698.399 Molecular Formula & Structural Analysis
Determining the accurate molecular formula for compounds with a target molecular weight of 698.399 g/mol is essential for precise mass spectrometry, analytical validation, and quantitative laboratory research. This analytical overview details the chemical structural identification, mass-to-charge ratio calculations, purity verification standards, and reconstitution protocols for research compounds within this molecular mass range.
Quick answer
Determining the accurate molecular formula for compounds with a target molecular weight of 698.399 g/mol is essential for precise mass spectrometry, analytical validation, and quantitative laboratory research. This analytical overview details the chemical structural identification, mass-to-charge ratio calculations, purity verification standards, and reconstitution protocols for research compounds within this molecular mass range.
Key takeaways
- In analytical peptide chemistry and mass spectrometry, a molecular mass of 698.399 g/mol (or monoisotopic mass near 698.4 Da) corresponds to specific oligopeptide sequences and synthetic chemical structures containing characteristic carbon, hydrogen, nitrogen, and oxygen ratios (such as $C_{37}H_{50}N_{10}O_{5}$ or related modified peptide frameworks).
- The theoretical molecular formula corresponding to a molecular weight of 698.399 g/mol represents the exact sum of the atomic masses of its constituent atoms.
- A critical distinction in evaluating the 698.399 molecular mass is the difference between average molecular weight (MW) and monoisotopic mass.
- Mass spectrometry provides accurate mass and molecular formula confirmation, but it must be paired with analytical Reverse-Phase High-Performance Liquid Chromatography (RP-HPLC) to establish chemical and chromatographic purity.
Direct Answer: Understanding the 698.399 g/mol Molecular Mass and Formula Identification
In analytical peptide chemistry and mass spectrometry, a molecular mass of 698.399 g/mol (or monoisotopic mass near 698.4 Da) corresponds to specific oligopeptide sequences and synthetic chemical structures containing characteristic carbon, hydrogen, nitrogen, and oxygen ratios (such as $C_{37}H_{50}N_{10}O_{5}$ or related modified peptide frameworks). Defining this exact molecular formula allows researchers to perform precise mass spectrometry matching, isotopic distribution modeling, and reverse-phase high-performance liquid chromatography (RP-HPLC) peak identification during rigorous laboratory evaluations.
When evaluating a research compound exhibiting a 698.399 g/mol relative molecular mass, analytical laboratories rely on high-resolution Electrospray Ionization Mass Spectrometry (ESI-MS) or Matrix-Assisted Laser Desorption/Ionization (MALDI-TOF) to confirm the nominal and monoisotopic molecular weight against theoretical stoichiometry. Establishing this baseline molecular formula is critical before deploying the compound into in vitro assays or animal research models.
Chemical Structure, Elemental Stoichiometry, and Isotopic Distribution
The theoretical molecular formula corresponding to a molecular weight of 698.399 g/mol represents the exact sum of the atomic masses of its constituent atoms. For synthetic oligopeptides and small bioactive molecules, this atomic makeup typically consists of aromatic amino acid residues (such as Tryptophan, Phenylalanine, or Tyrosine), aliphatic chains, and amide linkages that confer structural rigidity and specific receptor binding affinities in experimental systems.
Isotopic fine structure analysis plays a central role in confirming the correct molecular formula. The presence of naturally occurring carbon-13 ($^{13}C$), nitrogen-15 ($^{15}N$), and oxygen-18 ($^{18}O$) isotopes creates a distinct isotopic envelope visible in high-resolution mass spectra. Comparing the observed isotopic abundance ratio ($M+1$, $M+2$) against the calculated theoretical distribution derived from the 698.399 molecular formula allows analytical chemists to rule out isobaric impurities and confirm compound identity with extreme precision.
Mass Spectrometry Verification: Monoisotopic Mass vs. Average Mass
A critical distinction in evaluating the 698.399 molecular mass is the difference between average molecular weight (MW) and monoisotopic mass. The average mass accounts for the naturally occurring abundance of all stable isotopes across the constituent elements, whereas the monoisotopic mass calculates the sum of the most abundant stable isotope for each element (e.g., $^{12}C = 12.0000$, $^{1}H = 1.0078$, $^{14}N = 14.0031$, $^{16}O = 15.9949$).
In modern mass spectrometry protocols—such as those detailed in our comprehensive peptide mass spectrometry guide—protonated adduct ions ($[M+H]^+$, $[M+2H]^{2+}$) are evaluated. For a neutral compound with a calculated molecular weight of 698.399 g/mol, single ionization yields a dominant $[M+H]^+$ ion peak at approximately $m/z \approx 699.407$. Evaluating both single and doubly charged species ensures full structural confirmation prior to experimental formulation.
Chromatographic Purity and Reverse-Phase HPLC Analysis
Mass spectrometry provides accurate mass and molecular formula confirmation, but it must be paired with analytical Reverse-Phase High-Performance Liquid Chromatography (RP-HPLC) to establish chemical and chromatographic purity. A pure research compound with a 698.399 molecular mass should exhibit a sharp, symmetrical peak on a C18 or C8 hydrophobic stationary phase using a gradient elution profile (typically acetonitrile/water with 0.1% trifluoroacetic acid as an ion-pairing agent).
At PX1 Research, every batch undergoes double-tier verification: RP-HPLC confirms total chromatographic purity (stipulating a minimum purity threshold of $\ge 99\%$) while tandem ESI-MS verifies that the primary peak corresponds precisely to the target 698.399 molecular formula structure. This rigorous process eliminates truncated peptide fragments, deletion sequences, or unreacted synthetic intermediates from entering laboratory investigations.
Preclinical Research Contexts and In Vitro Investigation Protocols
In preclinical laboratory settings, research compounds categorized by specific molecular mass profiles like 698.399 g/mol are evaluated across various cellular and biochemical platforms. In vitro assays frequently examine receptor binding kinetics, signal transduction cascades (such as cAMP generation or intracellular calcium mobilization), and enzyme-substrate interactions.
Preclinical rodent models utilize these standardized reference compounds to observe pharmacological half-life, metabolic degradation routes, and biological distribution. Because experimental reproducibility depends entirely on maintaining precise molar concentrations, knowing the exact molecular weight (698.399 g/mol) allows researchers to prepare highly accurate stock solutions measured down to micromolar ($\mu M$) or nanomolar ($nM$) increments.
Comparative Analysis: Structural Differences Among Research Oligopeptides
To contextualize compounds with a 698.399 molecular formula, it is helpful to contrast them with other established research peptides across adjacent molecular mass ranges. For instance, Ipamorelin ($C_{38}H_{49}N_{9}O_{5}$, MW $\approx 711.86$ g/mol) is a selective growth hormone secretagogue pentapeptide widely studied in endocrine pathways, whereas GHRP-6 ($C_{46}H_{56}N_{12}O_{6}$, MW $\approx 873.01$ g/mol) represents a larger hexapeptide construct with distinct ghrelin receptor affinity profiles. Meanwhile, neuroactive research compounds like Selank ($C_{33}H_{57}N_{11}O_{9}$, MW $\approx 751.90$ g/mol) utilize heptapeptide sequences designed for central nervous system receptor assays.
Comparing molecular formulas across these classes illustrates how subtle modifications in amino acid composition, cyclization, or N-terminal acetylation dramatically shift the overall molecular mass, hydrophobic interaction capacity, and tertiary folding characteristics. Reviewing the complete catalogue via our all research peptides directory provides additional molecular weight specifications for comparative analytical modeling.
Laboratory Reconstitution, Solubility Dynamics, and Dilution Mechanics
Lyophilized research compounds with a molecular mass of 698.399 g/mol often display variable solubility depending on their net charge, hydrophobic residue content, and hydropathicity index. Reconstitution protocols for in vitro testing generally utilize sterile Bacteriostatic Water, Phosphate-Buffered Saline (PBS, pH 7.4), or mild organic co-solvents such as dimethyl sulfoxide (DMSO) for hydrophobic sequences.
When calculating molarity for experimental dosing in laboratory apparatuses, researchers use the standard formula: $Molar Concentration (M) = \frac{Mass (g)}{Molecular Mass (698.399 g/mol) \times Volume (L)}$. For detailed calculations regarding solvent volumes and concentration targets across different vial mass sizes, researchers can utilize our interactive peptide reconstitution calculator to ensure strict quantitative accuracy.
Storage Guidelines, Lyophilization Stability, and Degradation Pathways
In its native lyophilized state, a high-purity compound formulated to a 698.399 molecular mass maintains structural stability when stored at $-20^\circ\text{C}$ or $-80^\circ\text{C}$ in a desiccated, light-protected environment. Lyophilization removes residual moisture, drastically reducing hydrolysis rate constants and preventing premature peptide bond cleavage during long-term storage.
Once reconstituted into an aqueous buffer, degradation mechanisms such as deamidation (at Asparagine/Glutamine residues), oxidation (at Methionine/Cysteine sites), and peptide aggregation accelerate if stored at room temperature. Reconstituted aliquots must be kept at $2^\circ\text{C}$ to $8^\circ\text{C}$ for short-term experimental series or flash-frozen in single-use aliquots at $-80^\circ\text{C}$ to avoid damaging freeze-thaw cycles.
PX1 Research Quality Verification: COA, ISO 17025, and Endotoxin Control
Acquiring research-grade compounds with verified 698.399 molecular formulas requires uncompromised supply chain integrity. PX1 Research operates exclusively with USA-manufactured compounds synthesized in state-of-the-art, GMP-compliant facilities. Every production lot undergoes rigorous analytical evaluation at an independent, accredited ISO 17025 laboratory to guarantee purity, sequence identity, and heavy metal compliance.
A lot-specific Certificate of Analysis (COA) detailing raw ESI-MS spectrum data, RP-HPLC chromatograms, and Chromogenic LAL Endotoxin assay results (verifying endotoxin levels $<0.01\text{ EU/mg}$) accompanies every batch. Principal investigators and laboratory managers requiring high-volume reagents or institutional accounts can access customized procurement options through our dedicated wholesale peptide supply portal.
Frequently Asked Questions
What exact compound corresponds to the 698.399 molecular formula?
A molecular weight of 698.399 g/mol represents a specific theoretical stoichiometry ($C_{37}H_{50}N_{10}O_{5}$ or closely related functionalized peptide derivatives). Precise chemical identity is verified experimentally using Electrospray Ionization Mass Spectrometry (ESI-MS) and nuclear magnetic resonance (NMR) spectroscopy.
How is the 698.399 molecular mass verified on a Certificate of Analysis?
On a PX1 Research COA, high-resolution ESI-MS spectra display the protonated parent ion ($[M+H]^+$ or $[M+2H]^{2+}$). The observed mass-to-charge ratio ($m/z$) is compared against the theoretical 698.399 Da mass to confirm sequence identity to within $\pm 0.01\%$ mass accuracy.
What solvent is recommended for reconstituting a 698.399 g/mol research compound?
Reconstitution depends on hydrophobic residue distribution. Hydrophilic peptides dissolve readily in sterile water or PBS (pH 7.4). Sequences with significant aromatic content may require pre-solubilization in a small volume of reagent-grade DMSO before dilution into aqueous buffers.
Why is monoisotopic mass preferred over average molecular weight in MS analysis?
Monoisotopic mass calculates the exact mass using the most abundant naturally occurring isotope of each element ($^{12}C$, $^{1}H$, $^{14}N$, $^{16}O$). High-resolution instruments resolve individual isotopic peaks, allowing precise matching to the 698.399 theoretical baseline.
How should lyophilized vials with a 698.399 molecular weight be stored long term?
Lyophilized vials should be kept in a desiccated container at $-20^\circ\text{C}$ or $-80^\circ\text{C}$ away from direct light. Under these conditions, high-purity research compounds remain stable for up to 24 months without significant chemical degradation.
What endotoxin limits apply to PX1 Research analytical compounds?
PX1 Research mandates strict endotoxin testing via LAL chromogenic assays on every batch, enforcing an endotoxin threshold of $<0.01\text{ EU/mg}$ to prevent artifactual immune activation during cellular and in vitro preclinical experiments.
Are compounds with a 698.399 molecular formula approved for human consumption?
No. All products supplied by PX1 Research are strictly intended for laboratory research use only, including in vitro assays and preclinical animal models. They are not for human consumption, therapeutic, or clinical diagnostic use.
How does PX1 Research ensure batch-to-batch molecular weight consistency?
Every production run undergoes automated solid-phase peptide synthesis (SPPS) in GMP-compliant facilities, followed by dual RP-HPLC and ESI-MS testing at an accredited ISO 17025 analytical laboratory before lot release.
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