Three New Diterpenoids from Euphorbia wallichii

Three new abietane diterpene lactones, 3α-hydroxyjolkinolide A (1), ent-8α, 14β-dihydroxy-13(15)-ene-16(12α)-abietanolide (2) and ent-8α,14α-dihydroxy-13(15)-ene-16(12α)-abietanolide (3) as well as a known abietane diterpene jolkinolide A (4) were isolated from the roots of Euphorbia wallichii. Their structures were elucidated on the basis of spectroscopic analysis.     

Cytotoxic 8,9-secokaurane diterpenes from a New Zealand liverwort, Lepidolaena taylorii

The main cytotoxic compound from the liverwort Lepidolaena taylorii is the known ent-8,9-seco-7-hydroxy-kaura-8(14),16-dien-9,15-dione1. The relative stereochemistry of a new cytotoxic compound, 16,17-dihydro derivative 2, was supported by molecular modelling. Another new cytotoxic compound was identified as 8,14-epoxide 3 by preparation from 1. These compounds showed differential cytotoxic activity against human tumor cell lines.     

Metabolism of 24,25-dihydrolanosterol analogs by partially purified cytochrome P-450(14DM) from rat liver microsomes

27-Nor-24,25-dihydrolanosterol (27-nor-DHL), 26,27-dinor-24,25- dihydrolanosterol (26,27-dinor-DHL), and 25,26,27-trinor-24,25-dihydrolanosterol (25,26,27-trinor-DHL), analogs of 24,25-dihydrolanosterol (DHL) which have no C-27 carbon, C-26,27 carbons and C-25,26,27 carbons, were converted to the corresponding 14-demethylated products using a reconstituted monooxygenase system from rat liver microsomes which contained cytochrome P-450(14DM) catalyzing lanosterol 14-demethylation and reduced nicotinamide adenine dinucleotide phosphate (NADPH)-cytochrome P-450 reductase in the presence of NADPH and molecular oxygen. Each metabolite showed a relative retention time (RtR) of 0.72 with respect to each substrate in high-performance liquid chromatography (HPLC) on a reversed-phase column. Comparison of each gas chromatography-mass spectrum and RtR value with those of the metabolite of DHL, 4,4-dimethyl-5 alpha-cholesta-8,14-dien-3 beta-ol, indicated that the metabolites could be inferred to be 27-nor-4,4-dimethyl-5 alpha-cholesta-8,14-dien-3 beta-ol, 26,27-dinor-4,4- dimethyl-5 alpha-cholesta-8,14-dien-3 beta-ol, and 25,26,27-trinor-4,4-dimethyl-5 alpha-cholesta-8,14-dien-3 beta-ol. However, 24,25,26,27-tetranor- and 23,24,25,26,27-pentanor analogs of DHL and 20-iso-24,25-dihydrolanosterol were not metabolized by the reconstituted enzyme system.     

Five New Sesquiterpenes from the Heartwood of Juniperus Squamata Lamb

Extracts of the heartwood of Juniperus squamata Lamb. var. morrisonicola (Hay.) Li and Keng contain the known constituents 8,14-cedranoxide, 8,14-cedranolide, cedrol, β-sitosterol, widdrol, 7-oxototarol, procerin, 8,14-cedranediol, hinokiol, sugiol, hinokiic acid, cedrolic acid, and five new sesquiterpenoids, epicedranediol, 4-ketocedrol, 3β-hydroxycedrol, isocedrolic acid, and β-chamigrenic acid. These new sesquiterpenes were identified by spectroscopic data and chemical correlations.     

Conformational comparison of five follicular fluid meiosis-activating sterol-related active and inactive compounds

The crystal structures of five follicular fluid meiosis-activating sterol-related Δ^8,14-sterol compounds are presented. These are 4,4-di­methyl-23-phenyl-24-nor-5α-chola-8,14-dien-3β-ol, C₃₁H₄₄O, 4,4-di­methyl-22-phenyl-23,24-dinor-5α-chola-8,14-dien-3β-ol, C₃₀H₄₂O, (20R)-4,4-di­methyl-22-oxa-5α,20-chol­es­ta-8,14,24-trien-3β-ol, C₂₈H₄₄O₂, 4,4-di­methyl-23-phenyl-22-oxa-24-nor-5α-chola-8,14-dien-3β-ol–water (4/1), 4C₃₀H₄₂O₂·H₂O, and 4,4-di­methyl-5α-cholesta-8,14-dien-3-one, C₂₉H₄₆O. Two of the derivatives are inactive and three are active as agonists. Preliminary structure–activity relationship studies showed that the positions of the double bonds in the skeleton and the structures of the side chains are important determinants for activity. The conformations of the skeletons were compared with double-bond isomers retrieved from the Cambridge Structural Database [Allen & Kennard (1993). Chem. Des. Autom. News, 8 , 1, 31–37]; no significant differences were found. Thus, conformational changes induced by the double bonds are not discriminative with respect to the activity of the compounds. Comparisons of the side-chain conformations of active and inactive structures revealed that the crystal structures were not conclusive as far as correlation of conformation and activity of the side chains were concerned.     

Antifeedant triterpenoids from the seeds and bark of Lansium domesticum cv Kokossan (Meliaceae)

Two tetranortriterpenoids, kokosanolide A (1) and C (2) were isolated from the seeds and three onoceranoid-type triterpenoids: kokosanolide B (3), 8,14-secogammacera-7,14-diene-3,21-dione (4) and a 1.5:0.5 mixture of 8,14-secogammacera-7,14(27)-diene-3,21-dione (5) and compound 4 were isolated from the bark of kokossan (Lansium domesticum). Complete 1H- and 13C-NMR data of the triterpenoids 1-5 are reported. The triterpenoids' structures were elucidated primarily by means of high field 1D- and 2D-NMR, IR and HRMS spectral data. Triterpenoids 1-5 exhibited moderate to strong antifeedant activity against the fourth instar larvae of Epilachna vigintioctopunctata.     

Serratene triterpenoids fromLycopodium clavatum L. (Lycopodiaceae)

Three serratene triterpenoids, 3\,21α-dihydroxy-26-nor-8,14-sekogammaser-14(27)-en-n-8-one (1), 3ß,21a-dihydroxy-8,14-sekogammasera-8(26),14(2?)-diene (2), and 3α,21ß,24-trihydroxyserrat-14-ene (3), were isolated from the Siberian chemorace ofLycopodium clavatum L. and identified. Compound1 was isolated fromL. clavatum L. for the first time.     

Ionic hydrogenation of estra-1,3,5(10),8,14-pentaenes

The direction of ionic hydrogenation of estra-1,3,5(10),8,14-pentaenes with triethylsilane in the presence of trifluoroacetic acid is determined by the nature of substituents in the A and B rings. The hydrogenation of 7??-methyl-3-methoxy-D-homo-6-oxaestra-1,3,5(10),8,14-pentaen-17a??-yl acetate gives mainly 9??-analog, which provides the possibility for synthesizing new inhibitors of enzymes responsible for metabolism of steroidal estrogens.     

Syntheses of derivatives of oestrane and 19-norsteroids from 6-methoxytetralone and 6-hydroxytetralone

The corresponding derivatives of Δ^{1,3,5(10),9,(11)}-8,14-seco- -homo-oestratetraen-3-ol-14,17a-dione(VII, VIII, IX) have been obtained by the condensation of 3-methoxy-, 3-hydroxy-, and 3-tetrahydropyranyloxy-1-vinyltetralols (IV, V, VI) with methyldihydroresorcinol. The diketones VIII and IX cyclize to form Δ^{1,3,5(10),8,14}- -homo-oestrapentaen-3-ol-17a-one (XIII), and the diketone (VII) may be converted, according to conditions, into 3-methoxy-Δ^{1,3,5(10),8,14}- -homo-oestrapentaen-17a-one (X), 3-methoxy-Δ_{1,3,5(10),9,(11)}- -homo-oestratetraen-14-ol-17a-one (XIV), and -homoequilenin (XI). Hydrogenation of the ketones X and XIII leads to the dihydroketones XV and XVI with a trans junction of the C and D rings. Reduction or hydrogen of XV gives the methyl ethers of -homo-oestrone and 8-iso- -homo-oestrone XIX and XVII which have been converted into the methyl ethers of (±)-oestrone and 8-iso-oestrone (XX and XXI). 19-Nor- -homotestosterone (XXV) and its methyl and ethyl analogues, which possess anabolic activity, have been obtained by a series of reactions from the ketones X and XV.     

New analogs of D-homoequilenine with substituents in the D ring

Stereoselectivity of reaction with Raney nickel of D-homoestra-1,3,5(10),8,14-pentaenes containing one or two methyl groups in position 16 was investigated. The reaction direction is governed by the orientation of the substituent at C^17a. The signals in the ¹H and ¹³C NMR spectra of four synthesized compounds were completely assigned. Criteria for evaluation of the character of rings junction in analogs of D-homoequilenine were suggested. 16,16-Dimethyl-3-methoxy-D-homo-13α-estra-1,3,5(10),6,8-pentaen-17a-one was subjected to X-ray diffraction analysis.     

First seco-C oleananes from nature

[structure: see text] The triterpenes 8,14-seco-oleana-8(26),13-dien-3beta-ol (1) and its acetyl derivative 2 were isolated from Stevia viscida and Stevia eupatoria, respectively. Their structures were elucidated by 2D NMR, including carbon-carbon connectivity experiments, and confirmed by X-ray diffraction analysis of ketone 3. The absolute configuration was determined by NMR analysis of the Mosher esters of 1. The biogenetic implications of the new substances are discussed.     

Three New, 1‐Oxygenated ent‐8,9‐Secokaurane Diterpenes from Croton kongensis

Three new ent‐8,9‐secokaurane diterpenes, kongensins A–C ( 1 – 3 ), were isolated from the aerial parts of Croton kongensis, together with two known compounds, rabdoumbrosanin ( 4 ) and (7α,14β)‐7,14‐dihydroxy‐ent‐kaur‐16‐en‐15‐one ( 5 ). The structures of the new compounds were elucidated by HR‐MS as well as in‐depth 1D‐ and 2D‐NMR analyses. Compounds 1 – 3 showed an unusual oxygenation pattern, with an AcO or OH group at C(1), in combination with a Δ⁸⁽¹⁴⁾ unsaturation ( 1 ) or an 8,14‐epoxide function ( 2, 3 ).     

Diterpenic skeleton transformations : alumina catalysed rearrangements of epoxides

The 8,14 β-epoxide of methyl sandaracopimarate undergoes new rearrangements on contact with active alumina, yielding labdane and another compound having the cycloisopimarane skeleton.     

Pregnane and pregnane glycosides from the Malagasy plant,Cynanchum aphyllum

A new 8,14-seco-pregnane type of steroid called cynaphyllogenin and its eight glycosides, cynaphyllosides A-H, were isolated from the aerial parts of Cynanchum aphyllum. The structures of these compounds were elucidated based on chemical and spectroscopic evidence.     

Transformation of Cedrane Skeleton to Noracorane and Decahydroazulene Skeletons via Free Radical Reaction. Autooxidation of 8β-Hydroxycedran-13-Al

8-Cedren-14-ol ( 4d ) was oxidized with PCC, followed by autooxidation to yield 8,14-cedranolide ( 2a ) and 8-cedren-14-carboxylic peracid ( 4e ). 8β-Hydroxycedran-l3-al ( 1d ) was subjected to autooxidation in three different solvents to give eight products, from which the transformation from cedrane skeleton to noracorane and decahydroazulene skeletons were observed. A free radical pathway was proposed.     

黑龙骨中两个新强心苷的结构鉴定

系统研究黑龙骨Periploca forrestii Schltr.中的化学成分, 利用各种色谱技术进行分离, 得到2个新类型的强心苷,黑龙骨苷甲和乙. 并通过化学和光谱方法(MS, ¹H, ¹³C NMR和2D NMR)鉴定其结构为: 5β-羟基-8,14β-环氧-强心 甾- 20(22)-烯-3-O-β-D-磁麻吡喃糖苷(1)和5β-羟基-8,14β-环氧-强心甾-20(22)-烯-3-O-β-D-葡萄吡喃糖基-(1→4)-β-D-磁麻吡喃糖苷(2).     

Investigation of the products of the ozonolysis of larixol

On the ozonization of larixol in methanol followed by treatment with ammonium chloride, the main reaction products were 15,16,20-trisnorlabd-6-ene-8,13-dione and 6-hydroxy-8,13;8,14-diepoxy-15,20-bisnorlabd-14-one. When ozonization was performed in methanol in the presence of dimethyl sulfide or in methylene chloride in the presence of pyridine, 6,14-dihydroxy-8,13;8,14-diepoxy-15,20-bisnorlabdane and 6-hydroxy-14,50,20-trisnorlabd-8,13-dione predominated in the reaction products.     

玉柏石松的四环三萜成分研究

本文从玉柏石松中分得三种四环三萜化合物, 利用^1^3CNMR和^1H NMR测定为26-失碳-8-氧代-2-芒柄花萜醇1), 26, 27-双失碳-8,14-二氧代-α-芒柄花萜醇2), α-芒柄花萜醇3), 其中1是新水合物, 2是首次从自然界分得, 1,2的结构通过臭氧氧化分解产物得到证实, 本文报导了它们的化学结构。     

Investigation of the products of the ozonolysis of larixol

On the ozonization of larixol in methanol followed by treatment with ammonium chloride, the main reaction products were 15,16,20-trisnorlabd-6-ene-8,13-dione and 6-hydroxy-8,13;8,14-diepoxy-15,20-bisnorlabd-14-one. When ozonization was performed in methanol in the presence of dimethyl sulfide or in methylene chloride in the presence of pyridine, 6,14-dihydroxy-8,13;8,14-diepoxy-15,20-bisnorlabdane and 6-hydroxy-14,50,20-trisnorlabd-8,13-dione predominated in the reaction products.Institute of Chemistry of the MSSR Academy of Sciences, Kishinev, and Institute of Organic Chemistry of the Bashkir Branch of the USSR Academy of Sciences, Ufa. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 577–584, September–October, 1986.     

Chemical composition and antioxidant activity of Campanula alliariifolia

In this study, the chemical constituents of Campanula alliariifolia Willd. (Campanulaceae) are being investigated for the first time with the aid of this article. Five known compounds, which were quercetin-3-O-glucoside, quercetin-3-O-rutinoside, kaempferol-3-O-glucoside, lobetyolin (9-O-beta-D-glucopyranosyl-2,10-tetradecadien-4,6-diyne-8,14-diol) and lobetyol (2,10-tetradecadien-4,6-diyne-8,9,14-triol), were isolated from the methanol extract. The antioxidant activity of the methanol extract and the purified compounds of the plant was investigated with DPPH (1,1-diphenyl-picrilyhydrazyl) (free radical scavenging activity) and reducing power methods. The methanol extract has antioxidant capacity according to the mentioned methods. Lobetyol and lobetyolin showed significant antioxidant activity more than both methanol extract and other purified compounds.