- Biotechnological Production of Methyl-Branched Aldehydes
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A number of methyl-branched aldehydes impart interesting flavor impressions, and especially 12-methyltridecanal is a highly sought after flavoring compound for savory foods. Its smell is reminiscent of cooked meat and tallow. For the biotechnological production of 12-methyltridecanal, the literature was screened for fungi forming iso-fatty acids. Suitable organisms were identified and successfully grown in submerged cultures. The culture medium was optimized to increase the yields of branched fatty acids. A recombinant carboxylic acid reductase was used to reduce 12-methyltridecanoic acid to 12-methyltridecanal. The efficiency of whole-cell catalysis was compared to that of the purified enzyme preparation. After lipase-catalyzed hydrolysis of the fungal lipid extracts, the released fatty acids were converted to the corresponding aldehydes, including 12-methyltridecanal and 12-methyltetradecanal.
- Fraatz, Marco Alexander,Goldmann, Michael,Geissler, Torsten,Gross, Egon,Backes, Michael,Hilmer, Jens-Michael,Ley, Jakob,Rost, Johanna,Francke, Alexander,Zorn, Holger
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- The first total synthesis of the marine fatty acid (±)-2-methoxy-13- methyltetradecanoic acid: A cytotoxic fatty acid to leukemia cells
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The recently discovered marine fatty acid (±)-2-methoxy-13- methyltetradecanoic acid was synthesized for the first time in six steps (26% overall yield) starting from commercially available methyl 12- methyltridecanoate. The synthetic approach provided enough material to corroborate the structure of the acid, which was recently identified in the sponge Amphimedon complanata from Aguadilla, Puerto Rico, and to test its cytotoxicity to three leukemia cell lines. The key step in the synthesis was the addition of trimethylsilyl cyanide to 12-methyltridecanal under triethylamine catalysis. Nuclear magnetic resonance data are provided for the first time for this methoxylated fatty acid and the synthetic approach utilized is of general applicability since it can be used in the synthesis of other methyl-branched 2-methoxylated fatty acids. We also report that the acid (±)-2-methoxy-13-methyltetradecanoic acid is cytotoxic to human chronic myelogenous leukemia K-562 (EC50=238μM), histiocytic lymphoma U-937 (EC50=250μM), and promielocytic leukemia HL-60 (EC 50=476μM) in RPMI 1640 medium.
- Carballeira, Nestor M.,Cruz, Heidyleen,Orellano, Elsie A.,Gonzalez, Fernando A.
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- Biotechnological Production of Odor-Active Methyl-Branched Aldehydes by a Novel α-Dioxygenase from Crocosphaera subtropica
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As a result of their pleasant odor qualities and low odor thresholds, iso-and anteiso-fatty aldehydes represent promising candidates for applications in flavoring preparations. A novel cyanobacterial α-dioxygenase from Crocosphaera subtropica was heterologously expressed in Escherichia coli and applied for the biotechnological production of C12-C15 branched-chain fatty aldehydes. The enzyme has a sequence identity of less than 40% to well-investigated α-dioxygenase from rice. Contrary to the latter, it efficiently transformed short-chained fatty acids. The kinetic parameters of α-dioxygenase toward unbranched and iso-branched-chain substrates were studied by means of an oxygen-depletion assay. The transformation products (C12-C15 iso-and anteiso-aldehydes) were extensively characterized, including their sensory properties. The aldehydes exhibited green-soapy, sweety odors with partial citrus-like, metallic, peppery, and savory-tallowy nuances. Moreover, the two C14 isomers showed particularly low odor threshold values of 0.2 and 0.3 ng/L in air as determined by means of gas chromatography-olfactometry.
- Albrecht, Florian,Buchhaupt, Markus,Fraatz, Marco A.,Geissler, Torsten,Hahne, Friederike,Hammer, Andreas K.,Jordan, Paulina,Ley, Jakob,Schrader, Jens,Zorn, Holger
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p. 10432 - 10440
(2020/10/26)
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- Synthesis and evaluation of analogues of the glycinocin family of calcium-dependent antibiotics
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The glycinocins are a class of calcium-dependent, acidic cyclolipopeptide antibiotics that are structurally related to the clinically approved antibiotic daptomycin. In this article, we describe the synthesis of a small library of glycinocin analogues that differ by variation in the exocyclic fatty acyl substituent. The glycinocin analogues were screened against a panel of Gram-positive bacteria (as well as Gram-negative P. aeruginosa). These analogues exhibited similar calcium-dependent activity to the parent natural products against Gram-positive bacteria but showed no activity against P. aeruginosa. The length of the fatty acid was shown to be important for optimal biological activity, while the hybridisation at the α,β position and branching within the fatty acyl chain had only subtle effects on activity.
- Corcilius, Leo,Liu, Dennis Y.,Ochoa, Jessica L.,Linington, Roger G.,Payne, Richard J.
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p. 5310 - 5320
(2018/08/03)
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- Synthesis of ent-BE-43547A 1 reveals a potent hypoxia-selective anticancer agent and uncovers the biosynthetic origin of the APD-CLD natural products
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Tumour hypoxia is speculated to be a key driver of therapeutic resistance and metastatic dissemination. Consequently, the discovery of new potent agents that selectively target the hypoxic cell population may reveal new and untapped antitumour mechanisms. Here we demonstrate that the BE-43547 subclass of the APD-CLD (amidopentadienoate-containing cyclolipodepsipeptides) natural products possesses highly hypoxia-selective growth-inhibitory activity against pancreatic cancer cells. To enable this discovery, we have developed the first synthesis of the BE-43547-macrocyclic scaffold in 16 steps (longest linear sequence), which also allowed access to the full panel of relative stereoisomers and ultimately to the assignment of stereochemical configuration. Discrepancies between the spectroscopic signatures of the synthetic compounds with that originally reported for the BE-43547 members stimulated us to re-isolate the natural product from a BE-43547-producing microorganism during which we elucidated the biosynthetic gene clusters for the BE-43547 family as well as for all other known APD-CLDs. Our studies underline the exciting possibilities for the further development of the anticancer activities of these natural products.
- Villadsen, Nikolaj L.,Jacobsen, Kristian M.,Keiding, Ulrik B.,Weibel, Esben T.,Christiansen, Bj?rn,Vosegaard, Thomas,Bjerring, Morten,Jensen, Frank,Johannsen, Mogens,T?rring, Thomas,Poulsen, Thomas B.
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p. 264 - 272
(2017/03/09)
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- Preparation method of high-purity 12-methyltridecanal
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The invention relates to the field of fine chemical engineering, in particular to a preparation method of high-purity 12-methyltridecanal: 10-undecylenic acid is taken as a raw material, and is subjected to four-step reactions including amidation, Grignard reaction, hydrogenation reduction and alkenyl ozonation. The method has the advantages that the raw material is low in cost and easy to obtain, steps are few, reaction conditions are mild, the impurity content is low, the purification is easy, the reaction repeatability is high, the stability is high, and the method is suitable for industrial mass production.
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- 1H-pyrrole-2,4-dicarbonyl-derivatives and their use as flavoring agents
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The present invention primarily relates to 1H-pyrrole-2,4-dicarbonyl-derivatives of Formula (I) wherein R1, R2, R3, Z. Z' and J are as defined in the description, to mixtures thereof and to the use thereof as flavoring agents. The compounds in accordance with the present invention are suitable for producing, imparting, or intensifying an umami flavor. The invention further relates to flavoring mixtures, compositions for oral consumption as well as ready-to-eat, ready-to-use and semifinished products, comprising an effective amount of the compound of Formula (I) or of a mixture of compounds of Formula (I) and to specific methods for producing, imparting, modifying and/or intensifying specific flavor impressions.
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- Imidazo[1,2-a]pyridine-ylmethyl-derivatives and their use as flavoring agents
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The present invention primarily relates to imidazo[1,2-a]pyridine-ylmethyl-derivatives of Formula (I) wherein R1, R2, X, W e J are as defined in the description, to mixtures thereof and to the use thereof as flavoring agents. The compounds in accordance with the present invention are suitable for producing, imparting, or intensifying an umami flavor. The invention further relates to flavoring mixtures, compositions for oral consumption as well as ready-to-eat, ready-to-use and semifinished products, comprising an effective amount of the compound of Formula (I) and to specific methods for producing, imparting, modifying and/or intensifying specific flavor impressions.
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- CONVENIENT SYNTHESES OF SIX TUNICAMYCIN ACIDS
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10-Methylundecanol (15), obtained in five steps from sebacic acid, served as substrate for the synthesis of the ester 3-Et, via oxidation to aldehyde and Wittig condensation with stabilized ylid.From 3-Et next ester, 2-Et, was obtained by hydrogenation.Reduction of the ester grouping in 2-Et to the alcohol, followed by oxidation to aldehyde provided a substrate for another Wittig condensation leading to 8-Me.On the other hand, bromide 17, obtained from 15, was used for alkylation of propargylic alcohol.The product obtained, 18, served for the synthesis of acids 5 and 6.Ester 10-Et was obtained from 18 via hydrogenation of the triple bond, oxidation to aldehyde and condensation with a stabilized Wittig ylid.The yields of all steps were good to excellent. Key words: higher fatty acids, tunicamycin acids.
- Grzeszczyk, B.,Konowal, A.,Zamojski, A.
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p. 1627 - 1632
(2007/10/02)
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- Synthesis of 14-Methylpentadecan-3-one
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An unambiguous synthesis of the title compound (9), isolated recently by Haque et al. from the pet. ether extract of Parthenium hysterophorous Linn. is described.Significantly the natural compound has been isolated as a solid (m.p. 80 deg C) while our synthetic product is an oil (b.p. 118-20 deg C/0.4 mm).Besides this some of the reported spectral data do not tally with those of synthetic 9.
- Trivedi, S. V.,Mamdapur, V. R.
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p. 176 - 177
(2007/10/02)
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