1 H, 13 C-Nmr Spectrum Data Of At3 (Cd 3 Od, 500/125Mhz)

at δ H 3.51 and 3.42 (each signal 1H, dt , J = 10.5); an oxymethine group at δ H 3.86 (1H, dt, J = 11.0 and 5.0 Hz) and 5 singlets of five methyl groups at δ H 0.95; 1.04; 1.09; 1.10; 1.75 ppm. The 13C and DEPT spectra showed that the molecule contained 30 carbons, including

consisting of a ketone group at δ C 220.9; a carboxylic acid group at δ C 179.8; a double bond at δ C 151.5 and 110.6; a hydroxymethine group at δ C 71.1; a hydroxymethylene group at δ C 68.5; five methyl group signals at δ C 14.8; 17.2; 17.3; 17.4; 19.7 ppm; nine methylene groups, five methine groups and five quaternary carbons. From the above spectral data, it can be seen that compound AT3 is a lupane triterpene acid.

Table 4.11. 1 H, 13 C-NMR spectral data of AT3 (CD 3 OD, 500/125MHz)

Location

δH	δC	Location	δH	δC
1	2.39 ( m, 1H) 2.47 ( m, 1H)	37.2	16	1.48 ( m, 1H) 2.29 ( m, 1H)	33.3
2	1.68 ( m, 1H) 2.78 ( m, 1H)	41.8	17	-	57.4
3	-	220.9	18	1.72 ( m, 1H)	50.0
4	-	54.0	19	3.08 ( dt, J = 10.5;4.5, 1H)	48.2
5	2.04 ( m, 1H)	48.5	20	-	151.5
6	1.45 ( m, 2H)	20.6	21	1.54 ( m, 1H) 1.95 ( m, 1H)	37.9
7	1.47 ( m, 1H) 1.98 ( m, 1H)	31.7	22	1.52 ( m, 2H)	35.1
8	-	43.4	23	3.42;3.51 ( d AB , J = 10.5 , 2H)	68.5
9	1.64 ( d, J = 11.0 , 1H)	55.5	24	0.95 ( s , 3H)	17.4
10	-	39.1	25	1.04 ( s , 3H)	17.3
11	3.86 ( dt, J = 11.0;5.0 , 1H)	71.1	26	1.10 ( s , 3H)	17.2
12	1.32 ( m, 1H) 2.02 ( m, 1H)	38.3	27	1.09 ( s , 3H)	14.8
13	2.53 ( m, 1H)	38.6	28	-	179.8
14	-	43.4	29	4.65 ( br s, 1H) 4.79 ( br s, 1H)	110.6
15	1.25 ( m, 1H) 1.47 ( m, 1H)	30.8	30	1.75 ( s , 3H)	19.7

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The positions of hydroxyl and carboxylic acid groups were determined based on 2D-NMR spectra such as HSQC, HMBC, HH COSY and comparison with the literature. A hydroxyl group was attached at C-11 based on the interactions of H-11 (δ H 3.86) with H-9 (δ H 1.64) and H-12 (δ H 1.32 and 2.02) in the HH COSY spectrum. The interaction constant of H-9 with H-11 is J 11.9 = J ax,ax = 11.0 Hz, indicating that this hydroxyl group has an α configuration . The HMBC spectrum of AT3 shows interactions between the protons of the hydroxymethylene group (δ H 3.41 and 3.51) with C-3 (δ C 220.9), C-4 (δ C 54.0), C-5 (δ C 48.5) and the methyl group at C-4 (δ C 17.4). From these spectral data, it can be predicted that the hydroxymethylene group can be attached to position C-23 or C-24. , 1 , 2 ) ; and C-17 (δ C 57.4) with H-15 (δ H 1.52), H-16 (δ H 2.29) on HMBC spectrum ( Figure 4.34 ).

H 2

COUGH

11 26

H H

19 21

17 H 2

2 16

COOH

10 H 8

3 5

O HO

4 6

23 24

H 2

SY MBC

Figure 4.37. Some main interactions on the COSY and HMBC spectra of AT3

From the spectral data analyzed above, the structure of AT3 was determined to be 11α , 23-dihydroxy-3-oxo-lup-20(29)-ene-28-oic acid. This is a new compound, isolated and structurally determined for the first time.

Figure 4.38. FT-IR spectrum of AT3

[M+H] +

Figure 4.39. HR-ESI-MS spectrum (positive ion) of AT3

Figure 4.40. 1 H-NMR spectrum of AT3 ( 500 MHz, CD 3 OD)

Figure 4.41. 1 H-NMR spectrum (relaxation) of AT3 (500 MHz, CD 3 OD)

Figure 4.42. 13 C-NMR and DEPT spectrum of AT3 (125 MHz, CD 3 OD)

Figure 4.43. HSQC spectrum of AT3

Figure 4.44. HMBC spectrum of AT3

Figure 4.45. COSY spectrum of AT3

*** Comments on the chemical composition of the species Ngũ gia bì hương

Three lupane-frame triterpene compounds: 24-nor-11 α -hydroxy-3-oxo-lup-20(29)- ene-28-oic acid ( AT1 ), 24-nor-3 α ,11 α -dihydroxy-lup-20(29)-ene-28-oic acid ( AT2 ), 11 α ,23-dihydroxy-3-oxo-lup-20(29)-ene-28-oic acid ( AT3 ) were isolated and structurally determined from the species of Acanthopanax aculeatus collected in Mai Chau district, Hoa Binh province. In which AT3 is a new substance; The two known substances AT1, AT2 ( AT1 is substance 21 and AT2 is substance 20 isolated by Ph.D.Ty's research group in 1985) have quite high content (0.26% and 0.25% respectively compared to the dry sample). Therefore, we used AT1 and AT2 as starting materials to synthesize new derivatives and study their biological activities.

4.2.2. Chemical derivatives of compounds AT1, AT2

With the aim of synthesizing and searching for new active substances, 23 new derivatives were synthesized from three isolated compounds ( AT1, AT2, AT3) . These derivatives were surveyed for activity to find highly active substances for applied research.

From the two substances AT1 and AT2, we have synthesized 23 derivatives, of which AT1 has 5 derivatives converted at the 11-OH group , and 8 derivatives at both the 11-OH and 28-COOH groups; from AT2, we have synthesized 1 derivative converted at the two groups 3-OH and 11-OH, 7 derivatives converted at the three groups 3-OH, 11-OH and 28-COOH, and 2 derivatives converted at the 28-COOH group.

4.2.2.1. Derivatives of AT1

Scheme 4.1. Synthesis of derivatives of AT1

4.2.2.1.1.Ester derivatives of AT1

The OH group at C-11 position of AT1 was acylated with anhydrides such as acetic anhydride, phthalic anhydride , glutaric anhydride, succinic anhydride in pyridine at room temperature or in pyridine in the presence of 4-DMAP catalyst at 60 0 C to obtain esters AT4, AT5, AT6, AT7 with respective yields of 85%, 65%, 67%,

65%: