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To investigate and compare the pharmacokinetic profile and anti-cancer activity of fluorinated and iodinated photosensitizers (PSs), the 3-(1′-(o-fluorobenzyloxy)ethyl pyropheophorbide and the corresponding meta-(m-) and para (p-) fluorinated analogs (methyl esters and carboxylic acids) were synthesized. Replacing iodine with fluorine in PSs did not make any significant difference in fluorescence and singlet oxygen (a key cytotoxic agent) production. The nature of the delivery vehicle and tumor types showed a significant difference in uptake and long-term cure by photodynamic therapy (PDT), especially in the iodinated PS. An unexpected difference in the pharmacokinetic profiles of fluorinated vs. iodinated PSs was observed. At the same imaging parameters, the fluorinated PSs showed maximal tumor uptake at 2 h post injection of the PS, whereas the iodinated PS gave the highest uptake at 24 h post injection. Among all isomers, the m-fluoro PS showed the best in vivo anti-cancer activity in mice bearing U87 (brain) or bladder (UMUC3) tumors. A direct correlation between the tumor uptake and PDT efficacy was observed. The higher tumor uptake of m-fluoro PS at two hours post injection provides a solid rationale for developing the corresponding 18F-agent (half-life 110 min only) for positron imaging tomography (PET) of those cancers (e.g., bladder, prostate, kidney, pancreas, and brain) where 18F-FDG-PET shows limitations. [ABSTRACT FROM AUTHOR]

The energy-transferring organically modified silica nanoparticles are described for two-photon photodynamic therapy. A multidisciplinary nanophotonic approach is used to show indirect excitation of the photosensitization through efficient two-photon excited intraparticle energy transfer from the dye aggregates in the intracellular environment of tumor cells.

The methodology of chlorophyll allomerization in the bacteriochlorophyll a system is extended for the preparation of partly oxidized Bchl a derivatives, which could be important precursors as models for photosynthetic mimicking studies and potential candidates for photodynamic therapy (PDT). The highly stable bacteriopurpurinimides have a distinct advantage over other naturally occurring bacteriochlorins as photosensitizers for photodynamic therapy because of their strong absorptions in their near-IR regions.

Cancer refers to a group of illnesses that result from cell population in the body increasing unusually. These cells break up and create new cells in an uninhibited mode that can extend in the body and cause injury to vital organs. Analytical chemistry is the division of chemistry involved in separating, identifying and determining the relative quantity of the components in a sample. Analytical method development and validation play vital role in method development and manufacture of pharmaceuticals. The objective of this review article is to study divergent types of anticancer drugs and the different analytical methods assessed during their determination, like UV-Visible Spectrophotometer, GC, Mass Spectrophotometer, NMR, LC-MS, GC-MS and FT-IR. The involvement for analytical methods to establish an anticancer drug is of utmost importance. The development and validation of analytical methods is mandatory for preclinical and clinical studies and even for the development of formulations containing these compounds. This constitutes the next challenge in the analysis of anticancer drugs. This review outlines the recent position of method development and validation of anticancer drugs in bulk and solid dosage forms. [ABSTRACT FROM AUTHOR]

A study of the synthesis, photophysical and photochemical properties of a series of stable bacteriochlorins containing a fused six-member anhydride and amide ring is discussed. The results show that the Q(sub y) bands of the compounds are significantly red shifted as compared to the Q(sub y) band of BChla as the large red shift is reflected in the one-electron redox potentials of the substituted bacteriochlorins.

Research has been conducted on the beta-galactose-conjugated purpurinimides, a class of chlorins prepared from purpurin-N-propargylimide via enyne metathesis. The synthesis and biological evaluation of these compounds recognized as galectin-1 photosensitizers are reported.

The photochemical and electrochemical properties of four chlorin-C(sub 60) or porphyrin-C(sub 60) dyads having the same short spacer between the macrocycle and the fullerene are investigated. The ZnCh-C(sub 60) dyad gives a long-lived radical ion pair upon photoexcitation whereas photoexcitation of the other dyads having the same linkage gives short-lived radical ion pairs, which decay to give the triplet excited states, as the radical ion pair is higher in energy.

Research has been conducted on the reaction of porphyrins with osmium tetraoxide. The effect of the electron-donating and electron-withdrawing substituents on these porphyrins has been investigated.

Research describes the syntheses of a variety of fluorinated and nonfluorinated benzochlorins exhibiting varying lipophilicity from nickel(II)octaethylporphyrin. Results indicate that the lipophilicity variation, caused by increasing the length of the alkyl or alkyl ether carbon units of the phenyl ring system, alters benzochlorins' pharmacokinetic profiles and increses in tumor uptake.

Research has been conducted on the spirochlorin-chlorin dimer with fixed distances. The reaction of Witting reagent with photoprotoporphyrin IX dimethyl ester is discussed.

The effects of substituents in the benzobacteriochlorin series was investigated by preparing and evaluating the biological activity of the hexyl ether derivative. A chlorophyll biosynthetic intermediate was successfully synthesized, which was then extended to the preparation of another biosynthetic intermediate, methyl 3,8-divinylpheophorbide alpha. The results showed that the synthetic procedure developed provided the preparation of the target compound in the fewest steps possible, avoiding wasteful yield losses and minimizing synthesis time.

Methylpheophorbide-a (a chlorophyll a analog) was converted into methyl [13.sup.1]-deoxypyropheophorbide-a 2 in excellent yield. The Ni(II) complex of 2 on hydrogenation and subsequent Viismeier reaction with phosphorus oxychloride and 3-(N,N-dimethylamino)acrolein produced Ni(II) methyl 20-(2-formylvinyl)-[13.sup.1]-deoxypyropheophorbide-a 4. In contrast to other synthetic and naturally occurring isobacteriochlorins, the isobacteriochlorin obtained by acid-catalyzed cyclization of 4 was found to be unstable and oxidized to the corresponding benzochlorin. The free base benzochlorin 7, obtained by demetalation, up on DDQ/methanol treatment produced a mixture of [13.sup.2]-oxo- and [13.sup.1]-methoxy-[13.sup.2]-oxobenzochlorins 8, 9. Surprisingly, under similar reaction conditions, an ethanolic solution of DDQ afforded [13.sup.1], [13.sup.2]-dioxobenzochlorin 13 as a major product. Vilsmeier reaction ([POC1.sub.3]/DMF) of Ni(II) benzochlorin 6 gave unexpected 5-formyl-[13.sup.2]-oxobenzochlorin 15. Zn(II) complexes of the newly synthesized benzochlorins showed long wavelength absorptions in the range of 750-753 nm. Thus, compared to the respective free base analogues bathochromic shifts of 4042 nm were observed. Despite extensive studies in benzochlorins, these are the first examples which exhibit such remarkable long wavelength absorptions in their electronic absorption spectra. The structures of novel benzochlorins were confirmed by extensive NMR [2D NMR (ROESY), 13C NMR] and X-ray crystallographic studies. On the basis of the crystal structure of oxobenzochlorin 8, the chemical reactivity of other benzochlorin analogues were examined by semiempirical molecular orbital theory. Our results are in agreement with the previous qualitative electron sextet hypothesis proposed for chlorin systems by Woodward. The fluorescence quantum yields and the singlet oxygen yields of the free base and Zn(II) benzochlorins were measured relative to tetraphenylporphyrin (TPP) in benzene.