Results 151 to 160 of about 113,928,997 (189)

DNA Damage Induced by Hypocrellin-A Photosensitization

International Journal of Radiation Biology, 1992
Hypocrellin-A (HC-A) isolated from Hypocrellia bambusae Sacc., is a new and effective photosensitizer. Illumination of sarcoma 180 cells with visible light in the presence of HC-A leads to a decrease in cell viability and 3H-TdR incorporation, causes DNA strand breakage, and results in the selective destruction of guanine moieties in DNA.
E H, Cao, S M, Xin, L S, Cheng
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Experimental Photodynamic Effects of Hypocrellin A on the Choriocapillaris

Ophthalmic Surgery, Lasers and Imaging Retina, 2002
* OBJECTIVE: To investigate the use of the photosensitizer hypocrellin A as a photodynamic agent to occlude the choriocapillaris in the eyes of pigmented rabbits. * METHODS: Hypocrellin A (500 µg/kg) incorporated into liposomes was injected intravenously in pigmented rabbits.
Bahram, Khoobehi, Robert, Grinstead, Elke, Passos   +2 more
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Glycoconjugated hypocrellin: synthesis of [(β-d-glucosyl)ethylthiyl]hypocrellins and photosensitized generation of singlet oxygen

Biochimica et Biophysica Acta (BBA) - General Subjects, 1999
In order to improve the water solubility and specific affinity for malignant tumors of hypocrellin, glycoconjugated hypocrellins have been synthesized using an improved Königs-Knörr reaction from mercaptoethanol substituted hypocrellin B and 2,3,4,6-tetra-O-acetyl-alpha-D-glucopyranosyl bromide precursors.
Y Y, He, J Y, An, L J, Jiang
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[Simultaneous determination of hypocrellin A, hypocrellin B, and hypocrellin C by HPLC].

Zhongguo Zhong yao za zhi = Zhongguo zhongyao zazhi = China journal of Chinese materia medica, 2012
To develop a high-performance liquid chromatography (HPLC) method for simultaneous determination of hypocrellin A, hypocrellin B, and hypocrellin C.The separation was carried out on a Kromasil C18 (4.6 mm x 250 mm, 5 micrm) colum eluted with in mobile phases of water containing 0.5% glacial acetic acid and acetonitrile.
Ming, Kong, Zhanli, Chen, Zhiqi, Yin, Jian, Zhang   +3 more
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Studies on the photoinduced sulfonation of hypocrellins

Journal of Photochemistry and Photobiology A: Chemistry, 1993
Abstract Hypocrellin A (HA) and hypocrellin B (HB) are efficient phototherapeutic agents. Irradiation of HB with visible light in the presence of sodium sulfite in water-pyridine or water- N,N -dimethylformamide (1:1, v/v) solution gives hypocrellin B-5-sulfonic acid and hypocrellin B-5,8-disulfonic acid. HA reacts similarly under the same conditions.
Yi-zhen Hu, Jing-yi An, Li-chin Chiang
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Two-photon excitation of hypocrellin A

SPIE Proceedings, 2002
The two-photon excitation of hypocrellin A (HA) was examined at 800 nm. The two-photon excited fluorescence spectrum of HA was very similar to those obtained by one-photon excitation no matter whether or not the HA was dissolved in air-saturated or air-free solutions.
Jian Liu, Yuewei Zhao, Jinquan Zhao, Andong Xia, Lijin Jiang   +4 more
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Preclinical Assessment of Hypocrellin B and Hypocrellin B Derivatives as Sensitizers for Photodynamic Therapy of Cancer: Progress Update

Photochemistry and Photobiology, 1997
Abstract— Hypocrellins are perylenequinone pigments with substantial absorption in the red spectral region and high singlet oxygen yield. They are available in pure monomelic form and may be derivatized to optimize properties of red light absorption, tissue biodistribution and toxicity.
G G, Miller, K, Brown, A M, Ballangrud, O, Barajas, Z, Xiao, J, Tulip, J W, Lown, J M, Leithoff, M J, Allalunis-Turner, R D, Mehta, R B, Moore   +10 more
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Picosecond Linear Dichroism and Absorption Anisotropy of Hypocrellin:  Toward a Unified Picture of the Photophysics of Hypericin and Hypocrellin

The Journal of Physical Chemistry B, 1998
The photophysics of hypocrellin is examined by means of transient absorption spectroscopy. On the shortest time scale investigated, an ∼10 ps component is observed in the isotropic (“magic angle”) transient absorption, ΔA(t), and in the anisotropy decay, r(t), for hypocrellin in viscous solvents such as octanol and ethylene glycol.
K. Das, A. V. Smirnov, M. D. Snyder, J. W. Petrich   +3 more
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Quenching of fluorescence in membrane protein by hypocrellin B

Science in China Series C: Life Sciences, 1997
The hypocrellin B (HB) was used as a fluorescence quencher to study the basic physical charactcristics of HB in membrane systems, including the diffusion speed of quencher from aqueous phase into membrane phase, the partition coefficient (P) of quenchtr between membrane and water, and the fluorescence quenching constant of protein (K(sv); K(q),).
J, Yue, S, Pang
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Photochemistry of hypocrellin A (IV)--Hypocrellin A-sensitized photooxidation of diphenylamine.

Scientia Sinica. Series B, Chemical, biological, agricultural, medical & earth sciences, 1988
The photooxidation of diphenylamine is acetonitrile and methanol using Hypocrellin A as sensitizer will be reported in this paper. The products in the two solvents were isolated and identified. The reaction mechanisms were investigated. In acetonitrile, diphenylamine was oxidized by singlet oxygen to form N-phenyl-p-benzoquinonimine.
J N, Ma, M H, Zhang, J Y, An, L J, Jiang
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