A New Lupane from the Resin of Boswellia carterii

A new lupan-type triterpene was isolated from the resin of Boswellia carterii Birdw. Based on the spectral methods, its structure was elucidated as lup-20(29)-ene-3α-acetoxy-24-oic acid.     

Structural analysis of pentacyclic triterpenes from the gum resin of Boswellia serrata by NMR spectroscopy

3α‐Acetyl‐β‐boswellic acid ( 1 ), 3α‐acetyl‐α‐boswellic acid ( 2 ), 3α‐acetyl‐9,11‐dehydro‐β‐boswellic acid ( 3 ), 3α‐acetyl‐9,11‐dehydro‐α‐boswellic acid ( 4 ) and 3α‐acetyl‐11‐keto‐β‐boswellic acid ( 5 ) were isolated from the gum resin of Boswellia serrata. 1D and 2D NMR (COSY45, HMQC, HMBC, ROESY) spectra at 500 MHz were used for shift assignments and structure verification. All boswellic acids investigated share the cis conformation at ring D/E and the 3α orientation of the acetyl ester group. Owing to high‐order spectra, NMR could not determine the exact conformation of H‐20/H‐30 of the β‐boswellic acids. 3α‐Acetyl‐β‐boswellic acid methyl ester ( 1 ^′) was synthesized for experiments with a shift reagent, Eu(fod)₃, that enhanced the resolution considerably. The oxygen atoms of the 3α‐acetyl group form the apparent complex binding site for the shift reagent. Copyright © 2003 John Wiley & Sons, Ltd.     

Bitter principles of Picrasma ailanthoides planchon: Nigakilactones J,K, L,M and N

Five new crystalline bitter principles were isolated from the stem-chips of Picrasma ailanthoides Planchon (Simaroubaceae). Structures of nigakilactones J, K, L, M and N were shown to be 1a, 2a, 3d, 4c and 4b, respectively.     

Four new dammarane-type triterpenes derivatives from hydrolyzate of total Gynostemma pentaphyllum saponins and their bioactivities

Phytochemical investigation of hydrolysate of total G. pentaphyllum saponins led to the isolation of four novel triterpenes, Gypensapogenin U (1), Gypensapogenin V (2), Gypensapogenin W (3) and Gypensapogenin X (4). The structures of these compounds were identified by 1D, 2D-NMR and HR-ESI-MS evidences. Additionally, the protective activity of these new compounds against cardiomyocytes injury induced by H₂O₂ and their cytotoxic activity against t-HSC/Cl-6 cells were evaluated.     

Two new triterpenes from the seeds of Trichosanthes cucumeroides

Two new triterpenes named 7-oxodihydrokarounitriol (1) and 7,11-dioxodihydrokarounidiol (2), and one known triterpene, 7-oxodihydrokarounidiol (3), were isolated from the unsaponifiable matter of the seeds of Trichosanthes cucumeroides. The structures of 1 and 2 were elucidated as (3alpha, 11beta, 13alpha, 14beta, 20alpha)-3,11,29-trihydroxy-13-methyl-26-norolean-8-ene-7-one, and (3alpha,13alpha,14beta,20alpha)-3,29-dihydroxy-13-methyl-26-norolean-8-ene-7,11-dione on the basis of extensive NMR (1H, 13C, 1H-1H COSY, DEPT, HMQC, HMBC and NOESY) and MS studies.     

Structures of new cucurbitane-type triterpenes and glycosides, karavilagenins and karavilosides, from the dried fruit of Momordica charantia L. in Sri Lanka

Three new cucurbitane-type triterpene called karavilagenins A, B, and C and five new cucurbitane-type triterpene glycosides called karavilosides I, II, III, IV, and V were isolated from the dried fruit of Sri Lanka Momordica charantia L. (Cucurbitaceae) together with two known cucurbitane-type triterpenes, 19(R)-methoxy-5beta,19-epoxycucurbita-6,23-dien-3beta,25-diol and 5,19-epoxycucurbita-6,23-diene-3,25-diol, and nine known cucurbitane-type triterpene glycosides, goyaglycosides-b, -c, and -d, and momordicosides F1, F2, G, I, K, and L. The structures of karavilagenins and karavilosides were elucidated on the basis of chemical and physicochemical evidence.     

常用中药藁本中新化合物的结构, 合成及活性研究

藁本是常用中药。中国药典收录的藁本有两种植物: 中国藁本(Ligusticumsinense Oliv. )和辽藁本(L. jeholense Thell), 另外新疆藁本(Conioselinumvaginatum Thell)做为藁本代用品在新疆地区广泛应用。我们对三种藁本植物中的化学成分进行深入研究, 从中共分到30种单体化合物并进行结构鉴定, 其中4种新化合物。初步药理实验发现从新疆藁本中分到的几个化合物具明显降酶保肝活性; 从中国蒿本中分到的蒿本酚显示较强的免疫抑制活性, 为探讨构效关系,作者完成了这些具活性成分的合成研究, 并合成一些结构类似物, 详细的活性研究还在进行中。     

Halichonadins K and L, new dimeric sesquiterpenoids from a sponge Halichondria sp

Two new structurally unique dimeric sesquiterpenoids, halichonadins K (1) and L (2), were isolated from an Okinawan marine sponge Halichondria sp. The structures of 1 and 2 were elucidated on the basis of spectroscopic analysis including a single crystal X-ray diffraction analysis and chemical conversion. Halichonadins K (1) and L (2) are homodimers of the eudesmane sesquiterpene linked with a piperidine ring through amide bonds. Halichonadin K (1) showed moderate cytotoxicity against KB cells.     

Nagelamides M and N, new bromopyrrole alkaloids from sponge Agelas species

Two new bromopyrrole alkaloids, nagelamides M (1) and N (2), have been isolated from an Okinawan marine sponge Agelas species, and the structures and stereochemistry were elucidated from the spectroscopic data. Nagelamide M (1) is a novel bromopyrrole alkaloid possessing a 2-amino-octahydropyrrolo[2,3-d]imidazole ring with a taurine unit, while nagelamide N (2) is a new bromopyrrole alkaloid possessing a 2-amino-tetrahydroimidazole-4-one ring with a taurine unit and 3-(dibromopyrrole-2-carboxamido)propanoic acid moiety. Nagelamides M (1) and N (2) exhibited antimicrobial activity.     

Latifolosides K and L, two new triterpenoid saponins from the bark of Llex latifolia.

Two new triterpenoid saponins, latifoloside K (1), 3-O-beta-D-glucopyranosyl-(1-->3)-[alpha-L-rhamnopyranosyl-(1-->2)-]-alpha-L-arabinopyranosyl 3beta-hydroxy-urs-12,18-dien-28-oic acid 28-O-beta-D-glucopyranosyl ester and latifoloside L (2), 3-O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1-->3)-[alpha-L-rhamnopyranosyl-(1-->2)-]-alpha-L-arabinopyranosyl 3beta,19alpha-dihydroxyursolic acid, were isolated from the bark of Ilex latifolia Thunb. Also isolated were two known compounds, ilekudinoside A (3) and kudinoside G (4). Structural assignments were established on the basis of spectroscopic data and chemical evidence.     

Iridoid and acyclic monoterpene glycosides, kankanosides L, M, N, O, and P from Cistanche tubulosa

Three iridoid glycosides, kankanosides L, M, and N, and two acyclic monoterpene glycosides, kankanosides O and P, were isolated from fresh stems of Cistanche tubulosa (Orobanchaceae) together with eight iridoid glycosides, five acyclic monoterpene glycosides, three phenylpropanoid glycosides, and four lignan glycosides. Their structures were elucidated on the basis of chemical and physicochemical evidence.     

Botryllamides K and L, new tyrosine derivatives from the Australian ascidian Aplidium altarium

Chemical investigation of the Australian ascidian Aplidium altarium led to the isolation of two new tyrosine derivatives, botryllamides K (1) and L (2), together with six known metabolites, botryllamides A-C (3-5), botryllamide G (6) and perspicamides A (7) and B (8). The structures of these compounds were elucidated by spectroscopic analysis. This is the first reported chemistry from this species. Compounds 1-8 were evaluated for their cytotoxicity towards the tumour cell lines, MCF-7 (breast), H460 (lung) and SF268 (central nervous system).     

Maragenins I,II and III,new pentacyclic triterpenes from Marah macrocarpus

Maragenins I, II and III, new pentacyclic triterpenes from Marah macrocapus (Greene) Greene, are shown to be respectively Δ¹²-, Δ^12,17- and Δ¹⁷-3β-hydroxy-16-oxo-28-norloeananes on the basis of chemical and spectroscopic evidence. The structural proposal for maragenin I is confirmed by synthesis from echinocystic acid.     

Total syntheses of the marine illudalanes alcyopterosin I, L, M, N, and C

The combination of a modular assembly of enantiopure triynes and a powerful rhodium-catalyzed [2 + 2 + 2] alkyne cyclotrimerization reaction opens new and efficient entries to a set of alcyopterosins, including the first total synthesis of the alcyopterosins L, M, and C.     

Six new ursane- and oleanane-type triterpenes from the aerial roots of Ficus microcarpa

Four new ursane-type triterpenes, 3beta-acetoxy-11alpha-methoxy-12-ursene (1), 3beta-acetoxy-11alpha-ethoxy-12-ursene (2), 3beta-acetoxy-11alpha-hydroperoxy-12-ursene (3), 3beta-hydroxy-11alpha-hydroperoxy-12-ursene (4), and two new oleanane-type triterpenes, 3beta-acetoxy-11alpha-ethoxy-12-oleanene (5), 3beta-acetoxy-111alpha-hydroperoxy-12-oleanene (6), together with 3beta-acetoxy-11alpha-hydroxy-12-ursene (7), 3beta,11alpha-diacetoxy-12-ursene (8), 3beta-acetoxy-11alpha-hydroxy-12-oleanene (9), were isolated from the aerial roots of Ficus microcarpa L. f. Their structures were elucidated by spectroscopic and chemical methods.     

Isolation and Structure Elucidation of Enniatins L,M1, M2, and N: Novel Hydroxy Analogs

Four new cyclohexadepsipeptides, enniatins L ( 1 ), M₁ ( 2 ), M₂ ( 3 ), and N ( 4 ), have been isolated from an unidentified fungus (BCC 2629), together with the known enniatins B ( 5 ), H ( 6 ), and I ( 7 ), MK1688 ( 8 ), and enniatin B₄ ( 9 ). Compounds 1 – 4 are the first enniatin analogs with an OH group at the side chain of one of the 2‐hydroxycarboxylic acid residues. The structures of 1 – 4 were elucidated by spectroscopic means and by X‐ray crystallography.     

Sessilifoliamides K and L: new alkaloids from Stemona sessilifolia

Two new alkaloids, sessilifoliamides K and L, having a pyrido[1,2-a]azonine skeleton were isolated from the roots of Stemona sessilifolia (Miq.) Miq. (Stemonaceae). Their structures were determined by interpretation of their spectroscopic data and computational methods.     

New dammarane and ursane-type triterpenoids from the flower of Ixora coccinea Linn.

Two new esters of dammarane triterpenoids ixorene isovalerate (1), ixorene 3′,8′-dimethyloctanoate (2) and a new ursane-type triterpenoids Ixoroid acid (3) were isolated from the methanolic extract of flowers of Ixora coccinea Linn., along with the three known constituents. The structures of compounds 1 and 3 were elucidated on the basis of extensive 1D,2D NMR studies and mass spectrometry as 17β-dammara-12,20-diene-3β-isovelarate and 3β-hydroxy-18β-urs-12ene-29β-oic acid, respectively, whereas 2 was identified as 17β-dammara-12,20-diene-3β-3′,8′-dimethyloctanoate through ¹H NMR and mass spectral data. Compounds 1, 2, 4 and 5 were evaluated for their in vitro cytotoxic activity, which exhibited weak activity against the 3T3, PC3 and HeLa cell lines with the IC₅₀ value >30 μM. Antioxidant results of 1 – 5 revealed that only compound 5 showed antioxidant activity in DPPH radical scavenging inhibition with the IC₅₀ 1.31 × 10^? 6 ± 0.005 μm mL^? 1. Both activities are the first records of these isolated compounds from the flowers of Ixora coccinea Linn.