Description and references
A group of flavones isolated from the resinous
exudate of leaf buds of Gardenia lucida Roxb. Rubiaceae, a small spiny tree occurring throughout India. Isoln of the main
flavonoid pigment, gardenin A (originally thought to be the only component
and referred to in early literature as “gardenin”): J. Stenhouse,
C. G. Groves, J. Chem. Soc. 1877, 552; Ann. 200, 311 (1880); K. J. Balakrishna, T. R. Seshadri, Proc. Indian Acad. Sci. 27A, 91 (1948). Isoln
and structure of gardenins B, C, D, E: A. V. R. Rao et al., Indian J. Chem. 8, 398 (1970). Isoln of B from Citrus jambhiri lush. Rutaceae and synthesis: B. P. Chaliha et al., Tetrahedron 21, 1441 (1965).
Structure of A: P. K. Bose, J. Indian Chem.
Soc. 22, 233 (1945). Revised structure: A.
V. R. Rao, K. Venkataraman, Indian J. Chem. 6, 677 (1968). Synthesis of A: M. Krishnamurti et al., ibid. 8, 575 (1970); M. Kamalam, A. V. R. Rao, ibid. 573; of C:
A. J. Kalra et al., ibid. 11, 96 (1973); of E: eidem, ibid. 1092. Antineoplastic activity and cytotoxicity: J. Edwards et al., J. Nat. Prod. 42, 85 (1979). 13C-NMR study: M. Iinuma et
al., Chem. Pharm. Bull. 28, 708 (1980).
Derivative
Gardenin A.
Nomenclature
CAS number: 21187-73-5
5-Hydroxy-6,7,8-trimethoxy-2-(3,4,5-trimethoxyphenyl)-4
H-1-benzopyran-4-one.
C
21H
22O
9; mol wt 418.39.
C 60.28%, H 5.30%, O 34.42%.
Properties
Golden yellow needles from ethanol, mp 162-163°. Sol in alcohol, chloroform.
All the gardenins give a green color with alcoholic ferric chloride.Derivative
Gardenin B.
Nomenclature
CAS number: 2798-20-1
5-
O-Desmethyltangeretin.
C
19H
18O
7; mol wt 358.34.
C 63.68%, H 5.06%, O 31.25%.
Properties
Fine yellow needles from benzene/petr ether, mp 176-177°. uv max (ethanol): 292, 330 nm (log e 4.40, 4.35);
(l% AlCl3): 310, 350 nm (log ε 4.48, 4.49).Derivative
Gardenin C.
Nomenclature
CAS number: 29550-05-8
C
20H
20O
9; mol wt 404.37.
C 59.40%, H 4.99%, O 35.61%.
Properties
Yellow flakes from ethyl acetate-petr ether, mp 179-180°. uv max (methanol) 304, 323 nm (log ε 4.18, 4.20).Derivative
Gardenin D.
Nomenclature
CAS number: 29202-00-4
C
19H
18O
8; mol wt 374.34.
C 60.96%, H 4.85%, O 34.19%.
Properties
Cryst, mp 190-192°. uv max (ethanol): 256, 280, 343 nm.Derivative
Gardenin E.
Nomenclature
CAS number: 29550-07-0
C
19H
18O
9; mol wt 390.34.
C 58.46%, H 4.65%, O 36.89%.
Properties
Golden yellow needles from ethyl acetate/petr
ether, mp 234-235°. uv max (methanol): 280, 325 nm (log ε 4.37, 4.36).