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A new series of low-symmetry octasubstituted metal-free phthalocyanines with the general formula H₂N_xP^β_4−x(OBu)₈ (x = 0-4) were synthesized by mixed condensation of two different substituted precursors (4,5-dibutoxy- phthalonitrile and 1,4-dibutoxy-2,3-dicyanonaphthalene). Their electronic absorption spectra and MALDI-TOF-MS were investigated. The regiospecific, nonlinear and linear substituent effects of alkoxyl groups on the positions of the Q-bands of phthalocyanines with different substituent groups at different peripheral positions were systematically investigated. The results could provide a guide to the tuning of Q-band absorptions of phthalocyanine derivatives.

Tolyporphins are unusual tetrapyrrole macrocycles produced by the filamentous cyanobacterium–microbial community HT-58-2, the only known source to date. Numerous cyanobacterial samples have been collected worldwide but most have not been screened for secondary metabolites. Identification of tolyporphins typically has entailed lipophilic extraction followed by chromatographic fractionation and spectroscopic and/or mass spectrometric analysis. For quantitation, lengthy lipophilic extraction, sample processing and HPLC separation are needed. Examination by MALDI-TOF-MS (with the matrix 1,5-diaminonaphthalene) of lipophilic crude extracts of small-scale HT-58-2 samples (2 mL) without chromatographic fractionation enabled semi-quantitation of tolyporphin A over a 41-day growth period. Screening for tolyporphin A in intact or slightly sheared and vortexed HT-58-2 samples (no lipophilic extraction), and confirmation of identity by tandem MS, were carried out by IR-MALDESI-FTMS. Tolyporphin A was identified by the molecular ion and four characteristic fragments. The molecular ion of chlorophyll $a$ also was observed. The sheared and vortexed sample contained substantial numbers of intact cells as demonstrated by regrowth of the filamentous cyanobacterium–microbial culture. The semi-quantitative and rapid qualitative methods developed herein should facilitate examination of other tolyporphin-producing organisms among the vast worldwide strains of cyanobacteria as well as investigation of the biosynthesis of tolyporphins.

Global proteomics research is currently hampered by the extremely complexity of the proteome and the absence of techniques like the polymerase chain reaction in genomics which enables multiplication of a single protein molecule. Since all the existing analytical technologies cannot overcome the detection limit and the dynamic concentration barrier, development of improved analytical technologies at nanoscale, ideally those that could recognize single protein molecule in the presence of high abundant of others, is a high priority for proteomics. In this chapter, we will show the state-of-the-art of nanoproteomics, i.e., the application of nanotechnologies to proteomics. Various nanomaterials including carbon nanomaterials, magnetic nanoparticles, silica nanoparticles, polymer and copolymer nanoparticles, metal and metal oxide nanoparticles have been used to improve sensitivity, specificity, and repeatability of proteomic analysis especially when the multidimensional separation system coupled with MALDI-TOF-MS is used. Among them, gold nanoparticles (GNPs) and carbon nanotubes (CNTs) are the two most important nanomaterials: while GNPs are frequently utilized for enzyme immobilization, high throughput bioassay, selection of target-peptides and target-protein, CNTs including single-walled carbon nanotubes (SWCNTs) and mutiple-walled carbon nanotubes (MWCNTs) have wide applications to electronic sensor, sensitive immunodetection, nanobiocatalysis, affinity probes, MALDI matrices, protein digestion, peptides enrichment and analysis. In perspectives, a deep understanding of the structures and property of nanomaterials and interdisciplinary applications of nanotechnology to proteomics will certainly be revolutionary and intellectually rewarding.