SIMÃO, SHEILA MARINO; CARVALHO, MÁRIO GERALDO DE; BRAZ-FILHO, RAIMUNDO; MAGALHÃES, HÉLIO GUIGLIANELY

Artigo Original • Floresta Ambient. 4 • 1997 •

STRUCTURE OF A NEW TRITERPENE GLYCOSIDE FROM CENTROSEMA BRACTEOSUM*

Um novo Triperpeno 3-0-[α -L-Rhamnopiranosil (1 ->2)-(β-D-xylopiranosil 16 β, 23(R):16α, 30α - diepoxi-20(2)-hidroxidammar-24-eno(1) foi isolado a partir das raizes de centrosema bracteosum. A estrutura deste glicosídeo triterpenoidico foi elucidada por análise espectroscópica do produto natural (1) e seu derivado peracetil (1a), incluindo experimentos de 2D RMN.

Palavras chave:
Centrosema bracteosum, Leguminosae-Faboideae; Glicosídeo Triterpenoidico; Dados espectrais.

1		13^c
C	CDCI₃ δ_H^b	C₆D₆	δ_C CDCI₃	δ_C C₆D₅N	δ_H^b C₆D₅N	δ_C C₆D₅N	δ_H C₆D₅N
1'	4.46(d,J=5.9)	4.70(d,J=5.7)	103.47	106.62	4.86(d,J=6.7)
2'	3.80(dd, J=5.9,8.4)	4.2-3.9	74.51	80.93	4.2
3'	5.2-5.0	5.43(t,J=8)	69.14	79.29	4.2
4'	5.0-4.8	5.2-5.0	72.76	72.72	4.6
5'	3.37(t,J=8.6)	3.18(dd,J=8.6,11.6)	62.01	66.91	4.3
1"	4.2-3.9	4.2-3.9	-	-
2"	4.63(d,J=6.6)	4.79(d,J=6.2)	100.94	103.19	5.72(d,J=6.6)	102.60
	5.70(d,J=7.6)
3"	3.57(dd,J=6.6,8.6)	3.82(dd,J=6.2,8.3)	75.85	80.93	4.3	79.50
4"	5.2-4.9	5.41(t,J=8.3)	69.36	78.52	4.7	78.24
5"	5.0-4.8	5.2-5.0	72.76	71.68	4.1	70.90
1"'	3.31 (t,J=8.6)	3.31(dd,J=7.2,11.3)	61.48	66.91	4.3	66.90
2"'	4.2-3.9	4.2-3.9	-	-
3"'	4.89(br s)	5.24(br s)	97.94	102.31	6.35(s)	102.40	6.37(br
s)
4"'	5.07(br s)	5.50(d,J=2.9)	69.78	72.52	4.7	72.40
5"'	5.2-4.9	5.67(dd.J=2.9.9.6)	67.87	72.72	4.6	72.40
6"'	5.2-4.9	5.49(t, J=9.6)	70.65	74.43	4.3	74.36
OAc	4.1-3.9	4.47(dq,J=9.6,6.1)	66.84	69.72	4.9	69.51
	1.15(d,J=5.8)	1.53(d, J=6.1)	17.09	19.09	1.79(d, J=5.9)	18.91
	2.08(s)	2.01(s)	170.24	-	-
	2.06(s)	1.97(s)	170.11	-	-
	2.05(s)	1.79(s)	169.88	-	-
	2.01 (s)	1.77(s)	169.60	-	-
	1.99(s)	1.77(s)	20.72	-	-
	1.97(s)	1.72(s)	20.67	-	-
	1.94(s)	1.72(s)	20.60	-	-

1a(CDCI₃)	1(C₅D₅N)	9^b	CDCI₃	C₅D₅N
C	δ^C δ^H	δ^C δ^H	δ^C	10 11^c 12^c
1	38.49		39.90		39.00	39.0	39.5
	33.7
2	25.85		27.03		26.70	27.4	26.8
	25.5
3	89.69	3.1-2.9	89.54	3.25(m)	88.10	78.9	89.5
	75.9
4	39.37	-	40.11	-	39.70	39.0	39.8
	37.6
5	55.89	0.7	56.48	0.7	56.30	55.9	56.7
	49.5
6	17.88		18.64		18.30	18.3	18.6
7	35.52		37.33		36.00	35.3	35.3
8	37.13	-	37.49		37.30	40.4	40.3
9	52.51	0.8	53.29	0.8	53.00	50.7	50.4
10	36.98	-	37.49	-	37.30	37.1	37.2
11	21.30		22.03		21.80	21.6
12	27.91		28.77		28.60	25.4
13	36.85		38.96	2.80(m)	35.70	42.3
14	53.29	-	53.96		53.70	50.3
15	35.39	1.6-1.4	37.77	2.48(d, J=11.7)	37.10	31.2
16	109.48	-	110.87	-	110.60	27.6
17	52.62	1.1	54.15	1.4	53.90	49.9
18	18.51	1.06(s)	19.15	1.04(s)	18.30	16.2*	16.2*
19	15.88	0.77(s)	16.58	0.77(s)	16.40	15.5*	16.2*
20	69.23	-	68.72	-	68.50	75.4
21	29.84	1.14(s)	30.27	1.29(s)	30.00	24.9
22	44.36	1.6-1.4	45.60	1.7	45.30	40.5
23	68.60	4.60	68.93	5.27(dd, J=8.9,6.0)	68.50	22.6
24	125.04	5.15	127.21	5.51(d,J=6.0)	127.00	124.8
25	135.28	-	134.56	-	134.2	131.5
26	18.26	1.63(br s)	19.09	1.66(s)	25.50	17.7
27	25.51	1.67(br s)	25.91	1.64(s)	18.90	25.7
28	27.60	0.94(s)	28.77	1.22(s)	28.00	28.0	28.2
	28.5
29	16.02	0.80(s)	16.71	1.04(s)	16.80	15.4*	16.6*
	22.1
30	65.72		66.12		65.8	16.5

location_on

Floresta e Ambiente - Instituto de Florestas, Universidade Federal Rural do Rio de Janeiro. BR-465, Km 7, Instituto de Florestas, CEP 23.897-000, Telefone: +55 (21) 2681-4986 - Seropédica - RJ - Brazil
E-mail: floramjournal@gmail.com

rss_feed Acompanhe os números deste periódico no seu leitor de RSS

[1] a Chemical shifts in d (ppm), coupling constants (J) in Hz and TMS as internal standard. Assignments were made with the aid of the DEPT and 2D-shift-correlated [1H x 13C-COSY, optimized for one-bond couplings (1JCH)] spectra. 1H Chemical shifts described with only one decimal correspond to approximate values of 1a and 1 and may correspond to only one proton in the case of the methylene groups.

[2] b The assignments of carbon atoms C-7, C-8, C-10, C-13, and C-15 need to be re-examined.

[3] c We described only useful values for comparison.

[TFN2] ^*
From the authors of the paper: "values in any vertical column may be reversed although those given here are preference".