Preparation and conformational study of Z- and E-Isositsirikine epimers and model compounds. Determination of their C-16 configurations

Lousnasmaa, Mauri; Jokela, Reija; Hanhinen, Pirjo; Miettinen, Jari; Salo, Jaana

doi:10.1016/s0040-4020(01)85387-4

Cited by 33 publications

(17 citation statements)

References 20 publications

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“…A ROESY correlation between H-21b and H-19 and another one between the H-18 methyl protons and H-15 proved that the C-19/C-20 double bond had an E geometry. The high chemical shift value of H-3 (d 4.41) was only compatible with an H-3a cis (S) conformation of the C/D quinolizidine ring system and a H-16b configuration, as pointed out in Lounasmaa et al (1994). The assigned configuration was further supported by the use of molecular modeling with NOESY and J-coupling data.…”

Section: Resultsmentioning

confidence: 55%

Moandaensine, a dimeric indole alkaloid from Strychnos moandaensis (Loganiaceae)

Verpoorte

Frédérich

Delaude

et al. 2010

Phytochemistry Letters

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Section: Resultsmentioning

confidence: 55%

Moandaensine, a dimeric indole alkaloid from Strychnos moandaensis (Loganiaceae)

Verpoorte

Frédérich

Delaude

et al. 2010

Phytochemistry Letters

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“…7% yield) (Fig. 1a , Supplementary Figs 5 and 16 ) 24 , 25 . In addition, a homolog of GS1 ( GS2 , KF302078.1 16 ) was also identified and tested.…”

Section: Resultsmentioning

confidence: 98%

A three enzyme system to generate the Strychnos alkaloid scaffold from a central biosynthetic intermediate

Tatsis¹,

Carqueijeiro²,

Bernonville³

et al. 2017

Nat Commun

121

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Monoterpene indole alkaloids comprise a diverse family of over 2000 plant-produced natural products. This pathway provides an outstanding example of how nature creates chemical diversity from a single precursor, in this case from the intermediate strictosidine. The enzymes that elicit these seemingly disparate products from strictosidine have hitherto been elusive. Here we show that the concerted action of two enzymes commonly involved in natural product metabolism—an alcohol dehydrogenase and a cytochrome P450—produces unexpected rearrangements in strictosidine when assayed simultaneously. The tetrahydro-β-carboline of strictosidine aglycone is converted into akuammicine, a Strychnos alkaloid, an elusive biosynthetic transformation that has been investigated for decades. Importantly, akuammicine arises from deformylation of preakuammicine, which is the central biosynthetic precursor for the anti-cancer agents vinblastine and vincristine, as well as other biologically active compounds. This discovery of how these enzymes can function in combination opens a gateway into a rich family of natural products.

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“…Notably, isositsirikine isomers have been shown to exhibit anti-neoplastic activity (Mukhopadhyay et al, 1983). NMR analysis of all isositsirikine stereoisomers have been previously reported (Lounasmaa et al, 1994). The NMR data for the isolated aza compound 14 was most consistent with the NMR data reported for (3α, 16 R , 19 E )- isositsirikine (Lounasmaa et al, 1994) (Figure 3).…”

mentioning

confidence: 99%

“…NMR analysis of all isositsirikine stereoisomers have been previously reported (Lounasmaa et al, 1994). The NMR data for the isolated aza compound 14 was most consistent with the NMR data reported for (3α, 16 R , 19 E )- isositsirikine (Lounasmaa et al, 1994) (Figure 3). (3α, 16 R , 19 E )- isositsirikine has been previously isolated from C. roseus cell culture, though typically in small amounts.…”

mentioning

confidence: 99%

Aza-Tryptamine Substrates in Monoterpene Indole Alkaloid Biosynthesis

Lee

Yerkes

O’Connor

2009

Chemistry & Biology

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Biosynthetic pathways can be hijacked to yield novel compounds by introduction of novel starting materials. Here we have altered tryptamine, which serves as the starting substrate for a variety of alkaloid biosynthetic pathways, by replacing the indole with one of four aza-indole isomers. We show that two aza-tryptamine substrates can be successfully incorporated into the products of the monoterpene indole alkaloid pathway in Catharanthus roseus. Use of unnatural heterocycles in precursor directed biosynthesis, in both microbial and plant natural product pathways, has not been widely demonstrated, and successful incorporation of starting substrate analogs containing the aza-indole functionality has not been previously reported. This work serves as a starting point to explore fermentation of aza-alkaloids from other tryptophan and tryptamine derived natural product pathways.

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Preparation and conformational study of Z- and E-Isositsirikine epimers and model compounds. Determination of their C-16 configurations

Cited by 33 publications

References 20 publications

Moandaensine, a dimeric indole alkaloid from Strychnos moandaensis (Loganiaceae)

Moandaensine, a dimeric indole alkaloid from Strychnos moandaensis (Loganiaceae)

A three enzyme system to generate the Strychnos alkaloid scaffold from a central biosynthetic intermediate

Aza-Tryptamine Substrates in Monoterpene Indole Alkaloid Biosynthesis

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