Structures of Addition Products of Acetylenedicarboxylic Acid Esters with Various Dinucleophiles. An application of C, H‐spin‐coupling constants

Vögeli, Ulrich; Philipsborn, W. Von; Nagarajan, K.; Nair, M. D.

doi:10.1002/hlca.19780610207

Cited by 113 publications

(42 citation statements)

References 22 publications

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“…With larger amounts of both isomers at hand, it is now possible to establish that there is a larger H-C(8), C(5')=0 heteronuclear coupling constant [5] in the ( E ) than in the ( Z ) isomer, and the same is true for aplysinopsin (l), as shown in Table 3. Another polar pigment isolated in only 1-mg amount from the Tubastraea sp., 6-bromo-3'-deimino-3'-oxoaplysinopsin (6), contains a Br-atom according to MS (Exper.…”

Section: Imino-l'l'-his(demethyl)-3'-oxoaplysinopsin (I) Andfor Thementioning

confidence: 78%

Novel Aplysinopsin‐Type Alkaloids from Scleractinian Corals of the Family Dendrophylliidae of the Mediterranean and the Philippines. Configurational‐assignment criteria, stereospecific synthesis, and photoisomerization

Guella

Mancini

Zibrowius

et al. 1988

Helvetica Chimica Acta

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From the scleractinian coral Tubastraea sp. (Dendrophylliidae) collected at Palawan, Philippines, 3'-deimino-3'-oxoaplysinopsin (4) and 6-bromo-3'-deimino-3'-oxoaplysinopsin (6) are now isolated as 5 : 2 mixtures of ( E / Z ) stereoisomers. The 3'-deimino-2',4-bis(demethyl)-3'-oxoaplysinopsin (7) and 6-bromo-3'-deimino-2',4'-bis(demethyl)-3'-oxoaplysinopsin (5) are isolated as 2 :3 and 1 :1 (E/Z) mixtures, respectively, from another dendrophylliid, Leplopsammia pruuofi, collected near Marseille, Mediterranean coast of France. Larger amounts of these and related compounds, needed for a full structural determination, are obtained by synthesis. Thus, condensations of indol-3-carboxaldehyde (9) or of its 6-bromo derivative 14 with hydantoin (15), 3-methylhydantoin (ll), or 1,3-dimethylhydantoin (10) give the prevalent natural aplysinopsins with high stereospecificity. The minor stereoisomers (2)-4, (2)-6, (E)-7, and (E)-5 are obtained by (E/2) photoisomerization under UV light of the condensation mixtures. The configuration is assigned from larger H-C(S)/C(Y) ' H , ' k couplings in the ( E ) than in the ( Z ) isomer, and, in the case of 4 and 6, from NOE enhancement at Me-N(2') on irradiation at H-C(8). The stereospecificity of the condensations is attributed to steric inhibition to planarity in the rate-limiting transition states, due to N(2')/H-C(2) repulsion with (2)-4 and (2)-6, or to C(5')=0/H-C(2) repulsion with (E)-7 or (E)-5. As the aplysinopsins undergo (E/Z) photoisomerizdtion also under the daylight conditions of the kIbOrdtOry, their isomeric composition in nature can not be presently assessed.

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Section: Imino-l'l'-his(demethyl)-3'-oxoaplysinopsin (I) Andfor Thementioning

confidence: 78%

Novel Aplysinopsin‐Type Alkaloids from Scleractinian Corals of the Family Dendrophylliidae of the Mediterranean and the Philippines. Configurational‐assignment criteria, stereospecific synthesis, and photoisomerization

Guella

Mancini

Zibrowius

et al. 1988

Helvetica Chimica Acta

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“…In the literature it was reported that in reactions using unsubstituted imidazolidinediones and benzaldehydes or 3-substituted thiazolidinedione and 3-formyl chromone in an acidic medium, the main product was the Z isomer (15,18). The coupled 13 C NMR study of arylidene thiazolidinediones and imidazolidinediones also showed that only the Z isomer was formed (1,19). After the appropriate crystal of the compound 12 was obtained, Xray analysis was performed and the compound 12 (CCDC deposition number: CCDC-873382), was found to be Z isomer, as well ( Figure 1).…”

Section: Resultsmentioning

confidence: 99%

Alterations of aldose reductase and superoxide dismutase activities by some chromonyl-2, 4-thiazolidinedione derivatives

AMİRZADEH-KHİABANİ¹

2014

Ankara Üniversitesi Veteriner Fakültesi Dergisi

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Summary: Persistent hyperglycemia in diabetes mellitus (DM) leads to progression of secondary complications, such as neuropathy, nephropathy and retinopathy, which cause irreversible damage once initiated. During states of hyperglycemia, the polyol pathway has increased activity. As a result of the increased polyol pathway activity and the overutilization of NADPH by the enzyme aldose reductase (AR), a number of other homeostatic mechanisms are compromised. In view of the complex metabolic changes induced by hyperglycemia in which AR is critically involved and the prominent role performed by oxidative stress, derivatives endowed with dual activity as AR inhibitors (ARIs) and antioxidant agents could thus represent a promising way forward in the search for useful drugs to treat long-term complications associated with DM. However, many of the clinically tested aldose reductase inhibitors (ARIs) proved to be inadequate as drug candidates because of adverse pharmacokinetics, toxic side effects or low efficacy. For these reasons, nowadays the design of the ARIs which do not cause side effects is still carried on. In our study, AR enzyme was purified from bovine lens tissues. Then, the probable effects of 17 different chromonyl-2,4-thiazolidinedione derivatives on aldose reductase and superoxide dismutase (SOD) enzymes were investigated. Depending upon the results, compounds named 1 and 8 showed the best AR inhibitory activity at the ratio of 52.56% and 58.73 %, respectively. The most activator effect on SOD was found at the ratio of 24.74 % in compound 7.Key words: Aldose reductase, diabetes, inhibition, superoxide dismutase, TZD derivatives. Bazı kromonil-2,4-tiyazolidindiyon türevleri ile aldoz redüktaz ve süperoksit dismutaz aktivitelerindeki değişikliklerÖzet: Diabetes Mellitus (DM) hastalığındaki uzun süreli hiperglisemi nöropati, nefropati ve retinopati gibi geri-dönüşümsüz sekonder komplikasyonlara neden olmaktadır. Hiperglisemi sırasında polyol yolağının aktivitesi artmaktadır. Artan polyol yolağı aktivitesi ve aldoz redüktaz (AR) tarafından NADPH'ın aşırı tüketimi diğer homeostatik mekanizmaları etkilemektedir. AR'ın dahil olduğu hiperglisemiye bağlı kompleks metabolik değişiklikler ve oksidatif stres sonucunda oluşacak olan diyabetik komplikasyonların tedavisinde hem AR inhibitör etkisi olan hem de antioksidan özelliği bulunan dual etkili ajanların kullanılabilmesi olasılığı, araştırmalar ve tedavi açısından umut vericidir. Bunun yanısıra, klinik olarak denenmiş olan pekçok AR inhibitörünün (ARI) olumsuz farmakokinetikleri, toksik yan etkileri ve yetersiz etkileri nedeni ile ilaç adayı olarak yetersiz oldukları tespit edilmiştir. Bu nedenle, günümüzde hala yan etkisi az olan ARI leri üzerinde çalışmalar devam etmektedir. Çalışmamızda, AR enzimi sığır lenslerinden saflaştırılmıştır. Daha sonra, 17 farklı kromonil-2,4-tiyazolidindiyon türevlerinin AR ve süperoksit dismutaz (SOD) enzim aktiviteleri üzerine olası etkileri incelenmiştir. Sonuçlara göre; 1 ve 8 numaralı bileşikler en iyi ARI aktivitesini sırası i...

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“…In the literature it was reported that in reactions using unsubstituted imidazolidinediones and benzaldehydes or 3-substituted thiazolidinedione and 3-formyl chromone in an acidic medium, the main product was the Z isomer 16,17 . The coupled 13 C NMR study of arylidene thiazolidinediones and imidazolidinediones also showed that only the Z isomer was formed 18,19 . In this study, only one isomer of the 172.14 ± 7.98 Plus DMSO (1 µg/mL) 100.5 ± 4.87 Plus DMSO (10 µg/mL) 94.12 ± 5.32 Note.…”

Section: Resultsmentioning

confidence: 99%

Synthesis and antidiabetic activity of some new chromonyl-2,4-thiazolidinediones

Ceylan–Ünlüsoy

Verspohl

Ertan

2010

Journal of Enzyme Inhibition and Medicinal Chemistry

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Structures of Addition Products of Acetylenedicarboxylic Acid Esters with Various Dinucleophiles. An application of C, H‐spin‐coupling constants

Cited by 113 publications

References 22 publications

Novel Aplysinopsin‐Type Alkaloids from Scleractinian Corals of the Family Dendrophylliidae of the Mediterranean and the Philippines. Configurational‐assignment criteria, stereospecific synthesis, and photoisomerization

Novel Aplysinopsin‐Type Alkaloids from Scleractinian Corals of the Family Dendrophylliidae of the Mediterranean and the Philippines. Configurational‐assignment criteria, stereospecific synthesis, and photoisomerization

Alterations of aldose reductase and superoxide dismutase activities by some chromonyl-2, 4-thiazolidinedione derivatives

Synthesis and antidiabetic activity of some new chromonyl-2,4-thiazolidinediones

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