Xi'an Julong Bio-Tech Co., Ltd.
Free supplier
- Free
supplier - 4th
years
Free supplier
Product Certification&
Enterprise Certification
Country: 
China (Mainland)
Business Type:Trading Company
Tel: +008618049624045
Tel: +008615877690239
Tel: +0086-18792996027
Tel: +008618049624045
Tel: +008618291367393
Tel: +8618629260427
Tel: +008617802922472
Tel: +008618729964529
Mobile: 18049624045
Tel: +008618049624045
Fax:
URL: http://LookChem.com
Province/state: Shaan xi
City: xi'an
Street: Xi'an
MaxCard:
Ms.Amber Ms.Florence Ms.Lisa Ms.EllenCAS NO.434-16-2
90%(1-10)Kilogram
We promise our customer following items:
1.Support product customization:
We can provide OEM&ODM , Because we have a professional design team
2.Reasonable price:
We provide high quality products with competitive price in china,
3.Low moq:
No worry about the low moq, our moq is 1 gram or lower.
3.Good and efficient service,Fast Delivery
Fast respond save client's time, we promise to reply inquiry in 24 hours including holidays and send quotation sheet and other documents in 48 hours.
4.Super-good quality
We have strict quality control system .Good reputation in Market , And have the Third party test report is available
Pls contact us
If you have any further questions or need a sample,Please do not hesitate to contact us.
Xi'an Julong Bio-Tech Co., Ltd.
cas: 434-16-2
mf: c27h44o
mw: 384.64
einecs: 207-100-5
package:25kg/bucket
purity:95%
7-dehydrocholesterol is a zoosterol that functions in the serum as a cholesterol precursor, and is converted to vitamin d3 in the skin, therefore functioning as provitamin-d3. the presence of this compound in human skin enables humans to manufacture vitamin d3 from ultra-violet rays in the sun light, via an intermediate isomer pre-vitamin d3. it is also found in the milk of several mammalian species. in insects it is a precursor for the hormone ecdysone, required for reaching adulthood.it was discovered by nobel-laureate organic chemist adolf windaus
synthesis of pre-vitamin d3 in the skin involves uvb radiation which effectively penetrates only the epidermal layers of skin. 7-dehydrocholesterol absorbs uv light most effectively at wavelengths between 290-320nm and thus the production of vitamin d3 will only occur at those wavelengths. the two most important factors that govern the generation of pre-vitamin d3 are the quantity (intensity) and quality (appropriate wavelength) of the uvb irradiation reaching the 7-dehydrocholesterol deep in the stratum basale and stratum spinosum.[4] another important consideration is the quantity of 7-dehydrocholesterol present in the skin. under normal circumstances, ample quantities of 7-dehydrocholesterol (about 25-50 mg/cm2 of skin) are available in the stratum spinosum and stratum basale of human skin to meet the body's vitamin d requirements.
1. important intermediate in the synthesis of vitamin d3
2. skin sunscreen additive in cosmetics
3. other laboratory reagents
Q: What's your MOQ
A: For the high value product, our MOQ starts from 1g and generally starts from 10gs. For other low, price product, our MOQ starts from 100g and 1kg.
Q: Is there a discount
A: Yes, for larger quantity, we always support with better price.
Q: How to confirm the Product Quality before placing orders
A: You can get free samples for some products, you only need to pay the shipping cost or arrange a courier to us and take the samples. You can send us your product specifications and requests, we will manufacture the products according to your requests
Q: How to start orders or make payments
A: You can send our your Purchase order (if your company has), or just send a simple confirmation by email or by Trade Manager, and we will send you Proforma Invoice with our bank details for your confirmation, then you can make payment accordingly.
Q: How do you treat quality complaint
First of all, our quality control will reduce the quality problem to near zero. If there is a quality problem caused by us, we will send you free goods for replacement or refund your loss.