19-Nor-Vitamin D Analog A-Ring Modification for Selective Activity
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Solution Overview
Problem
Current vitamin D analogs, such as 19-nor-vitamin D compounds, face challenges in achieving selective biological activities for treating diseases like malignancies and metabolic bone diseases without significant calcemic activity, as they often exhibit high binding to vitamin D receptors and cell differentiation potency similar to natural hormones.
Innovation Solution
Development of seco-A-2,19-dinor-1,25-dihydroxyvitamin D3 (DA2HE) compounds with a modified structure lacking the A-ring exocyclic methylene group at carbon 10 and a seco-A ring, featuring a hydroxyl group at carbon 1 and a shortened side chain, which exhibit lower binding to vitamin D receptors and reduced cell differentiation potency but maintain high intestinal calcium transport activity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If 19-nor-vitamin D compounds are used to treat malignancies and metabolic bone diseases, then selective biological activity is achieved, but significant calcemic activity is also present which limits therapeutic selectivity
Solution Approach 1:
The patent removes the A-ring exocyclic methylene group at carbon 10 and introduces a seco-A ring structure, effectively extracting the portion of the molecule responsible for calcemic activity while preserving intestinal calcium transport function. This structural extraction resolves the contradiction by eliminating harmful calcemic effects while maintaining therapeutic benefits.
Solution Approach 2:
The patent introduces specific local modifications at the A-ring region (seco-A structure with hydroxyl group at carbon 1) while leaving the rest of the vitamin D structure intact. This local quality change selectively eliminates calcemic activity while preserving intestinal calcium transport, achieving therapeutic selectivity without sacrificing efficacy.
2Object-generated harmful factors
If vitamin D analogs are designed to reduce binding to vitamin D receptors, then calcemic activity is reduced, but intestinal calcium transport activity may also be compromised
Solution Approach 1:
The patent segments the functional activities of vitamin D by structurally separating the regions responsible for calcemic activity (A-ring exocyclic methylene group) from those responsible for intestinal calcium transport (seco-A ring with hydroxyl at carbon 1). This segmentation allows selective elimination of harmful calcemic effects while preserving beneficial intestinal transport function.
Solution Approach 2:
The patent changes the structural parameters of the A-ring region by removing the exocyclic methylene group and introducing a seco-A ring structure with a hydroxyl group at carbon 1. These parameter changes selectively modify receptor binding characteristics to eliminate calcemic activity while maintaining intestinal calcium transport capability.
3Reliability
If the A-ring exocyclic methylene group is removed to reduce calcemic activity, then therapeutic selectivity improves, but the molecular structure becomes more complex
Solution Approach 1:
The patent extracts the A-ring exocyclic methylene group and replaces it with a seco-A ring structure. Although this increases structural complexity locally, it achieves the broader goal of improved therapeutic selectivity by eliminating calcemic activity while preserving intestinal calcium transport function.
Solution Approach 2:
The patent applies local quality modification by introducing the seco-A ring structure with hydroxyl group at carbon 1 specifically at the A-ring region. This localized structural change improves overall therapeutic selectivity while confining the complexity increase to a specific molecular region rather than the entire molecule.
Data Source
AI summary
Disclosed are 19-nor-vitamin D compounds, and specifically seco-A-2,19-dinor-1,25-dihydroxyvitamin D3 as well as pharmaceutical uses therefor. These compounds exhibit relatively high activity in vivo, specifically in intestinal tissues, but relatively low VDR binding activity, cell differentiation activity and gene transcription activity. There is thus potential for these compounds to have strong cell selectivity for use as therapeutic agents against some cancers, such as colon cancer or polyps, as well as hyperplastic intestinal disorders, such as Crohn's disease, ulcerative colitis and celiac disease. These compounds also have relatively high intestinal calcium transport activity evidencing potential in the treatment of bone diseases.