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1.
Total Synthesis of (±)-Calanolide A and Its Anti-HIV Activity   总被引:1,自引:0,他引:1  
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Celaphanol A was a diterpene isolated from the stems of Celastrus stephanotifolius1, which have been the subject of continued and growing interest, due to the range of biological activities shown by many members of this family2. Some have been used in traditional medicine3 or as a stimulant4 from ancient times. In order to further study the relationship between the structure and biological activity of the diterpene compound and as an extension of diterpenoid synthesis in our laboratory5, 6, …  相似文献   

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Chrysotricine1wasisolatedfromtheChineseherbmedicineHedyotiSChrysotricha'anditssthectUrehasbeenestablishedasanew0-carbolinealkaloidwitha2,5-trans-substitutedtetrahydrofuranylgrouPatitsl-positionbyX-raydiffractionandspectralanalysis.PharmaceuticalstUdiesshowedpotentialantitUmoractivity.Theinterestingbiologicalactivityandthechemistryof6-carb0linesmict[JIehaveattiactedconsiderableattentioninrecentyears.InordertostUdythisstrUctUre-activityrelationshiPfurther,wewereillterestedinthedevelopmento…  相似文献   

6.
Most diterpenoids exhibit significant bioactivities, such as antidermatophytic, antibact- erial, and antioxidant. Although a large number of aromatic tricyclic diterpenoids have been isolated, there are a few of them having ethyl substituent. The synthesis of this type diterpenoids has been seldom reported. In order to further study the relationship between the structure and bioactivities of the diterpenoid, we extended the diterpene synthesis1,2,3. It is desirable to report herein the syn…  相似文献   

7.
(±)-13-Hydroxy-8 (14)-abietene, a rare alicyclic diterpene possessing an isopropyl group and a hydroxy group at the C-13 position, was isolated from Solidago missouriensis nutt1. Many diterpenes exhibit significant bioactivities, such as antibacterial. As a part of our synthetic studies on the naturally-occurring diterpenes, we are attemping the synthesis of the rare natural compound. To our knowledge no total synthetic work has been reported yet. In order to study the further relationship b…  相似文献   

8.
A convenient synthesis of cis-(±) isomer 1 and trans-(±) isomer 2 of lamivudine starting from benzoyloxyacetaldehyde and l,4-dithiane-2,5-diol is described. The key steps include chlorination of oxathiolane lactol 5 by SOCl2/DMF, followed by coupling with silylated N4-acetylcytosine and deprotection. The overall yield was 42.6 % and 20.1 %, respectively.  相似文献   

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The synthesis of (±)-5, 6, 7-trioxygenated dihydroflavonols was carried out. All synthetic compounds were passed through superoxide radical scavenging activity in vitro. Compounds 1e and 1g exhibited significant bioactivity with the inhibitory rates of 68.1% and 80.9% at 40 μg/mL, respectively.  相似文献   

11.
The total synthesis of (±)-Calanolide A, incorporating a ring-forming sequence different from previous procedures, is described.  相似文献   

12.
Trichodiene (1), a sesquiterpene hydrocarbon, was isolated from the extract of mycelium of Trichothecium roseum. The structure of trichodiene (1) was elucidated by Nozoe and Machida in 1970 via degradation and spectroscopy.1 Trichodiene (1) has been shown to be the biogenetic precursor of the trichothecane family of sesquiterpenoids as characterized by the cytotoxic fungal metabolite (-)-trichodermin (2).2,3 The structure and absolute stereochemistry of (-)-trichodermin (2) were determined by X-ray diffraction and, therefore, the structure and absolute stereochemistry of trichodiene (1) are now firmly established.4 We wish to report a total synthesis of (±)-trichodiene (1) via previously reported lactone 3.5,6  相似文献   

13.
雷建光  林国强 《中国化学》2002,20(11):1263-1267
Introduction   4 ,4′ Biisofraxidin (1) ,anewbiscoumarin ,1wasisolatedbyWanchaiDe Eknamkulandhisco workersfromtherootculturesofimpatiensbalsaminaL . (Bal saminaceae) ,whichhaslongbeenusedinThailandasatraditionalfolkmedicine .TheleavesofBalsaminaceaeareusuallyusedf…  相似文献   

14.
A biomimetic total synthesis of racemic homodimericin A was achieved in seven steps, including two cascade reactions. Aqueous buffer solutions are found to help both the oxidative dimerization cascade and the intramolecular Diels–Alder cascade. This synthetic sequence validates key steps in the biogenetic proposal of homodimericin A.  相似文献   

15.
李文玲  何侃侃  李瀛  侯自杰 《化学学报》2005,63(17):1607-1612
对四种天然二聚二苯乙烯类化合物Shegansu B (1), Gnetuhainin F (1a), Maackin A (2)以及Cassigarol E (3)的全合成进行了研究. 以3,5-二羟基苯甲酸(4)为起始原料, 经六步反应制得异丹叶大黄素(13)和白皮杉醇(14), 在HRP/H2O2酶催化氧化体系中, 1314分别进行自身的氧化偶联得到各自的二聚产物. 首次完成了1a, (±)-2和(±)-3的全合成, 并以较文献报道为高的氧化偶联产率合成了(±)-1.  相似文献   

16.
Chrysotricine 1 was isolated from the Chinese herb medicine Hedyotis Chrysotricha and was shown to possess antitumor activity1. Its structure has been elucidated as a novel zwitterionic (-carboline alkaloid containing a 2,2,5-trisubstituted tetrahydrofuranyl group. The (-carboline compounds have attracted considerable attraction in recent years because of their promising and intriguing biological activities2. Recently, we have established the absolute configuration of chrysotricine by the fir…  相似文献   

17.
Sesquiterpenic compounds of the Eudesmane family have attracted considerable attention due to their intriguing biological properties1,2, particularly significant antifeedant activity, cell growth inhibitory and plant growth regulating activities.In 1996, J. Hu and co-workers3 had isolated eudesmane sesquiterpene 5?-hydroxy-isopterocarpolone 1 from the aerial parts of chinese folk medicine Artemisia eriopoda and elucidated its structure by spectropic methods. Herein, we reported the first tota…  相似文献   

18.
The total synthesis of(土)-cembrene-A, a termite pheromone, was achieved from geranylacetone and geraniol as starting materials. The key steps were the phase transfer catalyzed coupling reaction of sulphone (6) with chloride (9) and the intramolecular macrocyclization of dicarbonyl precursor (12) induced by low valent titanium. The synthetic route was short with anoverall yield of 17%.  相似文献   

19.
以对羟基苯甲醛和2,4-二羟基苯乙酮为起始原料,经过C-异戊烯基化、选择性的保护酚羟基、羟醛缩合、催化环化、去保护基等步骤,以25%的总收率首次完成了天然产物(±)-AbyssinoneⅠ(1)的全合成。其中新化合物4,7,8和1的结构经1H NMR,IR和MS表征。  相似文献   

20.
The first total synthesis of the hexacyclic indole alkaloid (±)-corymine is described. Starting from the readily available N-protected tryptamine, the title compound was achieved in 21 steps in 3.4 % overall yield. Key steps of the synthesis include: a) the addition of a malonate to a 3-bromooxindole to afford 3,3-disubstituted oxindole, b) the formation of a 12-membered cyclic enol ether by intramolecular O-propargylation, immediately followed by propargyl Claisen rearrangement to provide the α-allenyl ketone stereospecifically, c) DMDO oxidation to install a hydroxy group in a highly stereoselective manner, and d) the SmI2-mediated reductive C−O bond cleavage to remove the α-keto carboxyl group.  相似文献   

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