A Novel Taxatetraene Framework Formed From a New Natural Taxane from Taxus cuspidata

2011 ◽  
Vol 66 (7) ◽  
pp. 759-761
Author(s):  
Yong Li ◽  
Yong-Li Wang ◽  
Zhi-Yu Ni ◽  
Mei Dong ◽  
Bin Cong ◽  
...  
Keyword(s):  
Double Bond ◽  
Taxus Cuspidata ◽  
Natural Sources ◽  
Conjugated Triene ◽  
First Time

Sinenxan H [2α,14β -diacetoxytaxa-4(20),11-diene-5α, 10β -diol, 1] was isolated from the heartwood of Taxus cuspidata, for the first time from natural sources. Compound 1 was found to be readily converted into 2α-acetoxytaxa-4(20),10,12(18),13-tetraen-5α-ol (2), the first example of a taxane with 10,11- and/or 13,14-double bond(s) and a conjugated triene system, in CDCl3.

A Novel Scheme for the Synthesis of 21-Acetoxypregna-1,4,9(11)-triene- 17α,21-diol-3,20-dione from 9α-Hydroxyandrostenedione

2020 ◽  
Vol 16 (5) ◽  
pp. 606-610
Author(s):  
Nguyen T. Diep ◽  
Luu D. Huy
Keyword(s):  
Double Bond ◽  
Chemical Synthesis ◽  
Economic Efficiency ◽  
Final Stage ◽  
Side Chain ◽  
Entire Process ◽  
Drug Synthesis ◽  
First Time

Background: Vietnam currently imports up to 90% of the pharmaceuticals it consumes and 100% of the steroid-based pharmaceuticals. The ability for efficient chemical synthesis of the steroids could create commercial opportunities to address this issue. Synthesis of 21-acetoxypregna-1,4,9(11)- triene-17α,21-diol-3,20-dione is considered a key intermediate in the scheme of steroidal drug synthesis. Previous synthesis attempts of such steroids (corticoids) introduce a double bond at C-1(2) in the final stage of synthesis, which delivers a poor yield and reduces the economic efficiency of the process. Objective: To study and develop a novel and effective method for the synthesis of 21-acetoxypregna- 1,4,9(11)-triene-17α,21-diol-3,20-dione. Methods: Using 9α-hydroxyandrostenedione as a substrate chemical synthesis was performed as follows: pregnane side chain construction at C-17 (acetylene method), introduction of C-1(2) double bond (using SeO2), epimerization of C-17 (via 17-ONO2 ester) and Stork’s iodination. Results: 21-acetoxypregna-1,4,9(11)-triene-17α,21-diol-3,20-dione was prepared from 9α- hydroxyandrostenedione with an improved yield compared to previous attempts. Conclusion: Here, 21-acetoxypregna-1,4,9(11)-triene-17α,21-diol-3,20-dione has been synthesized from 9α-hydroxyandrostenedione based on a novel, effective and commercially feasible scheme. The introduction of the C-1(2) double bond at an earlier stage of the synthesis has increased the economic efficiency of the entire process. For the first time, the indirect epimerization mechanism has been clarified along with the configuration of the C-17 stereo-center which has been confirmed using NOESY data.

scholarly journals Antimicrobial and Immunomodulating Activities of Two Endemic Nepeta Species and Their Major Iridoids Isolated from Natural Sources

2021 ◽  
Vol 14 (5) ◽  
pp. 414
Author(s):  
Neda Aničić ◽  
Uroš Gašić ◽  
Feng Lu ◽  
Ana Ćirić ◽  
Marija Ivanov ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Food Industry ◽  
Balkan Peninsula ◽  
Antimicrobial Activities ◽  
Natural Sources ◽  
E Coli ◽  
Food Borne ◽  
Metabolite Profiles ◽  
Aspergillus Sp ◽  
First Time

Two Balkan Peninsula endemics, Nepeta rtanjensis and N. argolica subsp. argolica, both characterized by specialized metabolite profiles predominated by iridoids and phenolics, are differentiated according to the stereochemistry of major iridoid aglycone nepetalactone (NL). For the first time, the present study provides a comparative analysis of antimicrobial and immunomodulating activities of the two Nepeta species and their major iridoids isolated from natural sources—cis,trans-NL, trans,cis-NL, and 1,5,9-epideoxyloganic acid (1,5,9-eDLA), as well as of phenolic acid rosmarinic acid (RA). Methanol extracts and pure iridoids displayed excellent antimicrobial activity against eight strains of bacteria and seven strains of fungi. They were especially potent against food-borne pathogens such as L. monocytogenes, E. coli, S. aureus, Penicillium sp., and Aspergillus sp. Targeted iridoids were efficient agents in preventing biofilm formation of resistant P. aeruginosa strain, and they displayed additive antimicrobial interaction. Iridoids are, to a great extent, responsible for the prominent antimicrobial activities of the two Nepeta species, although are probably minor contributors to the moderate immunomodulatory effects. The analyzed iridoids and RA, individually or in mixtures, have the potential to be used in the pharmaceutical industry as potent antimicrobials, and in the food industry to increase the shelf life and safety of food products.

Study of the biocompatibility of lactic acid bacteria and other microorganisms-antagonists isolated from natural sources

2021 ◽  
pp. 40-42
Author(s):  
Светлана Юрьевна Носкова ◽  
Мария Игоревна Зимина ◽  
Ольга Олеговна Бабич ◽  
Станислав Алексеевич Сухих ◽  
Александр Юрьевич Просеков ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Mutual Influence ◽  
Growth Characteristics ◽  
Natural Sources ◽  
Urgent Task ◽  
First Time

Изучение биосовместимости молочнокислых бактерий и других микроорганизмов-антагонистов, выделенных из природных источников, является актуальной задачей. В данной работе впервые показано взаимное влияние изолятов молочно-кислых бактерий и других микроорганизмов-антагонистов при совместном культивировании. Установлено, что изолят 1 является биосовместимым с изолятами 6, 13, 19 и 20. Изолят 6 активно растет в присутствии изолятов 7, 8, 9, 10, 11, 13 и 16. Изолят 7 биосовместим с изолятами 6, 8, 9, 10, 11, 12, 13, 16, изолят 8 является биосовместимым с изолятами 6, 7, 9, 10, 11, 13 и 16. Для изолята 9 наблюдается биосовместимость с изолятами 6, 7, 8, 10, 11, 12, 13, 16, для изолята 10 - с изолятами 6, 7, 8, 9, 11, 13, 16. Изолят 11 показывает удовлетворительные ростовые характеристики при совместном культивировании с изолятами 6, 7, 8, 9, 10, 12, 13, 16. Изолят 12 биосовместим с изолятами 7, 8, 9, 10, 11, 13 и 16. Изолят 13 является биосовместимым с изолятами 6, 7, 8, 9, 10, 11, 12, 16. Изолят 16 биосовместим с изолятами 6, 7, 8, 9, 10, 11, 12, 13. Изолят 19 является биосовместимым с изолятами 1, 6, 13 и 20, изолят 20 - с изолятами 1, 6, 13 и 19. Полученные результаты позволяют сделать вывод о том, что изоляты 1, 6, 19 и 20 являются близкородственными, так же как изоляты 7, 8, 9, 10, 11, 12, 13 и 16. The study of the biocompatibility of lactic acid bacteria and other antagonist microorganisms isolated from natural sources is an urgent task. This work shows for the first time the mutual influence of isolates of lactic acid bacteria and other microorganisms-antagonists during co-cultivation. It was found that isolate 1 is biocompatible with isolates 6, 13, 19, and 20. Isolate 6 actively grows in the presence of isolates 7, 8, 9, 10, 11, 13, and 16. Isolate 7 is biocompatible with isolates 6, 8, 9, 10 , 11, 12, 13, 16, isolate 8 is biocompatible with isolates 6, 7, 9, 10, 11, 13 and 16. Isolate 9 is biocompatible with isolates 6, 7, 8, 10, 11, 12, 13, 16, for isolate 10 - with isolates 6, 7, 8, 9, 11, 13, 16. Isolate 11 shows satisfactory growth characteristics when co-cultivated with isolates 6, 7, 8, 9, 10, 12, 13, 16. Isolate 12 is biocompatible with isolates 7, 8, 9, 10, 11, 13 and 16. Isolate 13 is biocompatible with isolates 6, 7, 8, 9, 10, 11, 12, 16. Isolate 16 is biocompatible with isolates 6, 7, 8 , 9, 10, 11, 12, 13. Isolate 19 is biocompatible with isolates 1, 6, 13 and 20, isolate 20 - with isolates 1, 6, 13, and 19. The results obtained suggest that isolates 1, 6, 19 and 20 are closely related as well as isolates 7, 8, 9, 10, 11, 1 2, 13 and 16.

Extractives of Australian timbers. X. Autoxidation and other reactions of the conjugated side-chain of eberlin lactone. Isolation of a new isomer of ebelin lactone

1970 ◽  
Vol 23 (10) ◽  
pp. 2085 ◽  
Author(s):  
RA Eade ◽  
J Ellis ◽  
JS Shannon ◽  
HV Simes ◽  
JJH Simes
Keyword(s):  
Double Bond ◽  
Solid State ◽  
Osmium Tetroxide ◽  
Side Chain ◽  
Methyl Groups ◽  
Stepwise Manner ◽  
Terminal Double Bond ◽  
Conjugated Triene

The conjugated triene side-chain of ebelin lactone has been degraded in a stepwise manner using osmium tetroxide. A new isomer of ebelin lactone has been isolated from the sapogenin mixture and has been assigned the structure (9) in which the 25(26) double bond has the cis configuration. Autoxidation of ebelin lactone in the solid state yields a mixture from which three compounds have been isolated and identified; all three arise from oxidation of the side-chain at the terminal double bond and methyl groups.

Neodymium-Promoted Highly Selective Carbon–Carbon Double Bond Formation of Ketones with Allyl Halides in the Presence of Diethyl Phosphite

Synthesis ◽  
2020 ◽  
Vol 52 (22) ◽  
pp. 3446-3451
Author(s):  
Songlin Zhang ◽  
Dengbing Xie ◽  
Yiqiong Wang ◽  
Bo Yang
Keyword(s):  
Double Bond ◽  
Bond Formation ◽  
Point Of View ◽  
Diethyl Phosphite ◽  
Reaction Conditions ◽  
One Pot ◽  
Mild Conditions ◽  
Carbon Double Bond ◽  
Allyl Halides ◽  
First Time

The carbon–carbon double bond formation via neodymium-mediated Barbier-type reaction of ketones and allyl halides in the presence of diethyl phosphite is reported for the first time. The reaction is highly α-regioselective and was conveniently carried out under mild conditions in a one-pot fashion. From a synthetic point of view, a series of conjugated alkenes were obtained in moderate to good yields in this one-pot reaction with feasible reaction conditions.

scholarly journals Identification of Pavinane Alkaloids in the Genera Argemone and Eschscholzia by GC-MS

2012 ◽  
Vol 7 (10) ◽  
pp. 1934578X1200701 ◽  
Author(s):  
Lucie Cahlíková ◽  
Radim Kučera ◽  
Anna Hošt’álková ◽  
Jiří Klimeš ◽  
Lubomír Opletal
Keyword(s):  
Mass Spectra ◽  
Fragmentation Pathway ◽  
Rich Source ◽  
Natural Sources ◽  
Structural Types ◽  
Alkaloid Extracts ◽  
Reported Data ◽  
First Time

The genera Eschscholtzia and Argemone(Papaveraceae) represent a rich source of pavinane alkaloids, the identification of which in alkaloid extracts is generally problematic without standards. The alkaloid extracts of three Argemone and four Eschscholtzia species were analyzed using GC-MS. The alkaloids were identified based on comparison of their mass spectra with commercial libraries, with reported data in the literature and with spectra of reference compounds. A total of 23 alkaloids of six structural types (pavinane, protopine, benzylisoquinoline, benzophenanthridine, aporphine and protoberberine) were identified. The fragmentation pathway of pavinane alkaloids was used for their identification. O-Methylneocaryachine has been reported for the first time from a natural sources and the alkaloid pattern of Eschscholzia pulchella has been analyzed and described for the first time.

Metal-Free Addition of Boronic Acids to Silylnitronates

Synlett ◽  
2020 ◽  
Vol 31 (09) ◽  
pp. 856-860
Author(s):  
Laurent El Kaïm ◽  
Mansour Dolé Kerim ◽  
Pakoupati Boyode ◽  
Julian Garrec
Keyword(s):  
Reaction Mechanism ◽  
Double Bond ◽  
Boronic Acids ◽  
Dft Study ◽  
Metal Free ◽  
Nitro Derivatives ◽  
Oxime Derivatives ◽  
Nitrogen Double Bond ◽  
First Time ◽  
Aryl Transfer

We report for the first time a metal-free addition of boronic acids to silylnitronates to afford oxime derivatives through aryl transfer on the carbon nitrogen double bond. A reaction mechanism has been proposed in relation with a DFT study on the key aryl transfer. This arylation process is effective for cycloalkenyl nitro derivatives leading to oximes that may be oxidatively converted into 3-arylisoxazole derivatives.

Antitumor Activities of Extracts and Compounds from Water Decoctions of Taxus cuspidata

2010 ◽  
Vol 38 (06) ◽  
pp. 1107-1114 ◽  
Author(s):  
Shougang Jiang ◽  
Yu Zhang ◽  
Yuangang Zu ◽  
Zhuo Wang ◽  
Yujie Fu
Keyword(s):  
Antitumor Activity ◽  
Water Soluble ◽  
Taxus Cuspidata ◽  
Antitumor Activities ◽  
Antitumor Effects ◽  
Anticancer Properties ◽  
Specific Host ◽  
First Time

Water decoctions from the leaves of Taxus cuspidata are used in traditional Chinese medicine to treat cancer, suggesting that water soluble constituents from these leaves may possess anticancer properties. Interestingly, hydrophilic paclitaxel derivatives, as opposed to paclitaxel itself, can be detected by high pressure liquid chromatography in water decoctions from these leaves. The remainder extracts, which are free of paclitaxel and hydrophilic paclitaxel derivatives, from the T. cuspidata leaves were investigated for antitumor activity in vivo and in vitro for the first time in this study. EE80B, 7-xylosyl-10-deacetylpaclitaxel and 7-xylosyl-10-deacetylpaclitaxel C displayed the most antitumor activity in vivo. However, in vitro studies with tumor cell lines showed that EE80B had a significantly smaller antitumor effect than paclitaxel. We hypothesize that water decoctions from T. cuspidata leaves exhibit antitumor effects in vivo, which may be aided by the activation of specific host mechanisms (e.g. stimulation of antitumor immunity) which are not present in vitro.

scholarly journals Facile rotation around a silicon–phosphorus double bond enabled through coordination to tungsten

2015 ◽  
Vol 51 (56) ◽  
pp. 11272-11275 ◽  
Author(s):  
Nora C. Breit ◽  
Tibor Szilvási ◽  
Shigeyoshi Inoue
Keyword(s):  
Double Bond ◽  
First Time

Coordination of a zwitterionic phosphasilene to tungsten significantly weakens its SiP bond, so rotation and E/Z-isomerization of a SiP bond were observed for the first time.

scholarly journals Chemical Constituents from the Fruits ofForsythia suspensaand Their Antimicrobial Activity

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Ping-Chung Kuo ◽  
Guo-Feng Chen ◽  
Mei-Lin Yang ◽  
Ya-Hua Lin ◽  
Chi-Chung Peng
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Activity ◽  
Column Chromatography ◽  
Chemical Constituents ◽  
Phenylethanoid Glycosides ◽  
Natural Sources ◽  
Methanol Extracts ◽  
Lead Compounds ◽  
Forsythia Suspensa ◽  
First Time

Lignans and phenylethanoid glycosides purified fromForsythia suspensawere reported to display various bioactivities in the previous literature, including the antimicrobial activity. Therefore, the present research is aimed to purify and identify the chemical constituents of the methanol extracts of fruits ofF. suspensa. The methanol extracts of fruits ofF. suspensawere fractionated and further purified with the assistance of column chromatography to afford totally thirty-four compounds. Among these isolates, 3β-acetoxy-20α-hydroxyursan-28-oic acid (1) was reported from the natural sources for the first time. Some of the purified principles were subjected to the antimicrobial activity examinations againstEscherichia colito explore new natural lead compounds.

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