, Chantal D. Bader, Peer Lukat, Markus Neuber et al. "Elucidation of unusual biosynthesis and DnaN-targeting mode of action of potent anti-tuberculosis antibiotics Mycoplanecins". Nature Communications 15, n.º 1 (26 de enero de 2024). http://dx.doi.org/10.1038/s41467-024-44953-5.

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AbstractDNA polymerase III sliding clamp (DnaN) was recently validated as a new anti-tuberculosis target employing griselimycins. Three (2 S,4 R)−4-methylproline moieties of methylgriselimycin play significant roles in target binding and metabolic stability. Here, we identify the mycoplanecin biosynthetic gene cluster by genome mining using bait genes from the 4-methylproline pathway. We isolate and structurally elucidate four mycoplanecins comprising scarce homo-amino acids and 4-alkylprolines. Evaluating mycoplanecin E against Mycobacterium tuberculosis surprisingly reveals an excitingly low minimum inhibition concentration at 83 ng/mL, thus outcompeting griselimycin by approximately 24-fold. We show that mycoplanecins bind DnaN with nanomolar affinity and provide a co-crystal structure of mycoplanecin A-bound DnaN. Additionally, we reconstitute the biosyntheses of the unusual l-homoleucine, l-homonorleucine, and (2 S,4 R)−4-ethylproline building blocks by characterizing in vitro the full set of eight enzymes involved. The biosynthetic study, bioactivity evaluation, and drug target validation of mycoplanecins pave the way for their further development to tackle multidrug-resistant mycobacterial infections.

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Artículos de revistas sobre el tema "Biosynthèse in vitro"

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