# US 8,846,751 B2 · Agent for inhibiting production of hepatitis C virus and its use

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- Number: US 8,846,751 B2
- Document ID: US8846751B2
- Status: Granted
- Kind: B2
- Application number: 13/204,219
- Filed: 2011-08-05
- Published: 2011-11-24
- Granted: 2014-09-30
- Earliest claimed: 2008-09-03
- Assignees: Miyazaki Enterprise Promotion Organization; Miyazaki Prefecture; Unkai Shuzo Co., Ltd.; Minami Nippon Dairy Co-Op Co., Ltd.
- Applicants: Masahiko Takeshita; Hirohito Tsubouchi; Hirofumi Uto; Hiroaki Kataoka; Takanori Kai; Hideaki Hirabaru; Miho Sakai; Ena Akamatsu
- Inventors: Masahiko Takeshita; Hirohito Tsubouchi; Hirofumi Uto; Hiroaki Kataoka; Takanori Kai; Hideaki Hirabaru; Miho Sakai; Ena Akamatsu
- Web page: https://patentgrep.com/patent/US8846751B2

## CPC

- A61K 31/74: Synthetic polymeric materials
- A61P 31/14: for RNA viruses
- A61P 43/00: Drugs for specific purposes, not provided for in groups A61P1/00-A61P41/00
- C07D 311/62: with oxygen atoms directly attached in position 3, e.g. anthocyanidins
- A61K 36/45: Ericaceae or Vacciniaceae (Heath or Blueberry family), e.g. blueberry, cranberry or bilberry
- A61K: PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES (devices or methods specially adapted for bringing pharmaceutical products into particular physical or administering forms A61J3/00; chemical aspects of, or use of materials for deodorisation of air, for disinfection or sterilisation, or for bandages, dressings, absorbent pads or surgical articles A61L; soap compositions C11D)
- A61P: SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
- C07D: HETEROCYCLIC COMPOUNDS (macromolecular compounds C08)

## Abstract

This invention provides an agent for inhibiting production of hepatitis C virus with notable anti-HCV activity and without side-effects. The agent comprises a proanthocyanidin polymer composition illustrated in the following the general formula (1), wherein R1 is hydrogen or hydroxyl, R2 is hydroxyl, R3 is hydrogen when R1 is either hydrogen or hydroxyl, but R3 is possibly hydroxyl when R1 is either hydrogen or hydroxyl to the extent that both R1 and R3 being hydroxyl is at most 40 percents in the proanthocyanidin polymer composition said units of flavan-3-ol being bonded each other in any one of three patterns as follows; (i) a bond between carbon at the position 4 and carbon at the position 8, (ii) a bond between carbon at the position 4 and carbon at the position 6, (iii) a bond between carbon at the position 4 and carbon at the position 8, and between carbon, at the position 2 and oxygen at the position 7.

## Claims

### Claim 1

A method for producing a composition for inhibiting production of hepatitis C virus (HCV), comprising:
preparing a proanthocyanidin composition
having an anti-HCV production activity value (IC50) which is:
less than 0.61 μg/ml, and
less than or equal to one tenth of the concentration of the proanthocyanidin composition for inhibiting 50% of cell proliferation (CC50); and
comprising a proanthocyanidin having 5 to 10 monomer units, each of which consists of the flavan-3-ol illustrated in the general formula (1):
wherein R1 is hydrogen, R2 is hydroxyl, R3 is hydrogen or hydroxyl, R4 is hydrogen or a gallate group, and n is 5-10;
said units of flavan-3-ol being bonded to each other in any one of three bond patterns as follows:
(i) the bond between carbon at position 4 and carbon at position 8,
(ii) the bond between carbon at position 4 and carbon at position 6,
(iii) the bond between carbon at position 4 and carbon at position 8, and between carbon at position 2 and oxygen at position 7; and
forming the composition for inhibiting production of HCV comprising the proanthocyanidin composition.

### Claim 2 (depends on 1)

The method according to claim 1, wherein the proanthocyanidin composition is prepared from an extract of blueberry leaves.

### Claim 3 (depends on 1)

The method according to claim 1, wherein the mean polymerization degree of the proanthocyanidin is 5 to 9.

### Claim 4 (depends on 1)

A method for inhibiting production of HCV comprising:
administering a composition prepared by the method according to claim 1 to a patient in need thereof.

### Claim 5 (depends on 4)

The method according to claim 4, wherein the proanthocyanidin composition is prepared from an extract of blueberry leaves.

### Claim 6 (depends on 4)

The method according to claim 4, wherein the mean polymerization degree of the proanthocyanidin is 5 to 9.