scholarly journals Multiple Stimuli-Responsive Conformational Exchanges of Biphen[3]arene Macrocycle

Molecules ◽  
2020 ◽  
Vol 25 (24) ◽  
pp. 5780
Author(s):  
Yiliang Wang ◽  
Liu-Pan Yang ◽  
Xiang Zhao ◽  
Lei Cui ◽  
Jian Li ◽  
...  
Keyword(s):  
Solid State ◽  
1H Nmr ◽  
13C Nmr ◽  
Current System ◽  
Molecular Switches ◽  
2D Nmr ◽  
Stimuli Responsive ◽  
Acid Base ◽  
Responsive Systems ◽  
Guest Binding

Conformational exchanges of synthetic macrocyclic acceptors are rather fast, which is rarely studied in the absence of guests. Here, we report multiple stimuli-responsive conformational exchanges between two preexisting conformations of 2,2′,4,4′-tetramethoxyl biphen[3]arene (MeBP3) macrocycle. Structures of these two conformations are both observed in solid state, and characterized by 1H NMR, 13C NMR and 2D NMR in solution. In particular, conformational exchanges can respond to solvents, temperatures, guest binding and acid/base addition. The current system may have a role to play in the construction of molecular switches and other stimuli-responsive systems.

scholarly journals Redox-triggered switching in three-dimensional covalent organic frameworks

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Chao Gao ◽  
Jian Li ◽  
Sheng Yin ◽  
Junliang Sun ◽  
Cheng Wang
Keyword(s):  
Solid State ◽  
Three Dimensional ◽  
Molecular Switches ◽  
Pore Channel ◽  
Pore Surface ◽  
Stimuli Responsive ◽  
Conversion Yield ◽  
Responsive Materials ◽  
Reversible Transformation ◽  
Internal Pore

Abstract The tuning of molecular switches in solid state toward stimuli-responsive materials has attracted more and more attention in recent years. Herein, we report a switchable three-dimensional covalent organic framework (3D COF), which can undergo a reversible transformation through a hydroquinone/quinone redox reaction while retaining the crystallinity and porosity. Our results clearly show that the switching process gradually happened through the COF framework, with an almost quantitative conversion yield. In addition, the redox-triggered transformation will form different functional groups on the pore surface and modify the shape of pore channel, which can result in tunable gas separation property. This study strongly demonstrates 3D COFs can provide robust platforms for efficient tuning of molecular switches in solid state. More importantly, switching of these moieties in 3D COFs can remarkably modify the internal pore environment, which will thus enable the resulting materials with interesting stimuli-responsive properties.

Solid state 13C NMR and high temperature 1H NMR determination of bulk structural properties for mesophase-containing semi-cokes prepared from coal tar pitch

Carbon ◽  
1998 ◽  
Vol 36 (7-8) ◽  
pp. 1043-1050 ◽  
Author(s):  
J.M. Andrésen ◽  
Y. Martín ◽  
S.R. Moinelo ◽  
M.M. Maroto-Valer ◽  
C.E. Snape
Keyword(s):  
High Temperature ◽  
Solid State ◽  
Structural Properties ◽  
1H Nmr ◽  
13C Nmr ◽  
Coal Tar ◽  
Coal Tar Pitch ◽  
Solid State 13C Nmr

scholarly journals ISOLASI SENYAWA ALKALOID TURUNAN FUROKUINOLIN DARI RANTING Toddalia asiatica L. DAN UJI AKTIVITAS ANTIKANKER

2019 ◽  
Vol 3 (2) ◽  
pp. 102
Author(s):  
Mulyadi Tanjung ◽  
Devina Oktari Rahayu ◽  
Tjitjik Srie Tjahjandarie
Keyword(s):  
Anticancer Activity ◽  
Cancer Cells ◽  
1H Nmr ◽  
13C Nmr ◽  
Room Temperature ◽  
Spectroscopic Analysis ◽  
2D Nmr ◽  
Activity Test ◽  
Key Word ◽  
Toddalia Asiatica

AbstrakToddalia asiatica merupakan tumbuhan perdu yang tersebar di Afrika, Asia, Madagascar, dan Australia (Hu et al., 2015). Senyawa metabolit sekunder yang ditemukan tumbuhan Toddalia asiatica L. adalah alkaloid. Ekstraksi senyawa alkaloid dari tumbuhan Toddalia asiatica L. dengan cara maserasi menggunakan pelarut metanol pada suhu kamar. Proses isolasi dilakukan melalui fraksinasi dan pemurnian menggunakan kromatografi kolom gravitasi, dan kromatografi radial. Hasil isolasi yang didapatkan merupakan senyawa alkaloid turunan furokuinolin yaitu skimmianin. Struktur senyawa alkaloid turunan furokuinolin yang  diketahui melalui analisa hasil spektroskopi UV, IR, 1D NMR (1H-NMR dan 13C-NMR),  serta 2D NMR (HMBC dan HMQC) dan uji aktivitas antikanker terhadap sel kanker murin leukemia P-388. Kata kunci : Alkaloid turunan furokuinolin, skimmianin, Toddalia asiatica L., antikanker AbstractToddalia asiatica L. is a bushy plant that spreads in Africa, Asia, Madagascar, and Australia (Hu et al., 2015). The secondary metabolite compound found in Toddalia asiatica L. is alkaloid. Extraction of alkaloid compounds from Toddalia asiatica L. by maceration using methanol at room temperature. The isolation process is diluted by fractionation and purification using column chromatography of gravity and radial chromatography. The result  of isolation is an alkaloid compound derived furokuinolin, skimmianin. The structure of alkaloid compounds derived from furokuinolin known through spectroscopic analysis including UV, IR, 1D NMR (1H-NMR and 13C-NMR), and 2D NMR (HMBC and HMQC) and the anticancer activity test against the cancer cells murine P-388.Key word :    Alkaloid  compound  derived  furokuinolin,  skimmianin,  Toddalia asiatica L., anticancer

scholarly journals THE PORIFERASTA COMPOUND-5,22E,25-TRIEN-3-Oβ FROM Clerodendrum paniculatum LEAF AS INDUCER AGENT OF SYSTEMIC RESISTANCE ON RED CHILLI PLANT Capsicum annuum L FROM CUCUMBER MOSAIC VIRUS (CMV

2010 ◽  
Vol 9 (3) ◽  
pp. 487-490
Author(s):  
Weny Musa ◽  
Hersanti Hersanti ◽  
Achmad Zainuddin ◽  
Roekmi-ati Tjokronegoro
Keyword(s):  
Cucumber Mosaic Virus ◽  
Mosaic Virus ◽  
Capsicum Annuum ◽  
1H Nmr ◽  
13C Nmr ◽  
Spectroscopic Data ◽  
2D Nmr ◽  
Systemic Resistance ◽  
Inhibition Activity ◽  
Chilli Plant

The poriferasta-5.22E.25-trien-3β-ol compound of leaves of this plant Clerodendrum paniculatum has activity as an inducer agent of plant systemic resistance of red plant toward Cucumber Mosaic Viruses (CMV), the inhibition activity compound shows 82% inhibition activity at 300 ppm. The structure of these compound were determined on the basis of spectroscopic data including UV, IR, 1H-NMR, 13C-NMR and 2D-NMR   Keywords: Poriferasta-5.22E.25-trien-3β-ol, Clerodendrum paniculatum, induction of systemic resistance, CMV

Two New Chalcone Glycoside Compounds from Viburnum lantana (Family Caprifoliaceae) and Antioxidant Activity of its Hydroalcoholic Extract

2019 ◽  
Vol 16 (2) ◽  
pp. 93-98
Author(s):  
Ali Shafaghat ◽  
Mohammad Shafaghatlonbar
Keyword(s):  
Antioxidant Activity ◽  
Ir Spectra ◽  
1H Nmr ◽  
13C Nmr ◽  
Natural Antioxidants ◽  
2D Nmr ◽  
Antioxidant Property ◽  
Hydroalcoholic Extract ◽  
First Time

In the present study, two novel chalcone glycosides, trans-3-ethoxy-4-O-(glucopyranoside) -2', 3', 4', 5', 6' -pentahydroxy chalcone (compound 1) and trans-3-methoxy-4-O-(glucopyranoside) -2', 3', 4', 5', 6' -pentahydroxy chalcone (compound 2) have been isolated from the leaves of Viburnum lantana L. The structures were elucidated by using 1H-NMR, 13C-NMR, 2D-NMR such as HMQC, HMBC and NOE experiments and UV-Vis, MS and IR spectra. The antioxidant property of hydroalcoholic extract was evaluated by DPPH style. The results revealed that the leave extract possesses significant antioxidant activity (IC50 = 52 µg/mL). This study indicates that hydroalcoholic extract of the leaves from this species is an important source of chalcone and flavonoid derivatives, as well as of useful natural antioxidants. These chalcone glycoside compounds were isolated for the first time from V. lantana leaves.

scholarly journals ISOLASI KUMARIN DARI KULIT BUAH LIMAU SUNDAI (Citrus nobilis Lour)

2017 ◽  
Vol 18 (02) ◽  
pp. 137-145
Author(s):  
Melindra Mulia
Keyword(s):  
Melting Point ◽  
Ir Spectra ◽  
Ethyl Acetate ◽  
1H Nmr ◽  
Column Chromatography ◽  
13C Nmr ◽  
Ethyl Acetate Extract ◽  
2D Nmr ◽  
White Needle ◽  
Pure White

Coumarin has been isolated and characteritated from rind of  Citrus nobilis Lour by maseration methode with methanol. After fractionation by n-hexane and ethyl acetate, collected the phase ethyl acetate which positive of coumarin. From ethyl acetate extract coumarin have been isolated by column chromatography. The isolation results was obtain 2,159 g of pure white needle-shape crystalline with the melting point of 126,2-127,60C. Structure of the isolated coumarine was elucidated by spectroscopic methodes, UV-Vis,13C-NMR, 1H-NMR, 2D-NMR (DEPT/HSQC, COSY, NOESY, HMBC) and IR spectra. Based on the spectra data the isolated coumarine is marmin.

scholarly journals Synthesis of new optically pure isoxazolines via 1,3-dipolar cycloaddition of nitrile oxides with allyl esters derived from eugenol

2016 ◽  
Vol 12 (4) ◽  
pp. 4333-4337 ◽  
Author(s):  
Ghada Lahouar ◽  
Amira Bahy ◽  
Ridha Touati ◽  
Bechir Ben hassine
Keyword(s):  
1H Nmr ◽  
13C Nmr ◽  
Chemical Structure ◽  
2D Nmr ◽  
Dipolar Cycloaddition ◽  
Nmr Analysis ◽  
Allyl Ester ◽  
Optically Pure ◽  
Tof Ms ◽  
Allyl Esters

1,3-dipolar cycloaddition of arylnitrile oxides with allyl ester prepared from eugenol afforded new chiral isoxazolines in good yields. The chemical structure of this compounds was characterized by 1H NMR,13C NMR, 2D NMR and TOF-MS analysis. All the cycloadducts were obtained through a regiospecific and stereospecific pathway and all cases, only one isomer was isolated, as established by unambiguous NMR analysis

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