G. Jerz et al. / Phytochemistry 66 (2005) 1698–1706
1705
enzyme Rohapectꢁ D5L (ROHM, Germany) in citric–
¨
6.30 (1H, d, J = 2 Hz, H-8), 6.25 (1H, d, J = 2 Hz, H-
6). For the 13C NMR spectroscopic data, see Table 1.
phosphorous acid McIllvine buffer (pH 5.5, 37 ꢂC, 24 h)
yielded 12 mg (ꢀ)-(S)-naringenin, 5 mg of which were
selectively methylated by diluted diazomethane solution
(MeOH–Et2O = 1:4) at room temperature for 6 h) to give
(ꢀ)-(S)-sakuranetin (6) in quantitative yield (Shinoda and
Sato, 1929) as ochre crystals (1 mg). Mp. 122–124 ꢂC.
TLC: Rf 0.42 (S-1); anisaldehyde: orange. [a]D: ꢀ9ꢂ (c
0.28). UV: kmax nm (loge) = 226 (4.19), 286 (4.02), 337
(3.42), 398 (3.07); +NaOH = 246 (4.05), 287 (3.90), 399
(3.80). IR: mmax = 3373 (OH), 1642 (C@O) cmꢀ1. EIMS:
m/z (rel. int.) = 287 [M + 1]+ (17), 286 [M]+ (100), 285
(61), 193 (41), 180 (53), 167 (99), 138 (35), 120 (44), 95
(29), 91 (23). 1H NMR: d = 2.79 (1H, dd, J1 = 13.5,
J2 = 3.5 Hz, H-3eq), 3.09 (1H, dd, J1 = 17, J2 = 13.5 Hz,
H-3ax), 3.80 (3H, s, 7-OCH3), 5.02 (1H, brs, 40-OH),
5.35 (1H, dd, J1 = 13.5, J2 = 3 Hz, H-2), 6.05 (1H, d,
J = 2 Hz, H-8), 6.07 (1H, d, J = 2 Hz, H-6), 6.89 (2H,
AA0-BB0, H-30, H-50), 7.35 (2H, AA0-BB0, H-20, H-60)
12.03 (1H, s, 5-OH). For the 13C NMR spectroscopic
data, see Table 1 Authenticity of (ꢀ)-(S)-naringin, and
Acknowledgements
The ÔDeutsche ForschungsgemeinschaftÕ, and ÔFonds
der Chemischen IndustrieÕ are thanked for financial sup-
port. Also, many thanks are due to Mrs. B. Barnowski
(Institute of Pharmacy and Food Chemistry, University
Erlangen-Nurnberg) for performing 1D-, and 2D NMR
¨
experiments. Particularly, we are grateful to Mr. Albert
A. Enti (Forestry Enterprises, Legon, Ghana) for his
assistance in collection and identification of the plant
material.
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1
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1
[M + 1+] (100), 0351 (15). H NMR: d = 1.43–1.60 (2H,
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,
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