Rearranged lanostane triterpenoids from Abies sachalinensis (III)

To isolate more rearranged lanostane-type triterpenes from Abies sachalinensis, continuous chemical investigation of the ethyl acetate soluble fraction of the methanol extract of A. sachalinensis afforded two new rearranged lanostane-type triterpenes (1, 2). Their structures were elucidated to be 3,4-seco-4(28),7,12,24-mariesatetraen-26,23-olide-23-hydroxy-3-oic acid (1) and ethyl 3,4-seco-8(14-->13R)abeo-17,13-friedo-4(28),7,14,24-lanostatetraen-26,23-olide-23-hydroxy-3-oate (2), respectively. The structure of these compounds was determined by spectral studies, especially by two-dimensional (2D)-NMR and high-resolution (HR)-MS. Compounds 1 and 2 have a tautomeric lactone structure in the side chain.     

Two new lanostane triterpenoids from Abies sachalinensis

The continuous chemical investigation on the ethyl acetate (EtOAc) soluble fraction of the MeOH extract afforded two new lanostane triterpenoid derivatives including one with a rearranged lanostane skeleton. They were identified as 3,4-seco-8-(14→,13R)abeo-17,13-friedo-9β-lanosta-4(28), 7,14(30),24-tetraen-26,23-olide-23-hydroxy-3-oic acid (1) and 7,14-mariesa-dien-3a-hydroxy-25-methoxy-26-oic acid (2). Structural determination of these compounds were carried out by the spectral studies especially by the two digital (2D)-NMR and high-resolution MS experiences.     

Two new lanostane triterpenoids from Abies sachalinensis

The continuous chemical investigation on the ethyl acetate （EtOAc） soluble fraction of the MeOH extract afforded two new lanostane triterpenoid derivatives including one with a rearranged lanostane skeleton. They were identified as 3,4-seco-8-（14→13R）abeo-17,13-friedo-9β-lanosta-4（28）, 7,14（30）,24-tetraen-26,23-olide-23-hydroxy-3-oic acid （1） and 7,14-mariesa- dien-3oL-hydroxy-25-methoxy-26-oic acid （2）. Structural determination of these compounds were carried out by the spectral studies especially by the two digital （2D）-NMR and high-resolution MS experiences.     

Novel A-seco-rearranged lanostane triterpenoids from Abies sachalinensis

From the needles of Abies sachalinensis, novel rearranged lanostane type triterpenes, 1-4, were isolated along with a known triterpene (5). The structures of the new compounds, 1-4, were elucidated to be 3,4-seco-8-(14-->13R)abeo-17,13-friedo-9beta-lanosta-4(28),7,14(30),22Z,24-pentaen-26,23-olide-3-oic acid, methyl 3,4-seco-8-(14-->13R)abeo-17,13-friedo-9beta-lanosta-4(28),7,14(30),22Z,24-penten-26,23-olide-3-oate, 3,4-seco-8(14-->13R)abeo-17,13-friedo-9beta-lanosta-4(28),7,14,22Z,24-pentaene-26,23-olide-3-oic acid and methyl 3,4-seco-8(14-->13R)abeo-17,13-friedo-9beta-lanosta-4(28),7,14,22Z,24-pentaene-26,23-olide-3-oate, respectively, by means of spectral experiments, especially two dimensional NMR spectroscopy, such as 1H-detected multiple quantum coherence (HMQC), 1H-detected heteronuclear multiple bond connectivity (HMBC) and 1H-1H-correlation spectroscopy (COSY) experiments. These new compounds have novel structures containing A-seco, rearranged spiro structure and a gamma-lactone conjugated with a diene. Some of these compounds showed potent antibacterial activity against gram positive bacteria.     

Triterpenoids from species ofAbies hill. II. Abiesolidic acid — A new 3,4-secolanostanoid from the oleoresin ofAbies sibirica

The oleoresin of the Siberian fir has yielded a new 3,4-secolanostanoid for which the structure of (20R,23S,25R)-3,4-seco-9β-lanosta-4(28),7-dien-26,23-olid-3-oic acid has been established by x-ray structural analysis. The pathways of the mass-spectrometric fragmentation of this acid and its esters have been investigated.     

Triterpenoids from the roots of Sanguisorba tenuifolia var. Alba

The ethyl acetate soluble fraction from the roots of Sanguisorba tenuifolia was found to have a hypoglucemic effect in alloxan-induced diabetic rats. Two new triterpenoids, identified as 2-oxo-3β,19α-dihydroxyolean-12-en-28-oic acid β-D-gluco-pyranosyl ester (1) and 2α,19α-dihydroxy-3-oxo-12-ursen-28-oic acid β-D-glucopyranosyl ester (4) were isolated from this fraction, along with thirteen known triterpenoids. Their structures were elucidated by chemical and spectroscopic methods. All these compounds demonstrated inhibitory activities against α-glucosidase with IC?? values in the 0.62-3.62 mM range.     

Rhizophorin A, a novel secolabdane diterpenoid from the Indian mangrove plant Rhizophora mucronata

The ethyl acetate extract of Rhizophora mucronata furnished rhizophorin A, a novel secolabdane diterpenoid, (6R,11S,13S)-6,11,13-trihydroxy-2,3-seco-14-labden-2,8-olide-3-oic acid (1).     

Chemoselective oxidation of oleanolic acid derivatives with ozone

A method for preparing methyl esters of 12-oxoolean-28-oic and 3,12-dioxoolean-28-oic acids via ozonolysis of oleanolic acid methyl ester in CH₂Cl₂ at –60°C was proposed. It was found that oxidation of 2-cyano3,4-seco-4(23)-oleanenoic acid was chemoselective depending on the amount of ozone used.     

白山毛桃根抗脑胶质瘤活性成分及其纳米胶束的制备

采用溶剂提取和萃取方法得到白山毛桃根乙酸乙酯、 正丁醇和水层萃取物. 通过噻唑蓝(MTT)比色法考察了各萃取物对脑胶质瘤细胞U87MG活性的抑制作用. 采用高效液相色谱(HPLC)指纹图谱法比对确认活性部位的主要化学成分为2α,3α,24-三羟基-12-烯-28-乌苏酸. 采用溶剂挥发法制备了2α,3α,24-三羟基-12-烯-28-乌苏酸纳米胶束, 对其包封率、 粒径及ζ电位等进行了表征, 并考察了其抗肿瘤活性. 体外细胞实验结果表明, 白山毛桃根乙酸乙酯萃取物对脑胶质瘤细胞U87MG具有抑制作用, 通过与标准品比对确认2α,3α,24-三羟基-12-烯-28-乌苏酸为乙酸乙酯部位的主要成分, 且该成分对脑胶质瘤细胞活性具有较强抑制作用. 通过溶剂挥发法制备的2α,3α,4-三羟基-12-烯-28-乌苏酸纳米胶束包封率为64.7%, 粒径为20 nm, 粒径分布宽度(PDI)为0.246, ζ电位为-5.7 mV. 细胞实验结果进一步证明, 与单体化合物相比, 2α,3α,24-三羟基-12-烯-28-乌苏酸纳米胶束对脑胶质瘤细胞活性具有更强的抑制作用, 为白山毛桃根在脑胶质瘤治疗中的应用提供了实验依据.     

Triterpenoids from Abies species X. Two new 3,4-secotriterpene acids from the oleoresin of the silver fir

Two new 3,4-secotriterpene acids have been isolated in the form of dimethyl esters from the acid fraction of the oleoresin of the silver firAbies alba Mill. On the basis of spectral characteristics and the results of a chemical correlation with the known triterpenoids methyl abiesolidate, dimethyl abiesonate and methyl firmanoate it has been established that they are (25R)-3,4-seco-9β-lanosta-4(28),7-dien-23-one-3,26-dioic acid and (25R)-3,4-seco-abiesa-4(28),7,14(30)-trien-23-one-3,26-dioic acid. Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR, Novosibirsk. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 765–770, November–December, 1990.     

<Emphasis Type="Italic">seco</Emphasis>-Kaurane skeleton diterpenoids from <Emphasis Type="Italic">Croton oblongifolius</Emphasis>

A new seco-kaurane type diterpenoid, ent-3,4-seco-17-oxo-kaur-4(19),15(16)-dien-3-oic acid, and a known compound, ent-3,4-seco-kaur-4(19),16(17)-dien-3-oic acid, were isolated from the stem bark of Croton oblongifolius. The structures of these compounds were established on the basis of spectroscopic data.     

New triterpenoids from Gentiana lutea

Three new triterpenoids, 2,3-seco-3-oxours-12-en-2-oic acid, 2,3-seco-3-oxoolean-12-en-2-oic acid, and betulin 3-O-palmitate, have been isolated from the rhizomes and roots of Gentiana lutea, together with five known ones. The structures of the new compounds were determined by spectral and chemical methods.     

The Terpenoids of Maytenus boaria MOL. (Celastraceae)

The known triterpenoids β-amyrin (= olean-12-en-3β-ol; 22 ), lupeol (= lup-20(29)-en-3β-ol; 17 ), betulin (= lup-20(29)-ene-3β,28-diol; 18 ), lup-20(29)-ene-3β,30-diol ( 20 ), oleanolic acid (= 3β-hydroxyolean-12-en-28-oic acid; 21 ), and betulonic acid (= 3-oxolup-20(29)-en-28-oic acid; 19 ), together with epicatechol (= cis-2-(3,4-dihydroxyphenyl)-3,4-dihydro-2H-1-benzopyran-3,5,7-triol; 23 ), 5′-O-methylgallocatechol (= trans-2-(3,4-dihydroxy-5-methoxyphenyl)-3,4-dihydro-2H-1-benzopyran-3,5,7-triol; 24 ), and 4-hydroxybenzaldehyde were isolated from the aerial parts of Maytenus boaria (MOL. ). Additonally, the eight 4,C⁴-dihydro-β-agarofuran sesquiterpenoids 1–8 , one of them a diol with a (4R)-configuration, and compound 9 were present in the extract. The structures of these compounds were established by spectroscopic and chemical means.     

Triterpenoids from Abies species X. Two new 3,4-secotriterpene acids from the oleoresin of the silver fir

Two new 3,4-secotriterpene acids have been isolated in the form of dimethyl esters from the acid fraction of the oleoresin of the silver firAbies alba Mill. On the basis of spectral characteristics and the results of a chemical correlation with the known triterpenoids methyl abiesolidate, dimethyl abiesonate and methyl firmanoate it has been established that they are (25R)-3,4-seco-9-lanosta-4(28),7-dien-23-one-3,26-dioic acid and (25R)-3,4-seco-abiesa-4(28),7,14(30)-trien-23-one-3,26-dioic acid.Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR, Novosibirsk. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 765–770, November–December, 1990.     

Two new triterpenoids from Psidium guajava

Two new triterpenoids,named as 2 α,3 β,23-trihydroxylurs-12,20(30)-dien-28-oic acid β-D-glucopyranoside(1),and 2 α,3 β,6 β,20 β,23,30-hexahydroxyurs-12-en-28-oic acid(2),together with four known triterpenoids were isolated from the leaves of Psidium guajava L.Their structures were elucidated on the basis of mass and spectral evidence.     

New Triterpenes from the Heartwood of Melaleuca leucadendron L.

Fourteen chemical constituents were isolated from the CHCl₃ soluble portion of the heartwood of Melaleuca leucadendron L. These compounds include β-sitosterol (1) , β-sitostenone (2) , 6-hydroxy-4,6-dimethyl-3-hepten-2-one (3) , naphthalene (4) , squalene (5) , 2α3β-dihydroxyurs-12-en-28-oic acid (6) , 3β-hydroxylup-20(29)-en-27,28-dioic acid (7) , 2α,3β-dihydroxyolean-12-en-28-oic acid (8) , 3β,23-dihydroxyolean-12-en-28-oic acid (9) , 2α,3β,23-trihydroxyolean-12-en-28-oic acid (10) , 3β-trans-p-coumaroyloxy-2α,23-dihydroxyolean-12-en-28-oic acid (11) , and three novel oleanane derivatives 23-trans-p-coumaroyloxy-2α,3β-dihydroxyotean-12-en-28-oic acid (12), 3β-trans-caffeoyloxy-2α,23-dihydroxyolean-12-en-28-oic acid (13) , and its isomer 3β-cis-caffeoyloxy-2α,23-dihydroxyolean-12-en-28-oic acid (14) , The three novel compounds were characterized as the two and three O-methylated derivatives, respectively.     

无柄新乌檀中一个新的三萜成分的分离和鉴定

对无柄新乌檀进行了持续的化学成分及药理作用的研究, 在对其枝干的进一步研究中, 又分离得到一个新的三萜化合物3,7,21,23-四羟基齐墩果烷-12-烯-28-酸. 本文报道其分离方法和结构鉴定结果.     

24-nor-Ursane type triterpenoids from the stems of Rumex japonicus

Fractionation of an EtOAc-soluble extract of the stems of Rumex japonicus led to the isolation of two new 24-norursane type triterpenoids, 2alpha,3alpha,19alpha-trihydroxy-24-norurs-4(23),12-dien-28-oic acid (1) and 4(R),23-epoxy-2alpha,3alpha,19alpha-trihydroxy-24-norurs-12-en-28-oic acid (2), along with the known compounds myrianthic acid (3), tormentic acid, and emodin. The structures of 1 and 2 were elucidated by spectroscopic methods, particularly by extensive 1D and 2D NMR studies.     

A new biologically active triterpenoid saponin from the leaves of Lepidagathis hyalina Nees

A new biologically active triterpenoid saponin m.f. C42H68O13, m.p. 315 degrees-317 degrees C was isolated from the ethyl acetate soluble fraction of the methanolic extract of the leaves of Lepidagathis hyalina. Its structure was characterized as 3-beta-O-[alpha-L-rhamnopyranosyl(1-->4)O-beta-D-glucopyranosyl]16-alpha-hydroxy-olean-12-en(13)-28-oic acid by several spectral and chemical analysis. This new triterpenoid saponin showed antimicrobial activity against various plants pathogenic bacteria and fungi.