DR ANTHONY MELVIN CRASTO

DR ANTHONY MELVIN CRASTO

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4,6,7,8,9,10-hexahydro-1H-6,10-methanopyrazino[2,3-h][3]benzazepine-2,3-dione.

 

 

An external file that holds a picture, illustration, etc. Object name is scipharm-2012-80-329f2.jpg

 

 

 

Chemical structures of Varenicline Tartrate and degradant product (DP-I).........4,6,7,8,9,10-hexahydro-1H-6,10-methanopyrazino[2,3-h][3]benzazepine-2,3-dione.

An external file that holds a picture, illustration, etc. Object name is scipharm-2012-80-329f4.jpg

(A) 1H NMR spectrum of DP-I. (B) Proton decoupled 13C NMR spectrum of DP-I.

 

An external file that holds a picture, illustration, etc. Object name is scipharm-2012-80-329f5.jpg

UHPLC-ToF MS+ of DP-I.

 

 

The impurity obtained as pale white crystals. mp 71–73. 

RP-UHPLC, tR = 1.8 min (98.5% purity).


MS (ESI, 70 eV): [M + H+] m/z 244. 


FT-IR (KBr), v, cm−1 3371, 3319, 3279, 3173, 3005, 2808, 1696, 1678, 1588, 1406, 1388, 1338, 1305, 1264, 1135, 1067, 873, 790, 680, 569, 485.


1H NMR (400 MHz, DMSO-d6 +D2O, TMS): δ 7.2 (s, 2H, H-7,8), 3.1–3.4 (m, 6H, H-11,13,14 & 16),2.3 (m, 1H, H-12), 2.0 (d, 1H, 11.2 Hz, H-12).


13C NMR (100 MHz, DMSO-d6, TMS): δ 173.8 (C-2,3), 155.1 (C-5,6), 137.6 (C-9,10), 125.1 (C-7,8), 38.8 (C-11), 37.9 (C-12), 38.8 (C-13), 45.8 (C-14), 48.6 (C-16).


UHPLC ToF MS+: m/z [M + H+].Calcd for C13H13N3O2: 244.1086; found: 244.1082.

 

Based on the above spectral data, the molecular formula of DP-I is C13H13N3O2 and the corresponding structure was characterized as 4,6,7,8,9,10-hexahydro-1H-6,10-methanopyrazino[2,3-h][3]benzazepine-2,3-dione.

PMC full text:

Published online 2012 Mar 20. doi:  10.3797/scipharm.1201-08

http://dx.doi.org/10.3797/scipharm.1201-08

 

An external file that holds a picture, illustration, etc. Object name is scipharm-2012-80-329f2.jpg

 

 

 

Chemical structures of Varenicline Tartrate and degradant product (DP-I).........4,6,7,8,9,10-hexahydro-1H-6,10-methanopyrazino[2,3-h][3]benzazepine-2,3-dione.

An external file that holds a picture, illustration, etc. Object name is scipharm-2012-80-329f4.jpg

(A) 1H NMR spectrum of DP-I. (B) Proton decoupled 13C NMR spectrum of DP-I.

 

An external file that holds a picture, illustration, etc. Object name is scipharm-2012-80-329f5.jpg

UHPLC-ToF MS+ of DP-I.

 

 

The impurity obtained as pale white crystals. mp 71–73. 

RP-UHPLC, tR = 1.8 min (98.5% purity).


MS (ESI, 70 eV): [M + H+] m/z 244. 


FT-IR (KBr), v, cm−1 3371, 3319, 3279, 3173, 3005, 2808, 1696, 1678, 1588, 1406, 1388, 1338, 1305, 1264, 1135, 1067, 873, 790, 680, 569, 485.


1H NMR (400 MHz, DMSO-d6 +D2O, TMS): δ 7.2 (s, 2H, H-7,8), 3.1–3.4 (m, 6H, H-11,13,14 & 16),2.3 (m, 1H, H-12), 2.0 (d, 1H, 11.2 Hz, H-12).


13C NMR (100 MHz, DMSO-d6, TMS): δ 173.8 (C-2,3), 155.1 (C-5,6), 137.6 (C-9,10), 125.1 (C-7,8), 38.8 (C-11), 37.9 (C-12), 38.8 (C-13), 45.8 (C-14), 48.6 (C-16).


UHPLC ToF MS+: m/z [M + H+].Calcd for C13H13N3O2: 244.1086; found: 244.1082.

 

Based on the above spectral data, the molecular formula of DP-I is C13H13N3O2 and the corresponding structure was characterized as 4,6,7,8,9,10-hexahydro-1H-6,10-methanopyrazino[2,3-h][3]benzazepine-2,3-dione.

PMC full text:

Published online 2012 Mar 20. doi:  10.3797/scipharm.1201-08

http://dx.doi.org/10.3797/scipharm.1201-08

ENDO EXO STORY.......cis-norborene-5,6-endo-dicarboxylic anhydride

 


6


You will react cyclopentadiene with maleic anhydride to form the Diels-Alder product below. This Diels-Alder reaction produces almost solely the endo isomer upon reaction at ambient temperature.


12

The preference for endo–stereochemistry is “observed” in most Diels-Alder reactions. The fact that the more hindered endo product is formed puzzled scientists until Woodward, Hoffmann, and Fukui used molecular orbital theory to explain that overlap of the p orbitals on the substituents on the dienophile with p orbitals on the diene is favorable, helping to bring the two molecules together.

Hoffmann and Fukui shared the 1981 Nobel Prize in chemistry for their molecular orbital explanation of this and other organic reactions. In the illustration below, notice the favorable overlap (matching light or dark lobes) of the diene and the substituent on the dienophile in the formation of the endo product:



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Oftentimes, even though the endo product is formed initially, an exo isomer will be isolated from a Diels-Alder reaction. This occurs because the exo isomer, having less steric strain than the Endo , is more stable, and because the Diels-Alder reaction is often reversible under the reaction conditions. In a reversible reaction, the product is formed, reverts to starting material, and forms again many times before being isolated.

The more stable the product, the less likely it will be to revert to the starting material. The isolation of an exo product from a Diels-Alder reaction is an example of an important concept: thermodynamic vs kinetic control of product composition. The first formed product in a reaction is called the kinetic product. If the reaction is not reversible under the conditions used, the kinetic product will be isolated. However, if the first formed product is not the most stable product and the reaction is reversible under the conditions used, then the most stable product, called the thermodynamic product, will often be isolated.



The NMR spectrum of  cis-5-norbornene-2,3- endo-dicarboxylic anhydride is given below:
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Cis-Norbornene-5,6-endo-dicarboxylic anhydride 
Cyclopentadiene was previously prepared through the cracking of dicyclopentadiene and kept under cold conditions.  In a 25 mL Erlenmeyer flask, maleic anhydride (1.02 g, 10.4 mmol) and ethyl acetate (4.0 mL) were combined, swirled, and slightly heated until completely dissolved.  To the mixture, ligroin (4 mL) was added and mixed thoroughly until dissolved.  Finally, cyclopentadiene (1 mL, 11.9 mmol) was added to the mixture and mixed extensively.  The reaction was cooled to room temperature and placed into an ice bath until crystallized.  The crystals were isolated through filtration in a Hirsch funnel.  The product had the following properties: 0.47 g (27.6% yield) mp: 163-164 °C (lit: 164 °C).  1H NMR (CDCl3, 300 MHz) δ: 6.30 (dd, J=1.8 Hz, 2H), 3.57 (dd, J=7.0 Hz, 2H), 3.45 (m, 2H), 1.78 (dt, J=9.0,1.8 Hz, 1H), 1.59 (m, 1H) ppm.  13C NMR (CDCl3, 75Hz) δ: 171.3, 135.5, 52.7, 47.1, 46.1 ppm.  IR 2982 (m), 1840 (s), 1767 (s), 1089 (m) cm-1.





Reaction Mechanism The scheme below depicts the concerted mechanism of the Diels-Alder reaction of cyclopentadiene and maleic anhydride to formcis-Norbornene-5,6-endo-dicarboxylic anhydride.



diels-alder reaction

Results and Discussion 
When combining the reagents, a cloudy mixture was produced and problems arose in the attempt to completely dissolve the mixture.  After heating for about 10 minutes and magnetically stirring, tiny solids still remained. The undissolved solids were removed form the hot solution by filtration and once they cooled, white crystals began to form. Regarding the specific reaction between cyclopentadiene and maleic anhydride, the endo isomer, the kinetic product, was formed because the experiment was directed under mild conditions.   The exo isomer is the thermodynamic product because it is more stable.3
A total of 0.47 g of the product was collected; a yield of 27.6%. The melting point was in the range of 163-164 °C which indicates the absence of impurities because the known melting point of the product is 164 °C.
Cis-Norbornene-5-6-endo-dicarboxylic anhydride

 
The 1H NMR spectrum of the product revealed a peak in the alkene range at 6.30 ppm, H-2 and H-3 (Figure 1).  In addition, it exhibited two peaks at 3.57 and 3.45 ppm because of the proximity of H-1, H-4, H-5, and H-6 to an electronegative atom, oxygen.  Finally, two peaks at 1.78 and 1.59 ppm corresponded to the sp3 hydrogens, Hb and Ha, respectively.  Impurities that appeared included ethyl acetate at 4.03, 2.03, and 1.31 ppm as well as acetone at 2.16 ppm.
Regarding the 13C NMR, a peak appeared at 171.3 ppm, accounting for the presence of two carbonyl functional groups, represented by C-7 and C-8 in Figure 1.  The alkene carbons, C-2 and C-3, exhibited a peak at 135.5 ppm, while the sp3 carbons close to oxygen, C-5 and C-6, displayed a peak at 52.7 ppm.  Finally, peaks at 46.1 and 47.1 ppm accounted for the sp3 carbons, C-1 and C-4, and C-9.  Impurities of ethyl acetate appeared at 46.6, 25.8, and 21.0 ppm accompanied with acetone at 30.9 ppm.
The IR spectrum revealed a peak at 2982 cm-1 representing the C-H stretches.  A peak at 1840 cm-1 accounted for the carbonyl functional group, while a peak at 1767 cm-1 accounted for the alkene bond.  A peak at 1089 cm-1 represented the carbon-oxygen functional group.
In order to distinguish between the two possible isomers, properties such as melting point and spectroscopy data were analyzed.  The exo product possessed a melting point in the range of 140-145 °C which is significantly lower than the endo product.  The observed melting point in this experiment supported the production of the endo isomer. 
The 1H NMR spectum exhibited a doublet of doublets at 3.57 ppm for the endo isomer.  The exo isomer would possess a triplet around 3.50 ppm due to the difference in dihedral angle between the hydrogen molecules of H-1 and H-4, and H-5 and H-6 (Figure 1).  A peak at 3.00 ppm would appear in the exo isomer spectra as opposed to a peak at 3.60 ppm as shown in the observed endo product.3 This is because of the interaction and coupling with the H-5 and H-6, as displayed in Figure 1.
 
Conclusion 
Through the Diels-Alder reaction, 27.6% yield of cis-Norbornene-5,6-endo-dicarboxylic anhydride was produced. The distinction of the presence of the endo isomer was proven by analyzing physical properties of both possible isomers.
Martin, J.; Hill, R.; Chem Rev, 196161, 537-562.
2 Pavia, L; Lampman, G; Kriz, G; Engel, R. A Small Scale Approach to Organic Laboratory   Techniques, 2011, 400-409.
3 Myers, K.; Rosark, J. Diels-Alder Synthesis, 2004, 259-265.
link 
http://orgspectroscopyint.blogspot.in/2014/08/cis-norborene-56-endo-dicarboxylic.html

ORGANIC SPECTROSCOPY INTERNATIONAL

Read all about Organic Spectroscopy onORGANIC SPECTROSCOPY INTERNATIONAL  

ANTHONY MELVIN CRASTO
THANKS AND REGARD’S
DR ANTHONY MELVIN CRASTO Ph.D
MOBILE-+91 9323115463
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Oleanolic acid spectral data and interpretation

  http://orgspectroscopyint.blogspot.in/2014/08/oleanolic-acid-spectral-data-and.html
Chemical structure for Oleanolic Acid Oleanolic acid

 

Oleanolic acid
(4aS,6aR,6aS,6bR,8aR,10S,12aR,14bS)-10-hydroxy-2,2,6a,6b,9,9,12a-heptamethyl-1,3,4,5,6,6a,7,8,8a,10,11,12,13,14b-tetradecahydropicene-4a-carboxylic acid

Oleanic acid, Caryophyllin, Astrantiagenin C, Giganteumgenin C, Virgaureagenin B, 3beta-Hydroxyolean-12-en-28-oic acid, OLEANOLIC_ACID
Molecular Formula: C 30H 48O 3
Molecular Weight: 456.70032

http://orgspectroscopyint.blogspot.in/2014/08/oleanolic-acid-spectral-data-and.html

Ursolic acid [(3b)-3-Hydroxyurs-12-en-28-oic acid] rarely occurs without its isomer oleanolic acid [(3b)-3-Hydroxyolean-12-en-28-oic acid] They may occur in their free acid form, as shown in Figure 1, or as aglycones for triterpenoid saponins which are comprised of a triterpenoid aglycone linked to one or more sugar moieties. Ursolic and oleanolic acids are similar in pharmacological activity

A pentacyclic triterpene that occurs widely in many PLANTS as the free acid or the aglycone for many SAPONINS. It is biosynthesized from lupane. It can rearrange to the isomer, ursolic acid, or be oxidized to taraxasterol and amyrin.

MS
EIMS m/z (rel. int.) 456 [M]+ (5), 412 (3), 248 (100), 203 (50), 167 (25), 44 (51)

IR KBR
(KBr) 3500, 2950, 2850, 1715; 1H-NMR (250 MHz, pyridine-d5) δ: 5.49 (1H, s, H-12), 3.47 (1H, t, J = 8.0 Hz, H-3), 3.30 (1H, m, H-18), 1.12 (3H, s, CH3-27), 0.96 (3H, s, CH3-30), 0.91 (3H, s, CH3-25), 0.89 (3H, s, CH3-23), 0.87 (3H, s, CH3-24), 0.75 (3H, s, CH3-26)

http://orgspectroscopyint.blogspot.in/2014/08/oleanolic-acid-spectral-data-and.html

1H NMR

 
(250 MHz, pyridine-d5)δ: 5.49 (1H, s, H-12), 3.47 (1H, t, J = 8.0 Hz, H-3), 3.30 (1H, m, H-18), 1.12 (3H, s, CH3-27), 0.96 (3H, s, CH3-30), 0.91 (3H, s, CH3-25), 0.89 (3H, s, CH3-23), 0.87 (3H, s, CH3-24), 0.75 (3H, s, CH3-26)

 

13 C NMR

 
(63 MHz, pyridine-d5) δ: 180.2 (C-28), 144.8 (C-13), 122.5 (C-12), 78.0 (C-3), 55.7 (C-5), 48.0 (C-9), 46.6 (C-8, 17), 42.1 (C-14), 39.7 (C-4), 39.4 (C-1), 37.3 (C-10), 33.2 (C-7), 32.9 (C-29), 32.4 (C-21), 30.9 (C-20), 28.7 (C-23), 27.2 (C-2), 26.9 (C-15), 26.1 (C-30), 23.7 (C-11), 23.6 (C-16), 18.7 (C-6), 17.4 (C-26), 16.5 (C-24), 15.5 (C-25)

http://orgspectroscopyint.blogspot.in/2014/08/oleanolic-acid-spectral-data-and.html

http://www.google.com/patents/US20120237629

FIG. 4 shows the  1H NMR spectrum of oleanolic acid;
FIG. 5 shows the  13C NMR spectrum of oleanolic acid;
FIG. 6 shows the  13C DEPT NMR spectrum of oleanolic acid;
FIG. 7 shows the  113C HSQC NMR spectrum of oleanolic acid;
 
see below

http://orgspectroscopyint.blogspot.in/2014/08/oleanolic-acid-spectral-data-and.html

EXAMPLE 2 Extraction and Isolation of Oleanolic Acid (9) and Maslinic Acid (10) from Cloves

Syzygium aromaticum dried buds or whole cloves were obtained commercially. The cloves (1.5 kg, whole) of  Syzygium aromaticum were sequentially and exhaustively extracted with hexane and ethyl acetate to give, after solvent removal in vacuo, a hexane extract (68.8 g, 4.9%) and an ethyl acetate extract (34.1 g, 2.3%). A portion of the ethyl acetate extract (10.0 g), was subjected to chromatographic separation on silica gel (60-120 mesh) column (40×5.0 cm). Elution with hexane/ethyl acetate solvent mixtures (8:2→6:4) afforded pure oleanolic acid (9) (4.7 g, 1.06%), a mixture of oleanolic acid (9) and maslinic acid (10) (0.5 g), and pure maslinic acid (10) (0.25 g). The structures of oleanolic acid (9) and maslinic acid (10) (as 2,3-diacetoxyoleanolic acid) were confirmed by spectroscopic data analysis (1D and 2D  1H NMR and  13C NMR experiments) (FIGS. 4-7 and FIGS. 8-10, respectively).
 
 
 
 
 
 
 
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ANTHONY MELVIN CRASTO

THANKS AND REGARD’S
DR ANTHONY MELVIN CRASTO Ph.D

amcrasto@gmail.com

MOBILE-+91 9323115463
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ARAB MEDICINE- Alyeadah (Teucrium Stocisianum Bois)

 

 Tree Germander (Teucrium fruticans)

This plant is used in folk medicine for treating diarrhea, cough, jaundice and abdominal pain

Medicinal plants are used for the treatment of different diseases in almost all cultures. Teucrium species grow wildly at different geographical locations around the world. Teucrium stocksianum is used in folk medicine for the treatment of diarrhea, cough, jaundice and abdominal pain. Scientific study on Teucrium stocksianum shows that it possesses anthelmintic, cytotoxic and antispasmodic activity. The aim of our present study is to identify the chemical composition and antinociceptive potential of the essential oil extracted from Teucrium stocksianum bioss.

Teucrium is a genus of perennial plants in the family Lamiaceae. The name is believed to refer to King Teucer of Troy. Members of the genus are commonly known as germanders. These species are herbs, shrubs or subshrubs. They are most common in Mediterranean climates.

An unusual feature of this genus compared with other members of Lamiaceae is that the flowers completely lack the upper lip of thecorolla, although it is somewhat reduced also in other genera (Ajuga among them).

Several species are used as food plants by the larvae of some Lepidoptera species including the Coleophora case-bearersColeophora auricella and Coleophora chamaedriella. The latter is only known from Wall Germander (T. chamaedrys).

Teucrium species are rich in essential oils. They are valued as ornamental plants and a pollen source, and some species have culinary and/or medical value.

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