NMR spectroscopy

Spectroscopy Analysis of Natural

Products-1

21.01.2014 EFG-704

By Omer Bayazeid

Introduction:

Origanum vulgare (Lamiaceae) is a perennial herb distributed in Europe,NorthAfrica,America and Asia.

The herb is widely used as a spice in Western diets, and is also commonly used as a traditional medicine for the treatment of various diseases, such as cold, cough, and digestive disorders.

The plant is known for its powerful antimicrobial and antioxidant activities.

The antimicrobial activity of O. vulgare is due to its high content of volatile oils.

The phenolic compounds including flavonoids and phenolic acids, another kind of constituent in O. vulgare, are responsible for its antioxidant activity.

In their work, they report the isolation of six new phenolic compounds (1–6) from O. vulgare, along with known ones:2,5-dihydroxybenzoic acid, 3,4-dihydroxybenzoic acid, rosmarinic acid, origanoside.

The structures of the new compounds were identified with spectroscopic analyses and acid hydrolysis experiments.

Plant material:

Whole plants of O. vulgare were collected in China, in September 2012.

Extraction and isolation:

The air-dried whole plants of O. vulgare (10.0 kg) were powdered and percolated with 95% (V/V) ethanol solution at room temperature. For Isolation Column chromatography and TLC was performed using precoated silica gel GF254 plates.

Identification of Compounds:

Compound-1:

4-[[(2’,5’-dihydroxybenzoy- l)oxy]methyl] phenyl-O-b-D-glucopyranoside

Carbon No.

Type of

Carbon

13C Signal δ/ppm

1H signalδ/ppm

1 Cq 157.3 -

2,6 CH 116.3 7.05 (d,8.6)

3,5 CH 129.7 7.37 (d,8.4)

4 Cq 129.8 -

7 CH2 065.4 5.16 (s)

Ring A

Carbon No.

Type of

Carbon

13C Signal δ/ppm

1H signalδ/ppm

1’ Cq 120.6 -

2’ Cq 150.6 -

3’ CH 115.5 6.81 (d, 8.3)

4’ CH 122.0 7.34 (dd, 8.3,2.1)

5’ Cq 145.1 -

6’ CH 116.3 7.38 (d, 2.1)

7’ Cq 165.6 -

Ring B

Carbon No.

Type of

Carbon

13C Signal δ/ppm

1H signalδ/ppm

1’’’ CH 100.4 4.89 (d,7.4)

2’’’ CH 73.3 3.26 (m)

3’’’ CH 76.7 3.34 (m)

4’’’ CH 69.8 3.18 (m)

5’’’ CH 77.1 3.27 (m)6’’’ CH2 60.8 3.70(m)

3.74(m)

Sugar Part

D-glucose

HMBC

The NMR data of ring B were identical to those of 2,5-dihydroxy- benzoic acid ,suggesting ring B had two hydroxyls at C-2’ and C-5’ positions, respectively.  It was also confirmed by the 1H–1H COSY and HMBC correlations

Identification of Compounds:

Compound-2:

4-[[(3’,4’-dihydroxybenzoyl)oxy]methyl]phenyl-O-B-D-[6-O-(3’’,5’’-dimethoxyl-4’’-hydrox- ybenzoyl)] glucopyranoside

Carbon No.

Type of

Carbon

13C Signal δ/ppm

1H signalδ/ppm

1 Cq 159.0 -

2,6 CH 117.9 7.03 (d,8.6)

3,5 CH 130.7 7.18 (d,8.6)

4 Cq 132.0 -

7 CH2 067.1 5.16 (s)

Ring A

Carbon No.

Type of

Carbon

13C Signal

δ/ppm

1H signalδ/ppm

1’ Cq 122.9 -

2’ CH 117.6 7.47 (d)

3’ Cq 146.3 -

4’ Cq 152.0 -

5’ CH 116.1 6.85 (d, 8.0)

6’ CH 123.9 7.48 (dd, 8.0,2.4)

7’ Cq 168.3 -

Ring B

Carbon No.

Type of

Carbon

13C Signal δ/ppm

1H signalδ/ppm

1’’ Cq 121.5 -

2’’,6’’

CH 108.7 7.33 (s)

3’’,5’’

Cq 149.1 -

4’’ Cq 142.4 -

7’’ Cq 168.0 -

3’’,5’-OMe

CH3 057.1 3.83 (s)

Ring C

Sugar Part Carbon No.

Type of

Carbon

13C Signal δ/ppm

1H signalδ/ppm

1’’’ CH 102.3 4.93 (d,7.4)

2’’’ CH 75.0 3.81 (m)

3’’’ CH 78.1 3.51 (m)

4’’’ CH 72.3 3.51 (m)

5’’’ CH 75.8 3.79 (m)

6’’’ CH2 65.4 4.73 (m) 4.42 (m)

D-glucose

HMBC

The HMBC correlations between δH 4.73 (H-6’’’) and δC 168 (C-7’’) suggested the benzoyl was connected to C-6’’’ through an ester bond.

The positions of methoxy groups were elucidated by the HMBC correlations.

Identification of Compound:

Compound-3:

acacetin 7-O-[4’’’O-acetyl-b-D-apiofuransyl-(1 -3)]- b-D-xylopyranoside

Ring ACarbon No.

Type of Carbon

13C Signal

δ/ppm

1H signalδ/ppm

2 Cq 163.8 -

3 CH 103.8 6.95 (s)

4 Cq 182.0 -

5 CH 161.1 12.91 (s)

6 CH 099.1 6.38 (d, 2.0)

7 Cq 162.4 -

8 CH 094.4 6.81 (d, 2.0)

9 Cq 157.0 -

10 Cq 105.4 -

Carbon No.

Type of

Carbon

13C Signal

δ/ppm

1H signalδ/ppm

Ring B1’ Cq 122.6 -

2’,6’ Cq 128.4 8.08 (br d, 8.8)

3’,5’ CH 114.6 7.12 (br d, 8.8)

4’ Cq 162.5 -

4’-OMe

Cq 55.6 3.88 (s)

D-xylose

D-apiose

Carbon No.

Type of

Carbon

13C Signal δ/ppm

1H signalδ/ppm

1’’ CH 98.2 5.20 (d,7.6)

2’’ CH 75.3 3.52 (m)

3’’ CH 76.5 3.43 (m)

4’’ CH 69.4 3.41 (m)

5’’ CH2 65.7 3.76 (m)3.42 (m)

Sugar Part 1

Sugar Part 2

Carbon No.

Type of

Carbon

13C Signal δ/ppm

1H signalδ/ppm

1’’’ CH 108.2 5.38 (br s)

2’’’ CH 76.7 3.43 (m)

3’’’ Cq 77.2 -

4’’’ CH2 73.8 3.98 (m)3.73 (m)

5’’’ CH 67.0 3.92 (s)

Ac CqCH3

169.920.3

-1.82 (s)

HMBC

Identification of Compounds:

Compound-4/5:

apigenin 7-O-[6’’’- O-acetyl-b-D-galactopyranosyl-(1 -3)]-b-D-xylopyranoside.

Ring ACarbon No.

Type of Carbon

13C Signal

δ/ppm

1H signalδ/ppm

2 Cq 164.3 -

3 CH 103.1 6.95 (s)

4 Cq 182.0 -

5 CH 161.1 12.91 (s)

6 CH 099.5 6.38 (d, 2.0)

7 Cq 162.6 -

8 CH 094.7 6.81 (d, 2.0)

9 Cq 156.9 -

10 Cq 105.4 -

Carbon No.

Type of

Carbon

13C Signal

δ/ppm

1H signalδ/ppm

Ring B1’ Cq 121.0 -

2’,6’ Cq 128.6 8.08 (br d, 8.8)

3’,5’ CH 116.0 7.12 (br d, 8.8)

4’ Cq 161.4 -

4’-OMe

Cq 55.6 3.88 (s)

Carbon No.

Type of

Carbon

13C Signal δ/ppm

1H signalδ/ppm

1’’ CH 98.7 5.24 (d,7.6)

2’’ CH 75.4 3.52 (m)

3’’ CH 82.7 3.42 (m)

4’’ CH 68.8 3.41 (m)

5’’ CH2 65.6 3.76 (m)3.42 (m)

Sugar Part 1

D-xylose

Sugar Part 2

Carbon No.

Type of

Carbon

13C Signal δ/ppm

1H signalδ/ppm

1’’’ CH 104.7 4.51 (d,7.6)

2’’’ CH 74.5 3.05 (m)

3’’’ CH 75.9 3.24 (m)

4’’’ CH 69.7 3.06 (m)

5’’’ CH 73.7 3.42 (m)

6’’ CH2 63.5 3.99 (m)4.09 (m)

Ac CqCH3

170.320.3

-1.82 (s)

D-glactose

HMBC

Identification of Compound:

Compound-6:

Ring ACarbon No.

Type of Carbon

13C Signal

δ/ppm

1H signalδ/ppm

2 Cq 163.8 -

3 CH 103.1 6.95 (s)

4 Cq 182.0 -

5 CH 161.1 12.91 (s)

6 CH 099.6 6.38 (d, 2.0)

7 Cq 162.5 -

8 CH 094.9 6.80 (d, 2.0)

9 Cq 156.9 -

10 Cq 105.4 -

Carbon No.

Type of

Carbon

13C Signal

δ/ppm

1H signalδ/ppm

Ring B1’ Cq 122.7 -

2’,6’ Cq 128.4 8.08 (br d, 8.8)

3’,5’ CH 114.6 7.12 (br d, 8.8)

4’ Cq 162.9 -

4’-OMe

Cq 55.6 3.87 (s)

Sugar Part 1

Carbon No.

Type of

Carbon

13C Signal δ/ppm

1H signalδ/ppm

1’’ CH 98.3 5.24 (d,6.3)

2’’ CH 83.3 3.51 (m)

3’’ CH 75.6 3.22 (m)

4’’ CH 69.1 3.26 (m)

5’’ CH2 77.0 3.50 (m)3.42 (m)

6’’ CH2 60.5 3.73 (m)3.49 (m)

D-glucose

Sugar Part 2

Carbon No.

Type of

Carbon

13C Signal δ/ppm

1H signalδ/ppm

1’’’ CH 104.7 4.52(d, 7.6)

2’’’ CH 74.6 3.02 (m)

3’’’ CH 75.9 3.51 (m)

4’’’ CH 69.7 3.09 (m)

5’’’ CH 73.7 3.42 (m)

6’’’ CH2 63.6 3.99 (m)4.13 (m)

Ac Cq CH3

170.320.3

-1.82 (s)

D-glactose

Thank You…