Biosynthesis of 24-ethylcholesta-5,22,25-trien-3β-ol, a new sterol from <i>Clerodendrum campbellii</i>

Bolger, Loretta M.; Rees, Huw H.; Ghisalberti, E. L.; Goad, L. John; Goodwin, T. W.

doi:10.1042/bj1180197

Cited by 44 publications

(9 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Reports (10,11) on the two species of Clerodendrum do not make clear the percentage of epimers, but we presume the absence of mention of 24~-sterols implies the 24/Yethylsterols to be dominant.…”

Section: Discussionmentioning

confidence: 64%

“…bThe plants listed are those examined in our present and previous (4) work. Included are also the only other two families known (10,11) to contain 24fl-ethylsterols. In all of the plants in Category I the tissues examined have only 24-ethylsterols in the 24cz-series, and the 24-methylsterols, when present, were always a minor fraction and principally, but not exclusively, of the cz-configuration.…”

Section: Discussionmentioning

confidence: 99%

“…The 25 (27)-designation rather than 25 (26) is made by the following analogy. When 25(27)-dehydroporiferasterol was labelled from 2-14C-MVA, the methylene carbon was found to be unlabelled (11). If we designate C-26 as the labelled carbon derived from 2A4C-MVA, then cyclolaudenol, codisterol, clerosterol, and the latter's 22:dehydro derivative become A25(27)-sterots on the assumption that the same biosynthetic stereospecificity occurs in both algal and Tracheophyte systems and is the same for the first as well as second C 1transfer.…”

Section: Kalanchoe Daigremontianamentioning

confidence: 98%

“…On the other hand, at the 24-ethyl level, a pathway usually exists apparently only for a single configuration (24a), but the problem is complicated by the fact that 24/3-ethylsterols do exist in higher Tracheophytes. They have been found in the seeds of several genera in the family Cucurbitaceae of the order Cucurbitales (6)(7)(8)(9) and in two species of the genus Clerodendrum in the order Verbenales (10,11). In order to ascertain just how common one or other of the configurations is, we have continued our investigation of plants arranged phylogenetically.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

The phylogenetic distribution of sterols in tracheophytes

Nes

Krevitz

Joseph

et al. 1977

Lipids

121

View full text Add to dashboard Cite

The sterols of nine mature plant species in seven families ranging from the subphylum Lycopsida through the Filicopsida and the classes Gymnospermae and Angiospermae in the Pteropsida were structurally and stereochemically defined. Two plant categories were found. In the first, comprised by Dryopteris {Thelypteris) noveboracensis, Polystichum acrostichoides, Dennstaedtia punctilobuIa, Osmunda cinnamomea, Ginkgo biloba, Cucurbita pepo, and Kalmia latifolia, 24ot-alkylsterols were dominant and were composed principally of 24~-ethylcholesterol (sitosterol) or (in Cucurbita pepo) 24a-ethyllathosterol and its trans-22-dehydro derivative (spinasterol). Depending on the species, small amounts of 24a-ethyl-trans-22-dehydrocholesterol (stigmasterol), 24a-methylcholesterol (campesterol), 2 4fl-methylcholesterol (dihydrobrassicasterol, always less than campesterol), cholesterol, lathosterol, 2 4a-ethyllathosterol, 24~-methyllathosterol, trans-24-ethylidenelathosterol (AT-avenasterol), and (tentatively identified) 24-ethyl-24(25)-dehydrolathosterol were present. Spinacea oleracea was alsoCucurbitaceae, from Magnoliales through Theales to Ericales, nor from Ranales to Saxifragales. However, they are consonant with a relationship between Cucurbitaceae and Theales and between Rosales and Lamiales. Triterpenoids found in various of the families studied included cycloartenol and friedelin. The spectroscopic properties of the latter are described.

show abstract

Section: Discussionmentioning

confidence: 64%

Section: Discussionmentioning

confidence: 99%

Section: Kalanchoe Daigremontianamentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

The phylogenetic distribution of sterols in tracheophytes

Nes

Krevitz

Joseph

et al. 1977

Lipids

121

View full text Add to dashboard Cite

show abstract

“…Cette fraction a 6th acetylee et BpoxydBe, l'ac6- (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22), C-23 peut 6tre introduite sur la chaine laterale des sterols apres l'alkylation en C-24.…”

Section: 28)unclassified

Biosynthese de la chaine lateale ethyle du stigmastanol et du stigmasten-22,ol-3beta du myxomycete Dictyostelium discoideum

Ellouz

Lenfant

1971

Eur J Biochem

View full text Add to dashboard Cite

(Repu le 7 mai/l2 octobre 1971) Several laboratories have shown that the two carbon atoms C-28 and C-29 of the ethyl or ethylidene side chains of phytosterols are introduced on to a C-24 unsaturated side chain by two methylation steps. A scheme based on previous work suggests the various intermediates which can be formed by stabilisation of the carbonium ion 3. We have shown previously that in the biosynthesis of 50i-stigmastan-3p-01 ( l l a ) and 5a-stigmast-22-en-3/3-01 (12a), sterols of the myxomycete Dictyosteliurn discoideurn, routes h and i could be excluded.I n the present paper we describe the in vivo conversion, by the myxomycete, of differently labelled lanosterol (13), stigmastanol ( l l c ) , and 5a-stigmast-22-en-3p-01 (12c), into the sterols 12a and l l a , and discuss the possible biosynthetic routes for the two sterols.After incorporation of a mixture of [26,27-14C2]lanosterol and [24-3H]lanosterol (3H/14C = 5.60 & 0.25), the isolated sterols l l a and 12a were converted into l l b (3H/14C = 5.54 0,28) and 14b (3H/14C = 5.61By ozonisation followed by oxidation in neutral or basic medium, 12a was converted into the esters 15 (3H/14C = 5.54 0.3), respectively. These results show that during the C-24 methylation, H-24 is not lost; the hydrogen which is lost is located neither a t C-24 nor a t C-23 and must therefore be a t C-25. This excludes routes a and b for sterol 12.After incorporation of a mixture of [26,27-14C2] These results show that during the conversion of 13 into 12a, 50°/, of the H-23 atoms migrate from C-23 to (2-24 and 25O/, remain on C-23 ; the other 25O/, are eliminated. During the conversion of 13 into l l a both H-23 atoms are retained. These results excluded route g for the two sterols. Since we have demonstrated that the conversion of l l c into 12a is possible in high yields (4.60/,) with an efficiency eight times greater than the conversion of 12c into l l a , we propose that the sterol l l a is synthesized in vivo according to route e with migration of H-23 from C-23 to C-24. The sterol 12a is biosynthetized either by route d, f, the 22,23 double bond being introduced during the alkylation step, or by desaturation of the sterol l l a , the C-22, C-23 double bond being introduced after the C-24 alkylation. 0.28).0.28) and 16 (3H/14C = 5.55 0.15).Les etudes de biosynthese des chaines ethyle et Bthylidbne en C-24 des phytosterols ont montre que les deux atomes de carbone proviennent de la mkthionine [1-3,3a].Plusieurs mecanismes ont kt6 proposes pour expliquer cette double methylation [I-81 (voir schirma) : la premiere methylation du prdcurseur sterolique 1 conduit B la formation d'un intermediaire methylenique 2, qui peut servir de substrat B une deuxiitme methylation pour donner le carbocation intermediaire 3. Le carbocation 3 peut, apres stabilisation, soit par elimination d'un proton, soit par fixation d'un ion hydrure, conduire B des composes portant deux atomes de carbone derivant du groupe methyle de la methionine. Si

show abstract

Zur Konfiguration der Jaborosalactone, ein neuer Abbauweg für Withanolide

1971

View full text Add to dashboard Cite

rn Die 14a.17c(H.20S-Konfiguration der Jaborosalactone wurde durch Verknupfung von Jaborosalacton D (4a) mit bekannten Steroiden bewiesen. Es wurde em neuer WithanolidAbbau entwickelt, dessen entscheidende Schritte die Reduktion von 6 zu 7, die Hydrogenolyse von 9 und die AtheroEnung bei 15 sind. On the Configuration of the Jaborosalactones I), a New Degradation Scheme for WithanolidesThe 14a.17ctH.20S-configuration in the Jaborosalactoiies was demonstrated by the dcgradation of Jaborosalactone D ( 4 4 to known steroids. A new degradation scheme was used, the crucial steps of which were the hydrogenation of 6 to give 7, the hydrogenolysis of 9, and the ether cleavage in 15.Bei der Untersuchung der Tnhaltsstoffe von Solanaceen-Arten wurden vor einiger Zeit neuartige Czs-Steroide mit einer Lacton-Seitenkette aufgefunden z), die nach Lavie Withanolide genannt werden3). Zu diesen Verbindungen gehoren auch die Jaborosalactone A --E (la, 2a, 3, 4a, 5), uber deren Isolierung und Konstitutionsermittlung berichtet wurdeIa-'). Unsere bisherigen Untersuchungen liel3en noch keine Aussagen uber die Konfiguration an C-14, C-17 und C-20 in den Jaborosalactonen zu. Im folgenden beschreiben wir den Abbau von Jaborosalacton D (4a) zu bekannten Steroiden. Es zeigte sich dabei, da13 die Jaborosalactone, die bereits frdher miteinander verknupft worden sind'", alle die 14x.17xH.20S-Konfiguration besit7en.Unser Abbau-Verfahren stellt eine Alternative zu dem von Lavie et al.4) zur Bestimmung der Stereochemie von Withaferin A (1 b) entwickelten dar-5). Die axiale Lage der OH-Gruppe an C-1 ergibt sich aus dem IR-Spektrum, das eine intramolekulare Wasserstoff bruckenbindung 7.8) anzeigt, die aus raumlichen Griinden nur zwischen der Sor-OH-und der lor-OH-Gruppe ausgebildet sein kann. Die OHBande bei 3620/cm entspricht dem 1 a-OH, wahrend die breite Bande bei 3490/cm dem 5a-OH zuzuschreiben ist.

show abstract

Biosynthesis of 24-ethylcholesta-5,22,25-trien-3β-ol, a new sterol from Clerodendrum campbellii

Cited by 44 publications

References 12 publications

The phylogenetic distribution of sterols in tracheophytes

The phylogenetic distribution of sterols in tracheophytes

Biosynthese de la chaine lateale ethyle du stigmastanol et du stigmasten-22,ol-3beta du myxomycete Dictyostelium discoideum

Zur Konfiguration der Jaborosalactone, ein neuer Abbauweg für Withanolide

Contact Info

Product

Resources

About