TAP CHI HOA HOC T. 50(1) 14-18 THANG 2 NAM 2012
DIODICTYONEMA A, MOT DAN X U A T M Q I CUA AXIT DIHYDROHAEMATINIC TU' LA CAY VAM
{DIOSPYROS DICTYONEMA HIERN.)
Luc Quang Tan', Nguyin Van Bang', Phan Van Kiem^ Chau Van Minh^ Dan Thi Thuy Hang^
Phan T6ng SoTi^, Pham Hai Yen^ Nguyen Xuan Nhiem^, Nguyin Tien Dat^ Ninh KhSc Ban\
Nguyen Thi Lieu*
'Khoa Hoa hoc, Tnrang Dgi hoc Supham Hd Noi 2
^Vten Hoa sinh bien. Vien Khoa hoc vd Cong nghe Viet Nam 'Khoa hoa hoc, Tnrang Dgi hoc Khoa hpc Tir nhien, Dgi hoc Quoc gia Hd Noi
^Tnr&ng Cao ddng Sic pham Hd Noi Din Toa soan 16-4-2011 Abstract
A new derivative of dihydrohaematinic acid named diodictyonema A (1), toghether with two megastigmanes,5,l 1- epoxy-3,9-megastigmanediol (2) and 5-megastigmene-3,9-diol 3-0-P-D-glucopyranoside (3) were isolated irom the methanol extract of Diospyros dictyonema leaves. Their structures were elucidated by spectroscopic methods including ESI-MS, 1D- and 2D-NMR in comparison with the literature values. Compound 2 was isolated for the first time from nature.
Keywords Diospyros dictyonema. Ebenaceae, diodictyonema A, megastigman.
1. MO DAU
Chi Thi (Diospyros) thudc hg Thj (Ebenaceae) la mdt chi kha Idn bao gom khoang 450-500 loai phan bd ehii yeu d viing nhiet ddi. Da sd cac loai trong chi nay deu la cay an qua, vira cd gia tri dinh duong vira co gia tri ve kinh te. Cay vam {Diospyros dictyonema) cung ta mdt cay an qua, phan bd chii yeu d viing chau thd sdng Hong. Cay cao tir 5-8 m, la moc so le, qua cd mau xanh, khi chin chuyen sang mau vang va cd miii thorn dac trung, qua cd dudng kinh khoang 3-3,5 cm. Cay ra hoa vao thang 4-5, qua chin vao thang 6-8 hang nam. Thanh phan hoa hgc chu yeu ciia chi Diospyros la cac hgp chat flavonoid, naphthoquinone, lignan, megastigman, tecpenoid [2], Tuy nhien, cho den nay chua cd nghien cuu nao vl thanh phan hda hgc ciia loai D. dictyonema.
Bai bao nay thdng bao qua trinh phan lap va xac djnh cau triic hda hgc ciia mgt dan xuat mdi ciia axit dihydrohaematinic, diodictyonema A (1), ciing vdi hai dan xuat megastigmane, 5,1 l-epoxy-3,9- megastigmanedioi (2) va 5-megastigmene-3,9-diol 3-(9-^D-glucopyranoside (3), Cau triic hda hgc ciia cac hgp chat 1-3 dugc xac dinh bang cac phuang phap pho khoi lugng (ESl-MS) va phd cdng hudng tir hat nhan (1D and 2D-NMR)
2, THUC NGHIEM v A PHU'ONG P H A P NGHIEN Ciru
2.1. Phuo'ng phap tach chiet
- Sac ky ldp mdng (TLC) dugc thue hien tren ban mdng trang san DC-Alufolien 60 F254 va RPis F254 (Merck-Dire). Cac vlt chat dugc phat hien biing den tir ngoai d hai budc sdng 254 va 368 nm hoac diing thudc thu la dung dich H2S04 10% phun deu len ban mdng rdi s4y d nhiet do cao cho din khi hien mau,
" Sac ky cgt (CC) dugc tiln hanh vdi chit h^p phu pha thudng (Silica gel 240-430 mesh, Merck) lioac pha dao (ODS-60-14/63, Fujisilisa-Nhat Ban), 2.2. Cac phirang phap phd
- Phd kh6i lugng phun mil dien tir (ESl-MS) dugc do tren may AGILENT 1200 LC-MSD Trap, Vien Hda hoc, Vien Khoa hpc va Cdng nghe Viet Nam,
- Phd cdng hudng tir nhan (NMR) dugc do tren may Bruker AM500 FT-NMR Spectrometer, Vien Hda hoc, Vien Khoa hgc va Cdng nghe Viet Nam, 3. Mau thue vat
Mau la cay vam Diospyros dictyonema Hiern, (Ebenaceae) dugc thu hai vao thang 11 nam 2010 tai
TCHH, T. 50(1), 2012 Phan Van Kiem vd cong su Xuan Trudng, Nam Djnh. Ten khoa hgc dugc TS.
Ninh Khic Ban, Ths. Nguyin Thi Cudng, Vien Sinh thai va Tai nguyen Sinh vat giam djnh. Mau tieu ban dugc luu tru tai phdng mau ciia Vien Hda sinh Bien.
2.4. Phan lap cac hap chat
La cay vam khd (4,0 kg) dugc chiet 3 lan bang metanol thu dugc 300 g can chiet Can chiet nay dugc hda tan vao 5 lit nude eat va tien hanh chiet phan bd lan lugt vdi cloroform ( 3 x 5 lit) va etyl axetat ( 3 x 5 lit) thu duac cac can chiet tuang ung:
cloroform (Fl, 80 g), etyl axetat (F2, 120 g) va ldp nude (F3). Can chiet cloroform (Fl) dugc lien hanh phan tach tho thanh 5 phan doan, F1A-F1E bang sac ky cdt silica gel pha thudng riia giai gradient n- hexan/axeton (100/1 - 1/1, v/v). Phan do^n FC2 (10 g) dugc tien hanh phan lap tren s5c ky cdt silica gel pha thudng su' dung he dung mdi rCra giai cloroform/metanol 30/1 (v/v) thu dugc hgp chll 1 (12 mg) Phan doan FIG (15 g) tilp tuc dugc phan tach b^ng sic ky cdt silica gel pha thudng sir dung he dung mdi rira giai cloroform/metanol 20/1 (v/v) thu dugc 5 phan doan nhd ho'n ky hieu la FCICI- FC1C5. Tinh chl phan doan FCIC3 bing sic ky cdt silica gel pha dao (YMC RP-18) rira giai bang metanol/nudc (8/1, v/v) thu dugc hgp chat 2 (7,5 mg).
Ldp nude (F3) dugc lien hanh phan tach tren cdt sic ky trao ddi ion Dianion HP-20 riia giai tang dan ndng dd MeOH trong nude (0, 25, 50, 75 va 100%
MeOH) thu dugc 5 phan doan tuong ung ky hieu la F3A-F3E. Phan tach phan doan F3E (100% MeOH) bang sac ky cdt silica gel pha thudng rua giai bang cloroform/metanol/nudc 10/1/0,05 thu dugc bdn phan doan nhd ban ky hieu la F3Dt-F3D4. Hgp chat 3 (10,0 mg) dugc tinh che tir phan doan F3D2 bang sic ky cot silica gel pha dao (YMC RP-18) rua giai bang he dung mdi metanol/nudc (3/1, v/v).
Diodictyonema A (1) Chal dang dau set khdng mau.
ESl-MS m/z 464 |:M-!-H]\ C2SH49NO4, M = 463 ' H - N M R (500 MHz, CD3OD) va "C-NMR (125 MHz, CD3OD), xem bang 1.
5,1 l-Epoxy-3,9-megastignianediol (2):
Chat ran khdng mau, nhiet do ndng chay 178- 180°C; [ a ] " : +21° (c = 1,0, MeOH).
ESl-MS: m/z 229 [M+H]\ 251 [M+Na]^ 211 [M-H2O + H ] \ C13H24O3, M - 228
'H-NMR (500 MHz, CD3OD) va '^C-NMR (125 MHz, CD3OD), xem bang 1.
5-Megastigmene-3,9-diol 3-0-/?-D-glucopyranoside (3)
Chat fin khdng mau, nhiet do nong chay 181- 182T; [ a g : -52° (c = 1,0, MeOH);
ESl-MS: m/z 375 [M+H]\ C,9H3407, M = 374 'H-NMR (500 MHz, CD3OD) va '^C-NMR (125 MHz, CD3OD), xem bang 1.
Hinh } : Ciu triie hoa hgc ciia 1-3
3. KET QUA VA T H A O LUAN
Hgp chit 1 nhan dugc dudi dang chat diu set khdng mau. Phd '^C-NMR va cac pho DEPT 90, DEPT 135 cua 1 xuat hien tin hieu ciia 3 nhdm cacbony! tai 6 178,80 (C-6'), 177,98 (C-7') va 172,47 (C-T), trong do tin hieu cd do djch chuyen hda hgc thip han (5 172,47) ggi y sir cd mat ciia mdt nhdm cacboxylat. Mdt ndi ddi thi 3 lan dugc khang
djnh tai 6 143,22 (C)/l 17,76 (CH), mdt nhdm oximetylen tai 5 61,69. Su xuat hien cua 6 cacbon metyl (5c 22,63, 22,72, 19,72, 19,76, 16,40 va 15,55), 5 cacbon metin (5 27,99, 32,69, 32,81, 48,16, 42,29) va 11 cacbon metylen (5 24,80, 24,48, 25,08, 25,53, 31,47, 36,69, 37,31, 37,38, 37,45, 39,39, 39,89) ma khdng xuat hien tin hieu cacbon bac bdn nao khac ggi y hgp chat 1 cd mach dai dang hgp chat phytol, Tren phd 'H-NMR xuat hien tin
TCHH,T. 50(1), 2012
hieu ciia mdt proton olefin duy nhat tai 5 5,32, mdt tin hieu doublet eiia nhdm oximetylen tai 5 4,61 va dae biet la tin hieu singlet tai 5 7,71 (tren phd HSQC, tin hieu nay khdng cd tuong tac vdi cacbon
Diodictyonema A, mot ddn xuat mai..
nao) cho thay su cd mat cua nhdm NH. Mdt nhdm metyl xuat hien dudi dang singlet cd dg djch chuyen hda hgc kha cao tai 5 1,56 cho thay nhdm metyl nay dugc ndi vao ndi ddi. Do dich chuyen hda hpc ciia 11: Dir kien ph6 NMR ciia 1 - 3 va cac chit tham khao
: , 'Sc 1 1 159,4
2 3
! "
5 1 6 1 7 8 9 10 11
; 12 13 14 15 16 17 18 19 20
r
2'
^ 3' 4' 5' 6' 7'
123,2 140,2 39,9 25,2 36,8 32,8 37,5 24,5 37,4 32,7
37,4 24,9 39.4 28,0 22,7 22,8 19,8 19,8 16,2
^
1
6 c " laH-'MMz) 61,69 4,61 d (7,0) 117,76 143,22 39,89 25,08 36,69 32,81 37,45 24,48 37,38 32,69
37,31
5,321(7,0)
2 '6c 44,0 40,6 j66,7 2,00*
1,30-1,50*
1,25-1,08*
1,40*
1,25-1,08*
1,30-1,50*
1,25-1,08*
1,39
1,25-1,08*
25,15 1,30-1,50*
39,39 27,"99""
22,63 22,72
2,00 m/1,13 ni*
1,53 m 0,87d (7,0) 0,87 d (7,0) 19,72 io,83d{7,0) 19,76
16,40 172,47 31,47
48.16 42,29 178.80
4 0,83 d (7,0) 1,67 s
-
2,56 m 42,3 85,4 55,5 22.1 40,0 68,8 23,5 78,221,8 25,7
l,96ra/2,15 m 2.53 m 2.56 m
177.98 1-
' -1 --i
NH
15,55 1 1,36 d (6,5) 7,71 s
6c'' 44,01 40,60 66,69 42,34 85,42 55,56 22,12 40,05 68,78 23,46 78,24
21,81 25,70
8„"(J. Hz)
l,65m/l,57m 3,97 m l,49m/l,81 dd (7,0, 13,5)
-
1,37*l,72m/l,38m 1,49 m 3,75 m 1,20 d (6,5) 3,44 dd (2,5, 8,0) 3,64 d (8,0) 1,02 s 1,25 s
i
3
®6c 38,9 47,5 73,3 39,8 125,1 138,5 25,6 40,8 69,2 23,3 28,9
30,3 20,5
he 38,78 47,50 73,26 39,77 125,10 138,54 25,54 40,67 69,17 23,24 28,81
30,26 20,01
102,4 75,2 78,2 71,7 77,9 62,8
i«\J. Hz)
-
1,86 brd (12,0) 1,52 m 4,07 m 3,45 dd (16,0, 5,0)/2,02d(16,0)-
2,14dt(l2,5, 5,0)/2,05d(12,5) 1,49 m 3,72 m 1,19 d (6,5) 1,06 s1,09 s 1,66 s
102,33 75,19 78,14 71,68 T7,8F
62,75
4,44 d (7,5) 3,17 dd (7,5, 8,5) 3,39t(8,5) 3,321(8,5) 3,30 m 3,87 dd (13,0, 2,5) 3,67 dd (13,0, 5,5)
^Do trong CDCl,, ''Do irong CDjODj,
niegasligmanediol [5], "6c cua 5-megasii '125 MHz, "500 MHz, "Sc ciia phytol [ 3 ] , % cua 5,1 l-epoxy-3,9- igmene-3,9-diol 3-0-p-D-glucopyranoside [6].
TCHH. T. 50(1). 2012
cac proton gan vao cacbon tiro'ng irng dugc xac dinh bang phd HSQC. Mdt nhanh la dan xuit ciia pliytol duac xac dinh trudc hct bang su so sanh cac dir lieu plid ciia 1 \'di cac dir lieu tuang irng ciia hgp chit phytol [3] (bang 1), Ket qua so sanh cho thiy ngoai tru 3 vi tri C-l. C-2. C-3 ciia 1 la cd su thay doi vl gia tri dp dich chuyen hda hgc so vdi hop chat phvtol. cdn lai 17 vi tri khac cd sd lieu hoan loan phli hgp. Nlur vay. kha nang da tao nen lien kit csle vdi nhom oximetylen \;i su lao thanh hen kit nay da lam thay ddi do dich chuyen hoa hpc ciia C-l. C-2
\'a C-3. Ke! luan ve sir cd mat cua lien ket eslc da duac khang dinh bang tuang tae IIMBC rat ro giira proton ciia nhdm CIli-0 ((5 4,6!) vdi cacbon C=0 ((>' 172.47). Ciiu inic cua phan nhanh eon lai dugc
\ac dmh diiu lien bang tuang lac HMBC ciia eac proton ciia ca hai nhdm Cli: {(i^ 2.56 \a 1,96/2,15)
\di C=0 {S 172.47). Dieu na> cho Ihay cau triic - CHrCHi- gan lien vao nhom C=0. Tuong lac HMBC ciia 11-2' (^2.56) vdi cacbon CH (5 48.16) ciing vdi luang tac cua 11-3" vdi C-5'. C-7" chung td lai \ i tri C-4 (CH) cd sir re nhanh. Tuang tac HMBC ciia proton metyl lai S 1,36 vdi C-4', C-5' va C-6*
(C=0, S 178.80) cimg vdi tuong lac ciia H-3" vdi C=0 lai S 177.98 chiing id nhdm C=0 cd 5c 177.98 phai gan lien vao C-4' \i\ nlidm C"-=0 cd 6c 178.80 gan vao C-4' qua cacbon CH-5", Su cd mat ciia nhdm Nil cho phep xac djnh eau tiiic etia vdng 5 canh nhu hinh 1. Vdi nhii'ng phan tich neu tren, cdng thirc phan liV ciia 1 duge du doan la C:iKH4gN04 vdi khdi lugng phiiu tir M ~ 463 Kcl qua na\ diroc khang dinh ihem bangpho ESl-MS vdi su xuat hien pic ion tai m/z 464 |M+H]'. Phan eau Iriic tir C-T- C-8' chinh la dan xuiit dihydro cua a\it hematinic Nhu \a>. hgp chal 1 duge xac dinh la mdt eslc ciia axit dih>drohacmalinic [4J vdi ph\lol Day la mpt hgp chal mdi lan dau lien dupe phan lap tii' thien iihicn va dugc d:il len la diodictjonema A.
Hpp chat 2 thu dupe dudi dang chat ran khdng mau CO nhiet do ndng chay I78-180°C. Phd ''C-NMR ciia hop chat nay xuat hien tin bieu ciia 13 ngu\en tu cacbon. trong dd ed 3 nhdm CH^ tai Sc 23.46 (C-IO). 21.81 (C-I2) \a 25.70 (C-I3): hai nhdm CH noi \ai nguyen til oxi tai Sc 66,69 va 68.78. moi nhdm CHi nil vdi nguyen tir oxi tai Sc 78,24; hai cacbon khdng ndi vdi nguyen tir hidro nao dugc xac djnh tai Sc 44,01 va 85.42. trong dd gia tri lai t'>"85.42 cho thii) ngu>en lir cacbon iia\ phai dugc noi vdi nguyen tu oxi; ngoai ra cdn cd mot cacbon CH tai ^55.56 vabon nhom CH: khac cdng hudng d
\img trudng kha cao lai (-5 42.34. 40.60, 40,05 va 22.12 Tat ca cae cacbon nay dirac xac dinh nhd phd DEPT 90 \a DEPT 135. Tren pho ' H - N M R , ba nhdm mctyl irong dd cd hai tin liicu singlet tai du 1.25 \a 1,02 va mdt tin hieu doublet tai S 1,20 (J ^ 6,5 Hz), Cac lin hieu cdng hudng proton tuang irng
Phan I 'an Kiem vd cong .sir vdi cac nguyen tir cacbon tuang irng dugc \;ic djnh thdng qua phi HSQC va ph6 'll-NMR Hai lin hieu proton tai Si^ 3,75. 3,97 cd tuong tac HSQC vdi cacbon tuong ling tai Sc 68.78 \a 66.69, hai lin hieu proton lai S\i 3,44 va 3.64 deu cd tuong tac vdi mdt cacbon duy nhat tai Sc 78,24, phii hgp vdi kel qua tren phd DEPT. cae tin hieu proton khac cua 4 nhdm metylen cung dugc xac dinh va dan ra tren bang I.
Cac hgp chat cd 13 nguyen tir cacbon phd bien la cd khung megastigman. do dd dieu ggi >' dau lien vdi cac dli' kicn phd neu tren la hap chat 2 c6 khung megastigman. Cac hgp chat cd khung megastigman CO ban thudng cd 4 nhdm melyl. trong dd cd hai nhdm mctyl tai C-I tao thanh cacbon bac bdn tai da\
(dicu nay ciing phii hgp vdi gia tri cacbon bac bdn tai 5 44.0 1), mdt nhdm metyl tai C-5 va mach nhanli ciia khung gdm cd 4 nguyen tu cacbon \di nlidm met)l d cudi mach nhanh. Tir cac luang lac HMBC giii'a proton H-IO vdi C-9, cimg vdi tin liicii doublet tai 5 1,20 ciia nhdm mctyl cho (hay nhdm hydroxy phai dugc ndi vao C-9, tuoiig tac cua H-13 (S 1.02) vdi cacbon C-l (^44,01)/C-2 (40.60)/C-6 {,555,56) va dac biel vdi C-11 (5 78,24, CH.) khong nhii'ng khang dinh cac gia iri dp djch chuyen boa hgc lai cac vi tri neu tren ma cdn clio thay nhom mel\l C-l 1 da duge hydro.xyl hda Chii y den luoiig tac i IMBC kha rd giira H-11 vdi C-5 (5 85,42) cho thay rd rang da cd su ddng vdng qua cau oxi giiia C-l I va C-5, Cac luang tac HMBC khac cung dugc xac dmh va neu ra tren liinh ve. Nhdm hydroxyl khde dugc khang dinh la noi \ao C-3 do cd tuang lac HMBC gifia H-2 \'a H-4 vdi C-3 ma khdng ed tuong tac ciia bat k\ nhom mctyl nao vdi C-3 Ngoai ra, pho H- H COSY cdn xuat hien luang tac giua H-2 va 11-3. giiia H-3 \a H- 4. giua H-6 vdi H-7. H-7 vdi H-8. H-8 vdi H-9 va 11-9 vdi 11-10. Kcl qua neu tren cho thay hgp chat 2 chinh la 5,1 l-epoxy-3,9-inegasligmanediol vdi cdng thirc phan lir du doan la CMH^.O, ( M = 228) Ket qua phd khdi lupng xuat hien pic ion lai m/z 229 [M+II]', 251 [M+Nal\211 |M-ILO+H] hoan loan phii hgp vdi cong Ihiic phan tu neu tren. Cac dil kicn pho ciia 2 dugc so sanli vdi cac du kicn da cdng bd cho hgp chat 5.1 l-epo.\y-3.9-megastigmanediol [5]
(bang 1) va cho kcl qua phii hop hoan loan, Su triing khdp cao ve cac gia trj phd NMR va dp quay cue giua hai hgp chat nay cho phep khang dinh hop chat 2 la 5.1 l-epoxy-3,9-megastigmanediol. Hgp chat na) la san pham ihiiy phan degluco ciia hgp chat ascleposide D (hgp chat ascleposide D cd nhom dudng glucosyl ndi vao C-3) [5] va chua duac phat hien thay trong thien nhien. Day la lan dau tien hgp chat 5,1 i-epoxy-3,9-megastiginanediol dugc tim thay Irong thien nhien
Hgp chat 3 thu dugc dudi dang chat ran v6 duih hinh khdng mau. Phd '•'C-NMR ciia 3 xuit hien lin hieu cua 19 nguyen tu cacbon tai ^38,78 (C-l),
'ICIIH. 1 50(1).2012 Diodictyonema A. mot ddn .xiidi mt'fi.
iriiih 2: Cac tuong tac HMBC va H-H COSY chinh ciia 1-3
47.50 (C-2). 73.26 {C-3). 39.77 (C-4), 125,10 {C-5), 138.54 (C-6). 25.54 (C-7). 40.67 (C-8). 69.17 (C-9).
23.24 (C-10). 28.81 (C-l!). 30.26 (C-12). 20.01 (C- 13). Glc: 102.33 (C-D. 75.19 {C-2'). 78,14 (C-3').
71.68 (C-4'). 77.88 (C-5'). 62.75 {C-6'). Trong do, 6 tin hieu cacbon thudc vao mgl gdc dudng glucose, 13 tin hieu cdn lai thuoc vao khung stigman, mdt kluing cd !3 cacbon dien hinh. Phan tich cac phd DF.I'T cho thay hap chat nay ngoai 6 tin hieu ciia goc dudng (5CH. I CHi). thi cdn mdt noi doi tai 5 125.10 (C-5). 138.54 (C-6). hai cacbon CH phai ndi vdi nguyCm tir oxi tai 6 73.26 (C-3). 69.17 (C-9), hon tin hieu CH, tai 523.24 (C-10). 28.81 (C-l I), 30,26 {C-12). 20.01 (C-l3). Tin hieu cacbon bac 4 cdng hudng lai 5 38.78 (C-!) dien hinh cho su co mat ciia 2 nhdm mel\ I cimg gan vao C-L Ddi vdi khung megastigman. noi doi thudng xuat hien tai C-5/C-6, cac nlidm ludroxyl thudng xuat hien tai C-3 va C-9 Nhir viiy vdi cac du kien pho neu ircn co the dir doan duac can iriic khung megastigman cua 3 nhir hinh 1.
Phd 'l 1 NMR ciia 3 xuat hien 4 lin hieu melyl tai 1.19 (d. ./ 6,5 H/. 11-10), 1.06 (s. H-11), 1.09 (s.
H-12). 1.66 (s. H-13). trong dd tin hieu singlel cpng hudng dich chusen manh ve phia trudng thap ban {S 1.66) dugc Xiic dinh la gan vao mdt ndi ddi, hai tin hieu singlet khac tai 6 1.06 va 1.09 diroe xac djnh la noi vao C-l dc lao nen cacbon bac bdn tai C-I, Tin hieu mcl\l cdn lai dudi dang doublet chirng td nhdm na> chiem \i tri C-13 va ddng thdi phai cd mpi nhdm OH gan vao C-12 de tao nen mdt doublet ciia nhdm melyl na) (neu nhdm OH khong gan vao C-12 thi tin hieu metyl C-13 phai la moi triplet), Tren pho cdn xuat hien hai tin hieu eua hai proton cua nhom CH cd ndi \di ngu\en tu oxi tai 54.07 {m, H-3) va 3.72 (m. 11-9). ngoai ra cdn cd cac tin hieu ciia phan tu dudng glucose lai 5 4.44 (d. J = 7,5 Hz, H-l'), 3.17 {dd.y --- 7.5.8.5 Hz. H-2'). 3.39 (1, J = 8,5 Hz,
H-3'), 3,32 (1, J = 8.5 Hz, H-4'), 3,30 (m, H-5'). 3,87 dd, J = 13.0. 2,5 Hz, H,-6'). 3.67 dd, J = 13.0, 5.5 Hz. Hb-6'). Dac biet, tin hieu tai 5 4.44 cd hang so,/
= 7.5 Hz chung td hai proton H-C va H-2" ciia phan tir dudng deu chiem vi tri axial, tire ta lien kel glycosit dugc tao thanh la lien ket p, Cac gia Irj do dich chuyen boa hgc ciia proton va cacbon duoc xac dinh bing phd HSQC va pho IIMBC. Dac bict. tren pho HMBC, tuong tac cua H-l" ciia dudng glucosyl tai S 4.44 vdi C-3 lai 5 73.26 chirng id phan tir dudng noi vao C-3. Vi tri ciia nhom OH tai C-9 ciing dugc xac djnh them bang tin liicu HMBC ciia H-13 vdi C-9. Cac krang tac HMBC khac hoan toan khang dinh cau triic ciia 3 la 5-megastigmene-3.9- diol 3-0-/?-D-glucopyranosidc. Cac dir kien phd NMR ciia 3 ciing hoan loan phii hop vdi lai lieu da cdng bo [6],
TAI LIEU THAM KllAO
1. Vo van Chi- Tir diSn Cdy thudc Viet Nam. Nxb. Y hoc 1 la Npi, Uang 728 (1997).
2. Dictionary of Natural Products on CD-ROM, Version 154, Copyright © 1982-2007 Chapman &
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Lien he. Phan \'an Kiem
Vien 1 loa sinh bien. Vien khoa hgc va Cdng nghe Viet Nam 18 Hoang Qudc N'lci. Cau Giay. Ha Noi
Email: phankiemi7\ast.ac.vn.
