New naphthopyranone glycosides from Paepalanthus vellozioides and Paepalanthus latipes

Article abstract of DOI:10.1021/np980082t

Three new compounds - 3,4-dihydro-10-hydroxy-7-methoxy-3-(R)-methyl-1H- 3,4-dihydronaphtho-]2,3c]-pyran-1-one-9-O-β-D-glucopyranoside (1), 3,4- dihydro-10-hydroxy-7-methoxy-3-(R)-methyl-1H-3,4-dihydronaphtho-[2,3c]- pyran-1-one-9-O-β-D-glucopyranosyl-(1→6)-glucopyranoside (2), and 3,4- dihydro-10-dihydroxy-7-methoxy-3-(R)-methyl-1H-3,4-dihydronaphtho-[2,3c]- pyran-1-one-9-O-β-D-allopyranosyl (1→6) glucopyranoside (3) - were isolated from the leaves of Paepalanthus vellozioides and Paepalanthus latipes and characterized by spectrometric methods, mainly electrospray mass spectrometry and 1D and 2D NMR experiments. These unusual glycosylated dihydronaphthopyranones may serve as taxonomic markers of the genus Paepalanthus, since these compounds were not detected in other genera belonging to the Eriocaulaceae family.

Full text of DOI:10.1021/np980082t

746
J . Nat. Prod. 1999, 62, 746-749
Notes
New Na p h th op yr a n on e Glycosid es fr om P a epa la n th u s vellozioid es a n d
P a epa la n th u s la tipes
Wagner Vilegas,† Anne Ligia Dokkeddal,† Sonia Piacente,‡ Luca Rastrelli,‡ and Cosimo Pizza*,‡
Universidade Estadual Paulista, Instituto de Quimica de Araraquara, Caixa Postal 355, 14800-900 Araraquara, SP, Brazil,
and Universita` degli Studi di Salerno, Facolta` di Farmacia, Dipartimento di Scienze Farmaceutiche,
Piazza V. Emanuele 9 - 84084, Penta di Fisciano (SA), Italy
Received March 6, 1998
Three new compoundss3,4-dihydro-10-hydroxy-7-methoxy-3-(R)-methyl-1H-3,4-dihydronaphtho-]2,3c]-
pyran-1-one-9-O-â-D-glucopyranoside (1), 3,4-dihydro-10-hydroxy-7-methoxy-3-(R)-methyl-1H-3,4-dihy-
dronaphtho-[2,3c]-pyran-1-one-9-O-â-D-glucopyranosyl-(1f6)-glucopyranoside (2), and 3,4-dihydro-10-
dihydroxy-7-methoxy-3-(R)-methyl-1H-3,4-dihydronaphtho-[2,3c]-pyran-1-one-9-O-â-D-allopyranosyl (1f6)-
glucopyranoside (3)swere isolated from the leaves of Paepalanthus vellozioides and Paepalanthus latipes
and characterized by spectrometric methods, mainly electrospray mass spectrometry and 1D and 2D
NMR experiments. These unusual glycosylated dihydronaphthopyranones may serve as taxonomic markers
of the genus Paepalanthus, since these compounds were not detected in other genera belonging to the
Eriocaulaceae family.
Several small shrubs called “sempre-vivas” (everlasting
plants) grow wild in the Serra do Cipo, Minas Gerais,
Brazil. This region is denominated “campos rupestres”, is
about 800 m in altitude, and has a sandy soil. The
Eriocaulaceae are the dominant herbal population of this
region, together with Poaceae, Cyperaceae, and Xyri-
daceae.1 According to Hensold and Giulietti, the monocoty-
ledonous family Eriocaulaceae has about 1200 species,
distributed in 10-14 genera.2 It is a pantropical family
with few species found in temperate regions.3 Although this
family has been botanically investigated for more than two
decades, the taxonomic position of some genera has still
been a matter of controversy.4 On the other hand, little is
known about the chemical composition of the plants from
this family.5,6 In previous reports,7 we have described the
isolation and structure determination of paepalantine, a
new isocoumarin (naphthopyran-1-one) isolated from the
chloroform extracts of the capitulae from Paepalanthus
bromelioides as well as from Paepalanthus vellozioides,
with potent antibiotic, cytotoxic, and mutagenic activities.8
Other compounds belonging to this class of natural me-
tabolites present antitumor, antileukemic, and even anti-
viral activities.9 Now we have examined the constituents
of the leaves from P. vellozioides and P. latipes, both
belonging to the subgenus Platycaulon.
m/z 297. Acid hydrolysis of 1 released D-glucose, identified
by GC-MS. The complete structure of 1 could be elucidated
by 1D and 2D NMR experiments at 600 MHz. The 13C NMR
and DEPT spectra showed 21 signals, six of which could
be assigned to a glucopyranosyl moiety. The 1H NMR
spectrum displayed two signals of meta-coupled protons (J
) 1.5 Hz) at δ 6.87 and 7.04 and one singlet at δ 6.99.
Further signals appeared at δ 1.53 (d, 3H, J ) 6.1 Hz),
2.97 (dd, 1H, J ) 11.4, 16.2), 3.11 (dd, 1H, J ) 2.6, 16.2
Hz), and 4.76 (m, 1H). The DQF-COSY spectrum indicated
the sequence -CH2(δ 2.97; 3.11)-CH(δ 4.76)-CH3(1.53),
typical of ring A of a naphthopyranone skeleton, and also
provided the correlations of the glucose moiety. The ano-
meric signal appeared at δ 5.01 with J ) 7.5 Hz, thus
indicating the â-configuration of the sugar. A signal at δ
3.93 (s, 3H) corresponded to a methoxyl group. Assign-
ments of all 1H and 13C NMR signals were based on HMBC,
HSQC, and DQF-COSY experiments.
The HSQC spectrum, which correlated the 1H resonances
with those of the corresponding carbons, and the HMBC
spectrum allowed us to deduce for the aglycon the structure
3,4-dihydro-9,10-dihydroxy-7-methoxy-3-methyl-1H-3,4-di-
hydronaphtho-[2,3c]-pyran-1-one. Diagnostic long-range
correlations were observed between the proton signal at δ
7.04 (H-8) and the carbon resonances at δ 102.0 (C-6), 111.2
(C-9a), 159.4 (C-9), and 163.0 (C-7); the proton at δ 6.99
(H-5) and the carbon resonances at δ 102.0 (C-6), 111.2 (C-
9a), and 142.2 (C-5a); the proton at δ 6.87 (H-6) and the
carbon resonances at δ 104.6 (C-8), 111.2 (C-9a), 116.9 (C-
5), and 163.0 (C-7); the proton signals at δ 2.97 and 3.11
(H2-4) and the carbon resonances at δ 20.9 (C-11), 77.3 (C-
3), 102.0 (C-10a), 116.9 (C-5), and 142.2 (C-4a); the methyl
doublet at δ 1.53 (Me-11) and the carbon at δ 35.0 (C-4).
Furthermore, the HMBC spectrum allowed us to confirm
the position of the methoxyl group, showing a correlation
Compound 1 was obtained as a gummy solid. Under UV
1 showed a blue spot with Rf 0.80 (BuOH-AcOH-H2O 12:
3:5). The ES-MS (100 V, positive ion) gave the protonated
molecular ion [M + H]+ at m/z 437, corresponding to the
molecular formula C21H24O10, as well as the peak at m/z
459 corresponding to the sodium adduct [M + Na]+. The
loss of a hexose moiety (162 u) led to the protonated aglycon
[A + H]+ at m/z 275 and a sodium adduct [A + Na]+ at
* To whom correspondence should be addressed: Tel.: ++39 89 968954.
Fax: ++39 89 968910. E-mail: pizza@ponza.unisa.it.
† Universidade Estadual Paulista.
1
between the H signal at δ 3.93 and C-7 of the aglycon (δ
‡ Universita` degli Studi di Salerno.
163.0), and to establish the position of the sugar residue,
10.1021/np980082t CCC: $18.00
© 1999 American Chemical Society and American Society of Pharmacognosy
Published on Web 04/24/1999

Notes
J ournal of Natural Products, 1999, Vol. 62, No. 5 747
showing a correlation between the anomeric signal of the
glucose (δ 5.01) and C-9 of the aglycon (δ 159.4). Thus, 1
was characterized as 3,4-dihydro-10-hydroxy-7-methoxy-
3-methyl-1H-3,4-dihydronaphtho-[2,3c]-pyran-1-one-9-O-â-
D-glucopyranoside.
naphtho-[2,3c]-pyran-1-one-9-O-â-D-allopyranosyl(1f6)-â-
D-glucopyranoside.
Compound 2 was obtained as a white amorphous powder.
It showed a blue spot on TLC in the same system described
above, with a Rf value of 0.40 (BuOH-AcOH-H2O 12:3:
5). The ES-MS (100 V, positive ion) also gave the signal
of a protonated aglycon [A + H]+ at m/z 275 and its sodium
adduct [A + Na]+ at m/z 297, thus suggesting the same
aglycon as in 1. The protonated molecular ion [M + H]+
occurred at m/z 599 and the adduct with sodium [M + Na]+
at m/z 621, clearly indicating a disaccharide moiety linked
to the aglycon. Loss of one hexose unit led to the fragment
[M - 162 + H]+ at m/z 437. Thus, the molecular formula
could be deduced as C27H35O15. Acid hydrolysis of 2 released
only D-glucose, identified as mentioned above. The 1H NMR
spectrum was similar to that of 1. The main difference was
the presence of two anomeric protons at δ 5.06 (d, J ) 7.5
Hz) and δ 4.41 (d, J ) 7.9 Hz) as well as of the signals
corresponding to two sugar units between δ 3.29 and δ 4.22.
Complete assignment of all 1H and 13C resonances were
performed by the 1D and 2D NMR experiments described
above. In addition, a 1D TOCSY secured the assignments
of the sugar spin system of each monosaccharide, thus
confirming the two sugar residues as â-D-glucopyranosyl
units. The location of the interglycosidic linkage could be
deduced from the downfield shift of C-6′ (δ 70.2) when
compared with the corresponding carbon in compound 1.
The interglycosidic linkage and the connecting point of the
saccharide to the aglycon were established by the HMBC
spectrum, which showed correlations between the proton
at δ 5.06 (H-1 glc′) with C-9 of the aglycon at δ 159.4,
between the proton at δ 4.41 (H-1 glc′′) with C-6 glc′ at δ
70.2, and between the protons at δ 4.22 and 3.90 (H-6a glc′
and H-6b glc′) with C-1 glc′′ at δ 104.6. The â-configuration
of both glucose moieties was deduced from their couplings
constant of 7.5 Hz. Thus, the structure of 2 was defined as
being 3,4-dihydro-10-hydroxy-7-methoxy-3-methyl-1H-3,4-
dihydronaphtho-[2,3c]-pyran-1-one-9-O-â-D-glucopyranosyl-
(1f6)-â-D-glucopyranoside.
To define the absolute configuration at C-3 of the
aglycon, the CD spectra of the hydrolyzed aglycons of
compounds 2 and 3 were recorded. The CD curve showed
negative Cotton effects at 268 and 222 nm, in good
agreement with the CD measurements reported for 3,4-
dihydro-9,10-dihydroxy-7-methoxy-3(R)-methyl-1H-3,4-di-
hydronaphtho-[2,3c]-pyran-1-one, which was previously
named semi-vioxanthin, an isocoumarin with antibiotic
properties isolated from Penicillium citreo-viride and iden-
tified by spectroscopic analysis.10 This finding indicated the
R configuration at C-3 and, together with the above data,
allowed for the identification of the aglycon of 2 and 3 as
3,4-dihydro-9,10-dihydroxy-7-methoxy-3(R)-methyl-1H-3,4-
dihydronaphtho-[2,3c]-pyran-1-one.Due tothe lower amount,
enzymatic hydrolysis of compound 1 was not performed.
The absolute configuration at C-3 of the aglycon, however,
is supposed, also in this case, to be R, and is also
3,4-dihydro-9,10-dihydroxy-7-methoxy-3(R)-methyl-1H-3,4-
dihydronaphtho-[2,3c]-pyran-1-one.
Chemical studies of the Eriocaulaceae are scarce. The
classic taxonomy of the family is rather complex. Paepal-
anthus is the largest genus and is the one that presents
the most morphological variations. The species from the
subgenus Platycaulon are characterized by having flat and
joined scapes. Based on the morphology of the flowers,
Giulietti has pointed out a relationship among the genera
Paepalanthus, Blastocaulon, and Syngonanthus.4 After
studying the parafinic profile of some plants from the
Eriocaulaceae family, Salatino et al. concluded that this
class of compound could not afford a secure differentiation
among the genera Paepalanthus, Syngonanthus, and Leio-
thrix.11 The unusual glycosylated naphthopyranones herein
Compound 3 was obtained as a gummy solid that showed
a blue spot on TLC with an Rf value of 0.45 (BuOH-
AcOH-H2O 12:3:5). The ES-MS was fully similar to that
of 2, indicating an isomeric compound with molecular
formula C27H35O15. Acid hydrolysis of 3 afforded D-glucose
1
and D-allose. Concerning the aglycon, λ, H and 13C NMR
signals were almost superimposable on those of 1 and 2.
The main differences refer to the sugar moieties attached
to the aglycon. The 1H NMR spectrum exhibited two
anomeric signals at δ 5.03 (d, J ) 7.9 Hz) and 4.78 (d, J )
7.4 Hz), showing the â-configuration of both sugars. The
complete sequence of the chemical shifts for each sugar was
obtained by 1D TOCSY and DFQ-COSY experiments
starting from the anomeric protons. Particularly charac-
teristic of the allose moiety was the presence of only three
signals after irradiating on H1′′ (δ 4.78), indicating the lack
of transference of coherence between H3′′ and H4′′ due to
the small coupling constant observed (J H-3′′-H4′′ ) 2.5 Hz).
The HMBC experiment showed correlations between the
proton at 5.03 (H-1 glc′) and C-9 of the aglycon (δ 159.0),
between the proton at δ 4.78 (H-1all) and C-6 glc′ (δ 69.9),
and between the protons at δ 3.91 and 4.26 (H-6a glc′ and
H-6b glc′) with C-1all′′ (δ 102.5). Thus, compound 3 is 3,4-
dihydro-10-hydroxy-7-methoxy-3-methyl-1H-3,4-dihydro-

748 J ournal of Natural Products, 1999, Vol. 62, No. 5
Notes
monosaccharides were reacted with TRISIL-Z (Pierce) and
analyzed by GC-MS. Retention times were identical to those
of the authentic silylated sugars.
En zym a tic Hyd r olysis of Com p ou n d s 2-3. The com-
pound (ca. 6 mg) in citrate buffer (pH 5.0) (1.5 mL) was
incubated with glycosidase mixture (6 mg) from Charonia
lampas (Scikagaku Kogyo) at 40 °C for 24-48 h. The hydro-
lyzed aglycon was extracted with n-BuOH, and the extract was
evaporated to dryness to give semi-vioxanthin.
isolated may serve as a taxonomic marker of the genus
Paepalanthus, because these compounds have not been
reported in other genera of the Eriocaulaceae family. This
is the first report of the occurrence of these compounds from
this genus. Indeed, to our knowledge, naphthopyranones
have never been used as taxonomic markers for any taxon.
For a better understanding of the chemical interrelation-
ships among the genera, however, it will be necessary to
investigate many other species both from Paepalanthus as
well as from other genera of the Eriocaulaceae family.
Com p ou n d 1: [R]25D -121° (c 0.1, MeOH); UV λmax (MeOH)
(log ꢀ) 360 (1.52), 306 (1.04), 261 (4.75), 216 (2.84), 204 (3.05);
1H NMR data (CD3OD, 600 MHz) δ 7.04 (1H, d, J ) 1.5 Hz,
H-8), 6.99 (1H, s, H-5), 6.87 (1H, d, J ) 1.5 Hz, H-6), 5.01 (1H,
d, J ) 7.5 Hz, H-1 glc′), 4.76 (1H, m, H-3), 3.98 (1H, dd, J )
2.5, 11.0 Hz, H-6b glc′), 3.93 (3H, s, OMe), 3.77 (1H, dd, J )
5.0, 11.0 Hz, H-6a glc′), 3.67 (1H, dd, J ) 7.5, 9.0 Hz, H-2 glc′),
3.55 (1H, dd, J ) 9.0, 9.0 Hz, H-3 glc′), 3.55 (1H, m, H-5 glc′),
3.47 (1H, dd, J ) 9.0, 9.0 Hz, H-4 glc′), 3.11 (1H, dd, J ) 2.6,
16.2 Hz, H-4b), 2.97 (1H, dd, J ) 11.4, 16.2 Hz, H-4a), 1.53
(3H, d, J ) 6.1 Hz, Me-11); 13C NMR data (CD3OD, 600 MHz)
δ 172.8 (C-1), 163.8 (C-10), 163.0 (C-7), 159.4 (C-9), 142.2 (C-
5a), 136.0 (C-4a), 116.9 (C-5), 111.2 (C-9a), 104.6 (C-8), 103.6
(C-1 glc′), 102.0 (C-6, C-10a), 78.2 (C-5 glc′), 77.4 (C-3 glc′),
77.3 (C-3), 74.8 (C-2 glc′), 71.4 (C-4 glc′), 62.9 (C-6 glc′), 56.1
(OMe), 35.0 (C-4), 20.9 (C-11) ES-MS m/z 459 [M + Na]+, m/z
437 [M + H]+, m/z 297 [M - 162 + Na]+, m/z 275 [M - 162 +
H]+.
Exp er im en ta l Section
Gen er a l Exp er im en ta l P r oced u r es. NMR spectra in CD3-
OD were obtained using a Bruker DRX-600 spectrometer,op-
erating at 599.19 MHz for 1H and 150.86 MHz for 13C. 2D
experiments: 1H-1H DQF-COSY12 (double quantum filtered
direct chemical shift correlation spectroscopy), inverse-detected
1H-13C HSQC13 (heteronuclear single quantum coherence),
HMBC14 (heteronuclear multiple bond connectivity). The selec-
tive excitation spectra, 1D TOCSY15 were acquired using
waveform generator-based GAUSS shaped pulses, mixing time
ranging from 100 to 120 ms and a MLEV-17 spin-lock field of
10 kHz preceded by a 2.5 ms trim pulse. Optical rotations were
measured on a Perkin-Elmer 141 polarimeter using a sodium
lamp operating at 589 nm in 1% w/v solutions in MeOH. ES-
MS were performed in a Fisons Platform spectrometer in the
positive mode (100 V). The samples were dissolved in MeOH
and injected directly. UV spectra were obtained on a Beckman
DU 670 spectrophotometer. CD measurement was performed
on a J ASCO J -7140 spectropolarimeter. HPLC separations
were achieved on a Waters 590 system equipped with a Waters
R401 refractive index detector and with a Waters µ-Bondapak
RP18 columns and a U6K injector. GC-MS were run using a
Hewlett-Packard 5890 gas chromatograph equipped with
mass-selective detector MSD 5970 MS and a fused-silica
column HP-5 (25 m × 0.2 mm; i.d. 0.33 mm film).
Com p ou n d 2: [R]25 -80° (c 0.1, MeOH); UV λmax (MeOH)
D
(log ꢀ) 360 (1.46), 304 (1.00), 260 (4.56), 216 (2.73), 202 (2.96);
1H NMR data (CD3OD, 600 MHz) δ 7.05 (1H, d, J ) 1.5 Hz,
H-8), 7.05 (1H, s, H-5), 6.90 (1H, d, J ) 1.5 Hz, H-6), 5.06 (1H,
d, J ) 7.5 Hz, H-1 GLC′), 4.81 (1H, m, H-3), 4.41 (1H, d, J )
7.9 Hz, H-1 GLC′′), 4.22 (1H, dd, J ) 2.5, 11.4 Hz, H-6b GLC′),
3.95 (3H, s, OMe), 3.90 (1H, dd, J ) 5.0, 11.4 Hz, H-6a GLC′),
3.90 (1H, dd, J ) 2.5, 11.4 Hz, H-6b GLC′′), 3.84 (1H, m, H-5
GLC′), 3.68 (1H, dd, J ) 7.5, 9.0 Hz, H-2 GLC′), 3.68 (1H, dd,
J ) 5.0, 11.4 Hz, H-6a GLC′′), 3.56 (1H, dd, J ) 9.0, 9.0 Hz,
H-3 GLC′), 3.48 (1H, dd, J ) 9.0, 9.0 Hz, H-4 GLC′), 3.39 (1H,
dd, J ) 9.0, 9.0 Hz, H-4 GLC′′), 3.35 (1H, dd, J ) 9.0, 9.0 Hz,
H-3 GLC′′), 3.29 (1H, dd, J ) 7.9, 9.0 Hz, H-2 GLC′′), 3.29
(1H, m, H-5 GLC′′), 3.10 (1H, dd, J ) 2.6, 16.2 Hz, H-4b), 3.00
(1H, dd, J ) 11.4, 16.2 Hz, H-4a), 1.53 (3H, d, J ) 6.1 Hz,
Me-11); 13C NMR data (CD3OD, 600 MHz) δ 172.8 (C-1), 163.9
(C-10), 163.0 (C-7), 159.4 (C-9), 142.0 (C-5a), 136.0 (C-4a),
116.8 (C-5), 111.0 (C-9a), 104.8 (C-8), 104.6 (C-1 GLC′′), 103.5
(C-1 GLC′), 102.0 (C-6, C-10a), 77.8 (C-5 GLC′′), 77.4 (C-3
GLC′′), 77.3 (C-3, C-5 GLC′), 77.2 (C-3 GLC′), 75.0 (C-2 GLC′′),
74.8 (C-2 GLC′), 71.8 (C-4 GLC′′), 71.4 (C-4 GLC′), 70.2 (C-6
GLC′), 62.6 (C-6 GLC′′), 56.1 (OMe), 35.0 (C-4), 20.9 (C-11);
ES-MS m/z 621 [M + Na]+, m/z 599 [M + H]+, m/z 297 [M -
162 + Na]+, m/z 437 [M - 162 + H]+.
P la n t Ma ter ia l. The leaves of P. vellozioides Ruhland
(voucher number CFSC 13842) and P. latipes Silv. (voucher
number CFSC 13840) were collected in J anuary 1996, at the
Serra do Cipo, State Minas Gerais, Brazil. Both species were
authenticated by Prof. Paulo Takeo Sano from Instituto de
Biocieˆncias, USP, Sao Paulo. Voucher specimens were depos-
ited at the Herbarium of the IB-ISP.
Extr a ction a n d Isola tion . The dried and powdered leaves
of P. vellozioides (500 g) were macerated successively with 4
L CHCl3 and then 4 L MeOH (one week each). Solvents were
evaporated under vacuum. The crude MeOH extract (61 g) was
dissolved in 5 L of H2O and centrifuged. The supernatant was
filtered on an Amberlite XAD-2 column (Aldrich, USA) eluted
first with H2O and then with MeOH, affording 6.0 g of the
MeOH fraction. Of this MeOH fraction 2.0 g were chromato-
graphed on a Sephadex LH-20 column (100 × 5 cm), with
MeOH as eluent. Fractions (8 mL) were collected and checked
by TLC [Si gel plates, n-BuOH-AcOH-H2O (12:3:5)]. Frac-
tions 32-40 (230 mg) containing the crude glycosidic mixture
were further purified by reversed-phase HPLC (RP18, MeOH-
H2O 2:3) to give pure compounds 1 (5 mg, tR ) 42.0 min), 2
(20 mg, tR ) 29.5 min), and 3 (1.5 mg, tR ) 33.0 min). P. latipes
(500 g) was submitted to the same procedure affording 59 g of
the crude MeOH extract, which, after filtering on XAD-2, led
to 5.5 g of the MeOH fraction. After fractioning 2.0 g of this
extract on Sephadex LH-20 and further purifying the fractions
29-40 in the same conditions described earlier, we obtained
compounds 1 (1.5 mg), 2 (6.5 mg), and 3 (15 mg).
Com p ou n d 3: [R]25D -109° (c 0.1, MeOH); UV λmax (MeOH)
(log ꢀ) 360 (1.50), 306 (1.02), 262 (4.68), 218 (2.86), 204 (3.01);
1H NMR data (CD3OD, 600 MHz) δ 6.97 (1H, d, J ) 1.5 Hz,
H-8), 6.96 (1H, s, H-5), 6.81 (1H, d, J ) 1.5 Hz, H-6), 5.03 (1H,
d, J ) 7.5 Hz, H-1 GLC′), 4.78 (1H, d, J ) 7.4 Hz, H-1 all),
4.76 (1H, m, H-3), 4.26 (1H, dd, J ) 2.5, 11.4 Hz, H-6b GLC′),
4.13 (1H, dd, J ) 2.8, 2.8 Hz, H-3 all), 3.93 (3H, s, OMe), 3.91
(1H, dd, J ) 5.0, 11.4 Hz, H-6a GLC′), 3.89 (1H, dd, J ) 3.0,
12.0 Hz, H-6b all), 3.84 (1H, m, H-5 GLC′), 3.76 (1H, m, H-5
all), 3.70 (1H, dd, J ) 7.9, 9.0 Hz, H-2 GLC′), 3.69 (1H, dd, J
) 5.0, 12.0 Hz, H-6a all), 3.59 (1H, dd, J ) 9.0, 9.0 Hz, H-3
GLC′), 3.55 (1H, dd, J ) 9.0, 9.0 Hz, H-4 GLC′), 3.55 (1H, dd,
J ) 2.8, 9.2 Hz, H-4 all), 3.45 (1H, dd, J ) 2.8, 7.4 Hz, H-2
all), 3.07 (1H, dd, J ) 11.4, 16.0 Hz, H-4a), 2.91 (1H, dd, J )
2.6, 16.0 Hz, H-4b), 1.53 (3H, d, J ) 6.1 Hz, Me-11); 13C NMR
data (CD3OD, 600 MHz): δ 172.8 (C-1), 163.9 (C-10), 162.8
(C-7), 159.0 (C-9), 142.4 (C-5a), 135.9 (C-4a), 117.0 (C-5), 111.2
(C-9a), 104.5 (C-8), 103.5 (C-1 GLC′), 102.5 (C-1 all), 102.2 (C-
6), 101.9 (C-10a), 77.3 (C-3), 77.1 (C-3 GLC′, C-5 GLC′), 75.3
(C-5 all), 74.9 (C-2 GLC′), 72.6 (C-3 all), 72.1 (C-2 all), 71.2
(C-4 GLC′), 69.9 (C-6 GLC′), 68.6 (C-4 all), 62.7 (C-6 all), 55.9
(OMe), 35.3 (C-4), 20.9 (C-11) 13C NMR data (CD3OD, 600
MHz) ES-MS m/z 621 [M + Na]+, m/z 599 [M + H]+, m/z 297
[M - 162 + Na]+, m/z 437 [M - 162 + H]+.
Acid Hyd r olysis of Com p ou n d s 1-3, Glycosid ic Con -
stitu en ts. A solution of each compound (4 mg) in 10% H2SO4-
EtOH (1:1, 3.5 mL) was refluxed for 4 h. The reaction mixture
was diluted with H2O and then extracted with Et2O. The Et2O
layer was dried with anhydrous Na2SO4 and evaporated to
dryness. The H2O layer was neutralized with Amberlite MB-3
ion-exchange resin and evaporated to dryness. The resulting

Notes
J ournal of Natural Products, 1999, Vol. 62, No. 5 749
(6) Dokkedal, A. L.; Salatino, A. Biochem. Syst. Ecol. 1992, 20, 31-32.
(7) Vilegas, W.; Roque, N. F.; Salatino, A.; Giesbrecht, A. M.; Davino, S.
Phytochemistry 1990, 29, 2299-2301.
(8) Varanda, E. A.; Raddi, M. S. G.; Dias, F. de Luz, Araujo, M. C. P.;
Gibran, S. C. A.; Takahashi, C. S.; Vilegas, W. Teratog. Carcinog.
Mutagen. 1997, 17, 85-95; Biol. Abstr. 104 (6), 92072 UD 9703.
(9) Hill, R. A. Fortsch. Chem. Org. Naturst. 1986, 49, 1-78.
(10) Zeeck, A.; Russ, P.; Laatsch, H.; Loeffler, W.; Weherle, H.; Zahner,
H.; Holst, H. Chem. Ber. 1979, 112, 957-978.
(11) Salatino, M. L. F.; Pereira, H. A. B.; Salatino, A.; Giulietti, A. M.
Bolm. Botanica, Univ. S. Paulo 1988, 10, 55-64.
(12) Bodenhausen, G.; Freeman, R.; Morrois, G. A.; Neidermeyer, R.;
Turner, J . J . Magn. Reson. 1977, 25, 559-564.
Hyd r olyzed Aglycon of Com p ou n d s 2 a n d 3 (sem i-
vioxa n th in ). CD curve (cyclohexan/5% dioxan: λmax ([Θ]25) )
268 (-28 000), 246 (+ 5000), 222 nm (-27 000).
Ack n ow led gm en t. We are grateful to FAPESP for finan-
cial aid and to CNPq for a fellowship to W.V.
Refer en ces a n d Notes
(1) Menezes, N. L.; Giulietti, A. M. Cieˆncia Hoje 1986, 5, 38-44.
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(3) Tomlinson, P. B. In Anatomy of monocotyledons; Metcalfe, C. R., Ed.;
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(4) Giulietti, A. M.; Amaral, M. C. E.; Bittrich, V. Kew Bull. 1995, 50,
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