Two unsymmetric tetracyclic triterpenoids from cissus quadrangularis

Two new unsymmetric tetracyclic triterpenoids onocer-7-ene-3α,21β-diol and onocer-7-ene-3β,21α-diol together with sitosterol, δ-amyrin and δ-amyrone have been isolated from Cissus quadrangularis. The structures of the new compounds were elucidated on the basis of ¹H NMR, mass spectral and chemical evidence.     

The conversion of 5α-lanost-24-ene-3β,9α-diol and parkeol into poriferasterol by the alga Ochromon as malhamensis

The 4,4-dimethylsterols 4α-lanost-24-ene-3β,9α-diol-[2-³H₂] and parkeol-[2-³H₂] were synthesized from lanosterol and subsequently incubated with cultures of Ochromonas malhamensis. 5α-Lanost-24-ene-3β,9α-diol was converted into poriferasterol with three times the efficiency of parkeol. Clionasterol was also found to be labelled from both parkeol and 5α-lanost-24-ene-3β,9α-diol. No significant incorporation of radioactivity into sterols was obtained after feeding 5α-lanost-24-ene-3β,9α-diol to higher plants, the chlorophyte alga Trebouxia, yeast or a cell free homogenate of rat liver.     

D:b-friedoolean-5-ene-3β,29-diol,an angular methyl oxygenated d: b-friedooleanene from elaeodendron balae

A new dioxygenated D: B-friedooleanene from Elaeodendron balae root bark was shown to be D:B–friedoolean-5-ene-3β,29-diol by relating it to 29-oxygenated D:A-friedooleanane. This is the first report of angular methyl oxygenation in the D: B-friedooleananes.     

龙芽草化学成分研究

从药用植物龙芽草(Agrimonia pilosa Ledeb)全草的95%乙醇提取物中分离得到4个化合物,通过理化性质及波谱学方法分别鉴定为豆甾-5-烯-3β,7β-二醇(1)、豆甾-5-烯-3β7,α-二醇(2)、豆甾-3β6,α-二醇(3)和β-谷甾醇(4)。化合物1～3均为首次从龙芽草中分离得到。     

Occurrence of 24-epimers of cycloart-25-ene-3β,24-diols in the stems of Euphorbia trigona

¹³C NMR spectroscopy has demonstrated that the cycloart-25-ene-3β,24-diol isolated from the stems of Euphorbia trigona is a 1:1 mixture of the 24-epimers. This seems to be the first instance of the detection of the natural occurrence of 24-epimeric cycloart-25-ene-3β,24-diols.     

Simultaneous radioimmunoassay of testosterone,dihydrotestosterone, 5α-androstane-3α, 17β-diol and 5α-androstane-3β, 17β-diol in the plasma of adult male rats

A single thin layer chromatography and three antibodies were used for the specific radioimmunoassay of four androgens in pooled rat plasma (Sprague-Dawley adult males). The following values were found (pg/ml ± SD). Testosterone : 3, 138 ± 173; dihydrotestosterone : 374 ± 20; 5α-androstane-3α 17β-diol : 284 ± 24; 5α-androstane-3β, 17β-diol : 223 ± 11.     

Triterpenes of five euphorbiaceae species of Sri Lanka

Five endemic species of Euphorbiaceae have been investigated. Aleuritolic acid and its derivatives were isolated from P. thwaitesii. A. cardiosperma had friedelan derivatives. The Glochidion species contained the same triterpenes, viz. glochidonol, lup-20(29)-ene-3α,23-diol and glochidiol. The bark extractives of a new Glochidion species had, in addition, glochidone and probably lup-20(29)-ene-1α,3α,23-triol. The latter is a new natural product. Glochidone was isolated for the first time outside the genus Glochidion from Bridelia moonii.     

Four new labdane diterpene oxides from Sideritis gomerae

Four new labdane diterpene oxides gomeraidehyde, 13-epigomeraldehyde, gomeric acid and 13-epigomeric acid as well as eperu-13-ene-8β,15-diol were isolated from the aerial part of Sideritis gomerae.     

Metabolism of 5β-pregnane-3,20-dione and 3β-hydroxy-5β-pregnan-20-one by Digitalis suspension cultures

Digitalis purpurea normal callus suspension culture is capable of metabolizing 5β-pregnane-3,20-dione (1) to 3β-hydroxy-5β-pregnan-20-one (2), 3α-hydroxy-5β-pregnan-20-one (3), 3β-hydroxy-5β-pregnan-20-one glucoside (7) and 3α-hydroxy-5β-pregnan-20-one glucoside (8). Digitalis purpurea habituated callus suspension culture is also capable of metabolizing 1 to 2, 3, 5β-pregnane-3β,20β-diol (5), (7), (8), 5β-pregnane-3β,20α-diol monoglucoside (9) and 5β-pregnane-3α,20α-diol monoglucoside (11). Furthermore, it was observed that 3β-hydroxy-5β-pregnan-20-one (2) is converted to 7, 9 and 11 by both suspension cultures. At the same time, 1, 3, 5 and 8 were detected in normal callus, while 5β-pregnane-3β,20α-diol (4) and 5β-pregnane-3β,20β-diol monoglucoside (10) were present in the habituated callus culture.     

Triterpenoids from Salvia phlomoides, three new lupane derivatives

Three new triterpenoids have been isolated from the aerial parts of Salvia phlomoides. Their structures have been established by chemical and spectroscopic means and by correlation with known products as lupane-3β,11α,20-triol, 3β-acetoxy-lupane-11α,20-diol and 3-keto-lupane-11α,20-diol.     

Biotransformation of progesterone by suspension cultures of Digitalis purpurea cultured cells

It has been shown that the cultured cells of Digitalis purpruea are capable of transforming progesterone (I) to 5α-pregnane-3,20-dione (II), 5α-pregnan-3β-ol-20-one (III), its glucoside (IV), 5α-pregnane-3β,20α-diol (V), its glucoside (VI), 5α-pregnane-3β,20β-diol (VII), its glucoside (VIII), Δ⁴-pregnen-20α-ol-3-one (IX), its glucoside (X), Δ-pregnen-20β-ol-3-one (XI) and its glucoside (XII). 5α-Pregnan-3β-ol-20-one glucoside (IV), 5α-pregnane-3β,20α-diol glucoside (VI), 5α-pregnane-3β,20β-diol glucoside (VIII), Δ⁴-pregnen-20α-ol-3-one glucoside (X) and Δ⁴-pregnen-20β-ol-3-one glucoside (XII) have been found for the first time as new metabolises by plant tissue cultures. A scheme for the biotransformation of progesterone (I) has been proposed, and the reduction and glucosidation activities distinctly have been observed in these cultured cells.     

Studies on the Structures of Two New Triterpene Saponins C and D from Polygala japoni-ca Houtt

Two new triterpene saponins C and D have been isolated from the aerial parts of Polygala japonica Houtt. Their molecular formulas: C42H68O15 were structural isomers of each other. Acid hydrolysis of the two saponins all produced a sapogenin (2a, 3a, 24-trihydroxyo-lean-12-ene-28-oic acid) and D-glucoses. But only the saponin D could be hydrolyzed in the alkaline solution, the products were identical with those from acid hydrolysis. Their structures have been established by means of 1HNMR,13CNMR and MS as 3-O-[β-D-glucopyranosyl(l→2)β-D-glucopyranosyl] 2α, 3α, 24-trihydroxyolean-12-ene-28-oic acid, 28-O-[β-D-glucopy-ranosyl (1→2)-β-D-glucopyranosyl] 2α, 3α, 24-trihydroxyolean-12-ene-28-oic acid.     

Androgens with activity at estrogen receptor beta have anxiolytic and cognitive-enhancing effects in male rats and mice

Testosterone (T) and its metabolites may underlie some beneficial effects for anxiety and cognition, but the mechanisms for these effects are unclear. T is reduced to dihydrotestosterone (DHT), which can be converted to 5α-androstane,3α,17β-diol (3α-diol) and/or 5α-androstane-3β,17β-diol (3β-diol). Additionally, T can be converted to androstenedione, and then to androsterone. These metabolites bind with varying affinity to androgen receptors (ARs; T and DHT), estrogen receptors (ERβ; 3α-diol, 3β-diol), or GABA_A/benzodiazepine receptors (GBRs; 3α-diol, androsterone). Three experiments were performed to investigate the hypothesis that reduced anxiety-like and enhanced cognitive performance may be due in part to actions of T metabolites at ERβ. Experiment 1: Gonadectomized (GDX) wildtype and ERβ knockout mice (βERKO) were subcutaneously (SC) administered 3α-diol, 3β-diol, androsterone, or oil vehicle at weekly intervals, and tested in anxiety tasks (open field, elevated plus maze, light–dark transition) or for cognitive performance in the object recognition task. Experiment 2: GDX rats were administered SC 3α-diol, 3β-diol, androsterone, or oil vehicle, and tested in the same tasks. Experiment 3: GDX rats were androsterone- or vehicle-primed and administered an antagonist of ARs (flutamide), ERs (tamoxifen), or GBRs (flumazenil), or vehicle and then tested in the elevated plus maze. Both rats and wildtype mice, but not βERKO mice, consistently had reduced anxiety and improved performance in the object recognition task. Androsterone was only effective at reducing anxiety-like behavior in the elevated plus maze and this effect was modestly reduced by flumazenil administration. Thus, actions at ERβ may be required for T's anxiety-reducing and cognitive-enhancing effects.     

3β-Acetoxyhopan-1β,22-diol,a triterpene from the lichen Pseudoparmelia texana

From the lichen Pseudoparmelia texana the triterpene 3β-acetoxyhopan-1β,22-diol has been isolated and its structure elucidated.     

Isopongaglabol and 6-methoxyisopongaglabol,two new hydroxyfuranoflavones from Pongamia glabra

Isopongaglabol and 6-methoxyisopongaglabol, two new hydroxyfuranoflavones, together with two furanoflavones 5-methoxyfurano(8,7-4″,5″)flavone and 5-methoxy-3′,4′-methylenedioxyfurano(8,7-4″,5″)flavone, two simple flavones, desmethoxykanugin and fisetin tetramethyl ether, a chromenoflavanone, ovalichromene B, two triterpenes, cycloart-23-ene-3β,25-diol and friedelin, and β-sitosterol-β-d-glucoside were isolated from the petrol and CHCl₃ extracts of the flowers of Pongamia glabra. The structures of isopongaglabol and 6-methoxyisopongaglabol have been established as 4′-hydroxyfurano(8,7-4″,5″)flavone and 4′-hydroxy-6-methoxyfurano(8,7-4″,5″)flavone, respectively, on the basis of the spectral evidence and they have been confirmed by synthesis.     

Triterpenoids from Mallotus repandus: Three new δ-lactones

The leaves of Mallotus repandus contain friedelin, 3β-hydroxy-13α-ursan-28,12β-olide (1), its benzoate (2) and ursolic acid. The stems contain friedelin, lupeol, α-amyrin, 2 and 3α-hydroxy-13α-ursan-28, 12β-olide (3), 21α-hop-22(29)-ene-3β,30-diol and ursolic acid. 1–3 are new compounds.     

Stereospecific reduction of progesterone by Pisum sativum

[4 -¹⁴C]-Progesterone was applied to the leaves of growing pea plants, Pisum sativum. After 3 weeks, about 50% of the administered steroid was reduced, about 20% being reduced to 5α-pregnane-3α,20β-diol as the major metabolite. The radioactivities of 5α-pregnane-3α,20α-diol and 5α-pregnane-3α,20β-diol after 3 weeks were more than twice those after one week. The following radioactive metabolises were also isolated: 5α-pregnane-3,20-dione; 20α-hydroxy-4- pregnen-3-one; 20β-hydroxy-4-pregnen-3-one; 3α-hydroxy-5α-pregnan-20-one; 3α-hydroxy-5β-pregnan-20-one; 3β-hydroxy- 5α-pregnan-20-one; 20β-hydroxy-5α-pregnan-3-one; 5α-pregnane-3β,20β-diol; and 5β-pregnane-3α,20β-diol. The radioactivities of the 5α-pregnane derivatives were considerably higher than those of the corresponding 5β-pregnane derivatives.     

New neutral diterpenes from southern pine tall oil

Five new diterpene natural products isolated from southern pine (Pinus spp.) tall oil were characterized as 8(14),15-pimaradiene-3β,18-diol, 19-hydroxy-15,16-dinorlabd-8(17)-en-13-one, 8,13β-epoxy-14-labden-6α-ol, 8,11, 13-abietatriene-15,18-diol and 9,10-secoabieta-8,11,13-trien-18,10-olide.     

Biotransformation of testosterone and other androgens by suspension cultures of Nicotiana tabacum “Bright yellow”

It has been shown that the cultured cells of Nicotiana tabacum “Bright Yellow” are capable of transforming testosterone to Δ⁴-androstene-3, 17-dione, 5α-androstan-17β-ol-3-one, 5α-androstane-3β, 17β-diol, its dipalmitate and 3- and 17-monoglucosides, epiandrosterone, its palmitate and glucoside, testosterone glucoside. 5α-Androstane-3β, 17β-diol dipalmitate and 3- and 17-monoglucosides, epiandrosterone palmitate and glucoside, and testosterone glucoside have been found for the first time as metabolites of testosterone in plant systems. Δ⁴-Androstene-3,17-dione was converted to testosterone. 5α-Androstan-17β-ol-3-one, which has been recognized as an active form of testosterone in mammals, was also detected. It has also been demonstrated that [4-¹⁴C]testosterone is actively incorporated in these transformations.     

Labdane diterpenes from Cistus symphytifolius

The investigation of the aerial part of Cistus symphytifolius afforded, in addition to sitosterol, trimethoxykaempferol, cativic acid, labdenic acid, labdanolic acid and labdan-8α,15-diol, three new bicyclic diterpenes: cistadienic acid, cistenolic acid and labd-13(E)- ene-8α,15-diol. The structures of these were determined by spectral studies and correlations. CD spectral studies showed that cistenolic acid and salvic acid are enantiomeric compounds, so the stereochemistry of salvic acid (7α-hydroxy-labd-8(17)-ene-15-oic acid) should be changed to 7β-hydroxy-eperu-8(17)-ene-15-oic acid (7β-hydroxy-ent-labd-8(17)-ene-15-oic acid).