Caryopristimerin, the First Example of a Sesquiterpene-Triterpene Homo Diels-Alder Adduct, and a New 29-nor-Friedelane from Roots of Salacia crassifolia

Two new compounds, caryopristimerin and 2α,3α,22β-trihydroxy-21-oxo-29-nor-friedelan-24-oic acid, were isolated from the hexane/ethyl ether extract of Salacia crassifolia roots. Caryopristimerin represents the first example of a homo Diels-Alder adduct of a sesquiterpene and a triterpene, and the new 29-nor-friedelane displays a highly oxygenated A ring with a carboxylic group at the unusual C-5 position. The new compounds were elucidated by infrared (IR), high-resolution-atmospheric pressure chemical ionization-mass spectrometry (HR-APCI-MS), 1D/2D nuclear magnetic resonance (NMR) and single crystal X-ray diffraction analysis. Additionally, the known compounds 3-oxo-29-hydroxyfriedelane, pristimerin, tingenone and netzahualcoyonol are herein reported for the first time as constituents of S. crassifolia. Their structures were established by spectroscopic analysis.

Keywords:
Salacia crassifolia; Celastraceae; homo Diels-Alder adduct; sesquiterpene-triterpene dimer

Authorship

Josana P. dos Santos

Departamento de Química, Universidade Federal de Minas Gerais, Av. Presidente Antônio Carlos, 6627, Pampulha, 31270-901 Belo Horizonte-MG, BrazilUniversidade Federal de Minas GeraisBrazilBelo Horizonte, MG, BrazilDepartamento de Química, Universidade Federal de Minas Gerais, Av. Presidente Antônio Carlos, 6627, Pampulha, 31270-901 Belo Horizonte-MG, Brazil

Departamento de Química, Universidade Federal dos Vales do Jequitinhonha e Mucuri, Campus JK, Rodovia MGT 367, km 583, 5000, Alto da Jacuba, 39100-000 Diamantina-MG, BrazilUniversidade Federal dos Vales do Jequitinhonha e MucuriBrazilDiamantina, MG, BrazilDepartamento de Química, Universidade Federal dos Vales do Jequitinhonha e Mucuri, Campus JK, Rodovia MGT 367, km 583, 5000, Alto da Jacuba, 39100-000 Diamantina-MG, Brazil

Bernardo L. Rodrigues

Willian X. C. Oliveira

https://orcid.org/0000-0003-0722-5352

Fernando C. Silva

Grasiely F. de Sousa

https://orcid.org/0000-0001-7425-2604

Sidney A. Vieira Filho

Escola de Farmácia, Universidade Federal de Ouro Preto, Campus Morro do Cruzeiro, s/n, Bauxita, 35400-000 Ouro Preto-MG, BrazilUniversidade Federal de Ouro PretoBrazilOuro Preto, MG, BrazilEscola de Farmácia, Universidade Federal de Ouro Preto, Campus Morro do Cruzeiro, s/n, Bauxita, 35400-000 Ouro Preto-MG, Brazil

Lucienir P. Duarte ^** e-mail: lucienir@ufmg.br; roquelinersm@yahoo.com.br

https://orcid.org/0000-0002-8885-6625

Roqueline R. Silva ^** e-mail: lucienir@ufmg.br; roquelinersm@yahoo.com.br

* e-mail: lucienir@ufmg.br; roquelinersm@yahoo.com.br

SCIMAGO INSTITUTIONS RANKINGS

Figures | Tables

Figures (4)
Tables (2)

Thumbnail

Figure 1
Compounds 1-6 from S. crassifolia roots.

Thumbnail

Figure 2
X-ray crystal structure of 1. Some hydrogen atoms were omitted for better 3D visualization. Dotted lines represent relevant interactions observed in the NOESY spectrum.

Thumbnail

Scheme 1
Diels-Alder reaction and hypothetical pathway of 1.

Thumbnail

Figure 3
X-ray crystal structure of 2. Some hydrogen atoms were omitted for better 3D visualization.

Thumbnail

Table 1
¹H and ¹³C NMR (400 and 100 MHz, respectively, CDCl₃) data assignments for compound 1

Thumbnail

Table 2
¹H and ¹³C NMR (400 and 100 MHz, respectively, DMSO-d₆) data assignments for compound 2

Figure 1 Compounds 1-6 from S. crassifolia roots.

Figure 2 X-ray crystal structure of 1. Some hydrogen atoms were omitted for better 3D visualization. Dotted lines represent relevant interactions observed in the NOESY spectrum.

Scheme 1 Diels-Alder reaction and hypothetical pathway of 1.

Figure 3 X-ray crystal structure of 2. Some hydrogen atoms were omitted for better 3D visualization.

Table 1 ¹H and ¹³C NMR (400 and 100 MHz, respectively, CDCl₃) data assignments for compound 1

No.	δ_C	δ_H^a a Splitting multiplicities are reported as singlet (s), broad signal (bs) and multiplet (m). (multiplicity, J in Hz)	HMBC (H → C)	NOESY
1 (CH)	49.07	3.23 (bs)	2, 3, 5, 9, 10, 4’,5’,6’	25, 5’, 6’a, 7’a, 14’
2 (C)	193.13
3 (C)	192.12
4 (C)	60.52
5 (C)	131.71
6 (CH₂)	28.25	2.01 (m) 2.13 (m)	5, 8, 10	8, 11b, 23 23
7 (CH₂)	18.31	(β) 1.37 (m) (α) 1.67 (m)	5, 6, 9, 14	7a, 26 7b
8 (CH)	45.66	1.60 (m)		6
9 (C)	37.43
10 (C)	148.80
11 (CH₂)	30.96	(α) 1.57 (m) (β) 2.16 (m)	25	12, 27 6
12 (CH₂)	29.69	1.34 (m)		11, 25
13 (C)	39.56
14 (C)	39.33
15 (CH₂)	28.91	1.32 (m)
16 (CH₂)	36.39	(β) 1.71 (m) (α) 1.60 (m)		26
17 (C)	30.27
18 (CH)	44.53	1.54 (m)	19, 28	19b
19 (CH₂)	30.45	(β) 1.60 (m) (α) 2.39 (m)	18, 29	18, 28
20 (C)	40.66
21 (CH₂)	29.98	0.98 (m)	30	22a
22 (CH₂)	36.70	(β) 1.01 (m) (α) 2.04 (m)		21, 27
23 (CH₃)	9.05	1.15 (s)	3, 4, 5, 4’	6, 11, 6’, 14’
25 (CH₃)	22.34	0.87 (s)	9, 10, 11	1, 12
26 (CH₃)	16.04	0.84 (s)	8, 15	16b
27 (CH₃)	17.20	0.82 (s)	18	11a, 19a, 22a, 31, 13’, 15’a, 15’b
28 (CH₃)	31.86	1.09 (s)	18	19b
29 (C)	179.17
30 (CH₃)	31.91	1.20 (s)	19, 20, 29	31
31 (O-CH₃)	51.59	3.69 (s)	29	27, 30, 13’, 15’b
1’ (CH)	60.81	1.25 (m)	9’, 11’, 12’	13’, 15’b
2’ (CH₂)	24.45	1.41 (m) 1.60 (m)	1’, 3’	9’, 12’, 14’ 6’a, 10’
3’ (CH₂)	41.29	0.98 (m)
1.60 (m)	1’
4’ (C)	39.76
5’ (CH)	44.39	1.54 (m)	1, 2, 10, 4’, 7’, 14’	1, 15’a
6’ (CH₂)	25.09	(α) 1.20 (s) (β) 1.79 (m)	8’	1, 2’, 6’b, 7’a, 9’, 14’
7’ (CH₂)	36.12	(α) 2.32 (m) (β) 1.40 (m)	5’	1, 6’a, 15’a
8’ (C)	151.40
9’ (CH)	42.52	2.43 (m)	1’, 2’, 8’, 10’, 15’	2’, 6’b, 10’, 12’
10’ (CH₂)	36.24	1.74 (m)	8’, 9’, 11’, 12’, 13’	2’, 9’, 13’, 15’b
11’ (C)	34.79
12’ (CH₃)	21.94	0.99 (m)	1’, 13’	2’, 9’
13’ (CH₃)	30.00	0.98 (m)	10’, 11’, 12’	27, 31, 1’, 10’
14’ (CH₃)	16.70	0.73 (s)	4, 3’, 4’, 5’	1, 23, 2’, 6’b
15’ (CH₂)	111.77	(α) 4.88 (s) (β) 5.01 (s)	7’, 8’, 9’	27, 31, 5’, 7’, 15’b 7, 31, 1’, 10’, 15’a

^a
Splitting multiplicities are reported as singlet (s), broad signal (bs) and multiplet (m).
HMBC: heteronuclear multiple bond correlation; NOESY: nuclear Overhauser effect spectroscopy.

Table 2 ¹H and ¹³C NMR (400 and 100 MHz, respectively, DMSO-d₆) data assignments for compound 2

No.	δ_C	δ_H^a a Splitting patterns are reported as singlet (s), broad signal (bs), doublet (d), double doublet (dd) and multiplet (m). (multiplicity, J in Hz)	HMBC (H → C)
1 (CH₂)	26.65	1.59 (m), 2.13 (m)	9
2 (CH)	68.46	3.82 (bs)
3 (CH)	71.21	3.51 (bs)
4 (CH)	42.80	1.46 (m)	3, 24
5 (C)	49.00
6 (CH₂)	37.21	0.84 (m), 2.45 (m)	8
7 (CH₂)	19.01	1.46 (m)	8
8 (CH)	49.22	1.42 (m)	7, 25
9 (C)	44.00
10 (CH)	50.01	1.73 (dd, J 13, 3)	24
11 (CH₂)	33.80	1.31 (m)	25
12 (CH₂)	28.85	1.53 (m), 2.06 (m)	14
13 (C)	39.62
14 (C)	38.78
15 (CH₂)	27.76	1.30 (m)	26
16 (CH₂)	28.90	1.53 (m), 2.06 (m)	22
17 (C)	36.40
18 (CH)	45.00	1.64 (m)	16, 19, 20, 22, 28
19 (CH₂)	30.91	1.51 (m), 2.15 (m)	18, 21
20 (CH)	40.81	2.70 (m)
21 (C)	213.22
22 (CH)	76.73	4.41 (d, J 5)	28
23 (CH₃)	11.35	0.79 (d, J 7)	3
24 (C)	176.48
25 (CH₃)	15.16	0.84 (s)
26 (CH₃)	17.27	0.80 (s)	13, 15
27 (CH₃)	18.65	1.27 (s)	12, 13, 18
28 (CH₃)	25.50	0.74 (s)	16, 17, 18, 22
30 (CH₃)	14.92	0.90 (d, J 6)	19, 20, 21
OH-2	–	4.08 (m)
OH-3	–	4.04 (d, J 6)
OH-22	–	4.46 (d, J 5)

^a
Splitting patterns are reported as singlet (s), broad signal (bs), doublet (d), double doublet (dd) and multiplet (m).
HMBC: heteronuclear multiple bond correlation.

How to cite

copy

Sociedade Brasileira de Química Instituto de Química - UNICAMP, Caixa Postal 6154, 13083-970 Campinas SP - Brazil, Tel./FAX.: +55 19 3521-3151 - São Paulo - SP - Brazil
E-mail: office@jbcs.sbq.org.br

Acompanhe os números deste periódico no seu leitor de RSS

Versão para download de PDF

PDF

Inglês

Versões e tradução automática

Versão original do texto

English

Tradução automática

Google Translator
Microsoft Translator

Como citar

RIS

BIBTEX

Outros formatos de citação e exportação:

SciELO - Scientific Electronic Library Online
Rua Dr. Diogo de Faria, 1087 – 9º andar – Vila Clementino 04037-003 São Paulo/SP - Brasil
E-mail: scielo@scielo.org

Leia a Declaração de Acesso Aberto

Métricas

Caryopristimerin, the First Example of a Sesquiterpene-Triterpene Homo Diels-Alder Adduct, and a New 29-nor-Friedelane from Roots of Salacia crassifolia

PlumX

Mensagem

[1] * e-mail: lucienir@ufmg.br; roquelinersm@yahoo.com.br