- ARTENOLIDE - A NEW DISESQUITERPENOID FROM Artemisia absinthium
-
A new sesquiterpene lactone, artenolide - C30H40O8, mp 163-174 deg C (ethanol) - has been isolated from the epigeal part of Artemisia absinthium L.On the basis of an analysis of spectral characteristics (IR, mass, and 1H and 13C NMR spectra) of the lactone itself and of a transformation product, a diguaiane structure is suggested for artenolide.
- Ovezdurdyev, A.,Abdullaev, N. D.,Yusupov, M. I.,Kasymov, Sh. Z.
-
-
Read Online
- A CEHICAL INVESTIGATION OF Achillea nobilis
-
From the flower heads and leaves of Achillea nobilis collected in the flowering phase close to Balytkykol, Egindybulak region, Karaganda Province, Kazakh SSR, by extraction with chloroform and chromatography of the combined substances on a column of silica gel we have isolated a new sesquiterpene lactone anobin C15H20O5, mp 175.5-177.5 deg C and have identified for the first time estafiatin, C15H18O3, mp 102-104 deg C, 20 -10.3 deg (chloroform); hanphyllin, C15H20O3, mp 189 deg C (decomp.), D20 +58.6 deg (c 0.39; chloroform), and 3,5-dihydroxy-6,7,8-trimethoxyflavone, C18H16O7, mp 148-150 deg C.On the basis of chemical and spectral characteristics it has been established that anobin has the structure of 4α,10α-dihydroxy-2α,3α-epoxy-5,7α(H),6β(H)-guai-11(13)-en-6,12-olide.It has been established that estafiatin possesses a pronounced growth regulating activity.
- Adekenov, S. M.,Mukhametzhanov, M. N.,Kagarlitskii, A. D.,Turmukhambetov, A. Zh.
-
-
Read Online
- Chamazulene carboxylic acid and matricin: A natural profen and its natural prodrug, identified through similarity to synthetic drug substances
-
Chamazulene carboxylic acid (1) is a natural profen with anti-inflammatory activity and a degradation product of proazulenic sesquiterpene lactones, e.g., matricin. Both 1 and proazulenes occur in chamomile (Matricaria recutita), yarrow (Achillea millefolium), and a few other Asteraceae species. It was isolated in improved yields, characterized physicochemically, and found to be an inhibitor of cyclooxygenase-2, but not of cyclooxygenase-1. It had anti-inflammatory activity in several animal models with local and systemic application. When human volunteers were given matricin orally, plasma levels of 1 were found to be in the micromolar range. Matricin was converted to 1 in artificial gastric fluid, but not in artificial intestinal fluid. Matricin and the yarrow proazulenes are proposed to be anti-inflammatory through conversion to 1. Intriguingly, the biological activity of the natural compound 1 was found because of its similarity to fully synthetic drug substances. This is the reverse process of the common lead function of natural compounds in drug discovery.
- Ramadan, Mai,Goeters, Susanne,Watzer, Bernhard,Krause, Eva,Lohmann, Klaus,Bauer, Rudolf,Hempel, Bernd,Imming, Peter
-
-
Read Online
- Synthetic transformations of sesquiterpene lactones 10*. Synthesis of 13-arylguaianolides
-
The Heck reaction of methylidene lactones of guaiane type, arglabin and ludartin, with aryl halides occurs with the formation of the respective (E)- and (Z)-13-arylidene-substituted derivatives and the respective endocyclic isomer, the ratio of which depends on the nature of methylidenelactone and the reaction conditions. The arylation of ludartin occurred with a lower yield of the target products and was accompanied by the formation of chamazulene. The interaction of grosheimin with aryl halides under Heck reaction led to the exocyclic products with (E)- and (Z)-configuration, with the latter as the major isomers. The structure of two compounds was established by X-ray structural analysis.
- Kihkentayeva, Anarkul S.,Shults, Elvira E.,Gatilov, Yurii V.,Patrushev, Sergey S.,Karim, Sultan,Atazhanova, Gayane A.,Adekenov, Sergazy M.
-
-
Read Online
- ISODEHYDROCOSTUS LACTONE AND ISOZALUZANIN C, TWO GUAIANOLIDES FROM SAUSSUREA LAPPA
-
Two new guaianolides have been isolated from Saussurea lappa as minor components and have been named isodehydrocostus lactone and isozaluzanin C.A structure has been assigned to isodehydrocostus lactone on the basis of spectral data and correlation with estafiatin.The 1H NMR data and dehydrogenation studies show that the other highly crystalline guaianolide is isomeric with zaluzanin C.Earlier 3β-H-zaluzanin C has however been reported to occur as a colourless oil.Key Word Index-Saussurea lappa; Compositae; sesquiterpene lactone; guaianolides; dehydrocostus lactone; eremanthine; estafiatin; zaluzanin C; isozaluzanin C; isodehydrocostuslactone.
- Kalsi, P. S.,Sharma, Sunila,Kaur, Gurdeep
-
-
Read Online
- Approach to the blues: A highly flexible route to the azulenes
-
(Chemical Equation Presented) A palette of blues: Chlorobicyclo-[5.3.0] decatrienones are readily prepared from cycloheptatrienes by cycloaddition of dichloroketene, ring expansion with a diazoalkane, and dehydrochlorination in dimethylformamide. These compounds are used as intermediates in the regiocontrolled synthesis of a wide variety of natural and nonnatural azulenes (see scheme).
- Carret, Sebastien,Blanc, Aurelien,Coquerel, Yoann,Berthod, Mikael,Greene, Andrew E.,Depres, Jean-Pierre
-
p. 5130 - 5133
(2007/10/03)
-