Jenisseensosides C and D, biologically active acylated triterpene saponins from Silene jenisseensis

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Eight new acylated preatroxigenin saponins 1 ± 8 were isolated as four inseparable mixtures of the transand cis-4-methoxycinnamoyl derivatives, atroximasaponins A 1 /A 2 (1/2), B 1 /B 2 (3/4), C 1 /C 2 (5/6) and D 1 /D 2 (7/8) from the roots of Atroxima congolana. These compounds are the first examples of triterpene saponins containing preatroxigenin ( (2b,3b,4a,22b)-2,3,22,27-tetrahydroxyolean-12-ene-23,28-dioic acid as aglycone. Their structures were elucidated on the basis of extensive 1D-and 2D-NMR studies and FAB-MS as 3- (7) and its cis-isomer 8.Introduction. ± In the course of our studies on the saponins of the family of Polygalaceae [1] [2], we have investigated the cortex of the roots of Atroxima congolana Stapf. This genus is distributed in the forests of Western and Central Africa [3]. Although the presence of preatroxigenin ( (2b,3b,4a,3,22, was reported in Atroxima afzeliana, there is no saponin previously elucidated containing this aglycone [4]. This paper describes the isolation and structure elucidation of eight new triterpene glycosides named atroximasaponins A 1 , A 2 , B 1 , B 2 , C 1 , C 2 , D 1 , and D 2 (1 ± 8) respectively, which were obtained as four inseparable mixtures of the trans-and cis-acylated derivatives from the EtOH extract of the roots of A. congolana.

Section: /2supporting

confidence: 52%

New Acylated Preatroxigenin Saponins from Atroxima congolana

Elbandy

Miyamoto

Delaude

et al. 2003

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“…Under these conditions, the geometrical-isomer structures of the trimethoxycinnamoyl moieties of 1 and 2 showed tautomer-like behavior. This phenomenon has already been observed in saponins from Silene jenisseensis [7], Atroxima congolana [8], and also in the previously reported saponins of this plant [2]. The extensive investigation of 1D-and 2D-NMR data of 1/2 (Tables 1 ± 3) resulted in the determination of the structure as 3- (1) and its (Z)-isomer 2, two new natural compounds [9].…”

mentioning

confidence: 52%

New Acylated Presenegenin Saponins from Two Species of Muraltia

Elbandy

Miyamoto

Delaude

et al. 2004

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Six new acylated bisdesmosidic triterpene glycosides 1 ± 6 were isolated from the roots of Muraltia heisteria (L.) DC., as three inseparable mixtures 1/2, 3/4, and 5/6 of the (E)-and (Z)-3,4,5-trimethoxycinnamoyl derivatives. The compound pair 1/2 along with four known saponins were also isolated from the roots of Muraltia satureioides DC. Their structures were elucidated mainly by spectroscopic experiments including 2D-NMR techniques as 3 (5) and its (Z)-isomer 6, respectively.Introduction. ± In a continuing program aiming at the discovery of novel natural products from the family of Polygalaceae, especially the genus Muraltia, we previously reported the isolation and characterization of five new medicagenic acid saponins from the roots of Muraltia ononidifolia [1] and of four new acylated presenegenin glycosides as two inseparable mixtures of the (E)-and (Z)-trimethoxycinnamoyl derivatives from the roots of Muraltia heisteria (L.) DC. [2]. As a result of our continous investigations of less polar saponin fractions of the EtOH extract of the roots of M. heisteria, the six additional new acylated oleanane-type triterpene saponins 1 ± 6 were isolated as three inseparable mixtures 1/2, 3/4, and 5/6 of the (E)-and (Z)-3,4,5-trimethoxycinnamoyl derivatives. Furthermore, we investigated Muraltia satureioides DC., which is a shrub distributed in the Cape region in South Africa [3]. Although, this plant was reported to contain presenegenin glycosides [4], there is no detailed report on its saponins. The compound pair 1/2 together with four known saponins [2] were isolated from the EtOH extract of the roots of M. satureiodes. This paper describes the isolation and structure elucidation of these triterpene glycosides.

“…These conclusions indicated that 1 and 2 are a mixture of (E)-and (Z)-4-methoxycinnamoyl triterpene glycosides, and all attempts to separate them were unsuccessful. Such a phenomenon, which could be explained by the tautomeric behavior of the 4-methoxycinnamoyl moiety in methanolic solutions under light, has already been described in saponins from Silene jenisseensis [8] and S. fortunei [9], senegasaponins from Polygala senega [10], and trimethoxycinnamoylated saponins from Muraltia heisteria [3]. …”

mentioning

confidence: 66%

New Acylated Triterpene Saponins from Polygala arenaria

Mitaine-Offer¹,

Miyamoto²,

Laurens³

et al. 2003

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Eight new acylated triterpene saponins 1–8 were isolated from the roots of Polygala arenaria as four inseparable (E)/(Z) mixtures of the 4‐methoxycinnamoyl and 3,4‐dimethoxycinnamoyl derivatives by repeated MPLC over silica gel. Their structures were established mainly by 600‐MHz 2D‐NMR techniques (1H,1H‐COSY, TOCSY, NOESY, HSQC, HMBC) as 3‐O‐(β‐D‐glucopyranosyl)presenegenin 28‐(O‐β‐D‐galactopyranosyl‐(1→4)‐O‐[β‐D‐glucopyranosyl‐(1→3)]‐O‐β‐D‐xylopyranosyl‐(1→4)‐O‐α‐L‐rhamnopyranosyl‐(1→2)‐{4‐O‐[(E)‐4‐methoxycinnamoyl]}‐β‐D‐fucopyranosyl) ester and its (Z)‐isomer (1/2), 3‐O‐(β‐D‐glucopyranosyl)presenegenin 28‐(O‐β‐D‐galactopyranosyl‐(1→4)‐O‐[β‐D‐glucopyranosyl‐(1→3)]‐O‐β‐D‐xylopyranosyl‐(1→4)‐O‐α‐L‐rhamnopyranosyl‐(1→2)‐{4‐O‐[(E)‐3,4‐dimethoxycinnamoyl]}‐β‐D‐fucopyranosyl) ester and its (Z)‐isomer (3/4), 3‐O‐(β‐D‐glucopyranosyl)presenegenin 28‐(O‐β‐D‐glucopyranosyl‐(1→3)‐O‐α‐L‐arabinopyranosyl‐(1→4)‐O‐α‐L‐rhamnopyranosyl‐(1→2)‐{4‐O‐[(E)‐4‐methoxycinnamoyl]}‐β‐D‐fucopyranosyl) ester and its (Z)‐isomer (5/6), and 3‐O‐(β‐D‐glucopyranosyl)presenegenin 28‐(O‐β‐D‐glucopyranosyl‐(1→3)‐O‐α‐L‐arabinopyranosyl‐(1→4)‐O‐α‐L‐rhamnopyranosyl‐(1→2)‐{4‐O‐[(E)‐3,4‐dimethoxycinnamoyl]}‐β‐D‐fucopyranosyl) ester and its (Z)‐isomer (7/8) (presenegenin=(2β,3β)‐2,3,27‐trihydroxyolean‐12‐ene‐23,28‐dioic acid). In our in vitro lymphocyte proliferation assay (Jurkat T‐leukemia cells), a fraction containing 1–4 showed a concentration‐dependent immunomodulatory effect. This effect was not found for the prosapogenin (tenuifolin=3‐O‐(β‐D‐glucopyranosyl)presenegenin), underlining the importance of the acyloligosaccharidic moiety.