Nothing in this division limits the rights of a holder in due course of a negotiable instrument (Section 3302) or a holder to whom a negotiable document of title has been duly negotiated (Section 7501) or a bona fide purchaser of a security (Section 8301) and such holders or purchasers take priority over an earlier security interest even though perfected. Filing under this division does not constitute notice of the security interest to such holders or purchasers.