Studies in relation to biosynthesis—XLIV

Birch, Arthur J.; Russell, Richard A.

doi:10.1016/0040-4020(72)80014-0

Cited by 146 publications

(62 citation statements)

References 13 publications

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“…When cultures of Penicillium brevicompactum were grown in the dark, only brevianamides A and B were detected thus verifying the hypothesis that brevianamides C and D are photochemical artifacts 21) and are not true metabolites of enzymic origin. A mechanism for the photochemical formation of brevianamides C and D from brevianamide A is provided below in Chart 2.…”

Section: The Brevianamides and Austamidesmentioning

confidence: 51%

“…21) The semi-synthetic and totally synthetic brevianamide B samples both exhibited the same specific optical rotation ([a] D 25 ϭϪ124°) and circular dichroism (CD) spectra. These workers found that natural brevianamide B obtained directly from cultures of Penicillium brevicompactum had a specific optical rotation [a] D 25 ϭϩ124°, and a CD spectrum with Cotton effects of exactly opposite sign to that of the synthetic and semi-synthetic materials.…”

Section: Synthesis Of (؊)-Brevianamide B Reveals Unusual Biogenesismentioning

confidence: 99%

“…Brevianamides C and D, also isolated in minor amounts from these Penicillium sp., were postulated by Birch and Russell 21) to be artifacts of isolation since, visible light irradiation of brevianamide A produces brevianamides C and D in virtually quantitative yield. When cultures of Penicillium brevicompactum were grown in the dark, only brevianamides A and B were detected thus verifying the hypothesis that brevianamides C and D are photochemical artifacts 21) and are not true metabolites of enzymic origin.…”

Section: The Brevianamides and Austamidesmentioning

confidence: 99%

“…The structural assignment for brevianamide B was based primarily on the semi-synthetic conversion of natural (ϩ)-brevianamide A into brevianamide B by borohydride reduction and acid dehydration to deoxybrevianamide A; subsequent air oxidation provided (Ϫ)-brevianamide B (Chart 1). 21) Birch and associates did not record optical rotation data for natural or semi-synthetic brevianamide B and this oversight later proved to constitute the basis of an intriguing stereochemical puzzle; the complete stereochemical elucidation of brevianamide B will be discussed below.…”

Section: The Brevianamides and Austamidesmentioning

confidence: 99%

“…19) Following the original isolation, Birch and Wright, reported the isolation and structural elucidation of brevianamides B-F from Penicillium brevicompactum. 20,21) Brevianamide A is the major fluorescent metabolite produced by this fungi; a minor metabolite named brevianamide B, that also exhibited the characteristic y-indoxyl chromophore, was assigned a structure that was epimeric to brevianamide A at the spiro-y-indoxyl quaternary center. The structural assignment for brevianamide B was based primarily on the semi-synthetic conversion of natural (ϩ)-brevianamide A into brevianamide B by borohydride reduction and acid dehydration to deoxybrevianamide A; subsequent air oxidation provided (Ϫ)-brevianamide B (Chart 1).…”

Section: The Brevianamides and Austamidesmentioning

confidence: 99%

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Total Synthesis and Biosynthesis of the Paraherquamides: An Intriguing Story of the Biological Diels–Alder Construction

Williams

2002

Chem. Pharm. Bull.

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The paraherquamides constitute an unusual family of prenylated indole alkaloids that are secondary metabolites produced by Penicillium sp. and Aspergillus sp. fungi. This review will cover both the biosynthesis as well as the chemical synthesis of this family of natural products. Particular emphasis will be placed on the provocative hypothesis that the core bicyclo[2.2.2]diazaoctan ring system, which is common to this entire family, is formed by a biological DielsAlder reaction.Despite its widespread use in synthetic organic chemistry, the Diels-Alder cycloaddition reaction does not occur frequently in nature. 1,2) There are just a few reports in the literature claiming the identification of an enzyme that catalyzes this most ubiquitous synthetic ring-forming reaction. [3][4][5][6] A possible explanation for this is that, enzymes generally catalyze reactions by stabilizing the structure and charge of the developing transition state. For most reactions subject to this stratagem of catalysis, both the starting substrate and the product differ significantly with respect to structure from the transition state; it is this fundamental difference that allows for turnover; i.e., both the product and the starting substrate must bind to the enzyme less tightly than the transition state structure. In the Diels-Alder reaction, the transition state is highly ordered and closely resembles the structure of the product (see Fig. 1, below). In other words, an enzyme that was designed to stabilize the transition state structure for this reaction would be expected to be inhibited by the product (via tight binding) and turnover (thus catalysis) would be precluded. It is from within the excitement of this fundamental question, that this review will hold as a guiding light.The only examples of protein-catalyzed Diels-Alder reactions are those of catalytic antibodies that have recently been shown to catalyze the intermolecular [4ϩ2] cycloaddition reaction.7-9) In these cases, the initial Diels-Alder adducts were high-energy substances that significantly change their structure or conformation after the initial cyclocondensation and were subsequently released from the antibody CDR (allowing for turnover). In addition, ribozymes have been reported to catalyze the Diels-Alder reaction and findings in this area have been reviewed. 10) The Penicillium sp. that produces the brevianamides/paraherquamides may be a rare, but vitally important example of the existence of DielsAlderases. It is further significant to note in the context of the catalytic antibody stratagem that, the brevianamide DielsAlder adducts (which are proposed to be the brevianamides themselves) are very rigid substances; therefore, a significant change in conformation or structure is either impossible or highly unlikely. Elucidation of the mechanism for turnover in the purported paraherquamide and brevianamide [4ϩ2] cycloaddition reaction should be an extremely interesting and significant finding.In order to do proper justice to the history of the biosynthetic Diels-Alder p...

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Section: The Brevianamides and Austamidesmentioning

confidence: 51%

Section: Synthesis Of (؊)-Brevianamide B Reveals Unusual Biogenesismentioning

confidence: 99%

Section: The Brevianamides and Austamidesmentioning

confidence: 99%

Section: The Brevianamides and Austamidesmentioning

confidence: 99%

Section: The Brevianamides and Austamidesmentioning

confidence: 99%

See 3 more Smart Citations

Total Synthesis and Biosynthesis of the Paraherquamides: An Intriguing Story of the Biological Diels–Alder Construction

Williams

2002

Chem. Pharm. Bull.

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Isolation and Synthesis ofN-(2-Methyl-3-oxodec-8-enoyl)-2-pyrroline and 2-(Hept-5-enyl)-3-methyl-4-oxo-6,7,8,8a-tetrahydro-4H-pyrrolo[2,1-b]1,3-oxazine – Two New Fungal Metabolites with in vivo Anti-Juvenile-Hormone and Insecticidal Activity

et al. 1999

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Two new natural products, N‐(2‐methyl‐3‐oxodec‐8‐enoyl)‐2‐pyrroline (2) and 2‐(hept‐5‐enyl)‐3‐methyl‐4‐oxo‐6,7,8,8a‐tetrahydro‐4H‐pyrrolo[2,1‐b]‐1,3‐oxazine (3), have been isolated from Penicillium brevicompactum Dierckx. Compound 2 has shown an important in vivo anti‐juvenile‐hormone (anti‐JH) activity while compound 3 has exhibited insecticidal activity against Oncopeltus fasciatus Dallas. Both products have been synthesized starting from 1,4‐hexadiene, by means of a sequence of reactions which includes the preparation of 6‐octenoic acid and its transformation into the corresponding acid chloride, in order to acylate Meldrum's acid. Subsequent aminolysis with pyrrolidine, followed by methylation at the activated position of the β‐oxo amide with iodomethane, introduction of a methoxy group at the pyrrolidine ring by anodic oxidation and final elimination of methanol on SiO2 led to 2 and 3. The fact that both metabolites can be prepared by the same sequence indicates that they must be biogenetically related. Based on structural similarities, compounds 2 and 3 are also closely related to the recently discovered brevioxime (1).

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Reverse und „normale”︁ Prenyltransferasen haben unterschiedliche Seitenselektivitäten bei der Biosynthese von Paraherquamid

1999

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Sowohl eine seitenspezifische als auch eine seitenunspezifische Bildung quartärer C‐Zentren aus von Isopren abgeleiteten Strukturelementen im Alkaloid Paraherquamid A 1 wurden durch [U‐13C6]Glucose‐ und [13C2]Acetat‐Fütterungsexperimente mit Penicillium fellutanum entdeckt. Aus dem Markierungsmuster läßt sich ableiten, daß die Methylgruppen (C22, C23) seitenunspezifisch durch eine Reverse Prenyltransferase eingeführt werden. In der C5‐Einheit, die den Dioxepinrest umfaßt, bleibt die relative Konfiguration erhalten, was für eine einzige, seitenspezifische Addition einer Phenoleinheit an die Dimethylallylgruppe spricht.

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Studies in relation to biosynthesis—XLIV

Cited by 146 publications

References 13 publications

Total Synthesis and Biosynthesis of the Paraherquamides: An Intriguing Story of the Biological Diels–Alder Construction

Total Synthesis and Biosynthesis of the Paraherquamides: An Intriguing Story of the Biological Diels–Alder Construction

Isolation and Synthesis ofN-(2-Methyl-3-oxodec-8-enoyl)-2-pyrroline and 2-(Hept-5-enyl)-3-methyl-4-oxo-6,7,8,8a-tetrahydro-4H-pyrrolo[2,1-b]1,3-oxazine – Two New Fungal Metabolites with in vivo Anti-Juvenile-Hormone and Insecticidal Activity

Reverse und „normale”︁ Prenyltransferasen haben unterschiedliche Seitenselektivitäten bei der Biosynthese von Paraherquamid

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Studies in relation to biosynthesis—XLIV

Cited by 146 publications

References 13 publications

Total Synthesis and Biosynthesis of the Paraherquamides: An Intriguing Story of the Biological Diels&ndash;Alder Construction

Total Synthesis and Biosynthesis of the Paraherquamides: An Intriguing Story of the Biological Diels&ndash;Alder Construction

Isolation and Synthesis ofN-(2-Methyl-3-oxodec-8-enoyl)-2-pyrroline and 2-(Hept-5-enyl)-3-methyl-4-oxo-6,7,8,8a-tetrahydro-4H-pyrrolo[2,1-b]1,3-oxazine – Two New Fungal Metabolites with in vivo Anti-Juvenile-Hormone and Insecticidal Activity

Reverse und „normale”︁ Prenyltransferasen haben unterschiedliche Seitenselektivitäten bei der Biosynthese von Paraherquamid

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Total Synthesis and Biosynthesis of the Paraherquamides: An Intriguing Story of the Biological Diels–Alder Construction

Total Synthesis and Biosynthesis of the Paraherquamides: An Intriguing Story of the Biological Diels–Alder Construction